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
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
Anthocyanins are important flavonoid pigments in the coloration of fruits.To identify candidate genes involved in anthocyanin accumulation,metabolic and transcriptome analyses were conducted in‘Nanguo'pear and it...Anthocyanins are important flavonoid pigments in the coloration of fruits.To identify candidate genes involved in anthocyanin accumulation,metabolic and transcriptome analyses were conducted in‘Nanguo'pear and its red sport cultivar‘Nanhong'pear.The results showed that‘Nanhong'pear had significantly higher anthocyanin and flavonol contents.Additionally,transcriptomic analysis showed that there were significant differences in the expression of genes involved in phenylpropanoid and flavonoid biosynthesis pathways between the two cultivars,with PuGSTF12 being the most upregulated gene in the‘Nanhong'cultivar.Further analysis identified a novel MYB transcription factor(PuMYB93),and its silencing repressed PuGSTF12 expression and anthocyanin accumulation,suggesting it plays an essential role in the regulation of anthocyanin biosynthesis.Moreover,yeast one-hybrid analysis,electrophoretic mobility shift assay,andβ-glucuronidase assay indicated that PuMYB93 can directly bind to the PuGSTF12 promoter to positively regulate its expression.Additionally,PuGSTF12 silencing suppressed the coloration of PuMYB93-OE peels,suggesting that PuGSTF12 act downstream of PuMYB93.Overall,the findings of this study show that PuMYB93 promotes anthocyanin transport in pears by regulating PuGSTF12 expression to further enhance anthocyanin accumulation.展开更多
In recent years,an unusual wilt disease affecting Pyrus pyrifolia has been observed in various regions of Jiangsu,China.This disease originates from the roots and progresses with distinctive browning patterns along va...In recent years,an unusual wilt disease affecting Pyrus pyrifolia has been observed in various regions of Jiangsu,China.This disease originates from the roots and progresses with distinctive browning patterns along vascular tissues,even extending over two meters above the ground.These symptoms set it apart from recognized pear diseases and typically lead to the death of affected trees within the same or the following year.Furthermore,this disease exhibits a tendency to spread to neighboring trees even after the removal of affected trees,presenting a substantial threat to pear production.To ascertain the causative agent,the present study encompassed pathogen isolation,morphological and molecular identification,as well as validation experiments adhering to Koch's postulates.The fungal isolates obtained were identified as Fusarium cugenangense based on characteristics of the colonies and conidia,in addition to a phylogenetic analysis using DNA sequences of the translation elongation factor 1-alpha(tef1),calmodulin(Ca M),and RNA polymerase second largest subunit(rpb2)genes.Pathogenicity of the isolated F.cugenangense on pear was confirmed by artificial inoculation.By introducing GFP-labeled pathogens into the roots,colonization in stem and leaf tissues was observed via fluorescence microscopy and transmission electron microscopy.Furthermore,these pathogens were successfully reisolated from stems and foliage,conclusively providing evidence of systemic infection within the pear plants.To the best of our knowledge,this is the first report of F.cugenangense causing pear wilt disease in China.展开更多
Pear is a popular and commercially important fresh fruit, and its texture is related to the presence of sclereid formatted by parenchyma cell with lignification in vascular plants. Previous studies have demonstrated t...Pear is a popular and commercially important fresh fruit, and its texture is related to the presence of sclereid formatted by parenchyma cell with lignification in vascular plants. Previous studies have demonstrated that content of lignin may be regulated by cinnamoyl CoA reductase(CCR) in various plants. However, the function of CCR in pears remains very limited. In the present study, we isolated a cDNA encoding CCR(PpCCR, GenBank accession No. KF999958) and its promoter(proPpCCR) from Whangkeumbae pear to investigate the function of CCR in lignin biosynthesis. PpCCR-GFP expressed in rice mesophyll protoplast demonstrated that PpCCR-GFP was localized in the cytoplasm, indicating that CCR may function in cytoplasm without localization signals. In transgenic plants carrying PpCCR, we observed higher lignin content compared with that in wild type plants, further suggesting that PpCCR can affect the lignin contents through regulating lignin biosynthesis in Arabidopsis thaliana. More studies in other plants are needed to confirm our conclusion.展开更多
The identification of self-incompatibility genotype （S-genotype） will be useful for selection of pollinizers and design of crossing in cultivar improvement of sand pear. This paper reported the identification of sel...The identification of self-incompatibility genotype （S-genotype） will be useful for selection of pollinizers and design of crossing in cultivar improvement of sand pear. This paper reported the identification of self-incompatibility genotypes of seven Chinese and two Japanese sand pear cultivars using PCR-RFLP analysis and S-RNase sequencing. The Sgenotypes of these cultivars were determined as follows： Huali 1 S1S3, Shounan S1S3, Xizilti S1S4, Qingxiang S3S7, Sanhua S2S7, Huangmi （Imamuranatsu） S1S6, Huali 2 S3S4, Baozhuli S7S33, Cangxixueli S5S15. S-RNase alleles （S1 to S9） in sand pear could be identified effectively by PCR-RFLP analysis.展开更多
