Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a...Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a comparative observation on the early hypocotyl development between two cultivars,‘SZQ’belonging to pak-choi(B.campestris ssp.chinensis var.communis)with longer hypocotyls,and‘WTC’belonging to Tacai(B.campestris L.ssp.chinensis var.rosularis)with shortter hypocotyls,and found that the difference in auxin biosynthesis might contribute to the varied hypocotyl phenotype between these two cultivars.By applying GWAS analysis using a total of 226 B.campestris accessions,we identified that the AT-Hook motif nuclear localized(AHL)gene BcAHL24-MF1 contributed to the natural variation in hypocotyl length.Functional variation of BcAHL24-MF1 was attributed to four haplotypes featuring four SNPs within the promoter region,of which Hap I accumulated more transcripts with shorter hypocotyls.Constitutive overexpression of BcAHL24-MF1 in B.campestris caused decreased hypocotyl length under light circumstances and even constant darkness,as BcAHL24-MF1 repressed the PIFmediated transcriptional activation of auxin biosynthesis genes BcYUC6-MF2 and BcYUC8-LF.Our research uncovered the important role of BcAHL24-MF1 in regulating light-triggered inhibition of hypocotyl elongation,therefore presenting a valuable genetic target for crop breeding.展开更多
Allopolyploid Brassica juncea is particularly enriched in sinigrin,a kind of 3C aliphatic glucosinolates(GSLs),giving rise to characteristic taste after picking.However,the molecular mechanism underlying 3C aliphatic ...Allopolyploid Brassica juncea is particularly enriched in sinigrin,a kind of 3C aliphatic glucosinolates(GSLs),giving rise to characteristic taste after picking.However,the molecular mechanism underlying 3C aliphatic GSLs biosynthesis in this species remains unknown.In this study,we genome-widely identified GSLs metabolic genes,indicating different evolutionary rate of GSLs metabolic genes between subgenomes of B.juncea.Eight methythioalkylmalate synthase(MAMs)homologs were identified from B.juncea,in which six MAM1s were located in chloroplast and the other two were not detected with any expression.Furthermore,BjMAM1-4,BjMAM1-5,and BjMAM1-6 displayed higher expression levels in leaves than other tissues.Silenced expression analysis revealed that BjMAM1-4 and BjMAM1-6 function in 3C and 4C aliphatic GSLs accumulation.The specificity of the substrate selection for the second cycle reaction is much lower than that of the first cycle,suggesting these genes may preferentially catalyze 3C aliphatic GSLs biosynthesis.Our study provides insights into the molecular mechanism underlying the accumulation of 3C aliphatic GSLs,thereby facilitating the manipulation of aliphatic GSLs content in B.juncea.展开更多
In an effort to provide some information relevant to the molecular mechanism of genic male sterility in plants, BcMF3 gene that encodes a pectin methylesterase was isolated from the fertile B line of Chinese cabbage-p...In an effort to provide some information relevant to the molecular mechanism of genic male sterility in plants, BcMF3 gene that encodes a pectin methylesterase was isolated from the fertile B line of Chinese cabbage-pak-choi （Brassica rapa ssp. chinensis, syn. B. campestris ssp. chinensis）. In the present paper, a 455-bp antisense cDNA fragment of BcMF3 was introduced to binary vector pB1121, and then was mobilized into Agrobacterium tumefaciens strain LBA4404. The A. tumefaciens harboring the BcMF3 antisense fragment was transformed to Arabidopsis thaliana by floral dip. Scanning electronic microscopy examination demonstrated that 47.8% of BcMF3 antisense pollen grains exhibited abnormal shape, which might lead to decreased germination of pollens, suggesting that the product of BcMF3 gene plays an important role during microsporogenesis. The evidence on burst of 45.7% of BcMF3 antisense pollen tubes in vitro and a majority of BcMF3 antisense pollens restricted within the stigmatic tissue revealed that BcMF3 is involved in aiding the growth of pollen tubes. The results suggest that BcMF3 acts at both stages of microsporogensis and pollen tube growth.展开更多
The study analyzed the silencing of BcMF12 gene regulated by BcA9 promoter in the transgenic pakchoi and confirmed the effect of antisense BcMF12 gene on the pollen development. A conserved BcMF12 gene fragment was am...The study analyzed the silencing of BcMF12 gene regulated by BcA9 promoter in the transgenic pakchoi and confirmed the effect of antisense BcMF12 gene on the pollen development. A conserved BcMF12 gene fragment was amplified from the cDNA of flower buds in pakchoi （Brassica campestris L. ssp. chinensis, syn. B. rapa L. ssp. chinensis） and was fused to the anther specific BcA9 promoter. The plant antisense expression vector was constructed and then introduced into pakchoi via Agrobacterium-mediated transformation. The transgenic plants were screened by antibiotics and molecular analysis. PCR and Southern blot revealed that the antisense BcMF12-GUS fusion gene regulated by BcA9 promoter was integrated into transgenic plants. Northern blot suggested that the expression of BcMF12 gene was down-regulated significantly. The pollen germination rate of transgenic plants with antisense BcMF12 gene decreased as compared with that of the control plants. The expression of the gene BcMF12 related to the pollen development was inhibited by the antisense BcMF12 driven by BcA9 promoter, which consequently affected the pollen development in pakchoi.展开更多
Plant structures and chemicals, which are developed from the shoot apical meristem（SAM）, form the main barriers to insect feeding. A plant chimera containing cells of different genetic origins in the SAM will be mor...Plant structures and chemicals, which are developed from the shoot apical meristem（SAM）, form the main barriers to insect feeding. A plant chimera containing cells of different genetic origins in the SAM will be morphologically and chemically different compared with the parents and thus may result in differential resistance to herbivores. In this study, we explore if particular elements of plant resistance are localized in one of the layers of SAM; the replacement of one cell layer in a chimera may be linked to change of a single resistance trait to herbivores. The morphology and glucosinolate profiles of two periclinal chimeras（labeled as TTC and TCC, respectively） and grafted parents tuber mustard（labeled as TTT） and red cabbage（labeled as CCC） were compared and the performance of whitefly（Bemisia tabaci） in host selection, oviposition preference and development were assessed under controlled conditions. Both chimeras possessed leaf trichomes as parent tuber mustard TTT, however, TTC had significantly more trichomes than TCC and parent TTT. Leaf wax content of both chimeras was intermediate between the two parents. Five aliphatic and two indole glucosinolates were detected in both chimeras, whereas three aliphatic glucosinolates（3-methyl-sulfinylpropyl, 4-methyl-sulfinylbutyl and 2-hydroxy-3-butenyl） were not detected in tuber mustard, and one aliphatic glucosinolate（3-butenyl） was not detected in red cabbage. Unexpectedly for a chimera, the quantities of two aliphatic glucosinolates（3-methyl-sulfinylpropyl and 4-methyl-sulfinylbutyl） in both TTC and TCC were 3-to 5-fold higher than parents. In olfactory preference assays, B. tabaci showed preference to CCC, followed by TCC, TTC and TTT, and number of eggs laid showed the same pattern： CCC〉TCC〉TTC〉TTT. Interestingly, more whiteflies landed on TTT plants than the other three types in a free choice experiment and the developmental duration from egg to adult was the shortest on TTT and increased in the order TTT展开更多
