Li Yixin, Yang Qian, Huang Hanmei, Guo Yawen, Sun Qiguo, Guo Zhenfei, Shi Haifan
College of Grassland Science, Key Laboratory of State Forestry and Grassland Administration on Grass Germplasm Resources Innovation and Utilization in the Middle and Lower Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China.
Department of Agronomy and Horticulture, Jiangsu Vocational College of Agriculture and Forestry, Jurong, 212400, China.
Plant Physiol Biochem. 2024 Feb;207:108337. doi: 10.1016/j.plaphy.2024.108337. Epub 2024 Jan 4.
Seashore paspalum (Paspalum vaginatum O. Swartz) is an important warm-season turfgrass species with extreme salt tolerance, but investigations on its salt tolerance mechanism are limited. A salt induced PvWAK3 from halophyte seashore paspalum was identified in this study. Overexpression of PvWAK3 in Arabidopsis led to increased salt tolerance. Transgenic plants had higher levels of seed germination rate, root length, number of lateral roots, shoot weight, survival rate, F/F, ETR, and NPQ compared with the wild type (WT) under salt stress. Na content was increased and K content was decreased after salinity treatment, with lower levels of Na and Na/K ratio but higher level of K in transgenic plants than in WT under salt stress. The improved maintenance of Na and K homeostasis was associated with the higher transcript levels of K + -Uptake Permease 4 (KUP4), Potassium Transport 2/3 (AKT2), Salt Overly Sensitive 1 (SOS1) and High-Affinity K + Transporter 5 (HAK5) in transgenic plants compared with WT. Superoxide dismutase (SOD), catalase (CAT) and ascorbate-peroxidase (APX) activities, proline concentration, and P5CS1 transcript were increased after salinity treatment, with higher levels in transgenic lines compared with WT, which led to reduced accumulation of O· and HO under salt stress. It is suggested that PvWAK3 regulates salt tolerance positively, which is associated with promoted Na and K homeostasis, activated antioxidant enzymes, and proline biosynthesis under salt stress.
海滨雀稗（Paspalum vaginatum O. Swartz）是一种重要的暖季型草坪草种，具有极强的耐盐性，但对其耐盐机制的研究有限。本研究从盐生植物海滨雀稗中鉴定出一个盐诱导的PvWAK3。在拟南芥中过表达PvWAK3导致耐盐性增强。在盐胁迫下，与野生型（WT）相比，转基因植物的种子发芽率、根长、侧根数、地上部重量、存活率、F/F、ETR和NPQ水平更高。盐处理后，Na含量增加，K含量降低，在盐胁迫下转基因植物中的Na和Na/K比值较低，但K水平高于WT。与WT相比，转基因植物中K + -吸收通透酶4（KUP4）、钾转运蛋白2/3（AKT2）、盐过敏1（SOS1）和高亲和性K + 转运蛋白5（HAK5）的转录水平较高，这与Na和K稳态的更好维持有关。盐处理后，超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）活性、脯氨酸浓度和P5CS1转录本增加，转基因株系中的水平高于WT，这导致盐胁迫下O·和HO的积累减少。表明PvWAK3正向调节耐盐性，这与盐胁迫下促进Na和K稳态、激活抗氧化酶和脯氨酸生物合成有关。
