Pear paste is a traditional preparation with both medicinal and nutritional functions.The“pear”,as its core ingredient,plays a crucial role in the efficacy of the preparation.This paper,through the interdisciplinary...Pear paste is a traditional preparation with both medicinal and nutritional functions.The“pear”,as its core ingredient,plays a crucial role in the efficacy of the preparation.This paper,through the interdisciplinary integration of evidence from traditional Chinese medicine,food chemistry,molecular biology,and clinical medicine,constructs a complete“raw material-component transformation-biological regulation”model for the first time.It is found that in pear paste,pears not only serve as a functional matrix.The polysaccharide-polyphenol-triterpene complex system forms a multi-target cough-relieving and anti-inflammatory network through dual regulation of TRPV1/TRPA1 ion channels,inhibition of the NLRP3 inflammasome,and metabolites of gut microbiota such as SCFAs.The research results provide a theoretical breakthrough for the modern development of pear paste and a scientific basis for the modernization of traditional preparations.展开更多
Pear(Pyrus bretschneideri)fruit stone cells are primarily composed of lignin and have strongly lignified cell walls.The presence of stone cells has a negative influence on fruit texture and taste,and thus the reductio...Pear(Pyrus bretschneideri)fruit stone cells are primarily composed of lignin and have strongly lignified cell walls.The presence of stone cells has a negative influence on fruit texture and taste,and thus the reduction of stone cell content in pear fruit is a key goal of breeding efforts.However,research into the key transcription factors and regulatory networks associated with pear fruit stone cell formation have been limited.We here used a combination of co-expression network and expression quantitative trait locus(eQTL)analyses in 206 pear cultivars with different stone cell contents to identify relevant genes;these analyses uncovered the gene PbrMYB4,a R2R3 MYB transcription factor gene.There was a strong positive correlation between relative PbrMYB4 expression levels in the fruit flesh and stone cell/lignin contents.Overexpression of PbrMYB4 significantly increased the lignin contents,whereas silencing of PbrMYB4 had the opposite effect,decreasing the contents of lignin.PbrMYB4 overexpression in pear calli significantly promoted lignin biosynthesis.In Arabidopsis thaliana,PbrMYB4 overexpression resulted in increasing lignin deposition,cell wall thickness of vessels and xylary fiber,and accelerating expression level of lignin biosynthetic genes.PbrMYB4 was found to activate 4-Coumarate:Coenzyme A Ligase(Pbr4CL1)by binding to AC-I elements in the promoter regions,as demonstrated with dual-luciferase reporter assays and a yeast one-hybrid assay.These results demonstrated that PbrMYB4 positively regulated lignin biosynthesis in pear fruit stone cells by activating lignin biosynthesis genes.This study improves our understanding of the gene regulatory networks associated with stone cell formation in pear fruit,providing guidance for molecular breeding of pear varieties with low stone cell content.展开更多
The WSC proteins produced by Penicillium expansum play a crucial role in causing blue mold on pears.To analyze the role of the WSC1 gene in the pathogenic process of this fungal pathogen,we conducted transcriptomic an...The WSC proteins produced by Penicillium expansum play a crucial role in causing blue mold on pears.To analyze the role of the WSC1 gene in the pathogenic process of this fungal pathogen,we conducted transcriptomic analysis of a WSC1 knockout(ΔWSC1)strain.The knockout of WSC1 significantly altered the gene expression profile in P.expansum,particularly for genes involved in cell wall integrity,signaling,stress response,and toxin production.The differential expression of these genes might make theΔWSC1 strain more vulnerable to environmental stress,while reducing the toxin production capacity,ultimately leading to a decrease in the pathogenicity.The transcriptomic analysis revealed that the expression of genes related to stress response signals,defense mechanisms and oxidative stress management changed when pear fruits were infected with theΔWSC1 strain.These changes may trigger a cascade of responses in pear fruits.In addition,compared with those infected with the wild-type strain,pear fruits infected with theΔWSC1 strain exhibited up-regulated expression of genes related to defense and oxidative stress.This study clarifies how the WSC1 gene influences P.expansum’s ability to infect pear fruits and how pear fruits respond to the infection.展开更多
Significant variations in global temperatures and weather patterns over time are known as climate change.Although it occurs naturally,human activities—particularly the burning of fossil fuels,deforestation,and indust...Significant variations in global temperatures and weather patterns over time are known as climate change.Although it occurs naturally,human activities—particularly the burning of fossil fuels,deforestation,and industrial processes—are accelerating these changes,which have various detrimental effects on the environment.This review aims to highlight the edapho-climatic requirements of this cactus and the advantages and challenges of its cultivation to mitigate climate change.The prickly pear cactus is a plant with numerous financial and environmental advantages.It needs well-draining,sandy or gravelly soil to avoid root rot and do best in full sun.With a strong tolerance for dryness,they thrive in arid or semi-arid regions with scorching summers and prefer sparing watering.Despite being suited to tropical climates,some species can tolerate freezing temperatures and sporadic frost.Once established,these hardy plants require little care and thrive in nutrient-poor soils,which makes them perfect for xeriscaping or challenging growing environments.Because of its high water use efficiency ratio and low water requirements,prickly pear can be grown in marginally dry and semi-arid areas.The cactus does contribute to the ecological and socioeconomic fight against climate change.For instance,it supports sustainable agriculture,biodiversity preservation,soil restoration,carbon sequestration,and effective water usage.Demarcating dry and semi-arid zones and fostering employment in these areas is beneficial from a socioeconomic standpoint.The prickly pear’s traditional cultural heritage supports its current economic function as a crop that can withstand drought.While ecological threats necessitate balanced management,this adaptability promotes sustainable growth.Innovations in bioenergy and value-added goods build on its historical applications,increasing its socioeconomic advantages and,eventually,its worldwide significance.展开更多
Korla fragrant pears are one of the“famous,excellent,and special”fruits in Xinjiang.They belong to the white pear variety in the genus Pyrus of the Rosaceae family.With a long-standing planting history and strong re...Korla fragrant pears are one of the“famous,excellent,and special”fruits in Xinjiang.They belong to the white pear variety in the genus Pyrus of the Rosaceae family.With a long-standing planting history and strong regional characteristics,they are mainly produced in southern Xinjiang.Due to unique natural conditions such as large temperature differences between day and night and sufficient sunlight,Korla fragrant pears have a crispy texture,a sweet but not cloying taste,and their flesh is delicate and juicy,with excellent quality.Korla fragrant pears contain a variety of bioactive substances,mainly including polysaccharides,polyphenolic compounds,flavonoid compounds,triterpenoids,and sterols.They have medical effects such as“moistening the lungs,calming the heart,reducing phlegm,anti-inflammation,relieving cough,and resolving carbuncle toxins”.Uyghur and Mongolian medicine often use them as a good dietary therapy product.Based on recent literature reports,this paper reviews the main chemical constituents and pharmacological effects of Korla fragrant pears,aiming to provide references for the research and utilization of the deep processing of Korla fragrant pears.展开更多
