The Betula genus contains pentacyclic triterpenoid betulin known for its environmental adaptation and medicinal properties.However,the mechanisms underlying betulin biosynthesis responding to climate change remain unc...The Betula genus contains pentacyclic triterpenoid betulin known for its environmental adaptation and medicinal properties.However,the mechanisms underlying betulin biosynthesis responding to climate change remain unclear.In this study,the role of epigenetic modification(DNA methylation) in betulin biosynthesis was examined and how climatic factors influence it.Whole-genome bisulfite sequencing was performed for greenhouse-grown Chinese white birch(Betula platyphylla Sukaczev) treated with DNA methylation inhibitor zebularine(ZEB) and a natural birch population in Northeast China.ZEB treatment significantly affected the CHH methylation level of transposable elements and betulin content in a hormesis dose-dependent manner.The methylation and expression of bHLH9,a key transcriptional factor controlling betulin biosynthesis,were also consistently affected by ZEB treatment as a hormetic dose-response.In the natural population,there was a positive correlation between promoter methylation of bHLH9 and summer precipitation,while winter temperature was negatively correlated.Thus climate-dependent methylation of bHLH9 regulates the expression of downstream genes involved in betulin biosynthesis.This study highlights the role of environmental signals to induce epigenetic changes that result in betulin production,possibly helping to develop resilient plants to combat ongoing climate change and enhance secondary metabolite production.展开更多
基金the National Non-profi t Institute Research Grant of the Chinese Academy of Forestry(CAFYBB2019ZY003)the National Natural Science Foundation of China(31871220 and 31801444)+2 种基金the Innovation Project of State Key Laboratory of Tree Genetics andBreeding(Northeast Forestry University)(2013A06)the Fundamental Research Funds for the Central Universities(2572017DA06 and 2572020DP01)Heilongjiang Provincial Natural Science Foundation of China(LH2021C005).
文摘The Betula genus contains pentacyclic triterpenoid betulin known for its environmental adaptation and medicinal properties.However,the mechanisms underlying betulin biosynthesis responding to climate change remain unclear.In this study,the role of epigenetic modification(DNA methylation) in betulin biosynthesis was examined and how climatic factors influence it.Whole-genome bisulfite sequencing was performed for greenhouse-grown Chinese white birch(Betula platyphylla Sukaczev) treated with DNA methylation inhibitor zebularine(ZEB) and a natural birch population in Northeast China.ZEB treatment significantly affected the CHH methylation level of transposable elements and betulin content in a hormesis dose-dependent manner.The methylation and expression of bHLH9,a key transcriptional factor controlling betulin biosynthesis,were also consistently affected by ZEB treatment as a hormetic dose-response.In the natural population,there was a positive correlation between promoter methylation of bHLH9 and summer precipitation,while winter temperature was negatively correlated.Thus climate-dependent methylation of bHLH9 regulates the expression of downstream genes involved in betulin biosynthesis.This study highlights the role of environmental signals to induce epigenetic changes that result in betulin production,possibly helping to develop resilient plants to combat ongoing climate change and enhance secondary metabolite production.
