The concentration and variational trend of As3 +and As 5+,the bacterial resistance for the As 3+and As 5+and converting conditions from As3 +to As 5+were analyzed.The additive was used to prompt the bacterial leaching...The concentration and variational trend of As3 +and As 5+,the bacterial resistance for the As 3+and As 5+and converting conditions from As3 +to As 5+were analyzed.The additive was used to prompt the bacterial leaching efficiency by changing valence state of arsenic.The results show that the concentration of As 3+ is larger than that of As 5+ in the lag phase.The concentration of As 3+ decreases in the log phase,and is lower than that of As5 +.HQ-0211 typed bacteria express better resistance for As 3+and As 5+and remain growing when the concentrations of As3 +and As 5+are above 6.0 g/L and 12.0 g/L,respectively.It is found that Fe 3+cannot oxidize As3 +singly as strong oxidant in the leaching system,but can cooperate with pyrite or chalcopyrite to do that.The oxidation of As 3+ is prompted with addition of H2O2.The bacterial activity is improved in favor of bacterial leaching efficiency.NaClO restrains the bacterial growth to depress leaching efficiency because of the chloric compounds affecting bacterial activity.展开更多
5-Methylcytosine （m^5C） is a well-characterized DNA modification, and is also predominantly reported in abundant non-coding RNAs in both prokaryotes and eukaryotes. However, the distribution and biological functions...5-Methylcytosine （m^5C） is a well-characterized DNA modification, and is also predominantly reported in abundant non-coding RNAs in both prokaryotes and eukaryotes. However, the distribution and biological functions of m^5C in plant mRNAs remain largely unknown. Here, we report transcriptome-wide profiling of RNA m^5C in Arabidopsis thaliana by applying m^5C RNA immunoprecipitation followed by a deep- sequencing approach （m^5C-RIP-seq）. LC-MS/MS and dot blot analyses reveal a dynamic pattern of m^5C mRNA modification in various tissues and at different developmental stages, m^5C-RIP-seq analysis identified 6045 m^5C peaks in 4465 expressed genes in young seedlings. We found that m^5C is enriched in coding sequences with two peaks located immediately after start codons and before stop codons, and is associated with mRNAs with low translation activity. We further demonstrated that an RNA （cytosine-5）-methyl- transferase, tRNA-specific methyltransferase 4B （TRM4B）, exhibits m^5C RNA methyltransferase activity. Mutations in TRM4B display defects in root development and decreased m^5C peaks. TRM4B affects the transcript levels of the genes involved in root development, which is positively correlated with their mRNA stability and m^5C levels. Our results suggest that m^5C in mRNA is a new epitranscriptome marker inArabidopsis, and that regulation of this modification is an integral part of gene regulatory networks underlying plant development.展开更多
Advances in the detection and mapping of messenger RNA(mRNA)N^6-methyladenosine(m 6A)and 5-methylcytosine(m 5C),and DNA N^6-methyldeoxyadenosine(6mA)redefined our understanding of these modifications as additional tie...Advances in the detection and mapping of messenger RNA(mRNA)N^6-methyladenosine(m 6A)and 5-methylcytosine(m 5C),and DNA N^6-methyldeoxyadenosine(6mA)redefined our understanding of these modifications as additional tiers of epigenetic regulation.In plants,the most prevalent internal mRNA modifications,m^6A and m^5C,play crucial and dynamic roles in many processes,including embryo development,stem cell fate determination,trichome branching,leaf morphogenesis,floral transition,stress responses,fruit ripening,and root development.The newly identified and widespread epigenetic marker 6mA DNA methylation is associated with gene expression,plant development,and stress responses.Here,we review the latest research progress on mRNA and DNA epigenetic modifications,including the detection,dynamics,distribution,functions,regulatory proteins,and evolution,with a focus on m^6A,m^5C,and 6mA.We also provide some perspectives on future research of the newly identified and unknown epigenetic modifications of mRNA and DNA in plants.展开更多