Germplasm resources are an important basis for genetic breeding and analysis of complex traits,and research on genetic diversity is conducive to the exploration and creation of new types of germplasm.In this study,the...Germplasm resources are an important basis for genetic breeding and analysis of complex traits,and research on genetic diversity is conducive to the exploration and creation of new types of germplasm.In this study,the distribution frequency,coefficient of variation,Shannon-Wiener index,and variance and cluster analyses were used to analyze the diversity and trait differences of 39 fruit phenotypic traits from 570 pear accessions,which included 456 pear accessions from 11 species and 114 interspecific hybrid cultivars that had been stored in the National Germplasm Repository of Apple and Pear(Xingcheng,China).The comprehensive evaluation indices were screened by correlation,principal component and regression analyses.A total of 132 variant types were detected in 28 categorical traits of pear germplasm fruit,which indicate a rich diversity.The diversity indices in decreasing order were:fruit shape(1.949),attitude of calyx(1.908),flesh texture type(1.700),persistency of calyx(1.681),russet location(1.658),relief of area around eye basin(1.644),flavor(1.610)and ground color(1.592).The coefficient of variation of titratable acidity in the 11 numerical traits of pear germplasm fruit was as high as 128.43%,which could more effectively reflect the differences between pear accessions.The phenotypic differentiation coefficient V_(st)(66.4%)among the five cultivated pear species,including Pyrus bretschneideri(White Pear),P.pyrifolia(Sand Pear),P.ussuriensis(Ussurian Pear),P.sinkiangensis(Xinjiang Pear),and P.communis(European Pear),was higher than the within population phenotypic differentiation coefficient V_(st)(33.6%).The variation among populations was the main source of variation in pear fruit traits.A hierarchical cluster analysis divided the 389 accessions of six cultivated pear species,including P.pashia(Himalayan Pear),into six categories.There were certain characteristics within the populations,and the differences between populations were not completely clustered by region.For example,Sand Pear cultivars from Japan and the Korean Peninsula clustered together with those from China.Most of the White Pear cultivars clustered with the Sand Pear,and a few clustered with the Ussurian Pear cultivars.The Ussurian Pear and European Pear cultivars clustered separately.The Xinjiang Pear and Himalayan Pear did not cluster together,and neither did the cultivars.Seventeen traits,three describing fruit weight and edible rate(fruit diameter,fruit length and fruit core size),five describing outer quality and morphological characteristics(over color,amount of russeting,dot obviousness,fruit shape,and stalk length),and nine describing inner quality(flesh color,juiciness of flesh,aroma,flavor,flesh texture,flesh texture type,soluble solid contents,titratable acidity,and eating quality)were selected from the 39 traits by principal component and stepwise regression analyses.These 17 traits could reflect 99.3%of the total variation and can be used as a comprehensive evaluation index for pear germplasm resources.展开更多
Plants encounter a variety of stresses in natural environments. One-year-old pot-grown trees of pear(Pyrus pyrifolia Nakai cv. Cuiguan and Wonhwang) were exposed to two heat stress regimes. Under constant short-term h...Plants encounter a variety of stresses in natural environments. One-year-old pot-grown trees of pear(Pyrus pyrifolia Nakai cv. Cuiguan and Wonhwang) were exposed to two heat stress regimes. Under constant short-term heat stress, chloroplasts and mitochondria were visibly damaged. Relative chlorophyll content and maximum photochemical efficiency of photosystem II were significantly decreased, which indicated that the leaf photosynthetic capability declined. Under chronic heat stress, mesophyll cell ultrastructure was not obviously damaged, but leaf photosynthetic capability was still restrained. As chronic heat stress was a simulation of the natural environment in summer, further study of the responses under this stress regime was undertaken. Ascorbate peroxidase(APX) activity was increased in ‘Cuiguan', but not in ‘Wonhwang'. Inducible expression of PpAPX genes in the cytoplasm, chloroplasts and peroxisomes was consistent with increased APX activity in ‘Cuiguan', whereas only weak induction of PpAPX genes was observed in ‘Wonhwang'. The isoenzymes cytosolic APX1(cAPX1) and stromal APX(sAPX) were confirmed to be localized in the cytoplasm and chloroplasts, respectively.展开更多
Stone cells have been described to substantially influence pear fruit quality,as lignin and cellulose are the main components of stone cells.However,there are limited studies on the relationship between the variation ...Stone cells have been described to substantially influence pear fruit quality,as lignin and cellulose are the main components of stone cells.However,there are limited studies on the relationship between the variation and molecular basis of stone cells,lignin and cellulose content among different pear varieties.Here,to reveal the variation of stone cell content within different cultivated species,we collected 236 germplasms of sand pear(Pyrus pyrifolia)at 50 days after flower blooming(DAFB),the key stage of stone cell formation.In our results,we measured the content of stone cells,lignin and cellulose and found that these contents ranged from2.82%to 29.00%,8.84%to 55.30%and 11.52%to 30.55%,respectively.Further analysis showed that the variation