Pear anthracnose,caused by Colletotrichum fructicola,is a devastating disease that seriously affects most pear varieties,compromising their yield and quality.However,effective control of this pathogen is lacking.Moreo...Pear anthracnose,caused by Colletotrichum fructicola,is a devastating disease that seriously affects most pear varieties,compromising their yield and quality.However,effective control of this pathogen is lacking.Moreover,the critical resistance responses to C.fructicola in pear are unknown.To investigate these resistance mechanisms of pear against C.fructicola,transcriptomic and metabolomic analyses were performed on the anthracnose-resistant variety‘Seli’and susceptible variety‘Cuiguan’after C.fructicola infection.Differentially expressed genes(DEGs)and differentially accumulated metabolites(DAMs)were mainly involved in metabolism and secondary metabolite synthetic pathways,includingα-linoleic acid metabolism,phenylalanine biosynthesis metabolism,unsaturated fatty acids biosynthesis,and biosynthesis of amino acids and their derivatives.In particular,the accumulation of unsaturated fatty acids(UFAs),amino acids,and their derivatives,such as linoleic acid and its derivatives,lauric acid,N-acetyl-L-glutamic acid,and L-proline,was significantly increased in‘Seli’after infection,while the amino acids of oxiglutatione and N-acetyl-L-glutamic acid,as well as the proanthocyanidins,were significantly decreased in‘Cuiguan’.These findings suggest that these metabolites may contribute to the differential anthracnose resistance between‘Seli’and‘Cuiguan’.Overall,our results provid new insights into the regulation of pear anthracnose resistance,which may assist in developing new control strategies and breeding anthracnose-resistant varieties.展开更多
Pyrus pyrifolia,commonly known as sand pear,is a key economic fruit tree in temperate regions that possesses highly diverse germplasm resources for pear quality improvement.However,research on the relationship between...Pyrus pyrifolia,commonly known as sand pear,is a key economic fruit tree in temperate regions that possesses highly diverse germplasm resources for pear quality improvement.However,research on the relationship between resistance and fruit quality traits in the breeding of fruit species like pear is limited.Pan-transcriptomes effectively capture genetic information from coding regions and reflect variations in gene expression between individuals.Here,we constructed a pan-transcriptome based on 506 samples from different tissues of sand pear,and explored the intrinsic relationships among phenotypes and the selection for disease resistance during improvement based on expression presence/absence variations(eP AVs).The pan-transcriptome in this study contains 156,744 transcripts,among which the novel transcripts showed significant enrichment in the defense response.Interestingly,disease resistance genes are highly expressed in landraces of pear but have been selected against during the improvement of this perennial tree species.We found that the genetically diverse landraces can be divided into two subgroups and inferred that they have undergone different dispersal processes.Through co-expression network analysis,we confirmed that the formation of stone cells in pears,the synthesis of fruit anthocyanins,and the ability to resist stress are interrelated.They are jointly regulated by several modules,and the expression of regulatory genes has significant correlations with these three processes.Moreover,we identified candidate genes such as HKL1 that may affect sugar content and are missing from the reference genome.This study provides insights into the associations between complex fruit traits,while providing a database resource for pear disease resistance and fruit quality breeding.展开更多
The new late-maturing pear cultivar‘Suyu’was bred through hybrid breeding using‘Mili’as the female parent and‘Dangshansuli’as the male parent.This cultivar has a nearly round fruit shape with a greenish-yellow s...The new late-maturing pear cultivar‘Suyu’was bred through hybrid breeding using‘Mili’as the female parent and‘Dangshansuli’as the male parent.This cultivar has a nearly round fruit shape with a greenish-yellow skin,an average single fruit weight of 394.3 g,and a small core.The flesh is white,fine-textured,crisp,juicy,sweet,and aromatic,with a soluble solid content of 12.8%.The tree has a strong growth vigor,an open canopy,high budding rate,and strong branching ability,making it suitable for spindle or cylindrical cultivation.The main color of the one-year-old branches on the sunny side is brown.The young leaves are yellowish-green,and the mature leaves are ovate with sharp serrations.Each inflorescence has 5 to 7 flowers with pink petals,a pistil that protrudes above the stamens,and purple-red anthers.The fruit development period is about 150 d,and it matures in mid-to-late September in Changli,Hebei.The cultivar is high-yielding,stable,and well-suited for storage.‘Suyu’can be cultivated in pear-growing areas of Hebei Province and regions with similar ecological types.展开更多
In order to enhance the guidance for Yuluxiang pear cultivation in hilly and mountainous regions, this study provides a comprehensive introduction to various aspects, including the establishment of high-standard orcha...In order to enhance the guidance for Yuluxiang pear cultivation in hilly and mountainous regions, this study provides a comprehensive introduction to various aspects, including the establishment of high-standard orchards and the reinforcement of integrated management techniques, in order to offer a valuable reference for fruit farmers engaged in scientific planting practices.展开更多
The fruit of Huangguan pear is deeply loved by consumers because of its rich nutrition and rich flavor.The quality evaluation system of Huangguan pear is composed of many quality types.In this study,the types and func...The fruit of Huangguan pear is deeply loved by consumers because of its rich nutrition and rich flavor.The quality evaluation system of Huangguan pear is composed of many quality types.In this study,the types and functions of nutritional quality indexes of Huangguan pear were summarized,such as vitamin C,soluble solids,soluble sugar and titratable acid,and the factors affecting the nutritional quality of Huangguan pear including genetic factors,environmental factors and agricultural management measures were overviewed,aiming to provide reference for establishing a comprehensive quality evaluation system of Huangguan pear and then promoting the high-quality development of Huangguan pear industry.展开更多
Dehydrin(DHN)enhances plant resistance to environmental stress by regulating the synthesis of osmotic adjustment substances and scavenging reactive oxygen species.However,the role of PbDHN3 under salt stress remains u...Dehydrin(DHN)enhances plant resistance to environmental stress by regulating the synthesis of osmotic adjustment substances and scavenging reactive oxygen species.However,the role of PbDHN3 under salt stress remains unclear.In this study,salt stress induced high expression of PbDHN3,and the overexpression of PbDHN3(OE-PbDHN3)enhanced plant growth under salt stress compared to wild-type(WT)plants.OE-PbDHN3 plants exhibited higher chlorophyll content and root growth capacity than WT plants under salt stress.Transcriptome analysis revealed that PbDHN3 expression is associated with ethylene signaling pathways.OE-PbDHN3 transgenic plants substantially influenced ethylene content and the expression of related genes.Following treatment with exogenous ethephon,the transgenic lines notably inhibited the processes of ethylene synthesis and signaling transduction.OE-PbDHN3 transgenic lines treated with exogenous ethylene and the ethylene inhibitor 1-MCP demonstrated significant inhibition of ethylene synthesis and signaling transduction,while promoting root development and chlorophyll content.Under salt stress,OE-PbDHN3 downregulated the expression of ethylene biosynthesis genes PbACO1-like and PbACO2,and signal transduction genes PbEIN3-like during the initial stress phase.This early regulation mitigated the adverse effects of salt stress on the plants.These findings demonstrate that PbDHN3 ameliorates the ethylene-mediated plant growth phenotype under salt stress through regulation of ethylene synthesis and signal transduction.展开更多
