RSM1, an Arabidopsis MYB protein, interacts with HY5/HYH to modulate seed germination and seedling development in response to abscisic acid and salinity
RSM1, an Arabidopsis MYB protein, interacts with HY5/HYH to modulate seed germination and seedling development in response to abscisic acid and salinity
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DOI：
10.1371/journal.pgen.1007839
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发表时间：
2018-12
期刊：
影响因子：
4.5
通讯作者：
B. Yang;Zihao Song;Chaonan Li;Jiahao Jiang;Yangyang Zhou;Ruipu Wang;Qi Wang;Chang Ni;Qing Liang;Haodong Chen;L. Fan
中科院分区：
文献类型：
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作者：
B. Yang;Zihao Song;Chaonan Li;Jiahao Jiang;Yangyang Zhou;Ruipu Wang;Qi Wang;Chang Ni;Qing Liang;Haodong Chen;L. Fan
MYB转录因子参与许多生物过程，包括新陈代谢、发育以及对生物和非生物胁迫的响应。RADILAS-LIKE SANT/MYB 1(RSM1)属于MYB相关亚家族，以往的转录组分析表明RSM1可能在植物发育、逆境反应和植物激素信号转导中发挥作用。然而，RSM1响应非生物胁迫的分子机制仍然不清楚。我们发现，RSM1表达的下调或上调改变了拟南芥种子萌发和子叶绿化对脱落酸(ABA)、氯化钠和甘露醇的敏感性。RSM1的表达受ABA和盐的动态调控。转录因子拉长下胚轴5(HY5)和HY5同源物(HYH)通过与RSM1启动子结合来调节RSM1的表达。遗传分析表明，RSM1在种子萌发、萌发后发育对ABA和非生物胁迫的响应以及幼苗对盐分的耐性等方面具有多种功能。Pull-Down和BIFC分析表明，RSM1在体内外与HY5/HYH相互作用。RSM1和HY5/HYH可能在响应ABA和非生物胁迫中发挥调节模块的作用。RSM1与ABA不敏感5(ABI5)启动子结合，从而调节其表达，而RSM1相互作用也刺激HY5与ABI5启动子结合。然而，在双荧光素酶瞬时表达实验中没有发现证据支持RSM增强HY对ABI5表达的激活。综上所述，HY5/HYH和RSM1可能会聚在ABI5启动子上，独立地或以某种方式依赖地调节ABI5的表达和ABI5下游的ABA和非生物胁迫响应基因，从而提高植物对环境的适应。
MYB transcription factors are involved in many biological processes, including metabolism, development and responses to biotic and abiotic stresses. RADIALIS-LIKE SANT/MYB 1 (RSM1) belongs to a MYB-related subfamily, and previous transcriptome analysis suggests that RSM1 may play roles in plant development, stress responses and plant hormone signaling. However, the molecular mechanisms of RSM1 action in response to abiotic stresses remain obscure. We show that down-regulation or up-regulation of RSM1 expression alters the sensitivity of seed germination and cotyledon greening to abscisic acid (ABA), NaCl and mannitol in Arabidopsis. The expression of RSM1 is dynamically regulated by ABA and NaCl. Transcription factors ELONGATED HYPOCOTYL 5 (HY5) and HY5 HOMOLOG (HYH) regulate RSM1 expression via binding to the RSM1 promoter. Genetic analyses reveal that RSM1 mediates multiple functions of HY5 in responses of seed germination, post-germination development to ABA and abiotic stresses, and seedling tolerance to salinity. Pull-down and BiFC assays show that RSM1 interacts with HY5/HYH in vitro and in vivo. RSM1 and HY5/HYH may function as a regulatory module in responses to ABA and abiotic stresses. RSM1 binds to the promoter of ABA INSENSITIVE 5 (ABI5), thereby regulating its expression, while RSM1 interaction also stimulates HY5 binding to the ABI5 promoter. However, no evidence was found in the dual-luciferase transient expression assay to support that RSM enhances the activation of ABI5 expression by HY. In summary, HY5/HYH and RSM1 may converge on the ABI5 promoter and independently or somehow dependently regulate ABI5 expression and ABI5-downstream ABA and abiotic stress-responsive genes, thereby improving the adaption of plants to the environment.