MLK1 and MLK2 Coordinate RGA and CCA1 Activity to Regulate Hypocotyl Elongation in Arabidopsis thaliana
MLK1 and MLK2 Coordinate RGA and CCA1 Activity to Regulate Hypocotyl Elongation in Arabidopsis thaliana
复制标题
MLK1和MLK2协调RGA和CCA1活性来调节拟南芥下胚轴伸长
DOI：
10.1105/tpc.17.00830
复制
发表时间：
2018
期刊：
影响因子：
11.6
通讯作者：
Ding Yong
中科院分区：
文献类型：
--
作者：
Zheng Han;Zhang Fei;Wang Shiliang;Su Yanhua;Ji Xiaoru;Jiang Pengfei;Chen Rihong;Hou Suiwen;Ding Yong
赤霉素在整个植物生命周期中调节着多种发育过程。然而，气体和昼夜节律之间的相互作用仍不清楚。在这里，我们报道了mut9p样的KINASE1 （MLK1）和MLK2介导GAs和生物钟之间的相互作用，以调节拟南芥的下胚轴伸长。DELLA蛋白作为主要生长抑制因子，在植物发育过程中整合了植物激素信号和环境途径。MLK1和MLK2与DELLA protein REPRESSOR OFga1-3（RGA）相互作用。mlk1和mlk2功能的缺失导致植物下胚轴短，对GAs不敏感。MLK1/2和RGA直接与CIRCADIAN CLOCK ASSOCIATED1 （CCA1）相互作用，CCA1靶向dwarf4的启动子（DWF4）来调节其在细胞扩增中的作用。MLK1/2可拮抗RGA结合CCA1的能力，这些因子协同调节dwf4的表达。RGA抑制CCA1激活dwf4启动子表达的能力，但MLK1/2逆转了这种抑制。遗传上，mlk1 /2与rga1和cca1在下胚轴伸长中的作用途径相同。总之，我们的研究结果揭示了MLK1和MLK2拮抗RGA下胚轴伸长的机制，并表明MLK1/2协调调节拟南芥植物发育的GAs和昼夜节律。
Gibberellins (GAs) modulate diverse developmental processes throughout the plant life cycle. However, the interaction between GAs and the circadian rhythm remains unclear. Here, we report that MUT9p-LIKE KINASE1 (MLK1) and MLK2 mediate the interaction between GAs and the circadian clock to regulate hypocotyl elongation inArabidopsis thaliana. DELLA proteins function as master growth repressors that integrate phytohormone signaling and environmental pathways in plant development. MLK1 and MLK2 interact with the DELLA protein REPRESSOR OFga1-3(RGA). Loss ofMLK1andMLK2function results in plants with short hypocotyls and hyposensitivity to GAs. MLK1/2 and RGA directly interact with CIRCADIAN CLOCK ASSOCIATED1 (CCA1), which targets the promoter ofDWARF4(DWF4) to regulate its roles in cell expansion. MLK1/2 antagonize the ability of RGA to bind CCA1, and these factors coordinately regulate the expression ofDWF4. RGA suppressed the ability of CCA1 to activate expression from theDWF4promoter, but MLK1/2 reversed this suppression. Genetically,MLK1/2act in the same pathway asRGAandCCA1in hypocotyl elongation. Together, our results provide insight into the mechanism by which MLK1 and MLK2 antagonize the function of RGA in hypocotyl elongation and suggest that MLK1/2 coordinately mediate the regulation of plant development by GAs and the circadian rhythm in Arabidopsis.