Red fruit peel is one of pear's most valuable economic traits and is mainly determined by anthocyanins.Many pear cultivars with a red peel originated from bud sports;however,little is known about the genetic mecha...Red fruit peel is one of pear's most valuable economic traits and is mainly determined by anthocyanins.Many pear cultivars with a red peel originated from bud sports;however,little is known about the genetic mechanisms underlying this trait.We have previously identified a mutant Pp BBX24 containing a 14-nucleotide deletion in the coding region(Ppbbx24-del)as the only known variant associated with the red coloration of the mutant‘Red Zaosu'pear(Pyrus pyrifolia White Pear Group).Herein,we analyzed the role of the mutant gene in red coloration and its mechanism of action.The results showed that light promoted red peel coloration in the‘Red Zaosu'pear,and Ppbbx24-del positively affected light-induced anthocyanin biosynthesis,while normal Pp BBX24 had the opposite effects.Transient and stable transformation experiments confirmed that Ppbbx24-del could promote anthocyanin accumulation in pear fruit peels,calli,and tobacco flowers.Due to the loss of nuclear localization sequence(NLS)and viral protein(VP)domains,Ppbbx24-del co-localized in the nucleus and cytoplasm,whereas PpBBX24 localized only in the nucleus.Real-time PCR and transcriptome analyses indicated that PpM YB10 and PpH Y5 are highly expressed in the‘Red Zaosu'pear.In yeast one-hybrid and dual-luciferase assays,Ppbbx24-del and PpHY5 independently promoted the expression of PpC HS,PpC HI,and PpM YB10 by binding to their promoters;however,PpBBX24 did not affect the expression of these genes.Additionally,we found that Ppbbx24-del and PpHY5 had additive effects on the expression of PpC HS,PpC HI,and PpMYB10,as they promote the expression of anthocyanin synthesis genes separately.The co-expression of PpB BX24 and PpHY5 inhibited the activation of downstream genes by PpHY5,which was attributed to the interaction between the two loci.In conclusion,our results clarify the molecular mechanism by which mutant Ppbbx24-del and PpBBX24 exert opposite effects in regulating anthocyanin accumulation in pear.These findings lay an important theoretical foundation for using Ppbbx24-del to create red pear cultivars.展开更多
Pear fruit corking disorder is a non-infectious physiological condition that primarily occurs during the late developmental stages of pear and significantly impacts fruit quality and economic value in several major cu...Pear fruit corking disorder is a non-infectious physiological condition that primarily occurs during the late developmental stages of pear and significantly impacts fruit quality and economic value in several major cultivars.As the underlying mechanism remains unclear,effective prevention strategies and genetic improvements continue to present major challenges.In this study,‘Akizuki’pear was used as experimental material,and the lignin content in cork-affected tissue was found to be significantly higher than in healthy tissue.Exogenous abscisic acid(ABA)treatment induced cork formation and promoted lignin biosynthesis,a major structural component,in both pear fruits and calli.Through integrated RNA-seq and expression analyses,we identified the ABA-responsive gene PbrMYB8,which was differentially expressed between healthy and diseased tissues and associated with lignin biosynthesis during corking disorder.Stable transformation of PbrMYB8 into pear calli and Arabidopsis confirmed its role in promoting lignin biosynthesis.Notably,PbrMYB8 not only activated lignin biosynthesis genes independently but also interacted with PbrMYB169 to form a protein complex that co-regulated their expression.These findings improve our understanding of lignin biosynthesis in pear fruit corking disorder by identifying a key regulator and its interaction network and provide a theoretical foundation for future strategies aimed at improving pear fruit quality.展开更多
Genetic variation contributes to the phenotypic diversity of plants.Most red pear cultivars that accumulate anthocyanins originated from somatic variation and are termed as bud sports.‘Hongzaosu’is a bud sport deriv...Genetic variation contributes to the phenotypic diversity of plants.Most red pear cultivars that accumulate anthocyanins originated from somatic variation and are termed as bud sports.‘Hongzaosu’is a bud sport derived from the green pear‘Zaosu’.A new genetic map was constructed from a population derived from the cross of‘Yuluxiang’and‘Hongzaosu’,from which PpBBX24 was identified as a crucial gene controlling anthocyanin accumulation.Genetic and phylogenetic evidences revealed that PpBBX24 is a repressor of anthocyanin biosynthesis in pear.A 14 bp deletion was detected in the third exon of PpBBX24 in‘Hongzaosu’,resulting in premature termination of protein translation.The truncated PpBBX24 protein was a positive regulator of anthocyanin biosynthesis by activating the transcription of PpCHS and PpUFGT.Three independent variations in the BBX24 coding region that led to premature termination of translation were detected in other pear bud sports and the progeny of a bud sport that all accumulate anthocyanins.The genome of‘Hongzaosu’was assembled using both long-read and short-read sequences.By combining genomic and transcriptomic data,allele-specific expression of PpMYB110a was observed in the fruit skin of‘Hongzaosu',which was likely caused by a large variation in the promoter.This work enhances understanding of coloration in red pears and provides a novel genomic resource for further studies on‘Hongzaosu’pear.展开更多
The pear(Pyrus spp.)is well known for diverse flavors,textures,and global horticultural importance.However,the genetic diversity responsible for its extensive phenotypic variations remains largely unexplored.Here,we d...The pear(Pyrus spp.)is well known for diverse flavors,textures,and global horticultural importance.However,the genetic diversity responsible for its extensive phenotypic variations remains largely unexplored.Here,we de novo assembled and annotated the genomes of the maternal(PsbM)and paternal(PsbF)lines of the hybrid‘Yuluxiang'pear and constructed the pear pangenome of 1.15 Gb by combining these two genomes with five previously published pear genomes representing cultivated and wild germplasm.Using the constructed pangenome,we identified 21224 gene PAVs(Presence-absence variation)and 1158812 SNPs(Single Nucleotide Polymorphism)in the non-reference genome that were absent in the PsbM reference genome.Compared with SNP markers,PAV-based analysis provides additional insights into the pear population structure.In addition,some genes associated with pear fruit quality traits have differential occurrence frequencies and differential gene expression between Asian and European populations.Moreover,our analysis of the pear pangenome revealed a mutated SNP and an insertion in the promoter region of the gene PsbMGH3.1 potentially enhance sepal shedding in‘Xuehuali'which is vital for pear quality.PsbMGH3.1 may play a role in the IAA pathway,contributing to a distinct low-auxin phenotype observed in plants by heterologously overexpressing this gene.This research helps capture the genetic diversity of pear populations and provides genomic resources for accelerating breeding.展开更多
The Arabidopsis Toxicos en Levadura(ATL)protein is a subfamily of the E3 ubiquitin ligases,which exists widely in plants and is extensively involved in plant growth and development.Although the ATL family has been ide...The Arabidopsis Toxicos en Levadura(ATL)protein is a subfamily of the E3 ubiquitin ligases,which exists widely in plants and is extensively involved in plant growth and development.Although the ATL family has been identified in other species,such as Arabidopsis,Oryza sativa,and grapevine,few reports on pear ATL gene families have been reported.In this study,92 PbrATL genes were identified and analyzed from the Pyrus breschneideri genome.Motif analysis and phylogenetic tree generation divided them into nine subgroups,and chromosome localization analysis showed that the 92 PbrATL genes were distributed in 16 of 17 pear chromosomes.Transcriptome data and quantitative real-time polymerase chain reaction(qRT-PCR)experiments demonstrated that PbrATL18,PbrATL41,and PbrATL88 were involved in both pear drought resistance and Colletotrichum fructicola infection.In addition,Arabidopsis thaliana overexpressing PbrATL18 showed greater resistance to drought stress than the wild type(WT),and PbrATL18-silenced pear seedlings showed greater sensitivity to drought and C.fructicola infection than the controls.PbrATL18 regulated plant resistance by regulating chitinase(CHI),phenylalanine ammonia-lyase(PAL),polyphenol oxidase(PPO),catalase(CAT),peroxidase(POD),and superoxide dismutase(SOD)activities.This study provided a reference for further exploring the functions of the PbrATL gene in drought resistance and C.fructicola infection.展开更多
Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberel...Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberellins(GAs)play crucial roles in plant growth,development,and responses to drought stress.Previous studies have shown significant reductions of GA levels in plants under drought stress;however,our understanding of the intrinsic regulation mechanisms of GA-mediated drought stress in pear remains very limited.Here,we show that drought stress can impair the accumulation of bioactive GAs(BGAs),and subsequently identified PbrGA2ox1 as a chloroplast-localized GA deactivation gene.This gene was significantly induced by drought stress and abscisic acid(ABA)treatment,but was suppressed by GA_(3)treatment.PbrGA2ox1-overexpressing transgenic tobacco plants(Nicotiana benthamiana)exhibited enhanced tolerance to dehydration and drought stresses,whereas knock-down of PbrGA2ox1 in pear(Pyrus betulaefolia)by virus-induced gene silencing led to elevated drought sensitivity.Transgenic plants were hypersensitive to ABA,and had a lower BGAs content,enhanced reactive oxygen species(ROS)scavenging ability,and augmented ABA accumulation and signaling under drought stress compared to wild-type plants.However,the opposite effects were observed with PbrGA2ox1 silencing in pear.Moreover,exogenous GA_(3)treatment aggravated the ROS toxic effect and restrained ABA synthesis and signaling,resulting in the compromised drought tolerance of pear.In summary,our results shed light on the mechanism by which BGAs are eliminated in pear leaves under drought stress,providing further insights into the mechanism regulating the effects of GA on the drought tolerance of plants.展开更多
Fruitlet calyx shedding in pear plants is apparently regulated via numerous pathways that involve both environmental triggers and phytohormones cues such as auxin. In this study, we found at 10 days after full bloom (...Fruitlet calyx shedding in pear plants is apparently regulated via numerous pathways that involve both environmental triggers and phytohormones cues such as auxin. In this study, we found at 10 days after full bloom (DAFB) higher levels of indoleacetic acid (IAA) and tryptophan (Trp) in calyx persistence fruitlet (CPF) than calyx shedding fruitlet (CSF) ofDanshan Suli’ pear (Pyrus bretschneideri Rhed.). Consisting with this, the activity of indolealdehyde oxidase (IAAIdO), which promotes IAA synthesis, was remarkably increased, and that of peroxidase(POD), which degrades IAA, dropped markedly in CPF but not in CSF. Further, qRT-PCR results revealed that most of 31 PbrARFs (encoding auxin response factors) in Pyrus bretschneideri were highly expressed in CPF, whereas PbrARF4, PbrARF24 and PbrARF26 were significantly downregulated in CPF vis-a-vis CSF. Phylogenetic analysis revealed that 6 PbrARFs clustered in the group III, where PbrARF4 showed the closest affinity with AtARF1 that promotes organ abscission, indicating a putative role of PbrARF4 in mediating the process of calyx shedding in pear. In fact, the ectopic overexpression of PbrARF4 in Solanum lycopersicum resulted in an earlier-formed and deeper abscission layer (AL) in the transgenic plants, whose calyxes were more prone to wilt at the mature red stage (MR) compared with the control plants (wild-type). More importantly, expression levels of the abscission genes SILS and Sl Cel2 in transgenic plants overexpressing PbrARF4 were significantly upregulated in comparation with the WT, whereas those of Sl BI and Sl TAPG2 were considerably inhibited. Further, PbrJOINTLESS and PbrIDA,the two genes related to calyx shedding in pear, were up-regulated more in CSF than CPF. The findings contribute to a better understanding of PbrARFs involved in fruitlet calyx shedding of pear, which could prove beneficial to improving the quality of pear fruit.展开更多
During storage at 20℃,specific pear cultivars may exhibit a greasy texture and decline in quality due to fruit senescence.Among these varieties,‘Yuluxiang’is particularly susceptible to peel greasiness,resulting in...During storage at 20℃,specific pear cultivars may exhibit a greasy texture and decline in quality due to fruit senescence.Among these varieties,‘Yuluxiang’is particularly susceptible to peel greasiness,resulting in significant economic losses.Therefore,there is an urgent need for a preservative that can effectively inhibit the development of greasiness.Previous studies have demonstrated the efficacy of 1-methylcyclopropene(1-MCP)in extending the storage period of fruits.We hypothesize that it may also influence the occurrence of postharvest peel greasiness in the‘Yuluxiang’pears.In this study,we treated‘Yuluxiang’pears with 1-MCP.We stored them at 20℃while analyzing the composition and morphology of the surface waxes,recording enzyme activities related to wax synthesis,and measuring indicators associated with fruit storage quality and physiological characteristics.The results demonstrate that prolonged storage at 20℃leads to a rapid increase in skin greasiness,consistent with the observed elevations in L^(*),greasiness score,and the content of total wax and greasy wax components.Moreover,there were indications that cuticular waxes underwent melting,resulting in the formation of an amorphous structure.In comparison to controls,the application of 1-MCP significantly inhibited increments in L^(*) values as well as grease scores while also reducing accumulation rates for oily waxes throughout most stages over its shelf period,additionally delaying transitions from flaky-wax structures towards their amorphous counterparts.During the initial 7 d of storage,several enzymes involved in the biosynthesis and metabolism of greasy wax components,including lipoxygenase(LOX),phospholipase D(PLD),andβ-ketoacyl-CoA synthase(KCS),exhibited an increase followed by a subsequent decline.The activity of LOX during early shelf life(0–7 d)and the KCS activity during middle to late shelf life(14–21 d)were significantly suppressed by 1-MCP.Additionally,1-MCP effectively maintained firmness,total soluble solid(TSS)and titratable acid(TA)contents,peroxidase(POD),and phenylalanine ammonia-lyase(PAL)activities while inhibiting vitamin C degradation and weight loss.Furthermore,it restrained polyphenol oxidase(PPO)activity,ethylene production,and respiration rate increase.These findings demonstrate that 1-MCP not only delays the onset of peel greasiness but also preserves the overall storage quality of‘Yuluxiang’pear at a temperature of 20℃.This study presents a novel approach for developing new preservatives to inhibit pear fruit peel greasiness and provides a theoretical foundation for further research on pear fruit preservation.展开更多
Genomic selection (GS) has the potential to improve selection efficiency and shorten the breeding cycle in fruit tree breeding. In this study,we evaluated the effect of prediction methods, marker density and the train...Genomic selection (GS) has the potential to improve selection efficiency and shorten the breeding cycle in fruit tree breeding. In this study,we evaluated the effect of prediction methods, marker density and the training population (TP) size on pear GS for improving its performance and reducing cost. We evaluated GS under two scenarios:(1) five-fold cross-validation in an interspecific pear family;(2) independent validation. Based on the cross-validation scheme, the prediction accuracy (PA) of eight fruit traits varied between 0.33 (fruit core vertical diameter)and 0.65 (stone cell content). Except for single fruit weight, a slightly better prediction accuracy (PA) was observed for the five parametrical methods compared with the two non-parametrical methods. In our TP of 310 individuals, 2 000 single nucleotide polymorphism (SNP) markers were sufficient to make reasonably accurate predictions. PAs for different traits increased by 18.21%-46.98%when the TP size increased from 50to 100, but the increment was smaller (-4.13%-33.91%) when the TP size increased from 200 to 250. For independent validation, the PAs ranged from 0.11 to 0.45 using rrBLUP method. In summary, our results showed that the TP size and SNP numbers had a greater impact on the PA than prediction methods. Furthermore, relatedness among the training and validation sets, and the complexity of traits should be considered when designing a TP to predict the test panel.展开更多
基金Science and Technology Achievements Transformation Project of the Autonomous Prefecture(Project No.:202401)National College Students'Innovation and Entrepreneurship Training Program(Project Title:"Li Zhiyun·Ku Li Chun"-Pioneer in Promoting National Geographic Brand,Project Number:202513561005).