Brassica campestris male fertility 19 （BcMF19; GenBank accession number GQ902048.1）, a gene that is specially expressed in tapetum cells and microspores during anther development in B. campestris ssp. chinensis, whi...Brassica campestris male fertility 19 （BcMF19; GenBank accession number GQ902048.1）, a gene that is specially expressed in tapetum cells and microspores during anther development in B. campestris ssp. chinensis, which is learned from the previous in situ hybridization study. In the present study, we constructed antisense-silenced plants of BcMF19 using B. campestris ssp. chinensis to validate this prediction. The morphology of the pistils, long anthers, and short anthers was significantly affected in 35sbcmf19 compared with the control samples. 4＇-6-Diamidino-2-phenylindole staining revealed that two generative nuclei and one large vegetative nucleus were not affected in the mutant compared with control. Statistical analysis of Alexander＇s staining results showed that 96% of the control pollen grains had vitality, whereas only 86% of the mutant pollen grains did. Under scanning electron microscopy, the mutant demonstrated numerous abnormal pollen grains and resembled dried persimmon. The frequency of normal pollen grains was approximately 18%. Under transmission electron microscopy, the pollen intine during the binucleate and mature pollen stages in 35sbcmf19 exhibited abnormal thickening, especially at the germinal furrows, compared with control. In vitro pollen germination test showed that the tips of the mutant pollen tubes transformed into globular alveoli and stopped growing compared with control. On the other hand, in vivo pollen germination test suggested that BcMF19 affected the pollen tube extension in the pistil. These findings indicate that BcMF19 is essential to the pollen development and pollen tube extension orB. campestris ssp. chinensis.展开更多
DNA barcodes have been proposed as a shortcut to provide species identification and as a way to accelerate the discovery of new species. A number of candidate gene regions have been suggested as possible barcodes for ...DNA barcodes have been proposed as a shortcut to provide species identification and as a way to accelerate the discovery of new species. A number of candidate gene regions have been suggested as possible barcodes for animals and plants, but for the identification of recently diverged species and/or varieties with only a few genetic differences it has been reported to be problematic in some cases. This study selected widely cultivated cruciferous vegetables as the primary samples, after failure of discrimination of each species using current DNA barcodes, we performed the fluorescent amplified fragment length polymorphism （F-AFLP） and successfully discriminated each species, subspecies, variety and their cultivar in 74 samples. Then the non-qualitative results obtained from F-AFLP were transformed into two-dimensional barcodes image file of each cultivar via the PDF417 software. This method was also successfully applied to the discrimination of 17 Chinese indigenous pig breeds. The barcode we constructed which greatly reduces the information storage space is genotypes-specific, and can be conveniently decoded into the original data and thereby be conveniently shared and referred to. We believe that it is possible to construct a new data sharing molecular barcode system that could discriminate the subspecies, varieties, cultivars and even individuals with close genetic relationships.展开更多
Iron(Fe)is an essential micronutrient for all organisms,including plants,whose limited bioavailability restricts plant growth,yield,and nutritional quality.While the transcriptional regulation of plant responses to Fe...Iron(Fe)is an essential micronutrient for all organisms,including plants,whose limited bioavailability restricts plant growth,yield,and nutritional quality.While the transcriptional regulation of plant responses to Fe deficiency have been extensively studied,the contribution of epigenetic modulations,such as DNA methylation,remains poorly understood.Here,we report that treatment with a DNA methylase inhibitor repressed Fe deficiency-induced responses in tomato(Solanum lycopersicum)roots,suggesting the importance of DNA methylation in regulating Fe deficiency responses.Dynamic changes in the DNA methylome in tomato roots responding to short-term(12 hours)and long-term(72 hours)Fe deficiency identified many differentially methylated regions(DMRs)and DMR-associated genes.Most DMRs occurred at CHH sites under short-term Fe deficiency,whereas they were predominant at CG sites following long-term Fe deficiency.Furthermore,no correlation was detected between the changes in DNA methylation levels and the changes in transcript levels of the affected genes under either short-term or long-term treatments.Notably,one exception was CG hypermethylation at the bHLH39 promoter,which was positively correlated with its transcriptional induction.In agreement,we detected lower CG methylation at the bHLH39 promoter and lower bHLH39 expression in MET1-RNA interference lines compared with wild-type seedlings.Virus-induced gene silencing of bHLH39 and luciferase reporter assays revealed that bHLH39 is positively involved in the modulation of Fe homeostasis.Altogether,we propose that dynamic epigenetic DNA methylation in the CG context at the bHLH39 promoter is involved in its transcriptional regulation,thus contributing to the Fe deficiency response of tomato.展开更多
To estimate genetic variation in rhizome lotus （Nelumbo nucifera Gaertn. ssp. nucifera） germplasms in China, a total of 94 rhizome lotus germplasms collected from 18 provinces in China were assessed. The RAPD （rand...To estimate genetic variation in rhizome lotus （Nelumbo nucifera Gaertn. ssp. nucifera） germplasms in China, a total of 94 rhizome lotus germplasms collected from 18 provinces in China were assessed. The RAPD （randomly amplified polymorphic DNA） marker was employed. The selected 17 random primers detected 139 polymorphic alleles out of a total 207 （67.15%）. Nei＇s gene diversity statistics and region differentiation parameters indicated that all germplasms had a relatively high level of genetic diversity with ne = 1.3202, h = 0.1937, I= 0.2982 and the gene flow among all regions was Nrn = 5.5742. The UPGMA dendrogram clustered all 94 germplasms into two clusters： One contained eight commercial cultivars and major landraces, and the other included the wild and some special landraces from five regions, and the PCA analysis exhibited the similar result. Those germplasms from southwestern and eastern China had higher genetic diversity than those from the southern, northern and central China. Predominant proportion of genetic variation （95.61%） was found significant within rather than among （4.39%） regions, as revealed by AMOVA analysis. The data analysis also revealed that the genetic diversity of rhizome lotus germplasms among different regions is positively related to their geographic distances, though it is ambiguous to find the trend from the UPGMA dendrogram and the PCA analysis. A relatively high genetic diversity and gene flow resided in the root lotus germplasms; about 96% of the variation was found within region; accessions from southwest and eastern China have higher genetic diversity than those from the southern, northern and central China.展开更多
An anti-gene CYP86MF was introduced into hypocotyls of broccoli （Brassica oleracea L.var. italica Plenck） with Agrobacterium tumefaciens, and the transgenic plants were obtained by kanamycin selection. The results o...An anti-gene CYP86MF was introduced into hypocotyls of broccoli （Brassica oleracea L.var. italica Plenck） with Agrobacterium tumefaciens, and the transgenic plants were obtained by kanamycin selection. The results of PCR, Southern blot and Northern blot indicated that the anti-CYP86MF has been integrated into chromosome of the transgenic plant. And also, plants with hypogenetic stamina or ungerminated pollen were observed. The transgenic male sterility plant could fructify via artificial pollination with normal pollen. Thus it was proved that the pistil of male sterility plant was normally developed, and the sterility originated from anti-CYP86MF.展开更多
