Glycosyltransferases(GTs)constitute a diverse family of synthetic polysaccharides with important roles in plant growth and development.This study characterized the GT14 family gene BpGT14;6 of birch(Betula platyphylla...Glycosyltransferases(GTs)constitute a diverse family of synthetic polysaccharides with important roles in plant growth and development.This study characterized the GT14 family gene BpGT14;6 of birch(Betula platyphylla Suk.).BpGT14;6 was highly expressed in the xylem and stem of birch plants.Subcellular localization analysis suggested that BpGT14;6 was located in the Golgi apparatus.RNA interference(RNAi)silencing of BpGT14;6 revealed lower lignin,hemicellulose,and pectin contents compared to wild type(WT)plants.Following treatment with abscisic acid(ABA),compared to WT plants,RNAi-BpGT14;6 plants were more sensitive to ABA,suffered more membrane lipid damage,and accumulated more reactive oxygen species.The inhibition of BpGT14;6 expression narrowed the birch xylem and thinned the cell wall,and increased the expression of multiple ABA pathway-related genes in birch under ABA treatment.Compared to WT plants,RNAi-BpGT14;6 plants showed increased tolerance to drought stress.Promoter analysis revealed that BpGT14;6 is involved in hormone regulation and adaptation to adversity.Using the 1156 bp BpGT14;6 promoter as bait,two potential transcription factors,BpWRKY1 and BpARF2,were identified through Y1H screening that may regulate its expression.EMSA confirmed that BpWRKY1 and BpARF2 can directly bind to the W-BOX and AuxRE cis-acting elements on the BpGT14;6 promoter,respectively.The collective results suggest that BpGT14;6 affects birch xylem and cell wall development by affecting lignin,hemicellulose,and pectin synthesis,and participates in birch adversity adaptation.展开更多
DNA methylation is widespread in plants and associated with plant development and defense mechanisms.However,the relationship between DNA methylation and plant secondary metabolism has rarely been reported.Here,when b...DNA methylation is widespread in plants and associated with plant development and defense mechanisms.However,the relationship between DNA methylation and plant secondary metabolism has rarely been reported.Here,when birch suspension cells were treated with 5-azacytidine(5-azaC),which blocks DNA methylation,triterpenoid accumulation was significantly promoted and antioxidant and defense enzymatic activity changed.For studying triterpenoid accumulation,0.1 mM azaC was optimal.A qRT-PCR assay revealed increased expression of genes encoding key triterpenoid biosynthetic enzymes.Evaluation of methylation polymorphisms at CCGG sites showed that the methylation level was lower in cells treated with 5-azaC.These results demonstrated that 5-azaC treatment led to an increase in the production of triterpenoids in cell cultures through a mechanism that involved in DNA methylation,which resulted in the induction of genes encoding the key enzymes.The study provides evidence of a relationship between DNA methylation and regulation of secondary metabolism.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.31870588 and 31200463)The Innovation Project of State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University)(Grant No.2022A03)Heilongjiang Touyan Innovation Team Program.
文摘Glycosyltransferases(GTs)constitute a diverse family of synthetic polysaccharides with important roles in plant growth and development.This study characterized the GT14 family gene BpGT14;6 of birch(Betula platyphylla Suk.).BpGT14;6 was highly expressed in the xylem and stem of birch plants.Subcellular localization analysis suggested that BpGT14;6 was located in the Golgi apparatus.RNA interference(RNAi)silencing of BpGT14;6 revealed lower lignin,hemicellulose,and pectin contents compared to wild type(WT)plants.Following treatment with abscisic acid(ABA),compared to WT plants,RNAi-BpGT14;6 plants were more sensitive to ABA,suffered more membrane lipid damage,and accumulated more reactive oxygen species.The inhibition of BpGT14;6 expression narrowed the birch xylem and thinned the cell wall,and increased the expression of multiple ABA pathway-related genes in birch under ABA treatment.Compared to WT plants,RNAi-BpGT14;6 plants showed increased tolerance to drought stress.Promoter analysis revealed that BpGT14;6 is involved in hormone regulation and adaptation to adversity.Using the 1156 bp BpGT14;6 promoter as bait,two potential transcription factors,BpWRKY1 and BpARF2,were identified through Y1H screening that may regulate its expression.EMSA confirmed that BpWRKY1 and BpARF2 can directly bind to the W-BOX and AuxRE cis-acting elements on the BpGT14;6 promoter,respectively.The collective results suggest that BpGT14;6 affects birch xylem and cell wall development by affecting lignin,hemicellulose,and pectin synthesis,and participates in birch adversity adaptation.
基金The work was supported by The Fundamental Research Funds for the Central Universities(2572017EA05)the National Natural Science Foundation of China(31870588).
文摘DNA methylation is widespread in plants and associated with plant development and defense mechanisms.However,the relationship between DNA methylation and plant secondary metabolism has rarely been reported.Here,when birch suspension cells were treated with 5-azacytidine(5-azaC),which blocks DNA methylation,triterpenoid accumulation was significantly promoted and antioxidant and defense enzymatic activity changed.For studying triterpenoid accumulation,0.1 mM azaC was optimal.A qRT-PCR assay revealed increased expression of genes encoding key triterpenoid biosynthetic enzymes.Evaluation of methylation polymorphisms at CCGG sites showed that the methylation level was lower in cells treated with 5-azaC.These results demonstrated that 5-azaC treatment led to an increase in the production of triterpenoids in cell cultures through a mechanism that involved in DNA methylation,which resulted in the induction of genes encoding the key enzymes.The study provides evidence of a relationship between DNA methylation and regulation of secondary metabolism.