coefficient of stone cell,lignin and cellulose content was 39.10%,28.03%and 16.71%,respectively.Additionally,a significant correlation between stone cell,lignin and cellulose content were detected,and the correlation coefficient between the contents of stone cell and lignin(0.912)was higher than between the contents of stone cell and cellulose(0.796).Moreover,the average lignin content(29.73%)was higher than the average cellulose content(18.03%)in stone cells in pear fruits,indicating that lignin is the main component of stone cell in pears.Finally,on the basic of the transcriptome data,we identified 10 transcription factors belonging to bHLH,ERF,MYB,and NAC transcript families,which might be involved in lignin formation in stone cells.qRT-PCR experiments verified coincident trends between expression of candidate genes and stone cell content.This research laid foundation for future studies on genetic variation of stone cells in pear fruits and provided important gene resources for stone cell regulation.展开更多
Salicylic acid(SA) plays a pivotal role in delaying fruit ripening and senescence. However, little is known about its underlying mechanism of action. In this study, RNA sequencing was conducted to analyze and compare ...Salicylic acid(SA) plays a pivotal role in delaying fruit ripening and senescence. However, little is known about its underlying mechanism of action. In this study, RNA sequencing was conducted to analyze and compare the transcriptome profiles of SA-treated and control pear fruits. We found a total of 159 and 419 genes differentially expressed between the SA-treated and control pear fruits after 12 and 24 h of treatment, respectively. Among these differentially expressed genes(DEGs), 125 genes were continuously differentially expressed at both treatment times, and they were identified as candidate genes that might be associated with SA-regulated fruit ripening and senescence. Bioinformatics analysis results showed that 125 DEGs were mainly associated with plant hormone biosynthesis and metabolism, cell wall metabolism and modification, antioxidant systems, and senescence-associated transcription factors. Additionally, the expression of several candidate DEGs in ripening and senescent pear fruits after SA treatments were further validated by quantitative real-time PCR(qRT-PCR). This study provides valuable information and enhances the understanding of the comprehensive mechanisms of SA-meditated pear fruit ripening and senescence.展开更多
Anthocyanins are important components in the peel of red pears and contribute to the appearance of the fruit.Melatonin application is known to affect anthocyanin biosynthesis,but the effect of preharvest melatonin app...Anthocyanins are important components in the peel of red pears and contribute to the appearance of the fruit.Melatonin application is known to affect anthocyanin biosynthesis,but the effect of preharvest melatonin application on fruit coloration remains largely unknown.The objective of this study was to determine the effects of preharvest melatonin application on pigmentation,phenolic compounds,and the expression of related genes in Nanhong pear(Pyrus ussuriensis).The applications were performed during the pre-color-change period by spraying 50 or 200μmol L^(-1)of melatonin on fruits.We found that treatment with melatonin had a significant effect on color development.The concentrations of anthocyanins and flavonols were enhanced by melatonin treatment,whereas hydroxycinnamate and flavanol concentrations were reduced.Quantitative real-time PCR analyses indicated that the transcription levels for most anthocyanin biosynthetic genes and anthocyanin-related transcription factors were induced by melatonin.Melatonin application also stimulated the expression of melatonin biosynthesis-related genes and consequently caused an increase in endogenous melatonin concentration.These results provide insights into melatonin-induced fruit coloration and will facilitate the application of exogenous melatonin in agriculture.展开更多
As there is a strong interest in red-skinned pears,the molecular mechanism of anthocyanin regulation in red-skinned pears has been widely investigated;however,little is known about the molecular mechanism of anthocyan...As there is a strong interest in red-skinned pears,the molecular mechanism of anthocyanin regulation in red-skinned pears has been widely investigated;however,little is known about the molecular mechanism of anthocyanin regulation in red-fleshed pears due to limited availability of such germplasm,primarily found in European pears(Pyrus communis).In this study,based on transcriptomic analysis in red-fleshed and white-fleshed pears,we identified an ethylene response factor(ERF)from P.communis,PcERF5,of which expression level in fruit flesh was significantly correlated with anthocyanin content.We then verified the function of PcERF5 in regulating anthocyanin accumulation by genetic transformation in both pear skin and apple calli.PcERF5 regulated anthocyanin biosynthesis by different regulatory pathways.On the one hand,PcERF5 can activate the transcription of flavonoid biosynthetic genes(PcDFR,PcANS and PcUFGT)and two key transcription factors encoding genes PcMYB10 and PcMYB114.On the other hand,PcERF5 interacted with PcMYB10 to form the ERF5-MYB10 protein complex that enhanced the transcriptional activation of PcERF5 on its target genes.Our results suggested that PcERF5 functioned as a transcriptional activator in regulating anthocyanin biosynthesis,which provides new insights into the regulatory mechanism of anthocyanin biosynthesis.This new knowledge will provide guidance for molecular breeding of red-fleshed pear.展开更多