Viruses are representative of a global threat to agricultural production. Genetic resistance is the preferred strategy for the control of viral infection and against loss of crop yield. Viral protein synthesis require...Viruses are representative of a global threat to agricultural production. Genetic resistance is the preferred strategy for the control of viral infection and against loss of crop yield. Viral protein synthesis requires host cellular factors for translating their viral RNAs, and for regulating their replication and cell to cell systemic movement. Therefore, the viruses are dependent on cellular translation factors. Mutations in the gene encoding eIF4E and eIF4G or their isoforms, eIFiso4 E, eIFiso4 G and eIF2Bβ have been mapped as a source of plant potyvirus while other genus of plant virus recessive resistance genes in many species are originated from these loci. Some of other plant translation factors, such as eIF3,eIF4 A-like helicases, eEF1A and eEF1B, which are required in interacting with viral RNAs and regulating various aspects of the infection cycle,have also been identified. Here, we summarized the mechanisms utilized by RNA viruses of eukaryotic plants and the essential roles of e IFs in virus infection. Moreover, we discussed the potential of e IFs as a target gene in the development of genetic resistance to viruses for crop improvement. This review highlighted newly revealed examples of abnormal translational strategies and provided insights into natural host resistance mechanisms that have been linked to 3 cap-independent translational enhancer activity.展开更多
The modern cultivated tomato(Solanum lycopersicum)was domesticated from Solanum pimpinellifolium native to the Andes Mountains of South America through a“two-step domestication”process.It was introduced to Europe in...The modern cultivated tomato(Solanum lycopersicum)was domesticated from Solanum pimpinellifolium native to the Andes Mountains of South America through a“two-step domestication”process.It was introduced to Europe in the 16th century and later widely cultivated worldwide.Since the late 19th century,breeders,guided by modern genetics,breeding science,and statistical theory,have improved tomatoes into an important fruit and vegetable crop that serves both fresh consumption and processing needs,satisfying diverse consumer demands.Over the past three decades,advancements in modern crop molecular breeding technologies,represented by molecular marker technology,genome sequencing,and genome editing,have significantly transformed tomato breeding paradigms.This article reviews the research progress in the field of tomato molecular breeding,encompassing genome sequencing of germplasm resources,the identification of functional genes for agronomic traits,and the development of key molecular breeding technologies.Based on these advancements,we also discuss the major challenges and perspectives in this field.展开更多
Brassica juncea is an allopolyploid originating from the interspecific hybridization between Brassica rapa and Brassica nigra, which is of multiple usage as a vegetable, oilseed and condiment worldwide. Both vernaliza...Brassica juncea is an allopolyploid originating from the interspecific hybridization between Brassica rapa and Brassica nigra, which is of multiple usage as a vegetable, oilseed and condiment worldwide. Both vernalization and non-vernalization under long-day photoperiod can promote floral transition in B. juncea suggesting merged flowering pathways of its ancestors and better environmental adaptability. We identified genomewide flowering regulatory genes in B. juncea, which include 84 and 79 genes from A and B sub-genomes, respectively. Ka/Ks analysis revealed a purification effect on both photoperiod and vernalization flowering regulation pathways during evolution. Expression profile of those genes during long-day and vernalization treatments suggested Bju ACO4, Bju AFT1, Bju BFT4, Bju ASOC1 and Bju ASOC4 may be the major functional copies of B. juncea flowering regulation. Further functional studies about Bju COs showed three days delayed flowering time in Bju ACO4 or Bju BCO3 silenced plants. Increased transcription of all BjuFLCs in Bju ACO4 or Bju BCO3 silenced plants suggested interactions between photoperiod and vernalization pathways governing flowering time. Our findings provided flowering regulating networks in allopolyploid B. juncea.展开更多
Tagetes erecta is an annual multifunctional plant which can be cultivated under a broad range of climatic conditions. Polyploidization and interspecific hybridization are applied to facilitate breeding cultivars of T....Tagetes erecta is an annual multifunctional plant which can be cultivated under a broad range of climatic conditions. Polyploidization and interspecific hybridization are applied to facilitate breeding cultivars of T. erecta with improved ornamental qualities. Colchicine treatment to the germinating seeds was proved to be a useful tool for chromosome doubling of the male sterile two-type line ‘M525AB', with the resulting frequency of polyploid seedlings ranging from 88.89%(following 0.05% w/v colchicine applied for a 3–6 h exposure period) to a maximum of100.00%(following 0.1% for 3–6 h, or 0.2% for 3 h). Morphological observation, stomatal size and density analysis, flow cytometric analysis and chromosome counting were conducted to identify the tetraploid plants. Distinctive morphological changes were observed in a notable proportion of polyploid plants. The colchicine-treated polyploid T. erecta plants showed dwarfed and more robust growth, thicker, larger and greener leaves, larger inflorescences and florets. The mutant plants identified through morphological observation all aligned as polyploid plants, thus morphological observation could be an effective method for the detection of polyploidy. The polyploid plants had significant larger stomata size over the abaxial leaf surface, whereas the density of stomata distribution was remarkably reduced. The survival rate of tetraploid cuttings(i.e. 38%)was greatly reduced compared to that of diploid plants. The fertility of tetraploid plants was also decreased, as shown by cross-pollination yields.Interspecific hybridizations between colchicine-induced tetraploid plants of a male sterile T. erecta line and the naturally tetraploid fully fertile Tagetes patula species resulted in hybrid progeny. Most of these hybrids displayed the dwarfed growth stature and compact, larger-flower morphology which is the typical ideotype of herbaceous flowers. Thus, polyploidization may be employed effectively as a means to facilitate interspecific hybridization, thereby contributing significantly to the improvement of quantitative traits of Tagetes spp.展开更多
Grafting is commonly used to overcome soilborne diseases. However, its effects on the rhizodeposits as well as the linkages between the rhizosphere chemical niche and microbiome remained unknown. In this paper,signifi...Grafting is commonly used to overcome soilborne diseases. However, its effects on the rhizodeposits as well as the linkages between the rhizosphere chemical niche and microbiome remained unknown. In this paper,significant negative correlations between the bacterial alpha diversity and both the disease incidence(r = – 0.832,P = 0.005) and pathogen population(r = – 0.786, P = 0.012)were detected. Moreover, our results showed that the chemical diversity not only predicts bacterial alpha diversity but also can impact on overall microbial community structure(beta diversity) in the rhizosphere.Furthermore, some anti-fungal compounds including heptadecane and hexadecane were identified in the rhizosphere of grafted watermelon. We concluded that grafted watermelon can form a distinct rhizosphere chemical niche and thus recruit microbial communities with high diversity. Furthermore, the diverse bacteria and the antifungal compounds in the rhizosphere can potentially serve as biological and chemical barriers, respectively, to hinder pathogen invasion. These results not only lead us toward broadening the view of disease resistance mechanism of grafting, but also provide clues to control the microbial composition by manipulating the rhizosphere chemical niche.展开更多
