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
Mitogen activated protein kinase kinase kinase 18(MAPKKK18)mediated signaling cascade plays important roles in Arabidopsis drought stress tolerance.However,the post-translational modulation patterns of MAPKKK18 are no...Mitogen activated protein kinase kinase kinase 18(MAPKKK18)mediated signaling cascade plays important roles in Arabidopsis drought stress tolerance.However,the post-translational modulation patterns of MAPKKK18 are not characterized.In this study,we found that the protein level of MAPKKK18 was tightly controlled by the 26 S proteasome.Ubiquitin ligases RGLG1 and RGLG2 ubiquitinated MAPKKK18 at lysine residue K32 and K154,and promoted its degradation.Deletion of RGLG1 and RGLG2 stabilized MAPKKK18 and further enhanced the drought stress tolerance of MAPKKK18-overexpression plants.Our data demonstrate that RGLG1 and RGLG2 negatively regulate MAPKKK18-mediated drought stress tolerance in Arabidopsis.展开更多
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.
基金supported by the National Natural Science Foundation of China(31771878 and 31901752)the Major Program of Shandong Province Natural Science Foundation(ZR2018ZB0212)。
文摘Mitogen activated protein kinase kinase kinase 18(MAPKKK18)mediated signaling cascade plays important roles in Arabidopsis drought stress tolerance.However,the post-translational modulation patterns of MAPKKK18 are not characterized.In this study,we found that the protein level of MAPKKK18 was tightly controlled by the 26 S proteasome.Ubiquitin ligases RGLG1 and RGLG2 ubiquitinated MAPKKK18 at lysine residue K32 and K154,and promoted its degradation.Deletion of RGLG1 and RGLG2 stabilized MAPKKK18 and further enhanced the drought stress tolerance of MAPKKK18-overexpression plants.Our data demonstrate that RGLG1 and RGLG2 negatively regulate MAPKKK18-mediated drought stress tolerance in Arabidopsis.
