The Alternaria alternata apple pathotype adversely affects apple(Malus domestica Borkh.)cultivation.However,the molecular mechanisms underlying enhanced resistance to this pathogen in apple remain poorly understood.We...The Alternaria alternata apple pathotype adversely affects apple(Malus domestica Borkh.)cultivation.However,the molecular mechanisms underlying enhanced resistance to this pathogen in apple remain poorly understood.We have previously reported that MdWRKY75 expression is upregulated by A.alternata infection in‘Sushuai’apples.In this study,we discovered that overexpression of MdWRKY75e increased the resistance of transgenic apple lines to A.alternata infection,whereas silencing this gene enhanced susceptibility to A.alternata infection.Furthermore,we found that MdWRKY75e directly binds to the MdLAC7 promoter to regulate the biosynthesis of laccase and increase the biosynthesis of lignin during A.alternata infection.Moreover,the thickening of the cell wall enhanced the mechanical defense capabilities of apple.In addition,we found that jasmonic acid remarkably induced MdWRKY75e expression,and its levels in transgenic apple lines were elevated.These results indicate that MdWRKY75e confers resistance to the A.alternata apple pathotype mainly via the jasmonic acid pathway and that pathogenesis-related genes and antioxidant-related enzyme activity are involved in the disease resistance of MdWRKY75e transgenic plants.In conclusion,our fi ndings provide insights into the importance of MdWRKY75e for resistance to A.alternata infection in apples.展开更多
The apple(Malus×domestica Borkh.)cultivar‘Su Shuai’exhibits greater disease resistance,shorter internodes and lighter fruit flavor compared with its parents‘Golden Delicious’and‘Indo’.To obtain a comprehens...The apple(Malus×domestica Borkh.)cultivar‘Su Shuai’exhibits greater disease resistance,shorter internodes and lighter fruit flavor compared with its parents‘Golden Delicious’and‘Indo’.To obtain a comprehensive overview of the sequence variation in these three horticultural traits,the genomes of‘Su Shuai’and‘Indo’were resequenced using next-generation sequencing and compared to the genome of‘Golden Delicious’.A wide range of genetic variations were detected,including 2454406 and 18749349 single nucleotide polymorphism(SNP)and 59547 and 50143 structural variants(SVs)in the‘Indo’and‘Su Shuai’genomes,respectively.Among the SVs in‘Su Shuai’,17 genes related to disease resistance,10 genes related to Gibberellin(GA)and 19 genes associated with fruit flavor were identified.The expression patterns of eight of the SV genes were examined using reverse transcription-quantitative polymerase chain reaction(RT-qPCR).The results of this study illustrate the genomic variation in these cultivars and provide evidence for a genetic basis for the horticultural traits of disease resistance,short internodes and lighter flavor exhibited in these cultivars.These results provide a genetic basis for the phenotypic characteristics of‘Su Shuai’and,as such,these SVs could serve as gene-specific molecular markers in maker-assisted breeding of apples.展开更多
基金This work was supported by the National Natural Science Foundation of China(grant number 31872074)the National Key R&D Program of China(2019YFD1000100)Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The Alternaria alternata apple pathotype adversely affects apple(Malus domestica Borkh.)cultivation.However,the molecular mechanisms underlying enhanced resistance to this pathogen in apple remain poorly understood.We have previously reported that MdWRKY75 expression is upregulated by A.alternata infection in‘Sushuai’apples.In this study,we discovered that overexpression of MdWRKY75e increased the resistance of transgenic apple lines to A.alternata infection,whereas silencing this gene enhanced susceptibility to A.alternata infection.Furthermore,we found that MdWRKY75e directly binds to the MdLAC7 promoter to regulate the biosynthesis of laccase and increase the biosynthesis of lignin during A.alternata infection.Moreover,the thickening of the cell wall enhanced the mechanical defense capabilities of apple.In addition,we found that jasmonic acid remarkably induced MdWRKY75e expression,and its levels in transgenic apple lines were elevated.These results indicate that MdWRKY75e confers resistance to the A.alternata apple pathotype mainly via the jasmonic acid pathway and that pathogenesis-related genes and antioxidant-related enzyme activity are involved in the disease resistance of MdWRKY75e transgenic plants.In conclusion,our fi ndings provide insights into the importance of MdWRKY75e for resistance to A.alternata infection in apples.
基金the Jiangsu Province Science Technology Independent Innovation Fund(CX(13)3006)the Sanxin Project of Jiangsu Province(SXGC(2013)046)for providing financial supportWe also acknowledge the National Natural Science Foundation of China(31171935)for providing financial support for a portion of this study.
文摘The apple(Malus×domestica Borkh.)cultivar‘Su Shuai’exhibits greater disease resistance,shorter internodes and lighter fruit flavor compared with its parents‘Golden Delicious’and‘Indo’.To obtain a comprehensive overview of the sequence variation in these three horticultural traits,the genomes of‘Su Shuai’and‘Indo’were resequenced using next-generation sequencing and compared to the genome of‘Golden Delicious’.A wide range of genetic variations were detected,including 2454406 and 18749349 single nucleotide polymorphism(SNP)and 59547 and 50143 structural variants(SVs)in the‘Indo’and‘Su Shuai’genomes,respectively.Among the SVs in‘Su Shuai’,17 genes related to disease resistance,10 genes related to Gibberellin(GA)and 19 genes associated with fruit flavor were identified.The expression patterns of eight of the SV genes were examined using reverse transcription-quantitative polymerase chain reaction(RT-qPCR).The results of this study illustrate the genomic variation in these cultivars and provide evidence for a genetic basis for the horticultural traits of disease resistance,short internodes and lighter flavor exhibited in these cultivars.These results provide a genetic basis for the phenotypic characteristics of‘Su Shuai’and,as such,these SVs could serve as gene-specific molecular markers in maker-assisted breeding of apples.