The T gene, which was cloned from the mitochondria of tumorous stem mustard （Brassica juncea var. tumida）, is a cytoplas- mic male sterility （CMS）-related gene that can produce two transcripts, T1170 and T1243. Th...The T gene, which was cloned from the mitochondria of tumorous stem mustard （Brassica juncea var. tumida）, is a cytoplas- mic male sterility （CMS）-related gene that can produce two transcripts, T1170 and T1243. The latter is transcribed with the un- cleaved intron Tinll. In our previous study, transgenic Arabidopsis thaliana plants over-expressing the T1243 transcript （OE-T1243） showed a severe male-sterile phenotype, whereas OE-Tll70 plants did not. However, the functional mechanism of the T gene in B. Juncea remained unknown. In this study, microscopic analyses of paraffin sections of anthers confirmed that OE-T1243 plants did not produce normal pollen, whereas OE-T1170 plants did. We analyzed the transcription of 15 anther development-related genes and found that transcript levels of nozzle/sporocyteless and barely any meristem 1 and 2 were markedly lower in OE-T1243 plants than those in wild type, while the transcript levels of these genes in OE-Tll70 plants were unchanged. To investigate the potential roles of TinH, we inserted the TinH sequence upstream of a minimal region （-60） of the cauliflower mosaic virus 35S promoter fused to the 5＇ end of the 13-glucuronidase （GUS） reporter gene. Analysis of the transgenic plants suggested that TinH acted as an enhancer to significantly increase GUS expression. The potential action mechanism is that the TinH intron acts as an enhancer to affect the function of the CMS-related gene T.展开更多
Tomato leaf curl New Delhi virus(ToLCNDV)is a member of the genus Begomovirus,and causes devastating disease in the world.In recent years,ToLCNDV was rapidly spreading in China and induces severe economic losses in ag...Tomato leaf curl New Delhi virus(ToLCNDV)is a member of the genus Begomovirus,and causes devastating disease in the world.In recent years,ToLCNDV was rapidly spreading in China and induces severe economic losses in agriculture.In this study,we sequenced and characterized the complete genome of ToLCNDV isolates from melon plants showing leaf curling and stunting symptoms in Jiangsu Province of China.We constructed a full-length infectious cDNA clone of ToLCNDV,which could induce systemic infection with typical symptoms in Nicotiana benthamiana,Cit-rullus melo,and Citrullus lanatus plants through agrobacterium-mediated inoculation.Further experimental evidence demonstrated that the virions produced in plants infected with the infectious clone of ToLCNDV are biologically active and sap-transmissible.We also evaluated the resistance of commercial melon cultivars to ToLCNDV and found all testing melon cultivars were susceptible to ToLCNDV.Collectively,the reverse genetic system developed herein will facilitate further research on biological functions of proteins encoded by ToLCNDV and plant-ToLCNDV interactions,which might provide new insights into breeding resistance germplasm in crops.展开更多
Tomato brown rugose fruit virus(ToBRFV)overcomes all known tomato resistance genes,including the durable Tm-2^(2),posing a serious threat to global tomato production.Here,we employed in vitro random mutagenesis to evo...Tomato brown rugose fruit virus(ToBRFV)overcomes all known tomato resistance genes,including the durable Tm-2^(2),posing a serious threat to global tomato production.Here,we employed in vitro random mutagenesis to evolve the Tm-2^(2)leucine-rich repeat(LRR)domain and screened~8,000 variants for gain-of-function mutants capable of recognizing the ToBRFV movement protein(MP)and triggering hypersensitive cell death.We identified five such mutants.Among them,Tm-2^(2-S723Y)and Tm-2^(2-N744D)induced strong,specific cell death upon co-expression with ToBRFV MP,while retaining recognition of TMV MP.Transgenic Nicotiana benthamiana and tomato plants expressing Tm-2^(2-S723Y)resisted the naturally occurring ToBRFV(ToBRFV^(E132)).However,after prolonged infection,ToBRFV^(E132)evolved an E132K substitution in its MP,and the newly appeared ToBRFV_(K132)evaded Tm-2^(2-S723Y)-mediated resistance.However,Tm-2^(2-N744D)still recognized MPK132,and the double mutant Tm-2^(2-S723Y/N744D)conferred broad resistance against ToBRFV^(E132),ToBRF^(VK132),and tobacco mosaic virus in stable transgenic tomato.Our work demonstrates that artificial NLR evolution can generate broad-spectrum resistance against tobamovirus.展开更多
The WRKY gene family is among the largest families of transcription factors （TFs） in higher plants. By regulating the plant hormone signal transduction pathway, these TFs play critical roles in some plant processes ...The WRKY gene family is among the largest families of transcription factors （TFs） in higher plants. By regulating the plant hormone signal transduction pathway, these TFs play critical roles in some plant processes in response to biotic and abiotic stress, Various bodies of research have demonstrated the important biological functions of WRKY TFs in plant response to different kinds of biotic and abiotic stresses and working mecha- nisms. However, very li2ttle summarization has been done to review their research progress. Not iust important TFs function in plant response to biotic and abiotic stresses, WRKY also participates in carbohydrate synthesis, senes- cence, development, and secondary metabolites synthesis. WRKY proteins can bind to W-box （TGACC （A/T）） in the promoter of its target genes and activate or repress the expression of downstream genes to regulate their stress response. Moreover, WRKY proteins can interact with other TFs to regulate plant defensive responses. In the present review, we focus on the structural characteristics of WRKY TFs and the research progress on their functions in plant responses to a variety of stresses.展开更多
Tomato leaf curl New Delhi virus(ToLCNDV),a bipartite begomovirus,was first reported to infect tomato and has recently spread rapidly as an emerging disease to Cucurbitaceae crops.To date,the virus has been reported t...Tomato leaf curl New Delhi virus(ToLCNDV),a bipartite begomovirus,was first reported to infect tomato and has recently spread rapidly as an emerging disease to Cucurbitaceae crops.To date,the virus has been reported to infect more than 11 cucurbit crops,in 16 countries and regions,causing severe yield losses.In autumn 2022,ToLCNDV was first isolated from cucurbit plants in Southeastern coastal areas of China.Phylogenetic analysis established that these isolates belong to the Asian ToLCNDV clade,and shared high nucleotide identity and closest genetic relationship with the DNA-A sequence from the Chinese tomato-infecting ToLCNDV isolate(Accession no.OP356207)and the tomato New Delhi ToLCNDV-Severe isolate(Accession no.HM159454).In this review,we summarize the occurrence and distribution,host range,detection and diagnosis,control strategies,and genetic resistance of ToLCNDV in the Cucurbitaceae.We then summarize pathways that could be undertaken to improve our understanding of this emerging disease,with the objective to develop ToLCNDV-resistant cucurbit cultivars.展开更多
基金supported by grants from the Key R and D Program of Zhejiang(Grant Nos.2022C02032 and 2022C02030)the SanNong JiuFang Science and Technology Cooperation Project of Zhejiang Province(Grant No.2023SNJF008)+1 种基金the Grand Science and Technology Special Project of Zhejiang Province(Grant No.2021C02065)the Science and Technology Plan Project of Jiaxing(Grant No.2023AZ11002).