基金Projects(50674029, 50874030) supported by the National Natural Science Foundation of ChinaProject(2006AA06Z127) supported by the National High-tech Research and Development Program of ChinaProject(20060145015) supported by Specialized Research Fund for the Doctoral Program of Higher Education, China
文摘The concentration and variational trend of As3 +and As 5+,the bacterial resistance for the As 3+and As 5+and converting conditions from As3 +to As 5+were analyzed.The additive was used to prompt the bacterial leaching efficiency by changing valence state of arsenic.The results show that the concentration of As 3+ is larger than that of As 5+ in the lag phase.The concentration of As 3+ decreases in the log phase,and is lower than that of As5 +.HQ-0211 typed bacteria express better resistance for As 3+and As 5+and remain growing when the concentrations of As3 +and As 5+are above 6.0 g/L and 12.0 g/L,respectively.It is found that Fe 3+cannot oxidize As3 +singly as strong oxidant in the leaching system,but can cooperate with pyrite or chalcopyrite to do that.The oxidation of As 3+ is prompted with addition of H2O2.The bacterial activity is improved in favor of bacterial leaching efficiency.NaClO restrains the bacterial growth to depress leaching efficiency because of the chloric compounds affecting bacterial activity.
文摘5-Methylcytosine （m^5C） is a well-characterized DNA modification, and is also predominantly reported in abundant non-coding RNAs in both prokaryotes and eukaryotes. However, the distribution and biological functions of m^5C in plant mRNAs remain largely unknown. Here, we report transcriptome-wide profiling of RNA m^5C in Arabidopsis thaliana by applying m^5C RNA immunoprecipitation followed by a deep- sequencing approach （m^5C-RIP-seq）. LC-MS/MS and dot blot analyses reveal a dynamic pattern of m^5C mRNA modification in various tissues and at different developmental stages, m^5C-RIP-seq analysis identified 6045 m^5C peaks in 4465 expressed genes in young seedlings. We found that m^5C is enriched in coding sequences with two peaks located immediately after start codons and before stop codons, and is associated with mRNAs with low translation activity. We further demonstrated that an RNA （cytosine-5）-methyl- transferase, tRNA-specific methyltransferase 4B （TRM4B）, exhibits m^5C RNA methyltransferase activity. Mutations in TRM4B display defects in root development and decreased m^5C peaks. TRM4B affects the transcript levels of the genes involved in root development, which is positively correlated with their mRNA stability and m^5C levels. Our results suggest that m^5C in mRNA is a new epitranscriptome marker inArabidopsis, and that regulation of this modification is an integral part of gene regulatory networks underlying plant development.
基金This work was supported by funding from the National Transgenic Major Program of China(2019ZX08010-002)to X.G.the National Natural Sci ence Foundation of China(31871606,31671670)toX.G.,and the Recruit ment Program of Global Youth Expert of China to X.G.
文摘Advances in the detection and mapping of messenger RNA(mRNA)N^6-methyladenosine(m 6A)and 5-methylcytosine(m 5C),and DNA N^6-methyldeoxyadenosine(6mA)redefined our understanding of these modifications as additional tiers of epigenetic regulation.In plants,the most prevalent internal mRNA modifications,m^6A and m^5C,play crucial and dynamic roles in many processes,including embryo development,stem cell fate determination,trichome branching,leaf morphogenesis,floral transition,stress responses,fruit ripening,and root development.The newly identified and widespread epigenetic marker 6mA DNA methylation is associated with gene expression,plant development,and stress responses.Here,we review the latest research progress on mRNA and DNA epigenetic modifications,including the detection,dynamics,distribution,functions,regulatory proteins,and evolution,with a focus on m^6A,m^5C,and 6mA.We also provide some perspectives on future research of the newly identified and unknown epigenetic modifications of mRNA and DNA in plants.
