Darkness and gulliver2/phyB mutation decrease the abundance of phosphorylated BZR1 to activate brassinosteroid signaling in Arabidopsis.
Darkness and gulliver2/phyB mutation decrease the abundance of phosphorylated BZR1 to activate brassinosteroid signaling in Arabidopsis.
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DOI：
10.1111/tpj.12423
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发表时间：
2014-03
期刊：
影响因子：
--
通讯作者：
Choe S
中科院分区：
文献类型：
--
作者：
Kim B;Jeong YJ;Corvalán C;Fujioka S;Cho S;Park T;Choe S
光对于植物的生存至关重要;因此，植物灵活地调整其生长和发育，以最好地收获光能。植物生长促进类固醇激素类化合物（BRs）对发育的可塑性至关重要。然而，在不同的光照条件下BR介导的生长的确切机制在很大程度上仍然未知。在这里，我们表明，黑暗增加BR特异性转录因子，BZR 1的活性，通过减少磷酸化（无活性）形式的BZR 1在蛋白酶体依赖的方式。我们观察到，COP 1，一种暗激活的泛素连接酶，捕获并降解BZR 1的非活性形式。为了支持这一点，BZR 1是丰富的cop 1 -4突变体。在黑暗中去除磷酸化的BZR 1增加了BZR 1的去磷酸化与磷酸化形式的比率，从而增加了在去磷酸化的BZR 1蛋白之间形成活性同源二聚体的机会。此外，转录组分析揭示了可能有助于下胚轴在光照条件下差异生长的基因的身份。在光照条件下，35 S启动子下的三个基因的转基因错误表达导致叶柄和下胚轴伸长。我们的研究结果表明，光条件直接控制BR信号通过调节BZR 1的稳定性，从而建立光依赖模式的下胚轴生长在拟南芥。
Light is essential for plant survival; as such, plants flexibly adjust their growth and development to best harvest light energy. Brassinosteroids (BRs), plant growth-promoting steroid hormones, are essential for this plasticity of development. However, the precise mechanisms underlying BR-mediated growth under different light conditions remain largely unknown. Here, we show that darkness increases the activity of the BR-specific transcription factor, BZR1, by decreasing the phosphorylated (inactive) form of BZR1 in a proteasome-dependent manner. We observed that COP1, a dark-activated ubiquitin ligase, captures and degrades the inactive form of BZR1. In support of this, BZR1 is abundant in the cop1-4 mutant. The removal of phosphorylated BZR1 in darkness increases the ratio of dephosphorylated to phosphorylated forms of BZR1, thus increasing the chance of active homodimers forming between dephosphorylated BZR1 proteins. Furthermore, a transcriptome analysis revealed the identity of genes that are likely to contribute to the differential growth of hypocotyls in light conditions. Transgenic misexpression of three genes under the 35S promoter in light conditions resulted in elongated petioles and hypocotyls. Our results suggest that light conditions directly control BR signaling by modulating BZR1 stability, and consequently by establishing light-dependent patterns of hypocotyl growth in Arabidopsis.
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影响因子：
4.9
作者：
Kozuka, T;Horiguchi, G;Tsukaya, H
通讯作者：
Tsukaya, H
DOI：
10.1073/pnas.93.8.3530
发表时间：
1996-04-16
影响因子：
11.1
作者：
Carabelli, M;Morelli, G;Ruberti, I
通讯作者：
Ruberti, I
影响因子：
7.4
作者：
Clouse, SD;Langford, M;McMorris, TC
通讯作者：
McMorris, TC
影响因子：
64.8
作者：
Hwang, I;Sheen, J
通讯作者：
Sheen, J
影响因子：
7.2
作者：
Alabadi, David;Gallego-Bartolome, Javier;Blazquez, Miguel A.
通讯作者：
Blazquez, Miguel A.