文摘Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a comparative observation on the early hypocotyl development between two cultivars,‘SZQ’belonging to pak-choi(B.campestris ssp.chinensis var.communis)with longer hypocotyls,and‘WTC’belonging to Tacai(B.campestris L.ssp.chinensis var.rosularis)with shortter hypocotyls,and found that the difference in auxin biosynthesis might contribute to the varied hypocotyl phenotype between these two cultivars.By applying GWAS analysis using a total of 226 B.campestris accessions,we identified that the AT-Hook motif nuclear localized(AHL)gene BcAHL24-MF1 contributed to the natural variation in hypocotyl length.Functional variation of BcAHL24-MF1 was attributed to four haplotypes featuring four SNPs within the promoter region,of which Hap I accumulated more transcripts with shorter hypocotyls.Constitutive overexpression of BcAHL24-MF1 in B.campestris caused decreased hypocotyl length under light circumstances and even constant darkness,as BcAHL24-MF1 repressed the PIFmediated transcriptional activation of auxin biosynthesis genes BcYUC6-MF2 and BcYUC8-LF.Our research uncovered the important role of BcAHL24-MF1 in regulating light-triggered inhibition of hypocotyl elongation,therefore presenting a valuable genetic target for crop breeding.
基金The authors thank Prof.Q.Wang for GSLs analysis.This work was supported by grants from the National Natural Science Foundation of Zhejiang Province(Grant no.LZ20C150002)the National Natural Science Foundation of China(Grant no.31872095).
文摘Allopolyploid Brassica juncea is particularly enriched in sinigrin,a kind of 3C aliphatic glucosinolates(GSLs),giving rise to characteristic taste after picking.However,the molecular mechanism underlying 3C aliphatic GSLs biosynthesis in this species remains unknown.In this study,we genome-widely identified GSLs metabolic genes,indicating different evolutionary rate of GSLs metabolic genes between subgenomes of B.juncea.Eight methythioalkylmalate synthase(MAMs)homologs were identified from B.juncea,in which six MAM1s were located in chloroplast and the other two were not detected with any expression.Furthermore,BjMAM1-4,BjMAM1-5,and BjMAM1-6 displayed higher expression levels in leaves than other tissues.Silenced expression analysis revealed that BjMAM1-4 and BjMAM1-6 function in 3C and 4C aliphatic GSLs accumulation.The specificity of the substrate selection for the second cycle reaction is much lower than that of the first cycle,suggesting these genes may preferentially catalyze 3C aliphatic GSLs biosynthesis.Our study provides insights into the molecular mechanism underlying the accumulation of 3C aliphatic GSLs,thereby facilitating the manipulation of aliphatic GSLs content in B.juncea.
基金the National Natural Science Foundation of China （30370975） the Key Scitechnology Project of Zhejiang Province （2005C 12019- 02） the Natural Science Foundation of Zhejiang Province, China （Y304180）.
文摘In an effort to provide some information relevant to the molecular mechanism of genic male sterility in plants, BcMF3 gene that encodes a pectin methylesterase was isolated from the fertile B line of Chinese cabbage-pak-choi （Brassica rapa ssp. chinensis, syn. B. campestris ssp. chinensis）. In the present paper, a 455-bp antisense cDNA fragment of BcMF3 was introduced to binary vector pB1121, and then was mobilized into Agrobacterium tumefaciens strain LBA4404. The A. tumefaciens harboring the BcMF3 antisense fragment was transformed to Arabidopsis thaliana by floral dip. Scanning electronic microscopy examination demonstrated that 47.8% of BcMF3 antisense pollen grains exhibited abnormal shape, which might lead to decreased germination of pollens, suggesting that the product of BcMF3 gene plays an important role during microsporogenesis. The evidence on burst of 45.7% of BcMF3 antisense pollen tubes in vitro and a majority of BcMF3 antisense pollens restricted within the stigmatic tissue revealed that BcMF3 is involved in aiding the growth of pollen tubes. The results suggest that BcMF3 acts at both stages of microsporogensis and pollen tube growth.
基金the National Natural Science Foundation of China(30671426)the Key Sci-Technology Project of Zhejiang Province,China(2005C12019-02)
文摘The study analyzed the silencing of BcMF12 gene regulated by BcA9 promoter in the transgenic pakchoi and confirmed the effect of antisense BcMF12 gene on the pollen development. A conserved BcMF12 gene fragment was amplified from the cDNA of flower buds in pakchoi （Brassica campestris L. ssp. chinensis, syn. B. rapa L. ssp. chinensis） and was fused to the anther specific BcA9 promoter. The plant antisense expression vector was constructed and then introduced into pakchoi via Agrobacterium-mediated transformation. The transgenic plants were screened by antibiotics and molecular analysis. PCR and Southern blot revealed that the antisense BcMF12-GUS fusion gene regulated by BcA9 promoter was integrated into transgenic plants. Northern blot suggested that the expression of BcMF12 gene was down-regulated significantly. The pollen germination rate of transgenic plants with antisense BcMF12 gene decreased as compared with that of the control plants. The expression of the gene BcMF12 related to the pollen development was inhibited by the antisense BcMF12 driven by BcA9 promoter, which consequently affected the pollen development in pakchoi.