文摘Pear paste is a traditional preparation with both medicinal and nutritional functions.The“pear”,as its core ingredient,plays a crucial role in the efficacy of the preparation.This paper,through the interdisciplinary integration of evidence from traditional Chinese medicine,food chemistry,molecular biology,and clinical medicine,constructs a complete“raw material-component transformation-biological regulation”model for the first time.It is found that in pear paste,pears not only serve as a functional matrix.The polysaccharide-polyphenol-triterpene complex system forms a multi-target cough-relieving and anti-inflammatory network through dual regulation of TRPV1/TRPA1 ion channels,inhibition of the NLRP3 inflammasome,and metabolites of gut microbiota such as SCFAs.The research results provide a theoretical breakthrough for the modern development of pear paste and a scientific basis for the modernization of traditional preparations.
基金funded by the Science Foundation of China(Grant No.32230097)Earmarked Fund for China Agriculture Research System(Grant No.CARS-28)+2 种基金the Earmarked Fund for Jiangsu Agricultural Industry Technology System(Grant No.JATS[2023]412)Natural Science Foundation of Jiangsu Province for Young Scholar(Grant No.BK20221010)supported by the high-performance computing platform of Bioinformatics Center,Nanjing Agricultural University。
文摘Pear(Pyrus bretschneideri)fruit stone cells are primarily composed of lignin and have strongly lignified cell walls.The presence of stone cells has a negative influence on fruit texture and taste,and thus the reduction of stone cell content in pear fruit is a key goal of breeding efforts.However,research into the key transcription factors and regulatory networks associated with pear fruit stone cell formation have been limited.We here used a combination of co-expression network and expression quantitative trait locus(eQTL)analyses in 206 pear cultivars with different stone cell contents to identify relevant genes;these analyses uncovered the gene PbrMYB4,a R2R3 MYB transcription factor gene.There was a strong positive correlation between relative PbrMYB4 expression levels in the fruit flesh and stone cell/lignin contents.Overexpression of PbrMYB4 significantly increased the lignin contents,whereas silencing of PbrMYB4 had the opposite effect,decreasing the contents of lignin.PbrMYB4 overexpression in pear calli significantly promoted lignin biosynthesis.In Arabidopsis thaliana,PbrMYB4 overexpression resulted in increasing lignin deposition,cell wall thickness of vessels and xylary fiber,and accelerating expression level of lignin biosynthetic genes.PbrMYB4 was found to activate 4-Coumarate:Coenzyme A Ligase(Pbr4CL1)by binding to AC-I elements in the promoter regions,as demonstrated with dual-luciferase reporter assays and a yeast one-hybrid assay.These results demonstrated that PbrMYB4 positively regulated lignin biosynthesis in pear fruit stone cells by activating lignin biosynthesis genes.This study improves our understanding of the gene regulatory networks associated with stone cell formation in pear fruit,providing guidance for molecular breeding of pear varieties with low stone cell content.
文摘The WSC proteins produced by Penicillium expansum play a crucial role in causing blue mold on pears.To analyze the role of the WSC1 gene in the pathogenic process of this fungal pathogen,we conducted transcriptomic analysis of a WSC1 knockout(ΔWSC1)strain.The knockout of WSC1 significantly altered the gene expression profile in P.expansum,particularly for genes involved in cell wall integrity,signaling,stress response,and toxin production.The differential expression of these genes might make theΔWSC1 strain more vulnerable to environmental stress,while reducing the toxin production capacity,ultimately leading to a decrease in the pathogenicity.The transcriptomic analysis revealed that the expression of genes related to stress response signals,defense mechanisms and oxidative stress management changed when pear fruits were infected with theΔWSC1 strain.These changes may trigger a cascade of responses in pear fruits.In addition,compared with those infected with the wild-type strain,pear fruits infected with theΔWSC1 strain exhibited up-regulated expression of genes related to defense and oxidative stress.This study clarifies how the WSC1 gene influences P.expansum’s ability to infect pear fruits and how pear fruits respond to the infection.
文摘Significant variations in global temperatures and weather patterns over time are known as climate change.Although it occurs naturally,human activities—particularly the burning of fossil fuels,deforestation,and industrial processes—are accelerating these changes,which have various detrimental effects on the environment.This review aims to highlight the edapho-climatic requirements of this cactus and the advantages and challenges of its cultivation to mitigate climate change.The prickly pear cactus is a plant with numerous financial and environmental advantages.It needs well-draining,sandy or gravelly soil to avoid root rot and do best in full sun.With a strong tolerance for dryness,they thrive in arid or semi-arid regions with scorching summers and prefer sparing watering.Despite being suited to tropical climates,some species can tolerate freezing temperatures and sporadic frost.Once established,these hardy plants require little care and thrive in nutrient-poor soils,which makes them perfect for xeriscaping or challenging growing environments.Because of its high water use efficiency ratio and low water requirements,prickly pear can be grown in marginally dry and semi-arid areas.The cactus does contribute to the ecological and socioeconomic fight against climate change.For instance,it supports sustainable agriculture,biodiversity preservation,soil restoration,carbon sequestration,and effective water usage.Demarcating dry and semi-arid zones and fostering employment in these areas is beneficial from a socioeconomic standpoint.The prickly pear’s traditional cultural heritage supports its current economic function as a crop that can withstand drought.While ecological threats necessitate balanced management,this adaptability promotes sustainable growth.Innovations in bioenergy and value-added goods build on its historical applications,increasing its socioeconomic advantages and,eventually,its worldwide significance.
基金Science and Technology Achievements Transformation Project of the Autonomous Prefecture(Project No.:202401)National College Students'Innovation and Entrepreneurship Training Program(Project Title:"Li Zhiyun·Ku Li Chun"-Pioneer in Promoting National Geographic Brand,Project Number:202513561005).
文摘Korla fragrant pears are one of the“famous,excellent,and special”fruits in Xinjiang.They belong to the white pear variety in the genus Pyrus of the Rosaceae family.With a long-standing planting history and strong regional characteristics,they are mainly produced in southern Xinjiang.Due to unique natural conditions such as large temperature differences between day and night and sufficient sunlight,Korla fragrant pears have a crispy texture,a sweet but not cloying taste,and their flesh is delicate and juicy,with excellent quality.Korla fragrant pears contain a variety of bioactive substances,mainly including polysaccharides,polyphenolic compounds,flavonoid compounds,triterpenoids,and sterols.They have medical effects such as“moistening the lungs,calming the heart,reducing phlegm,anti-inflammation,relieving cough,and resolving carbuncle toxins”.Uyghur and Mongolian medicine often use them as a good dietary therapy product.Based on recent literature reports,this paper reviews the main chemical constituents and pharmacological effects of Korla fragrant pears,aiming to provide references for the research and utilization of the deep processing of Korla fragrant pears.
基金supported by the China Agriculture Research System(CARS-28-14)the National Natural Science Foundation of China(32302484)the University Natural Science Research Project of Anhui Province,China(2022AHO50926 and 2022AH040129).
文摘Pear anthracnose,caused by Colletotrichum fructicola,is a devastating disease that seriously affects most pear varieties,compromising their yield and quality.However,effective control of this pathogen is lacking.Moreover,the critical resistance responses to C.fructicola in pear are unknown.To investigate these resistance mechanisms of pear against C.fructicola,transcriptomic and metabolomic analyses were performed on the anthracnose-resistant variety‘Seli’and susceptible variety‘Cuiguan’after C.fructicola infection.Differentially expressed genes(DEGs)and differentially accumulated metabolites(DAMs)were mainly involved in metabolism and secondary metabolite synthetic pathways,includingα-linoleic acid metabolism,phenylalanine biosynthesis metabolism,unsaturated fatty acids biosynthesis,and biosynthesis of amino acids and their derivatives.In particular,the accumulation of unsaturated fatty acids(UFAs),amino acids,and their derivatives,such as linoleic acid and its derivatives,lauric acid,N-acetyl-L-glutamic acid,and L-proline,was significantly increased in‘Seli’after infection,while the amino acids of oxiglutatione and N-acetyl-L-glutamic acid,as well as the proanthocyanidins,were significantly decreased in‘Cuiguan’.These findings suggest that these metabolites may contribute to the differential anthracnose resistance between‘Seli’and‘Cuiguan’.Overall,our results provid new insights into the regulation of pear anthracnose resistance,which may assist in developing new control strategies and breeding anthracnose-resistant varieties.
