bHLH122 is important for drought and osmotic stress resistance in Arabidopsis and in the repression of ABA catabolism
bHLH122 is important for drought and osmotic stress resistance in Arabidopsis and in the repression of ABA catabolism
复制标题
bHLH122 对于拟南芥的干旱和渗透胁迫抵抗以及 ABA 分解代谢的抑制非常重要
DOI：
10.1111/nph.12607
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发表时间：
2014-03-01
期刊：
影响因子：
9.4
通讯作者：
Li, Wen-Xue
中科院分区：
文献类型：
--
作者：
Liu, Wenwen;Tai, Huanhuan;Li, Wen-Xue
虽然碱性螺旋-环-螺旋（bHLH）家族中的蛋白质是真核生物中普遍存在的转录因子，但大多数bHLH家族成员在植物中的生物学作用尚不清楚。干旱、NaCl和渗透胁迫对拟南芥bHLH122转录本的诱导作用较强，而ABA处理对bHLH122转录本的诱导作用较弱。启动子：GUS分析显示bHLH122在维管组织和保护细胞中高表达。与野生型（WT）植物相比，过表达bHLH122的转基因植株对干旱、NaCl和渗透胁迫表现出更强的抗性。相比之下，bhlh122功能缺失突变体对NaCl和渗透胁迫的敏感性高于WT植株。微阵列分析表明bHLH122对许多非生物应激反应基因的表达很重要。在电泳迁移率转移实验和染色质免疫沉淀实验中，bHLH122可以直接结合到CYP707A3启动子的G-box/E-box顺式元件上，抑制其表达。此外，上调bHLH122显著增加细胞ABA水平。这些结果表明bHLH122对干旱、NaCl和渗透信号具有正向调节作用。
Although proteins in the basic helix-loop-helix (bHLH) family are universal transcription factors in eukaryotes, the biological roles of most bHLH family members are not well understood in plants.The Arabidopsis thaliana bHLH122 transcripts were strongly induced by drought, NaCl and osmotic stresses, but not by ABA treatment. Promoter::GUS analysis showed that bHLH122 was highly expressed in vascular tissues and guard cells. Compared with wild-type (WT) plants, transgenic plants overexpressing bHLH122 displayed greater resistance to drought, NaCl and osmotic stresses. In contrast, the bhlh122 loss-of-function mutant was more sensitive to NaCl and osmotic stresses than were WT plants.Microarray analysis indicated that bHLH122 was important for the expression of a number of abiotic stress-responsive genes. In electrophoretic mobility shift assay and chromatin immunoprecipitation assays, bHLH122 could bind directly to the G-box/E-box cis-elements in the CYP707A3 promoter, and repress its expression. Further, up-regulation of bHLH122 substantially increased cellular ABA levels.These results suggest that bHLH122 functions as a positive regulator of drought, NaCl and osmotic signaling.