Different temperatures and PEF packing treatments were carried out on postharvest Huanghua pear fruit to investigate their effects on fruit storability and the regulatory mechanism. LOX activity, O2- content, AOS acti...Different temperatures and PEF packing treatments were carried out on postharvest Huanghua pear fruit to investigate their effects on fruit storability and the regulatory mechanism. LOX activity, O2- content, AOS activity, ACC synthase activity, ACC content, ACC oxidase activity and ethylene production changed with peaks in the ripening fruit at 20℃ and were inhibited by cold storage, incidence of fruit woolness and fruit decay were lightened as well. Low temperature combined with PEF packing (PEF1 and PEF2) treatments could further improve the fruit storability, maintain preferable quality. There was no significant difference between PEF1 and PEF2 both during cold storage at 1℃ and shelf life at 20℃. The recommended storage period of Huanghua fruit was two months at It and could be extended one month longer with PEF packing treatments.展开更多
Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic aci...Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic acid(SA),a well-known phytohormone,can delay fruit senescence and improve shelf life.However,the mechanism by which SA regulates CONSTANS-LIKE genes(COLs)during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood.In this study,22 COL genes were identified in sand pear,including four COLs(Pp COL8,Pp COL9a,Pp COL9b,and Pp COL14)identified via transcriptome analysis and 18 COLs through genome-wide analysis.These COL genes were divided into three subgroups according to the structural domains of the COL protein.Pp COL8,with two B-box motifs and one CCT domain,belonged to the first subgroup.In contrast,the other three Pp COLs,Pp COL9a,Pp COL9b,and Pp COL14,with similar conserved protein domains and gene structures,were assigned to the third subgroup.The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development.Moreover,the expression of Pp COL8 was inhibited by exogenous SA treatment,while SA up-regulated the expression of Pp COL9a and Pp COL9b.Interestingly,Pp COL8 interacts with Pp MADS,a MADS-box protein preferentially expressed in fruit,and SA up-regulated its expression.While the production of ethylene and the content of malondialdehyde(MDA)were increased in Pp COL8-overexpression sand pear fruit,the antioxidant enzyme(POD and SOD)activity and the expression of Pp POD1 and Pp SOD1 in the sand pear fruits were down-regulated,which showed that Pp COL8 promoted sand pear fruit senescence.In contrast,the corresponding changes were the opposite in Pp MADS-overexpression sand pear fruits,suggesting that Pp MADS delayed sand pear fruit senescence.The co-transformation of Pp COL8 and Pp MADS also delayed sand pear fruit senescence.The results of this study revealed that Pp COL8 can play a key role in pear fruit senescence by interacting with Pp MADS through the SA signaling pathway.展开更多
The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the p...The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia)PY-9’ was identified and used as the material for anatomical analysis.PY-9’ grew to half the tree height of the normal cultivar Zhengdu’, along with fewer internodes and shorter length. Significant differences in growth rate betweenPY-9’ andZhengdu’ were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar.PY-9’ showed a higher photosynthetic rate thanZhengdu’. Anatomical analysis showed thatPY-9’ had higher area ratios of both phloem and xylem and more developed vascular tissues thanZhengdu’. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity inZhengdu’ than inPY-9’, which could contribute to the more vigorous growth ofZhengdu’. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity.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
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
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
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supported by the National Natural Science Foundation of China(32372641)the Shandong Provincial Natural Science Foundation,China(ZR2024QC143)the Liaoning Provincial Natural Science Foundation,China(2022-MS-258)。
文摘Anthocyanins are important flavonoid pigments in the coloration of fruits.To identify candidate genes involved in anthocyanin accumulation,metabolic and transcriptome analyses were conducted in‘Nanguo'pear and its red sport cultivar‘Nanhong'pear.The results showed that‘Nanhong'pear had significantly higher anthocyanin and flavonol contents.Additionally,transcriptomic analysis showed that there were significant differences in the expression of genes involved in phenylpropanoid and flavonoid biosynthesis pathways between the two cultivars,with PuGSTF12 being the most upregulated gene in the‘Nanhong'cultivar.Further analysis identified a novel MYB transcription factor(PuMYB93),and its silencing repressed PuGSTF12 expression and anthocyanin accumulation,suggesting it plays an essential role in the regulation of anthocyanin biosynthesis.Moreover,yeast one-hybrid analysis,electrophoretic mobility shift assay,andβ-glucuronidase assay indicated that PuMYB93 can directly bind to the PuGSTF12 promoter to positively regulate its expression.Additionally,PuGSTF12 silencing suppressed the coloration of PuMYB93-OE peels,suggesting that PuGSTF12 act downstream of PuMYB93.Overall,the findings of this study show that PuMYB93 promotes anthocyanin transport in pears by regulating PuGSTF12 expression to further enhance anthocyanin accumulation.
