The transcriptional co-activator MBF1c is a key regulator of thermotolerance in Arabidopsis thaliana
The transcriptional co-activator MBF1c is a key regulator of thermotolerance in Arabidopsis thaliana
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DOI：
10.1074/jbc.m709187200
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发表时间：
2008-04-04
影响因子：
4.8
通讯作者：
Mittler, Ron
中科院分区：
文献类型：
--
作者：
Suzuki, Nobuhiro;Bajad, Sunil;Mittler, Ron
生物体适应环境的能力是其全球分布和与其他生物体竞争能力的关键决定因素。热应激反应是真核生物和原核生物中高度保守的环境和发育过程，是植物适应反应的重要组成部分。以前的研究表明，热休克转录因子在植物和其他生物的耐热性中发挥着重要作用，控制着不同的热休克蛋白和解毒酶的表达。相反，尽管最近发现其他几种途径，包括乙烯、水杨酸(SA)和海藻糖，在植物的耐热性中发挥核心作用，但这些反应的关键调节因子尚未确定。在此，我们报道了高度保守的转录辅助激活因子MBF1c(多蛋白桥联因子1c)是拟南芥耐热性的关键调节因子。在热应激过程中，MBF1c蛋白快速积累并定位于细胞核。MBF1c是耐热性所必需的，在热应激过程中作用于SA、海藻糖、乙烯和病程相关蛋白1的上游。相反，编码HSFA2和不同热休克蛋白的转录本的表达并不需要MBF1c。有趣的是，MBF1c与TPS5(海藻糖磷酸合成酶5)相互作用，TPS5也是热诱导的，而TPS5缺失的突变体是温度敏感的。我们的结果为MBF1c控制下存在紧密协调的热应激反应网络提供了证据，该网络包括海藻糖、SA和乙烯信号通路。
The ability of an organism to acclimate to its environment is a key determinant in its global distribution and capacity to compete with other organisms. The heat stress response, a highly conserved environmental and developmental program in eukaryotic and prokaryotic organisms, is an important component of the acclimation response of plants. Previous studies have shown that heat shock transcription factors play an important role in thermotolerance in plants and other organisms, controlling the expression of different heat shock proteins and detoxifying enzymes. In contrast, although several other pathways, involving ethylene, salicylic acid ( SA), and trehalose, were recently shown to play a central role in thermotolerance in plants, a key regulator of these responses was not identified. Here we report that the highly conserved transcriptional coactivator, MBF1c ( multiprotein bridging factor 1c), is a key regulator of thermotolerance in Arabidopsis thaliana. MBF1c protein accumulates rapidly and is localized to nuclei during heat stress. MBF1c is required for thermotolerance and functions upstream to SA, trehalose, ethylene, and pathogenesis-related protein 1 during heat stress. In contrast, MBF1c is not required for the expression of transcripts encoding HSFA2 and different heat shock proteins. Interestingly, MBF1c interacts with TPS5 ( trehalose phosphate synthase 5), which is also heat-inducible, and mutants deficient in TPS5 are thermosensitive. Our results provide evidence for the existence of a tightly coordinated heat stress-response network, involving trehalose- ,SA-, and ethylene-signaling pathways, that is under the control of MBF1c.