基金supported by the National Science Foundation of China(32230097)the National Key Research and Development Program of China(2022YFD1200503)+2 种基金the earmarked fund for China Agriculture Research System(CARS-28)the earmarked fund for Jiangsu Agricultural Industry Technology System(JATS[2023]412)the Natural Science Foundation of Jiangsu Province for Young Scholar,China(BK20221010)。
文摘Pyrus pyrifolia,commonly known as sand pear,is a key economic fruit tree in temperate regions that possesses highly diverse germplasm resources for pear quality improvement.However,research on the relationship between resistance and fruit quality traits in the breeding of fruit species like pear is limited.Pan-transcriptomes effectively capture genetic information from coding regions and reflect variations in gene expression between individuals.Here,we constructed a pan-transcriptome based on 506 samples from different tissues of sand pear,and explored the intrinsic relationships among phenotypes and the selection for disease resistance during improvement based on expression presence/absence variations(eP AVs).The pan-transcriptome in this study contains 156,744 transcripts,among which the novel transcripts showed significant enrichment in the defense response.Interestingly,disease resistance genes are highly expressed in landraces of pear but have been selected against during the improvement of this perennial tree species.We found that the genetically diverse landraces can be divided into two subgroups and inferred that they have undergone different dispersal processes.Through co-expression network analysis,we confirmed that the formation of stone cells in pears,the synthesis of fruit anthocyanins,and the ability to resist stress are interrelated.They are jointly regulated by several modules,and the expression of regulatory genes has significant correlations with these three processes.Moreover,we identified candidate genes such as HKL1 that may affect sugar content and are missing from the reference genome.This study provides insights into the associations between complex fruit traits,while providing a database resource for pear disease resistance and fruit quality breeding.
基金Supported by Hebei Provincial Key Research and Development Program(21326308D-1-2)Hebei Provincial High-Level Talent Support Program(C20231157)Basic Research Funds of Hebei Academy of Agriculture and Forestry Sciences(2024020202).
文摘The new late-maturing pear cultivar‘Suyu’was bred through hybrid breeding using‘Mili’as the female parent and‘Dangshansuli’as the male parent.This cultivar has a nearly round fruit shape with a greenish-yellow skin,an average single fruit weight of 394.3 g,and a small core.The flesh is white,fine-textured,crisp,juicy,sweet,and aromatic,with a soluble solid content of 12.8%.The tree has a strong growth vigor,an open canopy,high budding rate,and strong branching ability,making it suitable for spindle or cylindrical cultivation.The main color of the one-year-old branches on the sunny side is brown.The young leaves are yellowish-green,and the mature leaves are ovate with sharp serrations.Each inflorescence has 5 to 7 flowers with pink petals,a pistil that protrudes above the stamens,and purple-red anthers.The fruit development period is about 150 d,and it matures in mid-to-late September in Changli,Hebei.The cultivar is high-yielding,stable,and well-suited for storage.‘Suyu’can be cultivated in pear-growing areas of Hebei Province and regions with similar ecological types.
文摘In order to enhance the guidance for Yuluxiang pear cultivation in hilly and mountainous regions, this study provides a comprehensive introduction to various aspects, including the establishment of high-standard orchards and the reinforcement of integrated management techniques, in order to offer a valuable reference for fruit farmers engaged in scientific planting practices.
基金Supported by The Fourth Batch of High-end Talent Project in Hebei ProvinceQuality Evaluation System Project of High-quality Fruits and Vegetables in Hebei Province.
文摘The fruit of Huangguan pear is deeply loved by consumers because of its rich nutrition and rich flavor.The quality evaluation system of Huangguan pear is composed of many quality types.In this study,the types and functions of nutritional quality indexes of Huangguan pear were summarized,such as vitamin C,soluble solids,soluble sugar and titratable acid,and the factors affecting the nutritional quality of Huangguan pear including genetic factors,environmental factors and agricultural management measures were overviewed,aiming to provide reference for establishing a comprehensive quality evaluation system of Huangguan pear and then promoting the high-quality development of Huangguan pear industry.
基金funded by the Earmarked Fund for CARS(CARS-28-07)the Agricultural Variety Improvement Project of Shandong Province,China(2022LZGC011)the Qingdao Agricultural University Doctoral Start-Up Fund,China.
文摘Dehydrin(DHN)enhances plant resistance to environmental stress by regulating the synthesis of osmotic adjustment substances and scavenging reactive oxygen species.However,the role of PbDHN3 under salt stress remains unclear.In this study,salt stress induced high expression of PbDHN3,and the overexpression of PbDHN3(OE-PbDHN3)enhanced plant growth under salt stress compared to wild-type(WT)plants.OE-PbDHN3 plants exhibited higher chlorophyll content and root growth capacity than WT plants under salt stress.Transcriptome analysis revealed that PbDHN3 expression is associated with ethylene signaling pathways.OE-PbDHN3 transgenic plants substantially influenced ethylene content and the expression of related genes.Following treatment with exogenous ethephon,the transgenic lines notably inhibited the processes of ethylene synthesis and signaling transduction.OE-PbDHN3 transgenic lines treated with exogenous ethylene and the ethylene inhibitor 1-MCP demonstrated significant inhibition of ethylene synthesis and signaling transduction,while promoting root development and chlorophyll content.Under salt stress,OE-PbDHN3 downregulated the expression of ethylene biosynthesis genes PbACO1-like and PbACO2,and signal transduction genes PbEIN3-like during the initial stress phase.This early regulation mitigated the adverse effects of salt stress on the plants.These findings demonstrate that PbDHN3 ameliorates the ethylene-mediated plant growth phenotype under salt stress through regulation of ethylene synthesis and signal transduction.
基金National Natural Science Foundation of China(32072531)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2016-RIP)+2 种基金the National Key Research and Development Program of China(2021YFE0190700)the ScienceTechnology&Innovation Funding Authority(STDF)of Egypt(43093)for funding this work。
文摘Red fruit peel is one of pear's most valuable economic traits and is mainly determined by anthocyanins.Many pear cultivars with a red peel originated from bud sports;however,little is known about the genetic mechanisms underlying this trait.We have previously identified a mutant Pp BBX24 containing a 14-nucleotide deletion in the coding region(Ppbbx24-del)as the only known variant associated with the red coloration of the mutant‘Red Zaosu'pear(Pyrus pyrifolia White Pear Group).Herein,we analyzed the role of the mutant gene in red coloration and its mechanism of action.The results showed that light promoted red peel coloration in the‘Red Zaosu'pear,and Ppbbx24-del positively affected light-induced anthocyanin biosynthesis,while normal Pp BBX24 had the opposite effects.Transient and stable transformation experiments confirmed that Ppbbx24-del could promote anthocyanin accumulation in pear fruit peels,calli,and tobacco flowers.Due to the loss of nuclear localization sequence(NLS)and viral protein(VP)domains,Ppbbx24-del co-localized in the nucleus and cytoplasm,whereas PpBBX24 localized only in the nucleus.Real-time PCR and transcriptome analyses indicated that PpM YB10 and PpH Y5 are highly expressed in the‘Red Zaosu'pear.In yeast one-hybrid and dual-luciferase assays,Ppbbx24-del and PpHY5 independently promoted the expression of PpC HS,PpC HI,and PpM YB10 by binding to their promoters;however,PpBBX24 did not affect the expression of these genes.Additionally,we found that Ppbbx24-del and PpHY5 had additive effects on the expression of PpC HS,PpC HI,and PpMYB10,as they promote the expression of anthocyanin synthesis genes separately.The co-expression of PpB BX24 and PpHY5 inhibited the activation of downstream genes by PpHY5,which was attributed to the interaction between the two loci.In conclusion,our results clarify the molecular mechanism by which mutant Ppbbx24-del and PpBBX24 exert opposite effects in regulating anthocyanin accumulation in pear.These findings lay an important theoretical foundation for using Ppbbx24-del to create red pear cultivars.