基金supported by the Jiangsu Agricultural Science and Technology Innovation Fund,China(CX(23)1011)the Earmarked Fund for China Agriculture Research System(CARS-28)+3 种基金the National Natural Science Foundation of China(31901837)the China Postdoctoral Science Foundation(2020M671389)the Basal Research Fund for the Jiangsu Academy of Agricultural Sciences,China(ZX(23)3016)the Yafu Technology Service Project,China(KF(23)1106)。
文摘In recent years,an unusual wilt disease affecting Pyrus pyrifolia has been observed in various regions of Jiangsu,China.This disease originates from the roots and progresses with distinctive browning patterns along vascular tissues,even extending over two meters above the ground.These symptoms set it apart from recognized pear diseases and typically lead to the death of affected trees within the same or the following year.Furthermore,this disease exhibits a tendency to spread to neighboring trees even after the removal of affected trees,presenting a substantial threat to pear production.To ascertain the causative agent,the present study encompassed pathogen isolation,morphological and molecular identification,as well as validation experiments adhering to Koch's postulates.The fungal isolates obtained were identified as Fusarium cugenangense based on characteristics of the colonies and conidia,in addition to a phylogenetic analysis using DNA sequences of the translation elongation factor 1-alpha(tef1),calmodulin(Ca M),and RNA polymerase second largest subunit(rpb2)genes.Pathogenicity of the isolated F.cugenangense on pear was confirmed by artificial inoculation.By introducing GFP-labeled pathogens into the roots,colonization in stem and leaf tissues was observed via fluorescence microscopy and transmission electron microscopy.Furthermore,these pathogens were successfully reisolated from stems and foliage,conclusively providing evidence of systemic infection within the pear plants.To the best of our knowledge,this is the first report of F.cugenangense causing pear wilt disease in China.
基金Supported by the Earmarked Fund for China Agriculture Research System(CARS-2917)Hubei Innovation Center of Agricultural Science and Technology(2011-620-005003)
文摘Pear is a popular and commercially important fresh fruit, and its texture is related to the presence of sclereid formatted by parenchyma cell with lignification in vascular plants. Previous studies have demonstrated that content of lignin may be regulated by cinnamoyl CoA reductase(CCR) in various plants. However, the function of CCR in pears remains very limited. In the present study, we isolated a cDNA encoding CCR(PpCCR, GenBank accession No. KF999958) and its promoter(proPpCCR) from Whangkeumbae pear to investigate the function of CCR in lignin biosynthesis. PpCCR-GFP expressed in rice mesophyll protoplast demonstrated that PpCCR-GFP was localized in the cytoplasm, indicating that CCR may function in cytoplasm without localization signals. In transgenic plants carrying PpCCR, we observed higher lignin content compared with that in wild type plants, further suggesting that PpCCR can affect the lignin contents through regulating lignin biosynthesis in Arabidopsis thaliana. More studies in other plants are needed to confirm our conclusion.
基金supported in part by Natural Science Foundation of JiangxiAgricultural University, China (1878).
文摘The identification of self-incompatibility genotype （S-genotype） will be useful for selection of pollinizers and design of crossing in cultivar improvement of sand pear. This paper reported the identification of self-incompatibility genotypes of seven Chinese and two Japanese sand pear cultivars using PCR-RFLP analysis and S-RNase sequencing. The Sgenotypes of these cultivars were determined as follows： Huali 1 S1S3, Shounan S1S3, Xizilti S1S4, Qingxiang S3S7, Sanhua S2S7, Huangmi （Imamuranatsu） S1S6, Huali 2 S3S4, Baozhuli S7S33, Cangxixueli S5S15. S-RNase alleles （S1 to S9） in sand pear could be identified effectively by PCR-RFLP analysis.
