National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China.
Plant Cell Rep. 2023 Mar;42(3):521-533. doi: 10.1007/s00299-022-02974-8. Epub 2022 Dec 31.
Overexpression in Arabidopsis of the maize shikimate kinase-like genes SKL1 and SKL2 enhances tolerance to drought stress. The shikimate pathway has been reported to play an important role in plant signaling, reproduction, and development. However, its role in abiotic stress has not yet been reported. Here, two shikimate kinase-like genes, SKL1 and SKL2, were cloned from maize and their functions in mediating drought tolerance were investigated. Transcript levels of ZmSKL1 and ZmSKL2 in roots and leaves were strongly induced by drought stress. Both proteins were localized in the chloroplast. Furthermore, compared to the wild-type, transgenic Arabidopsis plants overexpressing ZmSKL1 or ZmSKL2 exhibited improved drought stress tolerance through increases in relative water content and stomatal closure. Additionally, the transgenic lines showed reduced accumulation of reactive oxygen species as a results of increased antioxidant enzyme activity. Interestingly, overexpression of ZmSKL1 or ZmSKL2 also increased sensitivity to exogenous abscisic acid. In addition, the ROS-related and stress-responsive genes were activated in transgenic lines under drought stress. Moreover, ZmSKL1 and ZmSKL2 were found to separately interact with ZmASR3, which is an important regulatory protein in mediating drought tolerance, suggesting that ZmSKL1 and ZmSKL2, together with ZmASR3, are proteins that may confer drought tolerance as candidates in plant genetic breeding manipulations.
拟南芥中玉米莽草酸激酶样基因 SKL1 和 SKL2 的过表达增强了对干旱胁迫的耐受性。已报道莽草酸途径在植物信号转导、繁殖和发育中起重要作用。然而，其在非生物胁迫中的作用尚未报道。在这里，我们从玉米中克隆了两个莽草酸激酶样基因 SKL1 和 SKL2，并研究了它们在介导耐旱性中的功能。干旱胁迫强烈诱导根和叶中 ZmSKL1 和 ZmSKL2 的转录水平。两种蛋白质都定位于叶绿体中。此外，与野生型相比，过表达 ZmSKL1 或 ZmSKL2 的转基因拟南芥植株通过增加相对水含量和关闭气孔来提高耐旱性。此外，转基因系表现出活性氧物质积累减少，这是由于抗氧化酶活性增加所致。有趣的是，过表达 ZmSKL1 或 ZmSKL2 也增加了对外源脱落酸的敏感性。此外，在干旱胁迫下，ROS 相关和应激响应基因在转基因系中被激活。此外，发现 ZmSKL1 和 ZmSKL2 分别与 ZmASR3 相互作用，ZmASR3 是一种在介导耐旱性中起重要调节作用的蛋白质，这表明 ZmSKL1 和 ZmSKL2 与 ZmASR3 一起作为候选蛋白，可能赋予植物遗传育种操作中的耐旱性。