基金financially supported by the Special Fund for Agro-scientific Research in the Public Interest of China(201203036)the Key Science and Technology Innovation team of the Zhejiang Province,China(2013TD05)the Key Science and Technology Program of Zhejiang Province,China(2015C32048)
文摘Plant structures and chemicals, which are developed from the shoot apical meristem（SAM）, form the main barriers to insect feeding. A plant chimera containing cells of different genetic origins in the SAM will be morphologically and chemically different compared with the parents and thus may result in differential resistance to herbivores. In this study, we explore if particular elements of plant resistance are localized in one of the layers of SAM; the replacement of one cell layer in a chimera may be linked to change of a single resistance trait to herbivores. The morphology and glucosinolate profiles of two periclinal chimeras（labeled as TTC and TCC, respectively） and grafted parents tuber mustard（labeled as TTT） and red cabbage（labeled as CCC） were compared and the performance of whitefly（Bemisia tabaci） in host selection, oviposition preference and development were assessed under controlled conditions. Both chimeras possessed leaf trichomes as parent tuber mustard TTT, however, TTC had significantly more trichomes than TCC and parent TTT. Leaf wax content of both chimeras was intermediate between the two parents. Five aliphatic and two indole glucosinolates were detected in both chimeras, whereas three aliphatic glucosinolates（3-methyl-sulfinylpropyl, 4-methyl-sulfinylbutyl and 2-hydroxy-3-butenyl） were not detected in tuber mustard, and one aliphatic glucosinolate（3-butenyl） was not detected in red cabbage. Unexpectedly for a chimera, the quantities of two aliphatic glucosinolates（3-methyl-sulfinylpropyl and 4-methyl-sulfinylbutyl） in both TTC and TCC were 3-to 5-fold higher than parents. In olfactory preference assays, B. tabaci showed preference to CCC, followed by TCC, TTC and TTT, and number of eggs laid showed the same pattern： CCC〉TCC〉TTC〉TTT. Interestingly, more whiteflies landed on TTT plants than the other three types in a free choice experiment and the developmental duration from egg to adult was the shortest on TTT and increased in the order TTT
基金supported by the National Basic Research Program of China (2012CB113900)the National Natural Science Foundation of China (31071805)the Key Sci-Technology Project of Zhejiang Province, China (2010C12004)
文摘Brassica campestris male fertility 19 （BcMF19; GenBank accession number GQ902048.1）, a gene that is specially expressed in tapetum cells and microspores during anther development in B. campestris ssp. chinensis, which is learned from the previous in situ hybridization study. In the present study, we constructed antisense-silenced plants of BcMF19 using B. campestris ssp. chinensis to validate this prediction. The morphology of the pistils, long anthers, and short anthers was significantly affected in 35sbcmf19 compared with the control samples. 4＇-6-Diamidino-2-phenylindole staining revealed that two generative nuclei and one large vegetative nucleus were not affected in the mutant compared with control. Statistical analysis of Alexander＇s staining results showed that 96% of the control pollen grains had vitality, whereas only 86% of the mutant pollen grains did. Under scanning electron microscopy, the mutant demonstrated numerous abnormal pollen grains and resembled dried persimmon. The frequency of normal pollen grains was approximately 18%. Under transmission electron microscopy, the pollen intine during the binucleate and mature pollen stages in 35sbcmf19 exhibited abnormal thickening, especially at the germinal furrows, compared with control. In vitro pollen germination test showed that the tips of the mutant pollen tubes transformed into globular alveoli and stopped growing compared with control. On the other hand, in vivo pollen germination test suggested that BcMF19 affected the pollen tube extension in the pistil. These findings indicate that BcMF19 is essential to the pollen development and pollen tube extension orB. campestris ssp. chinensis.
基金supported by the Key Sci-Technology Project of Zhejiang Province (2010C12004)the Sci-Technology Project of Zhejiang Province (2009C32026)the Sci-Technology Project of Jiaxing City, Zhejiang, China-(2010AZ1004)
文摘DNA barcodes have been proposed as a shortcut to provide species identification and as a way to accelerate the discovery of new species. A number of candidate gene regions have been suggested as possible barcodes for animals and plants, but for the identification of recently diverged species and/or varieties with only a few genetic differences it has been reported to be problematic in some cases. This study selected widely cultivated cruciferous vegetables as the primary samples, after failure of discrimination of each species using current DNA barcodes, we performed the fluorescent amplified fragment length polymorphism （F-AFLP） and successfully discriminated each species, subspecies, variety and their cultivar in 74 samples. Then the non-qualitative results obtained from F-AFLP were transformed into two-dimensional barcodes image file of each cultivar via the PDF417 software. This method was also successfully applied to the discrimination of 17 Chinese indigenous pig breeds. The barcode we constructed which greatly reduces the information storage space is genotypes-specific, and can be conveniently decoded into the original data and thereby be conveniently shared and referred to. We believe that it is possible to construct a new data sharing molecular barcode system that could discriminate the subspecies, varieties, cultivars and even individuals with close genetic relationships.
基金This work was supported financially by the Natural Science Foundation of Zhejiang Province(LZ22C150001)the China Postdoctoral Science Foundation(2019 M652064).
文摘Iron(Fe)is an essential micronutrient for all organisms,including plants,whose limited bioavailability restricts plant growth,yield,and nutritional quality.While the transcriptional regulation of plant responses to Fe deficiency have been extensively studied,the contribution of epigenetic modulations,such as DNA methylation,remains poorly understood.Here,we report that treatment with a DNA methylase inhibitor repressed Fe deficiency-induced responses in tomato(Solanum lycopersicum)roots,suggesting the importance of DNA methylation in regulating Fe deficiency responses.Dynamic changes in the DNA methylome in tomato roots responding to short-term(12 hours)and long-term(72 hours)Fe deficiency identified many differentially methylated regions(DMRs)and DMR-associated genes.Most DMRs occurred at CHH sites under short-term Fe deficiency,whereas they were predominant at CG sites following long-term Fe deficiency.Furthermore,no correlation was detected between the changes in DNA methylation levels and the changes in transcript levels of the affected genes under either short-term or long-term treatments.Notably,one exception was CG hypermethylation at the bHLH39 promoter,which was positively correlated with its transcriptional induction.In agreement,we detected lower CG methylation at the bHLH39 promoter and lower bHLH39 expression in MET1-RNA interference lines compared with wild-type seedlings.Virus-induced gene silencing of bHLH39 and luciferase reporter assays revealed that bHLH39 is positively involved in the modulation of Fe homeostasis.Altogether,we propose that dynamic epigenetic DNA methylation in the CG context at the bHLH39 promoter is involved in its transcriptional regulation,thus contributing to the Fe deficiency response of tomato.
文摘To estimate genetic variation in rhizome lotus （Nelumbo nucifera Gaertn. ssp. nucifera） germplasms in China, a total of 94 rhizome lotus germplasms collected from 18 provinces in China were assessed. The RAPD （randomly amplified polymorphic DNA） marker was employed. The selected 17 random primers detected 139 polymorphic alleles out of a total 207 （67.15%）. Nei＇s gene diversity statistics and region differentiation parameters indicated that all germplasms had a relatively high level of genetic diversity with ne = 1.3202, h = 0.1937, I= 0.2982 and the gene flow among all regions was Nrn = 5.5742. The UPGMA dendrogram clustered all 94 germplasms into two clusters： One contained eight commercial cultivars and major landraces, and the other included the wild and some special landraces from five regions, and the PCA analysis exhibited the similar result. Those germplasms from southwestern and eastern China had higher genetic diversity than those from the southern, northern and central China. Predominant proportion of genetic variation （95.61%） was found significant within rather than among （4.39%） regions, as revealed by AMOVA analysis. The data analysis also revealed that the genetic diversity of rhizome lotus germplasms among different regions is positively related to their geographic distances, though it is ambiguous to find the trend from the UPGMA dendrogram and the PCA analysis. A relatively high genetic diversity and gene flow resided in the root lotus germplasms; about 96% of the variation was found within region; accessions from southwest and eastern China have higher genetic diversity than those from the southern, northern and central China.
基金The study was supported by the National Natural Science Foundation of China(NSFC，30370975)Zhejiang Province Key Program of Science and Technology(021102536)
文摘An anti-gene CYP86MF was introduced into hypocotyls of broccoli （Brassica oleracea L.var. italica Plenck） with Agrobacterium tumefaciens, and the transgenic plants were obtained by kanamycin selection. The results of PCR, Southern blot and Northern blot indicated that the anti-CYP86MF has been integrated into chromosome of the transgenic plant. And also, plants with hypogenetic stamina or ungerminated pollen were observed. The transgenic male sterility plant could fructify via artificial pollination with normal pollen. Thus it was proved that the pistil of male sterility plant was normally developed, and the sterility originated from anti-CYP86MF.
