Liu Weijuan, Xiang Yang, Zhang Xiaoyun, Han Gaoqiang, Sun Xiujuan, Sheng Yu, Yan Jingwei, Scheller Henrik Vibe, Zhang Aying
College of Life Sciences, Nanjing Agricultural University, Nanjing, China.
Environmental Genomics and Systems Biology Division, Joint Bioenergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
Front Plant Sci. 2019 Jan 4;9:1902. doi: 10.3389/fpls.2018.01902. eCollection 2018.
Water deficit is a key limiting factor that affects the growth, development and productivity of crops. It is vital to understand the mechanisms by which plants respond to drought stress. Here an -acetylglutamate kinase gene, , was cloned from maize (). was expressed at high levels in maize leaves and at lower levels in root, stem, female flower and male flower. The expression of was significantly induced by PEG, NaCl, ABA, brassinosteroid and HO. The ectopic expression of in tobacco resulted in higher tolerance to drought compared to plants transformed with empty vector. Further physiological analysis revealed that overexpression of could enhance the activities of antioxidant defense enzymes, and decrease malondialdehyde content and leakage of electrolyte in tobacco under drought stress. Moreover, the transgenic tobacco accumulated more arginine and nitric oxide (NO) than control plants under drought stress. In addition, the transgenic tobaccos activated drought responses faster than vector-transformed plants. These results indicate that can play a vital role in enhancing drought tolerance by likely affecting the arginine and NO accumulation, and could be involved in different strategies in response to drought stress.
水分亏缺是影响作物生长、发育和生产力的关键限制因素。了解植物对干旱胁迫的响应机制至关重要。在此，从玉米（Zea mays）中克隆了一个N - 乙酰谷氨酸激酶基因ZmNAGK。ZmNAGK在玉米叶片中高水平表达，而在根、茎、雌花和雄花中低水平表达。ZmNAGK的表达受到聚乙二醇（PEG）、氯化钠（NaCl）、脱落酸（ABA）、油菜素内酯和过氧化氢（H₂O₂）的显著诱导。与用空载体转化的植物相比，ZmNAGK在烟草中的异位表达导致对干旱的耐受性更高。进一步的生理分析表明，ZmNAGK的过表达可以增强干旱胁迫下烟草中抗氧化防御酶的活性，降低丙二醛含量和电解质渗漏。此外，在干旱胁迫下，ZmNAGK转基因烟草比对照植物积累更多的精氨酸和一氧化氮（NO）。此外，ZmNAGK转基因烟草比载体转化植物更快地激活干旱响应。这些结果表明，ZmNAGK可能通过影响精氨酸和NO的积累在增强耐旱性方面发挥重要作用，并且ZmNAGK可能参与应对干旱胁迫的不同策略。
