Sundar L S, Wu J-Y, Tu Y-K, Chen H-W, Chao Y-Y
Department of Crop Science, College of Agriculture, Fisheries and Forestry, Fiji National University, Nausori, Fiji.
Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Neipu, Pingtung, Taiwan.
Plant Biol (Stuttg). 2025 Apr;27(3):388-400. doi: 10.1111/plb.13773. Epub 2025 Feb 3.
Salt stress, intensified by climate change, is a significant threat to rice production, a vital staple for over half the world's population. This makes addressing salt stress in rice cultivation a pressing issue. This study investigates the role of PNSB as a biostimulant in enhancing salinity tolerance of salt-sensitive rice seedlings, addressing existing gaps in knowledge on physiological and biochemical impacts under saline stress. We inoculated salt-sensitive rice seedlings with PNSB under 80 mmol NaCl stress in a controlled environment. After a 5-day treatment, we conducted biochemical and physiological analyses. Salinity stress induced oxidative stress in salt-sensitive rice seedlings. However, application of 5-ALA-producing PNSB mitigated stress, elevated 5-ALA in shoots by 23%, roots by 190.5%, and chlorophyll content by 105.0%. PNSB treatment also reduced superoxide radicals (O ) and HO by 26.7% and 38.7%, respectively, related to increased activity of the antioxidant enzymes, SOD (142.9%) and APX (41.8%). This led to lower electrolyte leakage (25.2%) and MDA (17.4%), indicating reduced ROS. Additionally, proline and soluble sugar content decreased by 29.2% and 72.5%, respectively. PNSB treatment also reduced sodium to potassium ion content in both shoots (31.2%) and roots (27.4%) of salt-stressed rice seedlings. These findings suggest that PNSB may facilitate nutrient solubilization and ion balance, thereby mitigating the adverse effects of salinity, with potential implications for sustainable agricultural practices to improve crop yield in saline environments. Future research should focus on elucidating the specific biochemical pathways involved in PNSB-mediated stress tolerance and exploring their application across diverse crop species and varying stress conditions.
气候变化加剧了盐胁迫，这对水稻生产构成了重大威胁，而水稻是全球一半以上人口的重要主食。这使得解决水稻种植中的盐胁迫问题成为一个紧迫的问题。本研究调查了光合细菌作为生物刺激剂在提高盐敏感水稻幼苗耐盐性方面的作用，填补了盐胁迫下生理和生化影响方面现有知识的空白。我们在可控环境中，于80 mmol NaCl胁迫下用光合细菌接种盐敏感水稻幼苗。经过5天的处理后，我们进行了生化和生理分析。盐胁迫在盐敏感水稻幼苗中诱导了氧化应激。然而，应用产5-氨基乙酰丙酸的光合细菌减轻了胁迫，使地上部5-氨基乙酰丙酸含量提高了23%，根部提高了190.5%，叶绿素含量提高了105.0%。光合细菌处理还分别使超氧自由基（O）和过氧化氢（HO）减少了26.7%和38.7%，这与抗氧化酶超氧化物歧化酶（SOD）（142.9%）和抗坏血酸过氧化物酶（APX）（41.8%）活性增加有关。这导致电解质渗漏（25.2%）和丙二醛（17.4%）降低，表明活性氧减少。此外，脯氨酸和可溶性糖含量分别降低了29.2%和72.5%。光合细菌处理还降低了盐胁迫水稻幼苗地上部（31.2%）和根部（27.4%）的钠钾离子含量。这些发现表明，光合细菌可能促进养分溶解和离子平衡，从而减轻盐胁迫的不利影响，对改善盐渍环境中作物产量的可持续农业实践具有潜在意义。未来的研究应集中在阐明光合细菌介导的胁迫耐受性所涉及的具体生化途径，并探索其在不同作物品种和不同胁迫条件下的应用。
