DEAR1, a transcriptional repressor of DREB protein that mediates plant defense and freezing stress responses in Arabidopsis
DEAR1, a transcriptional repressor of DREB protein that mediates plant defense and freezing stress responses in Arabidopsis
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DOI：
10.1007/s10265-009-0252-6
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发表时间：
2009-11-01
影响因子：
2.8
通讯作者：
Yamaguchi, Junji
中科院分区：
文献类型：
--
作者：
Tsutsui, Tomokazu;Kato, Wataru;Yamaguchi, Junji
植物已经进化出复杂的机制来响应和适应环境中各种各样的生物和非生物胁迫。拟南芥DEAR1 （DREB和EAR基序蛋白1；At3g50260）基因编码一个与DREB1/CBF（脱水反应元件结合蛋白1/ c -重复结合因子）结构域和EAR（乙烯反应因子相关的两亲性抑制）基序具有显著同源性的蛋白。我们在这里表明，DEAR1 mRNA在对病原体感染和冷处理的反应中积累。过表达DEAR1 （dear10ox）的转基因拟南芥表现出矮化表型和病变样细胞死亡，PR基因组成性表达和水杨酸积累。与野生型相比，dear10x也表现出更有限的丁香假单胞菌病原体生长，与激活防御表型一致。此外，瞬时表达实验显示，DEAR1蛋白抑制DRE/CRT（脱水响应元件/C-repeat）依赖转录，该转录受低温调控。此外，冷处理对DREB1/CBF家族基因的诱导在dear10x中被抑制，导致抗冻性降低。这些结果表明，DEAR1在介导生物和非生物胁迫应答信号通路之间的串扰中具有上游调控作用。
Plants have evolved intricate mechanisms to respond and adapt to a wide variety of biotic and abiotic stresses in their environment. The Arabidopsis DEAR1 (DREB and EAR motif protein 1; At3g50260) gene encodes a protein containing significant homology to the DREB1/CBF (dehydration-responsive element binding protein 1/C-repeat binding factor) domain and the EAR (ethylene response factor-associated amphiphilic repression) motif. We show here that DEAR1 mRNA accumulates in response to both pathogen infection and cold treatment. Transgenic Arabidopsis overexpressing DEAR1 (DEAR1ox) showed a dwarf phenotype and lesion-like cell death, together with constitutive expression of PR genes and accumulation of salicylic acid. DEAR1ox also showed more limited P. syringae pathogen growth compared to wild-type, consistent with an activated defense phenotype. In addition, transient expression experiments revealed that the DEAR1 protein represses DRE/CRT (dehydration-responsive element/C-repeat)-dependent transcription, which is regulated by low temperature. Furthermore, the induction of DREB1/CBF family genes by cold treatment was suppressed in DEAR1ox, leading to a reduction in freezing tolerance. These results suggest that DEAR1 has an upstream regulatory role in mediating crosstalk between signaling pathways for biotic and abiotic stress responses.