基金supported by the China Agriculture Research System of MOF and MARA(CARS-29-01)the Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ASTIP2016-RIP-01)。
文摘Germplasm resources are an important basis for genetic breeding and analysis of complex traits,and research on genetic diversity is conducive to the exploration and creation of new types of germplasm.In this study,the distribution frequency,coefficient of variation,Shannon-Wiener index,and variance and cluster analyses were used to analyze the diversity and trait differences of 39 fruit phenotypic traits from 570 pear accessions,which included 456 pear accessions from 11 species and 114 interspecific hybrid cultivars that had been stored in the National Germplasm Repository of Apple and Pear(Xingcheng,China).The comprehensive evaluation indices were screened by correlation,principal component and regression analyses.A total of 132 variant types were detected in 28 categorical traits of pear germplasm fruit,which indicate a rich diversity.The diversity indices in decreasing order were:fruit shape(1.949),attitude of calyx(1.908),flesh texture type(1.700),persistency of calyx(1.681),russet location(1.658),relief of area around eye basin(1.644),flavor(1.610)and ground color(1.592).The coefficient of variation of titratable acidity in the 11 numerical traits of pear germplasm fruit was as high as 128.43%,which could more effectively reflect the differences between pear accessions.The phenotypic differentiation coefficient V_(st)(66.4%)among the five cultivated pear species,including Pyrus bretschneideri(White Pear),P.pyrifolia(Sand Pear),P.ussuriensis(Ussurian Pear),P.sinkiangensis(Xinjiang Pear),and P.communis(European Pear),was higher than the within population phenotypic differentiation coefficient V_(st)(33.6%).The variation among populations was the main source of variation in pear fruit traits.A hierarchical cluster analysis divided the 389 accessions of six cultivated pear species,including P.pashia(Himalayan Pear),into six categories.There were certain characteristics within the populations,and the differences between populations were not completely clustered by region.For example,Sand Pear cultivars from Japan and the Korean Peninsula clustered together with those from China.Most of the White Pear cultivars clustered with the Sand Pear,and a few clustered with the Ussurian Pear cultivars.The Ussurian Pear and European Pear cultivars clustered separately.The Xinjiang Pear and Himalayan Pear did not cluster together,and neither did the cultivars.Seventeen traits,three describing fruit weight and edible rate(fruit diameter,fruit length and fruit core size),five describing outer quality and morphological characteristics(over color,amount of russeting,dot obviousness,fruit shape,and stalk length),and nine describing inner quality(flesh color,juiciness of flesh,aroma,flavor,flesh texture,flesh texture type,soluble solid contents,titratable acidity,and eating quality)were selected from the 39 traits by principal component and stepwise regression analyses.These 17 traits could reflect 99.3%of the total variation and can be used as a comprehensive evaluation index for pear germplasm resources.
基金supported by the Earmarked Fund for the Modern Agro-industry Technology Research System,China
文摘Plants encounter a variety of stresses in natural environments. One-year-old pot-grown trees of pear(Pyrus pyrifolia Nakai cv. Cuiguan and Wonhwang) were exposed to two heat stress regimes. Under constant short-term heat stress, chloroplasts and mitochondria were visibly damaged. Relative chlorophyll content and maximum photochemical efficiency of photosystem II were significantly decreased, which indicated that the leaf photosynthetic capability declined. Under chronic heat stress, mesophyll cell ultrastructure was not obviously damaged, but leaf photosynthetic capability was still restrained. As chronic heat stress was a simulation of the natural environment in summer, further study of the responses under this stress regime was undertaken. Ascorbate peroxidase(APX) activity was increased in ‘Cuiguan', but not in ‘Wonhwang'. Inducible expression of PpAPX genes in the cytoplasm, chloroplasts and peroxisomes was consistent with increased APX activity in ‘Cuiguan', whereas only weak induction of PpAPX genes was observed in ‘Wonhwang'. The isoenzymes cytosolic APX1(cAPX1) and stromal APX(sAPX) were confirmed to be localized in the cytoplasm and chloroplasts, respectively.
基金the National Key Research and Development Program(Grant No.2018YFD1000200)the Earmarked Fund for Jiangsu Agricultural Industry Technology System(Grant No.JATS[2019]420)the Earmarked Fund for China Agriculture Research System(Grant No.CARS-28).