基金The authors thank Mr.Tomas Maher from the Department of Biology at the Pennsylvania State University for language editing.This work is supported by the National Natural Science Foundation of Zhejiang Province(Grant No.LZ20C150002)and the National Natural Science Foundation of China(Grant No.31872095).
文摘Viruses are representative of a global threat to agricultural production. Genetic resistance is the preferred strategy for the control of viral infection and against loss of crop yield. Viral protein synthesis requires host cellular factors for translating their viral RNAs, and for regulating their replication and cell to cell systemic movement. Therefore, the viruses are dependent on cellular translation factors. Mutations in the gene encoding eIF4E and eIF4G or their isoforms, eIFiso4 E, eIFiso4 G and eIF2Bβ have been mapped as a source of plant potyvirus while other genus of plant virus recessive resistance genes in many species are originated from these loci. Some of other plant translation factors, such as eIF3,eIF4 A-like helicases, eEF1A and eEF1B, which are required in interacting with viral RNAs and regulating various aspects of the infection cycle,have also been identified. Here, we summarized the mechanisms utilized by RNA viruses of eukaryotic plants and the essential roles of e IFs in virus infection. Moreover, we discussed the potential of e IFs as a target gene in the development of genetic resistance to viruses for crop improvement. This review highlighted newly revealed examples of abnormal translational strategies and provided insights into natural host resistance mechanisms that have been linked to 3 cap-independent translational enhancer activity.
基金supported by the Beijing Rural Revitalization Agricultural Science and Technology Project(NY2401080000)the National Natural Science Foundation of China(31991184,32372705,32302567,32402586)+6 种基金the Chinese Universities Scientific Fund(15053344,15054001)the 2115 Talent Development Program of China Agricultural Universitythe Tai-Shan Scholars Program from the Shandong Province(TSQN202312148)the Natural Science Foundation of Shandong Province(ZR2024JQ014,ZR2024QC172)the Hainan Provincial Natural Science Foundation of China(324CXTD426)the Science and Technology Special Fund of Hainan Province(ZDYF2025XDNY082)Taishan Academy of Tomato Innovation。
文摘The modern cultivated tomato(Solanum lycopersicum)was domesticated from Solanum pimpinellifolium native to the Andes Mountains of South America through a“two-step domestication”process.It was introduced to Europe in the 16th century and later widely cultivated worldwide.Since the late 19th century,breeders,guided by modern genetics,breeding science,and statistical theory,have improved tomatoes into an important fruit and vegetable crop that serves both fresh consumption and processing needs,satisfying diverse consumer demands.Over the past three decades,advancements in modern crop molecular breeding technologies,represented by molecular marker technology,genome sequencing,and genome editing,have significantly transformed tomato breeding paradigms.This article reviews the research progress in the field of tomato molecular breeding,encompassing genome sequencing of germplasm resources,the identification of functional genes for agronomic traits,and the development of key molecular breeding technologies.Based on these advancements,we also discuss the major challenges and perspectives in this field.
基金supported by the grant from the National Natural Science Foundation of China (31872095)
文摘Brassica juncea is an allopolyploid originating from the interspecific hybridization between Brassica rapa and Brassica nigra, which is of multiple usage as a vegetable, oilseed and condiment worldwide. Both vernalization and non-vernalization under long-day photoperiod can promote floral transition in B. juncea suggesting merged flowering pathways of its ancestors and better environmental adaptability. We identified genomewide flowering regulatory genes in B. juncea, which include 84 and 79 genes from A and B sub-genomes, respectively. Ka/Ks analysis revealed a purification effect on both photoperiod and vernalization flowering regulation pathways during evolution. Expression profile of those genes during long-day and vernalization treatments suggested Bju ACO4, Bju AFT1, Bju BFT4, Bju ASOC1 and Bju ASOC4 may be the major functional copies of B. juncea flowering regulation. Further functional studies about Bju COs showed three days delayed flowering time in Bju ACO4 or Bju BCO3 silenced plants. Increased transcription of all BjuFLCs in Bju ACO4 or Bju BCO3 silenced plants suggested interactions between photoperiod and vernalization pathways governing flowering time. Our findings provided flowering regulating networks in allopolyploid B. juncea.
基金supported by grants from the National Natural Science Foundation of China (31201647, 31672181)
文摘Tagetes erecta is an annual multifunctional plant which can be cultivated under a broad range of climatic conditions. Polyploidization and interspecific hybridization are applied to facilitate breeding cultivars of T. erecta with improved ornamental qualities. Colchicine treatment to the germinating seeds was proved to be a useful tool for chromosome doubling of the male sterile two-type line ‘M525AB', with the resulting frequency of polyploid seedlings ranging from 88.89%(following 0.05% w/v colchicine applied for a 3–6 h exposure period) to a maximum of100.00%(following 0.1% for 3–6 h, or 0.2% for 3 h). Morphological observation, stomatal size and density analysis, flow cytometric analysis and chromosome counting were conducted to identify the tetraploid plants. Distinctive morphological changes were observed in a notable proportion of polyploid plants. The colchicine-treated polyploid T. erecta plants showed dwarfed and more robust growth, thicker, larger and greener leaves, larger inflorescences and florets. The mutant plants identified through morphological observation all aligned as polyploid plants, thus morphological observation could be an effective method for the detection of polyploidy. The polyploid plants had significant larger stomata size over the abaxial leaf surface, whereas the density of stomata distribution was remarkably reduced. The survival rate of tetraploid cuttings(i.e. 38%)was greatly reduced compared to that of diploid plants. The fertility of tetraploid plants was also decreased, as shown by cross-pollination yields.Interspecific hybridizations between colchicine-induced tetraploid plants of a male sterile T. erecta line and the naturally tetraploid fully fertile Tagetes patula species resulted in hybrid progeny. Most of these hybrids displayed the dwarfed growth stature and compact, larger-flower morphology which is the typical ideotype of herbaceous flowers. Thus, polyploidization may be employed effectively as a means to facilitate interspecific hybridization, thereby contributing significantly to the improvement of quantitative traits of Tagetes spp.
基金supported by the National Basic Research Program of China (2015CB150503)National Natural Science Foundation of China (31301853)the Fundamental Research Funds for the Central Universities (KYZ201307)
文摘Grafting is commonly used to overcome soilborne diseases. However, its effects on the rhizodeposits as well as the linkages between the rhizosphere chemical niche and microbiome remained unknown. In this paper,significant negative correlations between the bacterial alpha diversity and both the disease incidence(r = – 0.832,P = 0.005) and pathogen population(r = – 0.786, P = 0.012)were detected. Moreover, our results showed that the chemical diversity not only predicts bacterial alpha diversity but also can impact on overall microbial community structure(beta diversity) in the rhizosphere.Furthermore, some anti-fungal compounds including heptadecane and hexadecane were identified in the rhizosphere of grafted watermelon. We concluded that grafted watermelon can form a distinct rhizosphere chemical niche and thus recruit microbial communities with high diversity. Furthermore, the diverse bacteria and the antifungal compounds in the rhizosphere can potentially serve as biological and chemical barriers, respectively, to hinder pathogen invasion. These results not only lead us toward broadening the view of disease resistance mechanism of grafting, but also provide clues to control the microbial composition by manipulating the rhizosphere chemical niche.
