Recent studies have shown that the R2R3-MYB transcription factor MdMYB73 is involved in salt stress response in apple. However, no research was done whether MdMYB73 mediated cold tolerance in apple or not. In this stu...Recent studies have shown that the R2R3-MYB transcription factor MdMYB73 is involved in salt stress response in apple. However, no research was done whether MdMYB73 mediated cold tolerance in apple or not. In this study, we found that the expression of MdMYB73 was obviously induced by cold stress. Functional analysis showed that MdMYB73 significantly increased cold tolerance in transgenic apple calli and Arabidopsis. Quantitative real-time PCR （qRT-PCR） assay indicated that the expression levels of cold-responsive genes including MdCBF2, MdCBF3, MdCBF4, and MdCBF5 were obviously enhanced in MdMYB73 transgenic calli, suggesting that MdMYB73 increased cold tolerance via C-repeat binding factor （CBF） cold response pathway. Finally, we found that soluble sugar, which provides an osmoticum for cells, was increased in MdMYB73 transgenic calli compared to that in the wild type control. These findings provide a new insights into how MdMYB73 is involved in cold stress response.展开更多
As the main organic acid in fruits,malate is produced in the cytoplasm and is then transported into the vacuole.It accumulates by vacuolar proton pumps,transporters,and channels,affecting the taste and flavor of fruit...As the main organic acid in fruits,malate is produced in the cytoplasm and is then transported into the vacuole.It accumulates by vacuolar proton pumps,transporters,and channels,affecting the taste and flavor of fruits.Among the three types of proton pumps(V-ATPases,V-PPases,and P-ATPases),the P-ATPases play an important role in the transport of malate into vacuoles.In this study,the transcriptome data,collected at different stages after blooming and during storage,were analyzed and the results demonstrated that the expression of MdPH5,a vacuolar proton-pumping P-ATPase,was associated with both pre-and post-harvest malate contents.Moreover,MdPH5 is localized at the tonoplast and regulates malate accumulation and vacuolar pH.In addition,MdMYB73,an upstream MYB transcription factor of MdPH5,directly binds to its promoter,thereby transcriptionally activating its expression and enhancing its activity.In this way,MdMYB73 can also affect malate accumulation and vacuolar pH.Overall,this study clarifies how MdMYB73 and MdPH5 act to regulate vacuolar malate transport systems,thereby affecting malate accumulation and vacuolar pH.展开更多
基金supported by the National Natural Science Foundation of China (31601728,31272142,31325024)the Natural Science Foundation of Shandong Province,China (ZR2016CQ13)the Youth Science and Technology Innovation Fund of Shandong Agricultural University,China (24024)
文摘Recent studies have shown that the R2R3-MYB transcription factor MdMYB73 is involved in salt stress response in apple. However, no research was done whether MdMYB73 mediated cold tolerance in apple or not. In this study, we found that the expression of MdMYB73 was obviously induced by cold stress. Functional analysis showed that MdMYB73 significantly increased cold tolerance in transgenic apple calli and Arabidopsis. Quantitative real-time PCR （qRT-PCR） assay indicated that the expression levels of cold-responsive genes including MdCBF2, MdCBF3, MdCBF4, and MdCBF5 were obviously enhanced in MdMYB73 transgenic calli, suggesting that MdMYB73 increased cold tolerance via C-repeat binding factor （CBF） cold response pathway. Finally, we found that soluble sugar, which provides an osmoticum for cells, was increased in MdMYB73 transgenic calli compared to that in the wild type control. These findings provide a new insights into how MdMYB73 is involved in cold stress response.
基金supported by grants from the National Key Research and Development Program of China(2022YFD2100102)National Natural Science Foundation of China(32122080,31972375)Shandong Province(ZR2020YQ25).
文摘As the main organic acid in fruits,malate is produced in the cytoplasm and is then transported into the vacuole.It accumulates by vacuolar proton pumps,transporters,and channels,affecting the taste and flavor of fruits.Among the three types of proton pumps(V-ATPases,V-PPases,and P-ATPases),the P-ATPases play an important role in the transport of malate into vacuoles.In this study,the transcriptome data,collected at different stages after blooming and during storage,were analyzed and the results demonstrated that the expression of MdPH5,a vacuolar proton-pumping P-ATPase,was associated with both pre-and post-harvest malate contents.Moreover,MdPH5 is localized at the tonoplast and regulates malate accumulation and vacuolar pH.In addition,MdMYB73,an upstream MYB transcription factor of MdPH5,directly binds to its promoter,thereby transcriptionally activating its expression and enhancing its activity.In this way,MdMYB73 can also affect malate accumulation and vacuolar pH.Overall,this study clarifies how MdMYB73 and MdPH5 act to regulate vacuolar malate transport systems,thereby affecting malate accumulation and vacuolar pH.
