Mitogen-activated protein kinase(MAPK)cascades play vital roles in regulating plant growth,development,and stress responses.Nevertheless,the complete MAPK cascade that regulates the flowering time of Arabidopsis thali...Mitogen-activated protein kinase(MAPK)cascades play vital roles in regulating plant growth,development,and stress responses.Nevertheless,the complete MAPK cascade that regulates the flowering time of Arabidopsis thaliana has not been established.A MAPK module comprising MAPKKK18,MAPKK3,and MAPK1/2/7/14accelerates flowering in Arabidopsis.Through direct interaction,MAPK1/2/7/14 phosphorylates the S^(24)residue of NF-YB2.Phosphorylated NFYB2 enhances the stability of the heterotrimeric CO~NF-YB2~NF-YC3/C9 complex and the expression of FT.Accumulation of NF-YB2 significantly promotes flowering,whereas the role of NF-YB2^(S24A)in this process is less pronounced.Compared with the transgenic plants overexpressing MAPKKK18 in the wild-type(WT)background,the nf-yb2 plants overexpressing MAPKKK18 bolt considerably later.Taken together,the MAPKKK18-mediated signaling cascade exerts tight control over the flowering time of Arabidopsis by modulating the phosphorylation status of NF-YB2,unveiling a flexible regulatory pathway to fine-tune plant development.展开更多
文摘核因子(Nuclear Factor-Y,NF-Y)是一类能够在植物应对非生物胁迫过程中发挥转录调控作用的转录因子。为探究GmNF-YB2在大豆应对非生物胁迫过程中的功能和分子调控机制,本研究从大豆中克隆GmNF-YB2基因并对其进行生物信息学分析,采用实时荧光定量PCR(qRT-PCR)方法对GmNF-YB2的表达量进行检测,通过酵母双杂交方法分析GmNF-YB2蛋白与GmNF-YC6蛋白和GmNF-YC15蛋白的互作情况。结果显示:以大豆叶片cDNA为模板,PCR扩增获得678 bp GmNF-YB2基因序列。生物信息学分析结果显示,GmNF-YB2基因编码1个含有225个氨基酸的蛋白质,预测分子量为24.66 kD,等电点为6.97,是不稳定的亲水性蛋白质,定位于细胞核中;GmNF-YB2蛋白序列中含有一段保守的组蛋白折叠基序HFM。蛋白系统进化分析表明,GmNF-YB2与杨树PdNF-YB7和拟南芥AtNF-YB2的亲缘关系最近。qRT-PCR结果显示,GmNF-YB2在大豆幼苗中能够被干旱、盐和低温胁迫诱导表达,GmNF-YB2在大豆茎中的表达量最高。酵母双杂交结果显示,GmNF-YB2蛋白与GmNF-YC6蛋白和GmNF-YC15蛋白均存在互作关系。结果表明GmNF-YB2可能参与大豆对非生物胁迫的应答。
基金supported by grants from the National Natural Science Foundation of China(32071931 and 32170306)。
文摘Mitogen-activated protein kinase(MAPK)cascades play vital roles in regulating plant growth,development,and stress responses.Nevertheless,the complete MAPK cascade that regulates the flowering time of Arabidopsis thaliana has not been established.A MAPK module comprising MAPKKK18,MAPKK3,and MAPK1/2/7/14accelerates flowering in Arabidopsis.Through direct interaction,MAPK1/2/7/14 phosphorylates the S^(24)residue of NF-YB2.Phosphorylated NFYB2 enhances the stability of the heterotrimeric CO~NF-YB2~NF-YC3/C9 complex and the expression of FT.Accumulation of NF-YB2 significantly promotes flowering,whereas the role of NF-YB2^(S24A)in this process is less pronounced.Compared with the transgenic plants overexpressing MAPKKK18 in the wild-type(WT)background,the nf-yb2 plants overexpressing MAPKKK18 bolt considerably later.Taken together,the MAPKKK18-mediated signaling cascade exerts tight control over the flowering time of Arabidopsis by modulating the phosphorylation status of NF-YB2,unveiling a flexible regulatory pathway to fine-tune plant development.
