Transcription factor WRKY46 regulates osmotic stress responses and stomatal movement independently in Arabidopsis
Transcription factor WRKY46 regulates osmotic stress responses and stomatal movement independently in Arabidopsis
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DOI：
10.1111/tpj.12538
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发表时间：
2014-07-01
期刊：
影响因子：
7.2
通讯作者：
Zheng, Shao Jian
中科院分区：
文献类型：
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作者：
Ding, Zhong Jie;Yan, Jing Ying;Zheng, Shao Jian
干旱和盐胁迫严重抑制植物的生长发育；然而，植物对这些胁迫的调控机制尚不完全清楚。在这里，我们报道了WRKY转录因子WRKY46的表达在干旱、盐和氧化胁迫下被快速诱导。T-DNA插入导致WRKY46对干旱和盐胁迫更敏感，而过表达WRKY46 （OV46）导致土生植物超敏感，失水率更高，但在密封琼脂板上的耐受性增强。由于保护细胞中活性氧（ROS）的积累减少，OV46系的气孔关闭对ABA不敏感。我们进一步发现WRKY46在保护细胞中表达，其表达不受脱水影响，并参与光依赖性气孔打开。微阵列分析显示，WRKY46调控了脱水胁迫下参与细胞渗透保护和氧化还原稳态的一系列基因，这一点通过胁迫幼苗的ROS和丙二醛（MDA）水平得到证实。此外，WRKY46通过调节QUA-QUINE starch （QQS）基因的表达来调节保护细胞的光依赖性淀粉代谢。综上所述，我们证明WRKY46在调节植物对干旱和盐胁迫的反应以及保护细胞中依赖光的气孔打开中起双重作用。
Drought and salt stress severely inhibit plant growth and development; however, the regulatory mechanisms of plants in response to these stresses are not fully understood. Here we report that the expression of a WRKY transcription factor WRKY46 is rapidly induced by drought, salt and oxidative stresses. T-DNA insertion of WRKY46 leads to more sensitivity to drought and salt stress, whereas overexpression of WRKY46 (OV46) results in hypersensitivity in soii-grown plants, with a higher water loss rate, but with increased tolerance on the sealed agar plates. Stomatal closing in the OV46 line is insensitive to ABA because of a reduced accumulation of reactive oxygen species (ROS) in the guard cells. We further find that WRKY46 is expressed in guard cells, where its expression is not affected by dehydration, and is involved in light-dependent stomatal opening. Microarray analysis reveals that WRKY46 regulates a set of genes involved in cellular osmoprotection and redox homeostasis under dehydration stress, which is confirmed by ROS and malondialdehyde (MDA) levels in stressed seedlings. Moreover, WRKY46 modulates light-dependent starch metabolism in guard cells via regulating QUA-QUINE STARCH (QQS) gene expression. Taken together, we demonstrate that WRKY46 plays dual roles in regulating plant responses to drought and salt stress and light-dependent stomatal opening in guard cells.