基金supported by the National Natural Science Foundation ofChina(31071809)to Pei YanXi
文摘The T gene, which was cloned from the mitochondria of tumorous stem mustard （Brassica juncea var. tumida）, is a cytoplas- mic male sterility （CMS）-related gene that can produce two transcripts, T1170 and T1243. The latter is transcribed with the un- cleaved intron Tinll. In our previous study, transgenic Arabidopsis thaliana plants over-expressing the T1243 transcript （OE-T1243） showed a severe male-sterile phenotype, whereas OE-Tll70 plants did not. However, the functional mechanism of the T gene in B. Juncea remained unknown. In this study, microscopic analyses of paraffin sections of anthers confirmed that OE-T1243 plants did not produce normal pollen, whereas OE-T1170 plants did. We analyzed the transcription of 15 anther development-related genes and found that transcript levels of nozzle/sporocyteless and barely any meristem 1 and 2 were markedly lower in OE-T1243 plants than those in wild type, while the transcript levels of these genes in OE-Tll70 plants were unchanged. To investigate the potential roles of TinH, we inserted the TinH sequence upstream of a minimal region （-60） of the cauliflower mosaic virus 35S promoter fused to the 5＇ end of the 13-glucuronidase （GUS） reporter gene. Analysis of the transgenic plants suggested that TinH acted as an enhancer to significantly increase GUS expression. The potential action mechanism is that the TinH intron acts as an enhancer to affect the function of the CMS-related gene T.
基金supported by the National Key Research and Development Program of China(2021YFD1400400)the National Natural Science Foundation of China(31930089).
文摘Tomato leaf curl New Delhi virus(ToLCNDV)is a member of the genus Begomovirus,and causes devastating disease in the world.In recent years,ToLCNDV was rapidly spreading in China and induces severe economic losses in agriculture.In this study,we sequenced and characterized the complete genome of ToLCNDV isolates from melon plants showing leaf curling and stunting symptoms in Jiangsu Province of China.We constructed a full-length infectious cDNA clone of ToLCNDV,which could induce systemic infection with typical symptoms in Nicotiana benthamiana,Cit-rullus melo,and Citrullus lanatus plants through agrobacterium-mediated inoculation.Further experimental evidence demonstrated that the virions produced in plants infected with the infectious clone of ToLCNDV are biologically active and sap-transmissible.We also evaluated the resistance of commercial melon cultivars to ToLCNDV and found all testing melon cultivars were susceptible to ToLCNDV.Collectively,the reverse genetic system developed herein will facilitate further research on biological functions of proteins encoded by ToLCNDV and plant-ToLCNDV interactions,which might provide new insights into breeding resistance germplasm in crops.
基金supported by the National Natural Science Foundation of China(32130086,32430085)the National Key Research and Development Program of China(2024ZD0407702,2022YFD1400800)。
文摘Tomato brown rugose fruit virus(ToBRFV)overcomes all known tomato resistance genes,including the durable Tm-2^(2),posing a serious threat to global tomato production.Here,we employed in vitro random mutagenesis to evolve the Tm-2^(2)leucine-rich repeat(LRR)domain and screened~8,000 variants for gain-of-function mutants capable of recognizing the ToBRFV movement protein(MP)and triggering hypersensitive cell death.We identified five such mutants.Among them,Tm-2^(2-S723Y)and Tm-2^(2-N744D)induced strong,specific cell death upon co-expression with ToBRFV MP,while retaining recognition of TMV MP.Transgenic Nicotiana benthamiana and tomato plants expressing Tm-2^(2-S723Y)resisted the naturally occurring ToBRFV(ToBRFV^(E132)).However,after prolonged infection,ToBRFV^(E132)evolved an E132K substitution in its MP,and the newly appeared ToBRFV_(K132)evaded Tm-2^(2-S723Y)-mediated resistance.However,Tm-2^(2-N744D)still recognized MPK132,and the double mutant Tm-2^(2-S723Y/N744D)conferred broad resistance against ToBRFV^(E132),ToBRF^(VK132),and tobacco mosaic virus in stable transgenic tomato.Our work demonstrates that artificial NLR evolution can generate broad-spectrum resistance against tobamovirus.
基金supported by the Natural Science Foundation of China(No.31301790)Guangdong Natural Science Foundation (S2013040016220)+1 种基金China Postdoctoral Science Foundation (2013M530375,2014T70827)Shenzhen Vegetable Molecular Biotechnological Engineering Lab Scheme (Development and Reform Commission of Shenzhen Municipal Government)
文摘The WRKY gene family is among the largest families of transcription factors （TFs） in higher plants. By regulating the plant hormone signal transduction pathway, these TFs play critical roles in some plant processes in response to biotic and abiotic stress, Various bodies of research have demonstrated the important biological functions of WRKY TFs in plant response to different kinds of biotic and abiotic stresses and working mecha- nisms. However, very li2ttle summarization has been done to review their research progress. Not iust important TFs function in plant response to biotic and abiotic stresses, WRKY also participates in carbohydrate synthesis, senes- cence, development, and secondary metabolites synthesis. WRKY proteins can bind to W-box （TGACC （A/T）） in the promoter of its target genes and activate or repress the expression of downstream genes to regulate their stress response. Moreover, WRKY proteins can interact with other TFs to regulate plant defensive responses. In the present review, we focus on the structural characteristics of WRKY TFs and the research progress on their functions in plant responses to a variety of stresses.
基金supported by a grant from the Key Research and Development Program of Hainan Province(ZDYF2021XDNY166)the Key Science and Technology Program for Agricultural(Vegetable)New Variety Breeding of Zhejiang Province(2021C02065)the Earmarked Fund for Modern Agro-Industry Technology Research System of China(CARS-26-17).
文摘Tomato leaf curl New Delhi virus(ToLCNDV),a bipartite begomovirus,was first reported to infect tomato and has recently spread rapidly as an emerging disease to Cucurbitaceae crops.To date,the virus has been reported to infect more than 11 cucurbit crops,in 16 countries and regions,causing severe yield losses.In autumn 2022,ToLCNDV was first isolated from cucurbit plants in Southeastern coastal areas of China.Phylogenetic analysis established that these isolates belong to the Asian ToLCNDV clade,and shared high nucleotide identity and closest genetic relationship with the DNA-A sequence from the Chinese tomato-infecting ToLCNDV isolate(Accession no.OP356207)and the tomato New Delhi ToLCNDV-Severe isolate(Accession no.HM159454).In this review,we summarize the occurrence and distribution,host range,detection and diagnosis,control strategies,and genetic resistance of ToLCNDV in the Cucurbitaceae.We then summarize pathways that could be undertaken to improve our understanding of this emerging disease,with the objective to develop ToLCNDV-resistant cucurbit cultivars.