文摘Stone cells have been described to substantially influence pear fruit quality,as lignin and cellulose are the main components of stone cells.However,there are limited studies on the relationship between the variation and molecular basis of stone cells,lignin and cellulose content among different pear varieties.Here,to reveal the variation of stone cell content within different cultivated species,we collected 236 germplasms of sand pear(Pyrus pyrifolia)at 50 days after flower blooming(DAFB),the key stage of stone cell formation.In our results,we measured the content of stone cells,lignin and cellulose and found that these contents ranged from2.82%to 29.00%,8.84%to 55.30%and 11.52%to 30.55%,respectively.Further analysis showed that the variation coefficient of stone cell,lignin and cellulose content was 39.10%,28.03%and 16.71%,respectively.Additionally,a significant correlation between stone cell,lignin and cellulose content were detected,and the correlation coefficient between the contents of stone cell and lignin(0.912)was higher than between the contents of stone cell and cellulose(0.796).Moreover,the average lignin content(29.73%)was higher than the average cellulose content(18.03%)in stone cells in pear fruits,indicating that lignin is the main component of stone cell in pears.Finally,on the basic of the transcriptome data,we identified 10 transcription factors belonging to bHLH,ERF,MYB,and NAC transcript families,which might be involved in lignin formation in stone cells.qRT-PCR experiments verified coincident trends between expression of candidate genes and stone cell content.This research laid foundation for future studies on genetic variation of stone cells in pear fruits and provided important gene resources for stone cell regulation.
基金supported by the National Natural Science Foundation of China (31301761)the China Scholarship Council (201608130248)the Second Round of the Youth Top-Notch Talent Support Programs of Hebei Province, China (2019)。
文摘Salicylic acid(SA) plays a pivotal role in delaying fruit ripening and senescence. However, little is known about its underlying mechanism of action. In this study, RNA sequencing was conducted to analyze and compare the transcriptome profiles of SA-treated and control pear fruits. We found a total of 159 and 419 genes differentially expressed between the SA-treated and control pear fruits after 12 and 24 h of treatment, respectively. Among these differentially expressed genes(DEGs), 125 genes were continuously differentially expressed at both treatment times, and they were identified as candidate genes that might be associated with SA-regulated fruit ripening and senescence. Bioinformatics analysis results showed that 125 DEGs were mainly associated with plant hormone biosynthesis and metabolism, cell wall metabolism and modification, antioxidant systems, and senescence-associated transcription factors. Additionally, the expression of several candidate DEGs in ripening and senescent pear fruits after SA treatments were further validated by quantitative real-time PCR(qRT-PCR). This study provides valuable information and enhances the understanding of the comprehensive mechanisms of SA-meditated pear fruit ripening and senescence.
基金This research was supported by the National Natural Science Foundation of China(31701865)the earmarked fund for the China Agriculture Research System(CARS-28)the Liaoning Provincial Natural Science Foundation of China(2019-MS-276).
文摘Anthocyanins are important components in the peel of red pears and contribute to the appearance of the fruit.Melatonin application is known to affect anthocyanin biosynthesis,but the effect of preharvest melatonin application on fruit coloration remains largely unknown.The objective of this study was to determine the effects of preharvest melatonin application on pigmentation,phenolic compounds,and the expression of related genes in Nanhong pear(Pyrus ussuriensis).The applications were performed during the pre-color-change period by spraying 50 or 200μmol L^(-1)of melatonin on fruits.We found that treatment with melatonin had a significant effect on color development.The concentrations of anthocyanins and flavonols were enhanced by melatonin treatment,whereas hydroxycinnamate and flavanol concentrations were reduced.Quantitative real-time PCR analyses indicated that the transcription levels for most anthocyanin biosynthetic genes and anthocyanin-related transcription factors were induced by melatonin.Melatonin application also stimulated the expression of melatonin biosynthesis-related genes and consequently caused an increase in endogenous melatonin concentration.These results provide insights into melatonin-induced fruit coloration and will facilitate the application of exogenous melatonin in agriculture.
基金funded by the National Natural Science Foundation of China(31820103012)the earmarked fund for China Agriculture Research System(CARS-28)the earmarked fund for Jiangsu Agricultural Industry Technology System,China(JATS[2022]454).
