Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing University of Agriculture, Beijing, 102206, China.
Beijing Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, RNA Center, College of Life Sciences, Capital Normal University, Beijing, 100048, China.
BMC Plant Biol. 2020 Feb 7;20(1):64. doi: 10.1186/s12870-020-2274-0.
Gibberellin (GA) and jasmonate (JA) are two essential phytohormones for filament elongation in Arabidopsis. GA and JA trigger degradation of DELLAs and JASMONATE ZIM-domain (JAZ) proteins through SCF and SCF separately to activate filament elongation. In JA pathway, JAZs interact with MYB21 and MYB24 to control filament elongation. However, little is known how DELLAs regulate filament elongation.
Here we showed that DELLAs interact with MYB21 and MYB24, and that R2R3 domains of MYB21 and MYB24 are responsible for interaction with DELLAs. Furthermore, we demonstrated that DELLA and JAZ proteins coordinately repress the transcriptional function of MYB21 and MYB24 to inhibit filament elongation.
We discovered that DELLAs interact with MYB21 and MYB24, and that DELLAs and JAZs attenuate the transcriptional function of MYB21 and MYB24 to control filament elongation. This study reveals a novel cross-talk mechanism of GA and JA in the regulation of filament elongation in Arabidopsis.
赤霉素（GA）和茉莉酸（JA）是拟南芥丝状伸长所必需的两种植物激素。GA 和 JA 通过分别的 SCF 和 SCF 触发 DELLAs 和 JASMONATE ZIM 结构域（JAZ）蛋白的降解，从而激活丝状伸长。在 JA 途径中，JAZs 与 MYB21 和 MYB24 相互作用以控制丝状伸长。然而，对于 DELLAs 如何调节丝状伸长知之甚少。
在这里，我们表明 DELLAs 与 MYB21 和 MYB24 相互作用，并且 MYB21 和 MYB24 的 R2R3 结构域负责与 DELLAs 相互作用。此外，我们证明 DELLA 和 JAZ 蛋白协同抑制 MYB21 和 MYB24 的转录功能，以抑制丝状伸长。
我们发现 DELLAs 与 MYB21 和 MYB24 相互作用，并且 DELLAs 和 JAZs 减弱了 MYB21 和 MYB24 的转录功能，从而控制丝状伸长。这项研究揭示了 GA 和 JA 在拟南芥丝状伸长调控中的一种新的交叉对话机制。
