The synthesis of smectite clays is discussed. From literature studies the optimal ratios of precursor materials are suggested for the preparation of the four different basic forms of smectite clays. Conditions for the...The synthesis of smectite clays is discussed. From literature studies the optimal ratios of precursor materials are suggested for the preparation of the four different basic forms of smectite clays. Conditions for the preparation of clays with intermediate compositions are also suggested.展开更多
DNA methylation and demethylation activities are coordinated to maintain DNA methylation patterns.However,the interplay between them remains to be explored.In this study,we found that loss of DNA demethylase in maize ...DNA methylation and demethylation activities are coordinated to maintain DNA methylation patterns.However,the interplay between them remains to be explored.In this study,we found that loss of DNA demethylase in maize results in a significant decrease in CHH methylation,a hallmark of RNA-directed DNA methylation(RdDM).Further analyses suggested that this is caused by reduced expression in the DNA demethylase mutant of three CLASSY(CLSY)genes,which encode chromatin remodelers controlling small RNA production.Series of molecular assays confirm that the expression of three maize CLSY genes is sensitive to the DNA methylation levels at their promoter regions,which are regulated by both the DNA demethylase and the RdDM pathway.Moreover,we revealed that Arabidopsis DNA demethylase mutants also show decreased CHH methylation and reduced expression of CLSY1,one of four CLSY genes in Arabidopsis.Similar to the observations in maize,the expression of CLSY1 is associated with DNA methylation levels of its promoter that is targeted by both DNA demethylase and RdDM pathways.Taken together,these results suggest a conserved interplay between DNA demethylation and RdDM pathways,revealing a mechanism to maintain the homeostasis of DNA methylation levels across plants.展开更多
文摘The synthesis of smectite clays is discussed. From literature studies the optimal ratios of precursor materials are suggested for the preparation of the four different basic forms of smectite clays. Conditions for the preparation of clays with intermediate compositions are also suggested.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(32321005)the 111 Project Crop Genomics and Molecular Breeding(B20051)+1 种基金the Outstanding Youth Team Cultivation Project of Central Universities(2662023PY007)the Postdoctoral Fellowship Program of CPSF undergrantnumberGZB20240254.
文摘DNA methylation and demethylation activities are coordinated to maintain DNA methylation patterns.However,the interplay between them remains to be explored.In this study,we found that loss of DNA demethylase in maize results in a significant decrease in CHH methylation,a hallmark of RNA-directed DNA methylation(RdDM).Further analyses suggested that this is caused by reduced expression in the DNA demethylase mutant of three CLASSY(CLSY)genes,which encode chromatin remodelers controlling small RNA production.Series of molecular assays confirm that the expression of three maize CLSY genes is sensitive to the DNA methylation levels at their promoter regions,which are regulated by both the DNA demethylase and the RdDM pathway.Moreover,we revealed that Arabidopsis DNA demethylase mutants also show decreased CHH methylation and reduced expression of CLSY1,one of four CLSY genes in Arabidopsis.Similar to the observations in maize,the expression of CLSY1 is associated with DNA methylation levels of its promoter that is targeted by both DNA demethylase and RdDM pathways.Taken together,these results suggest a conserved interplay between DNA demethylation and RdDM pathways,revealing a mechanism to maintain the homeostasis of DNA methylation levels across plants.
