Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture/Sino-Africa Joint Research Center, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, People's Republic of China.
Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, People's Republic of China.
Plant Cell Rep. 2020 May;39(5):621-634. doi: 10.1007/s00299-020-02519-x. Epub 2020 Feb 27.
Expression of VaNAC17 improved drought tolerance in transgenic Arabidopsis by upregulating stress-responsive genes, modulating JA biosynthesis, and enhancing ROS scavenging. Water deficit severely affects the growth and development of plants such as grapevine (Vitis spp.). Members of the NAC (NAM, ATAF1/2, and CUC2) transcription factor (TF) family participate in drought-stress-induced signal transduction in plants, but little is known about the roles of NAC genes in drought tolerance in grapevine. Here, we explored the role of VaNAC17 in Vitis amurensis, a cold-hardy, drought-tolerant species of grapevine. VaNAC17 was strongly induced in grapevine by drought, exogenous abscisic acid (ABA), and methyl jasmonate (MeJA). A transient expression assay in yeast indicated that VaNAC17 functions as a transcriptional activator. Notably, heterologous expression of VaNAC17 in Arabidopsis thaliana enhanced drought tolerance. VaNAC17-expressing Arabidopsis plants showed decreased reactive oxygen species (ROS) accumulation compared to wild-type plants under drought conditions. RNA-seq analysis indicated that VaNAC17 expression increased the transcription of downstream stress-responsive genes after 5 days of drought treatment, especially genes involved in jasmonic acid (JA) biosynthesis (such as LOX3, AOC1 and OPR3) and signaling (such as MYC2, JAZ1, VSP1 and CORI3) pathways. Endogenous JA levels increased in VaNAC17-OE plants under drought stress. Taken together, these results indicate that VaNAC17 plays a positive role in drought tolerance by modulating endogenous JA biosynthesis and ROS scavenging.
VaNAC17 的表达通过上调应激响应基因、调节茉莉酸（JA）生物合成和增强 ROS 清除来提高转基因拟南芥的耐旱性。水分亏缺严重影响植物（如葡萄）的生长和发育。NAC（NAM、ATAF1/2 和 CUC2）转录因子（TF）家族的成员参与植物中干旱胁迫诱导的信号转导，但关于 NAC 基因在葡萄耐旱性中的作用知之甚少。在这里，我们研究了 VaNAC17 在葡萄属耐寒耐旱品种 Vitis amurensis 中的作用。干旱、外源脱落酸（ABA）和茉莉酸甲酯（MeJA）强烈诱导葡萄中的 VaNAC17。酵母中的瞬时表达试验表明 VaNAC17 作为转录激活因子起作用。值得注意的是，VaNAC17 在拟南芥中的异源表达增强了耐旱性。与野生型植物相比，在干旱条件下，表达 VaNAC17 的拟南芥植物的活性氧（ROS）积累减少。RNA-seq 分析表明，在干旱处理 5 天后，VaNAC17 的表达增加了下游应激响应基因的转录，特别是与茉莉酸（JA）生物合成（如 LOX3、AOC1 和 OPR3）和信号转导（如 MYC2、JAZ1、VSP1 和 CORI3）途径相关的基因。干旱胁迫下 VaNAC17-OE 植物内源 JA 水平升高。综上所述，这些结果表明 VaNAC17 通过调节内源 JA 生物合成和 ROS 清除在耐旱性中发挥积极作用。
