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
Myeloblastosis(MYB)transcription factors,particularly those in the R2R3 MYB subclass,are pivotal in plant growth,development,and environmental stress responses.As one of the largest transcription factor families in pl...Myeloblastosis(MYB)transcription factors,particularly those in the R2R3 MYB subclass,are pivotal in plant growth,development,and environmental stress responses.As one of the largest transcription factor families in plants,the MYB family significantly regulates plant secondary metabolism,including the biosynthetic pathways for phenylpropanoids,which are crucial for stress resistance.This review presents a comprehensive overview of MYB transcription factor classification and their regulatory mechanisms in plant metabolism and stress responses.We discuss the roles of MYB transcription factors in biotic stress resistance,such as defense against pathogens and pests,and in abiotic stress tolerance,including responses to drought and salinity.Special attention is given to the interactions of R2R3 MYB with other transcription factors and co-repressors,focusing on how these synergistic or antagonistic relationships modulate physiological processes.The multifunctional role of R2R3 MYBs in stress responses positions them as promising targets for enhancing crop resilience through genetic breeding.Furthermore,this review highlights potential applications of MYB transcription factors in developing stress-resistant crops and their utility in plant resistant breeding programs.展开更多
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.
基金supported by the Faculty Startup Fund from Jining Medical University,the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2023QC309)the National Natural Science Foundation of China(Grant No.32102236)。
文摘Myeloblastosis(MYB)transcription factors,particularly those in the R2R3 MYB subclass,are pivotal in plant growth,development,and environmental stress responses.As one of the largest transcription factor families in plants,the MYB family significantly regulates plant secondary metabolism,including the biosynthetic pathways for phenylpropanoids,which are crucial for stress resistance.This review presents a comprehensive overview of MYB transcription factor classification and their regulatory mechanisms in plant metabolism and stress responses.We discuss the roles of MYB transcription factors in biotic stress resistance,such as defense against pathogens and pests,and in abiotic stress tolerance,including responses to drought and salinity.Special attention is given to the interactions of R2R3 MYB with other transcription factors and co-repressors,focusing on how these synergistic or antagonistic relationships modulate physiological processes.The multifunctional role of R2R3 MYBs in stress responses positions them as promising targets for enhancing crop resilience through genetic breeding.Furthermore,this review highlights potential applications of MYB transcription factors in developing stress-resistant crops and their utility in plant resistant breeding programs.