基金funded by the National Science Foundation of China(32230097)the Earmarked Fund for China Agriculture Research System(CARS-28)the Project of Zhongshan Biological Breeding Laboratory(Grant No.ZSBBL-KY2023-08).
文摘Pear fruit corking disorder is a non-infectious physiological condition that primarily occurs during the late developmental stages of pear and significantly impacts fruit quality and economic value in several major cultivars.As the underlying mechanism remains unclear,effective prevention strategies and genetic improvements continue to present major challenges.In this study,‘Akizuki’pear was used as experimental material,and the lignin content in cork-affected tissue was found to be significantly higher than in healthy tissue.Exogenous abscisic acid(ABA)treatment induced cork formation and promoted lignin biosynthesis,a major structural component,in both pear fruits and calli.Through integrated RNA-seq and expression analyses,we identified the ABA-responsive gene PbrMYB8,which was differentially expressed between healthy and diseased tissues and associated with lignin biosynthesis during corking disorder.Stable transformation of PbrMYB8 into pear calli and Arabidopsis confirmed its role in promoting lignin biosynthesis.Notably,PbrMYB8 not only activated lignin biosynthesis genes independently but also interacted with PbrMYB169 to form a protein complex that co-regulated their expression.These findings improve our understanding of lignin biosynthesis in pear fruit corking disorder by identifying a key regulator and its interaction network and provide a theoretical foundation for future strategies aimed at improving pear fruit quality.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(LR22C150001 to SB,LY22C150003 to JN)the Specialized Research Fund for Major Science and Technique of Zhejiang Province of China(2021C02066-5)+1 种基金the National Natural Science Foundation of China(32072545 to YT,32272639 to SB)the China Agriculture Research System of MOF and MARA(CARS-28)and the Yunnan Science and Technology Talent and Platform Program(202205AF150041)。
文摘Genetic variation contributes to the phenotypic diversity of plants.Most red pear cultivars that accumulate anthocyanins originated from somatic variation and are termed as bud sports.‘Hongzaosu’is a bud sport derived from the green pear‘Zaosu’.A new genetic map was constructed from a population derived from the cross of‘Yuluxiang’and‘Hongzaosu’,from which PpBBX24 was identified as a crucial gene controlling anthocyanin accumulation.Genetic and phylogenetic evidences revealed that PpBBX24 is a repressor of anthocyanin biosynthesis in pear.A 14 bp deletion was detected in the third exon of PpBBX24 in‘Hongzaosu’,resulting in premature termination of protein translation.The truncated PpBBX24 protein was a positive regulator of anthocyanin biosynthesis by activating the transcription of PpCHS and PpUFGT.Three independent variations in the BBX24 coding region that led to premature termination of translation were detected in other pear bud sports and the progeny of a bud sport that all accumulate anthocyanins.The genome of‘Hongzaosu’was assembled using both long-read and short-read sequences.By combining genomic and transcriptomic data,allele-specific expression of PpMYB110a was observed in the fruit skin of‘Hongzaosu',which was likely caused by a large variation in the promoter.This work enhances understanding of coloration in red pears and provides a novel genomic resource for further studies on‘Hongzaosu’pear.
基金supported by the National Natural Science Foundation of China(Grant No.32102364)the General Program of Shandong Natural Science Foundation(Grant No.ZR2022MC064)+3 种基金the Shanxi Province Postdoctoral Research Activity Fund(Grant No.K462101001)the Doctoral Research Initiation Fund of Shanxi Datong University(Grant No.2023-B-15)the Earmarked Fund for Modern Agro-industry Technology Research System(Grant No.2023CYJSTX07)the Shanxi Province Excellent Doctoral Work Award Project(Grant No.606-02010609)。
文摘The pear(Pyrus spp.)is well known for diverse flavors,textures,and global horticultural importance.However,the genetic diversity responsible for its extensive phenotypic variations remains largely unexplored.Here,we de novo assembled and annotated the genomes of the maternal(PsbM)and paternal(PsbF)lines of the hybrid‘Yuluxiang'pear and constructed the pear pangenome of 1.15 Gb by combining these two genomes with five previously published pear genomes representing cultivated and wild germplasm.Using the constructed pangenome,we identified 21224 gene PAVs(Presence-absence variation)and 1158812 SNPs(Single Nucleotide Polymorphism)in the non-reference genome that were absent in the PsbM reference genome.Compared with SNP markers,PAV-based analysis provides additional insights into the pear population structure.In addition,some genes associated with pear fruit quality traits have differential occurrence frequencies and differential gene expression between Asian and European populations.Moreover,our analysis of the pear pangenome revealed a mutated SNP and an insertion in the promoter region of the gene PsbMGH3.1 potentially enhance sepal shedding in‘Xuehuali'which is vital for pear quality.PsbMGH3.1 may play a role in the IAA pathway,contributing to a distinct low-auxin phenotype observed in plants by heterologously overexpressing this gene.This research helps capture the genetic diversity of pear populations and provides genomic resources for accelerating breeding.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFD1200503)Jiangsu Agriculture Science and Technology Innovation Fund[Grant No.CX(22)3046]+2 种基金the National Science Foundation of China(Grant No.32072538)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Earmarked Fund for China Agriculture Research System(Grant No.CARS-28).
文摘The Arabidopsis Toxicos en Levadura(ATL)protein is a subfamily of the E3 ubiquitin ligases,which exists widely in plants and is extensively involved in plant growth and development.Although the ATL family has been identified in other species,such as Arabidopsis,Oryza sativa,and grapevine,few reports on pear ATL gene families have been reported.In this study,92 PbrATL genes were identified and analyzed from the Pyrus breschneideri genome.Motif analysis and phylogenetic tree generation divided them into nine subgroups,and chromosome localization analysis showed that the 92 PbrATL genes were distributed in 16 of 17 pear chromosomes.Transcriptome data and quantitative real-time polymerase chain reaction(qRT-PCR)experiments demonstrated that PbrATL18,PbrATL41,and PbrATL88 were involved in both pear drought resistance and Colletotrichum fructicola infection.In addition,Arabidopsis thaliana overexpressing PbrATL18 showed greater resistance to drought stress than the wild type(WT),and PbrATL18-silenced pear seedlings showed greater sensitivity to drought and C.fructicola infection than the controls.PbrATL18 regulated plant resistance by regulating chitinase(CHI),phenylalanine ammonia-lyase(PAL),polyphenol oxidase(PPO),catalase(CAT),peroxidase(POD),and superoxide dismutase(SOD)activities.This study provided a reference for further exploring the functions of the PbrATL gene in drought resistance and C.fructicola infection.
基金supported by grants from the China Agriculture Research System(CARS-28-14)the Technical System of Fruit Industry in Anhui Province,China(AHCYTX-10)the Scientific Research Projects for Postgraduates of Anhui Universities,China(YJS20210207).
