ABA-INSENSITIVE3, ABA-INSENSITIVE5, and DELLAs Interact to Activate the Expression of SOMNUS and Other High-Temperature-Inducible Genes in Imbibed Seeds in Arabidopsis
ABA-INSENSITIVE3, ABA-INSENSITIVE5, and DELLAs Interact to Activate the Expression of SOMNUS and Other High-Temperature-Inducible Genes in Imbibed Seeds in Arabidopsis
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DOI：
10.1105/tpc.113.118604
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发表时间：
2013-12-01
期刊：
影响因子：
11.6
通讯作者：
Choi, Giltsu
中科院分区：
文献类型：
--
作者：
Lim, Soohwan;Park, Jeongmoo;Choi, Giltsu
种子监测环境，在适当的时间发芽，但不同的物种对环境条件的反应不同，特别是光线和温度。在拟南芥中，光促进萌发，但高温抑制萌发。我们以前报道过，光促进发芽抑制SOMNUS（SOM）。在这里，我们研究了高温是否也通过SOM调节发芽，发现高温激活SOM表达。与此相一致的是，在高温下，som突变体比野生型更频繁地发芽。高温下SOM mRNA的诱导需要脱落酸（阿坝）和赤霉酸的生物合成，ABA-不敏感3（ABI 3）、ABI 5和DELLA正调控SOM的表达。染色质免疫沉淀分析表明，ABI 3，ABI 5，和DELLA都靶向SOM启动子。在蛋白质水平上，ABI 3、ABI 5和DELLA都相互作用，表明它们在SOM启动子上形成复合物以在高温下激活SOM表达。我们发现，高温诱导基因的启动子中经常有RY基序和ABA反应元件，其中一些是由ABI 3，ABI 5和DELLA体内靶向的。综上所述，我们的数据表明，ABI 3，ABI 5和DELLA介导高温信号，激活SOM和其他高温诱导基因的表达，从而抑制种子萌发。
Seeds monitor the environment to germinate at the proper time, but different species respond differently to environmental conditions, particularly light and temperature. In Arabidopsis thaliana, light promotes germination but high temperature suppresses germination. We previously reported that light promotes germination by repressing SOMNUS (SOM). Here, we examined whether high temperature also regulates germination through SOM and found that high temperature activates SOM expression. Consistent with this, som mutants germinated more frequently than the wild type at high temperature. The induction of SOM mRNA at high temperature required abscisic acid (ABA) and gibberellic acid biosynthesis, and ABA-INSENSITIVE3 (ABI3), ABI5, and DELLAs positively regulated SOM expression. Chromatin immunoprecipitation assays indicated that ABI3, ABI5, and DELLAs all target the SOM promoter. At the protein level, ABI3, ABI5, and DELLAs all interact with each other, suggesting that they form a complex on the SOM promoter to activate SOM expression at high temperature. We found that high-temperature-inducible genes frequently have RY motifs and ABA-responsive elements in their promoters, some of which are targeted by ABI3, ABI5, and DELLAs in vivo. Taken together, our data indicate that ABI3, ABI5, and DELLAs mediate high-temperature signaling to activate the expression of SOM and other high-temperature-inducible genes, thereby inhibiting seed germination.