Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, People's Republic of China.
University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
Plant Cell Rep. 2018 Aug;37(8):1159-1172. doi: 10.1007/s00299-018-2302-9. Epub 2018 May 23.
Overexpression of VaWRKY14 increases drought tolerance in Arabidopsis by modulating the expression of stress-related genes, including COR15A, COR15B, COR413, KIN2, and RD29A. The WRKY family is one of a largest transcription factors in plants, and it is a key component of multiple stress responses. In this study, the drought- and cold-induced WRKY family gene VaWRKY14 was isolated and characterized. Phylogenetic analysis indicated that VaWRKY14 belongs to the WRKY IIa subfamily, of which several members participate in biotic and abiotic stress responses in plants. Fluorescence observation from Arabidopsis mesophyll protoplasts transformed with the VaWRKY14::eGFP fusion vector suggested that VaWRKY14 was localized in the nucleus. The VaWRKY14 in yeast cells did not display any transcriptional activity. The expression of VaWRKY14 could be induced by exogenous phytohormones, including salicylic acid (SA) and abscisic acid (ABA). Overexpression of VaWRKY14 enhanced the drought tolerance of transgenic Arabidopsis. Compared with wild-type Arabidopsis, the VaWRKY14-OE lines exhibited higher water content and antioxidant enzyme activities in leaves after drought treatment. RNA sequencing analysis revealed that several stress-related genes, including COR15A, COR15B, COR413, KIN2, and RD29A, were upregulated in transgenic plants relative to their expression in wild-type Arabidopsis under normal conditions. Several genes (3 upregulated and 49 down-regulated) modulated by VaWRKY14 were also affected by drought stress in wild-type plants. These data suggest that VaWRKY14 responds to drought and cold stresses and that drought tolerance may be enhanced by regulating the expression of stress-related genes in Arabidopsis.
VaWRKY14 的过表达通过调节与胁迫相关基因（包括 COR15A、COR15B、COR413、KIN2 和 RD29A）的表达，增加拟南芥的耐旱性。WRKY 家族是植物中最大的转录因子家族之一，是多种胁迫反应的关键组成部分。本研究分离并鉴定了干旱和冷诱导的 WRKY 家族基因 VaWRKY14。系统进化分析表明，VaWRKY14 属于 WRKY IIa 亚家族，该亚家族的几个成员参与植物的生物和非生物胁迫反应。用 VaWRKY14::eGFP 融合载体转化的拟南芥叶肉原生质体的荧光观察表明，VaWRKY14 定位于细胞核内。酵母细胞中的 VaWRKY14 不具有任何转录活性。VaWRKY14 的表达可被外源植物激素如水杨酸（SA）和脱落酸（ABA）诱导。VaWRKY14 的过表达增强了转基因拟南芥的耐旱性。与野生型拟南芥相比，干旱处理后 VaWRKY14-OE 系叶片的水分含量和抗氧化酶活性更高。RNA 测序分析表明，与野生型拟南芥在正常条件下的表达相比，转基因植物中几种与胁迫相关的基因（包括 COR15A、COR15B、COR413、KIN2 和 RD29A）上调。VaWRKY14 调节的几个基因（3 个上调和 49 个下调）也受到野生型植物干旱胁迫的影响。这些数据表明 VaWRKY14 响应干旱和寒冷胁迫，通过调节拟南芥中与胁迫相关基因的表达，可能增强其耐旱性。