文摘Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberellins(GAs)play crucial roles in plant growth,development,and responses to drought stress.Previous studies have shown significant reductions of GA levels in plants under drought stress;however,our understanding of the intrinsic regulation mechanisms of GA-mediated drought stress in pear remains very limited.Here,we show that drought stress can impair the accumulation of bioactive GAs(BGAs),and subsequently identified PbrGA2ox1 as a chloroplast-localized GA deactivation gene.This gene was significantly induced by drought stress and abscisic acid(ABA)treatment,but was suppressed by GA_(3)treatment.PbrGA2ox1-overexpressing transgenic tobacco plants(Nicotiana benthamiana)exhibited enhanced tolerance to dehydration and drought stresses,whereas knock-down of PbrGA2ox1 in pear(Pyrus betulaefolia)by virus-induced gene silencing led to elevated drought sensitivity.Transgenic plants were hypersensitive to ABA,and had a lower BGAs content,enhanced reactive oxygen species(ROS)scavenging ability,and augmented ABA accumulation and signaling under drought stress compared to wild-type plants.However,the opposite effects were observed with PbrGA2ox1 silencing in pear.Moreover,exogenous GA_(3)treatment aggravated the ROS toxic effect and restrained ABA synthesis and signaling,resulting in the compromised drought tolerance of pear.In summary,our results shed light on the mechanism by which BGAs are eliminated in pear leaves under drought stress,providing further insights into the mechanism regulating the effects of GA on the drought tolerance of plants.
基金supported by the China Agriculture Research System (Grant No.CARS-28-14)。
文摘Fruitlet calyx shedding in pear plants is apparently regulated via numerous pathways that involve both environmental triggers and phytohormones cues such as auxin. In this study, we found at 10 days after full bloom (DAFB) higher levels of indoleacetic acid (IAA) and tryptophan (Trp) in calyx persistence fruitlet (CPF) than calyx shedding fruitlet (CSF) ofDanshan Suli’ pear (Pyrus bretschneideri Rhed.). Consisting with this, the activity of indolealdehyde oxidase (IAAIdO), which promotes IAA synthesis, was remarkably increased, and that of peroxidase(POD), which degrades IAA, dropped markedly in CPF but not in CSF. Further, qRT-PCR results revealed that most of 31 PbrARFs (encoding auxin response factors) in Pyrus bretschneideri were highly expressed in CPF, whereas PbrARF4, PbrARF24 and PbrARF26 were significantly downregulated in CPF vis-a-vis CSF. Phylogenetic analysis revealed that 6 PbrARFs clustered in the group III, where PbrARF4 showed the closest affinity with AtARF1 that promotes organ abscission, indicating a putative role of PbrARF4 in mediating the process of calyx shedding in pear. In fact, the ectopic overexpression of PbrARF4 in Solanum lycopersicum resulted in an earlier-formed and deeper abscission layer (AL) in the transgenic plants, whose calyxes were more prone to wilt at the mature red stage (MR) compared with the control plants (wild-type). More importantly, expression levels of the abscission genes SILS and Sl Cel2 in transgenic plants overexpressing PbrARF4 were significantly upregulated in comparation with the WT, whereas those of Sl BI and Sl TAPG2 were considerably inhibited. Further, PbrJOINTLESS and PbrIDA,the two genes related to calyx shedding in pear, were up-regulated more in CSF than CPF. The findings contribute to a better understanding of PbrARFs involved in fruitlet calyx shedding of pear, which could prove beneficial to improving the quality of pear fruit.
基金supported by the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-RIP)the earmarked fund for the China Agriculture Research System(CARS-28)the Natural Science Foundation of Liaoning Province,China(2021-MS-036)。
文摘During storage at 20℃,specific pear cultivars may exhibit a greasy texture and decline in quality due to fruit senescence.Among these varieties,‘Yuluxiang’is particularly susceptible to peel greasiness,resulting in significant economic losses.Therefore,there is an urgent need for a preservative that can effectively inhibit the development of greasiness.Previous studies have demonstrated the efficacy of 1-methylcyclopropene(1-MCP)in extending the storage period of fruits.We hypothesize that it may also influence the occurrence of postharvest peel greasiness in the‘Yuluxiang’pears.In this study,we treated‘Yuluxiang’pears with 1-MCP.We stored them at 20℃while analyzing the composition and morphology of the surface waxes,recording enzyme activities related to wax synthesis,and measuring indicators associated with fruit storage quality and physiological characteristics.The results demonstrate that prolonged storage at 20℃leads to a rapid increase in skin greasiness,consistent with the observed elevations in L^(*),greasiness score,and the content of total wax and greasy wax components.Moreover,there were indications that cuticular waxes underwent melting,resulting in the formation of an amorphous structure.In comparison to controls,the application of 1-MCP significantly inhibited increments in L^(*) values as well as grease scores while also reducing accumulation rates for oily waxes throughout most stages over its shelf period,additionally delaying transitions from flaky-wax structures towards their amorphous counterparts.During the initial 7 d of storage,several enzymes involved in the biosynthesis and metabolism of greasy wax components,including lipoxygenase(LOX),phospholipase D(PLD),andβ-ketoacyl-CoA synthase(KCS),exhibited an increase followed by a subsequent decline.The activity of LOX during early shelf life(0–7 d)and the KCS activity during middle to late shelf life(14–21 d)were significantly suppressed by 1-MCP.Additionally,1-MCP effectively maintained firmness,total soluble solid(TSS)and titratable acid(TA)contents,peroxidase(POD),and phenylalanine ammonia-lyase(PAL)activities while inhibiting vitamin C degradation and weight loss.Furthermore,it restrained polyphenol oxidase(PPO)activity,ethylene production,and respiration rate increase.These findings demonstrate that 1-MCP not only delays the onset of peel greasiness but also preserves the overall storage quality of‘Yuluxiang’pear at a temperature of 20℃.This study presents a novel approach for developing new preservatives to inhibit pear fruit peel greasiness and provides a theoretical foundation for further research on pear fruit preservation.
基金supported by the National Key Research and Development Program (Grant No.2022YFD1200503)Jiangsu Agricultural Science and Technology Innovation Fund [Grant No.CX(22)3043]+1 种基金the Earmarked Fund for China Agriculture Research System (Grant No.CARS-28)the Earmarked Fund for Jiangsu Agricultural Industry Technology System (Grant No.JATS [2022]454)。
文摘Genomic selection (GS) has the potential to improve selection efficiency and shorten the breeding cycle in fruit tree breeding. In this study,we evaluated the effect of prediction methods, marker density and the training population (TP) size on pear GS for improving its performance and reducing cost. We evaluated GS under two scenarios:(1) five-fold cross-validation in an interspecific pear family;(2) independent validation. Based on the cross-validation scheme, the prediction accuracy (PA) of eight fruit traits varied between 0.33 (fruit core vertical diameter)and 0.65 (stone cell content). Except for single fruit weight, a slightly better prediction accuracy (PA) was observed for the five parametrical methods compared with the two non-parametrical methods. In our TP of 310 individuals, 2 000 single nucleotide polymorphism (SNP) markers were sufficient to make reasonably accurate predictions. PAs for different traits increased by 18.21%-46.98%when the TP size increased from 50to 100, but the increment was smaller (-4.13%-33.91%) when the TP size increased from 200 to 250. For independent validation, the PAs ranged from 0.11 to 0.45 using rrBLUP method. In summary, our results showed that the TP size and SNP numbers had a greater impact on the PA than prediction methods. Furthermore, relatedness among the training and validation sets, and the complexity of traits should be considered when designing a TP to predict the test panel.