文摘As there is a strong interest in red-skinned pears,the molecular mechanism of anthocyanin regulation in red-skinned pears has been widely investigated;however,little is known about the molecular mechanism of anthocyanin regulation in red-fleshed pears due to limited availability of such germplasm,primarily found in European pears(Pyrus communis).In this study,based on transcriptomic analysis in red-fleshed and white-fleshed pears,we identified an ethylene response factor(ERF)from P.communis,PcERF5,of which expression level in fruit flesh was significantly correlated with anthocyanin content.We then verified the function of PcERF5 in regulating anthocyanin accumulation by genetic transformation in both pear skin and apple calli.PcERF5 regulated anthocyanin biosynthesis by different regulatory pathways.On the one hand,PcERF5 can activate the transcription of flavonoid biosynthetic genes(PcDFR,PcANS and PcUFGT)and two key transcription factors encoding genes PcMYB10 and PcMYB114.On the other hand,PcERF5 interacted with PcMYB10 to form the ERF5-MYB10 protein complex that enhanced the transcriptional activation of PcERF5 on its target genes.Our results suggested that PcERF5 functioned as a transcriptional activator in regulating anthocyanin biosynthesis,which provides new insights into the regulatory mechanism of anthocyanin biosynthesis.This new knowledge will provide guidance for molecular breeding of red-fleshed pear.
基金the National Natural Science Foundation of China(30270917) the Key Project of Zhejiang Provincial Natural Science Foundation(ZD0004)
文摘Different temperatures and PEF packing treatments were carried out on postharvest Huanghua pear fruit to investigate their effects on fruit storability and the regulatory mechanism. LOX activity, O2- content, AOS activity, ACC synthase activity, ACC content, ACC oxidase activity and ethylene production changed with peaks in the ripening fruit at 20℃ and were inhibited by cold storage, incidence of fruit woolness and fruit decay were lightened as well. Low temperature combined with PEF packing (PEF1 and PEF2) treatments could further improve the fruit storability, maintain preferable quality. There was no significant difference between PEF1 and PEF2 both during cold storage at 1℃ and shelf life at 20℃. The recommended storage period of Huanghua fruit was two months at It and could be extended one month longer with PEF packing treatments.
基金supported by the National Natural Science Foundation of China(32272654)the Natural Science Foundation of Hebei Province China(C2023204016)+2 种基金the Hebei Province Introduced Overseas-Scholar Fund China(C20220361)the S&T Program of Hebei China(20326330D)the Hebei Province Outstanding Youth Fund China(2016,2019)。
文摘Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic acid(SA),a well-known phytohormone,can delay fruit senescence and improve shelf life.However,the mechanism by which SA regulates CONSTANS-LIKE genes(COLs)during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood.In this study,22 COL genes were identified in sand pear,including four COLs(Pp COL8,Pp COL9a,Pp COL9b,and Pp COL14)identified via transcriptome analysis and 18 COLs through genome-wide analysis.These COL genes were divided into three subgroups according to the structural domains of the COL protein.Pp COL8,with two B-box motifs and one CCT domain,belonged to the first subgroup.In contrast,the other three Pp COLs,Pp COL9a,Pp COL9b,and Pp COL14,with similar conserved protein domains and gene structures,were assigned to the third subgroup.The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development.Moreover,the expression of Pp COL8 was inhibited by exogenous SA treatment,while SA up-regulated the expression of Pp COL9a and Pp COL9b.Interestingly,Pp COL8 interacts with Pp MADS,a MADS-box protein preferentially expressed in fruit,and SA up-regulated its expression.While the production of ethylene and the content of malondialdehyde(MDA)were increased in Pp COL8-overexpression sand pear fruit,the antioxidant enzyme(POD and SOD)activity and the expression of Pp POD1 and Pp SOD1 in the sand pear fruits were down-regulated,which showed that Pp COL8 promoted sand pear fruit senescence.In contrast,the corresponding changes were the opposite in Pp MADS-overexpression sand pear fruits,suggesting that Pp MADS delayed sand pear fruit senescence.The co-transformation of Pp COL8 and Pp MADS also delayed sand pear fruit senescence.The results of this study revealed that Pp COL8 can play a key role in pear fruit senescence by interacting with Pp MADS through the SA signaling pathway.
基金supported by grants from the Agriculture Science and Technology of Shandong Province (Grant No.2019YQ015)the Agricultural Variety Improvement Project of Shandong Province (Grant No.2022LZGC011)the earmarked fund for CARS (Grant No.CARS-28-07)。
文摘The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia)PY-9’ was identified and used as the material for anatomical analysis.PY-9’ grew to half the tree height of the normal cultivar Zhengdu’, along with fewer internodes and shorter length. Significant differences in growth rate betweenPY-9’ andZhengdu’ were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar.PY-9’ showed a higher photosynthetic rate thanZhengdu’. Anatomical analysis showed thatPY-9’ had higher area ratios of both phloem and xylem and more developed vascular tissues thanZhengdu’. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity inZhengdu’ than inPY-9’, which could contribute to the more vigorous growth ofZhengdu’. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity.
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.
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.
