Department of Life Sciences, National Taitung University, Taitung, 95002, Taiwan.
Institute of Biotechnology, National University of Kaohsiung, Kaohsiung, 81148, Taiwan.
Plant Physiol Biochem. 2020 Oct;155:136-146. doi: 10.1016/j.plaphy.2020.07.025. Epub 2020 Jul 24.
High-salinity stress is one of the major limiting factors on crop productivity. Physiological strategies against high-salinity stress include generation of reactive oxygen species (ROS), induction of stress-related genes expression, accumulation of abscisic acid (ABA) and up-regulation of antiporters. ROS are metabolism by-products and involved in signal transduction pathway. Constitutive expression of plant ferrodoxin-like protein (PFLP) gene enhances pathogen-resistance activities and root-hair growth through promoting ROS generation. However, the function of PFLP in abiotic stress responses is unclear. In this study, PFLP-1 and PFLP-2-transgenic rice plants were generated to elucidate the role of PFLP under salinity stress. PFLP overexpression significantly increased salt tolerance in PFLP-transgenic rice plants compared with non-transgenic plants (Oryza sativa japonica cv. Tainung 67, designated as TNG67). In high-salinity conditions, PFLP-transgenic plants exhibited earlier ROS production, higher antioxidant enzyme activities, higher ABA accumulation, up-regulated expression of stress-related genes (OsRBOHa, Cu/Zn SOD, OsAPX, OsNCED2, OsSOS1, OsCIPK24, OsCBL4, and OsNHX2), and leaf sodium ion content was lower compared with TNG67 plant. In addition, transgenic lines maintained electron transport rates and contained lower malondialdhyde (MDA) content than TNG67 plant did under salt-stress conditions. Overall results indicated salinity tolerance was improved by PFLP overexpression in transgenic rice plant. The PFLP gene is a potential candidate for improving salinity tolerance for valuable agricultural crops.
高盐胁迫是影响作物生产力的主要限制因素之一。植物应对高盐胁迫的生理策略包括产生活性氧（ROS）、诱导与胁迫相关的基因表达、积累脱落酸（ABA）和上调转运蛋白。ROS 是代谢的副产物，参与信号转导途径。植物铁氧还蛋白样蛋白（PFLP）基因的组成型表达通过促进 ROS 产生，增强了植物的抗病活性和根毛生长。然而，PFLP 在非生物胁迫响应中的功能尚不清楚。在本研究中，我们生成了 PFLP-1 和 PFLP-2 转基因水稻植株，以阐明 PFLP 在盐胁迫下的作用。与非转基因植株（粳稻品种 Tainung 67，简称 TNG67）相比，PFLP 过表达显著提高了 PFLP 转基因水稻植株的耐盐性。在高盐条件下，PFLP 转基因植株表现出更早的 ROS 产生、更高的抗氧化酶活性、更高的 ABA 积累、与胁迫相关基因（OsRBOHa、Cu/Zn SOD、OsAPX、OsNCED2、OsSOS1、OsCIPK24、OsCBL4 和 OsNHX2）的上调表达，以及叶片钠离子含量低于 TNG67 植株。此外，与 TNG67 植株相比，转基因株系在盐胁迫条件下保持了电子传递速率，且丙二醛（MDA）含量较低。综上所述，PFLP 过表达提高了转基因水稻植株的耐盐性。PFLP 基因是提高有价值农作物耐盐性的潜在候选基因。
