Abdollah Hosseini Seyed, Gharechahi Javad, Heidari Manzar, Koobaz Parisa, Abdollahi Shapour, Mirzaei Mehdi, Nakhoda Babak, Hosseini Salekdeh Ghasem
Department of Molecular Physiology, Agricultural Biotechnology Research Institute of Iran, PO Box 31535-1897, Karaj 3135933151, Iran.
Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, PO Box 19395-5478, Tehran 1435916471, Iran.
Funct Plant Biol. 2015 Jun;42(6):527-542. doi: 10.1071/FP14274.
Salinity is a limiting factor affecting crop growth. We evaluated the responses of a salt-tolerant recombinant inbred rice (Oryza sativa L.) line, FL478, and the salt-sensitive IR29. Seedlings were exposed to salt stress and the growth rate was monitored to decipher the effect of long-term stress. At Day 16, IR29 produced lower shoot biomass than FL478. Significant differences for Na+ and K+ concentrations and Na+ : K+ ratios in roots and shoots were observed between genotypes. Changes in the proteomes of control and salt-stressed plants were analysed, identifying 59 and 39 salt-responsive proteins in roots and leaves, respectively. Proteomic analysis showed greater downregulation of proteins in IR29. In IR29, proteins related to pathways involved in salt tolerance (e.g. oxidative stress response, amino acid biosynthesis, polyamine biosynthesis, the actin cytoskeleton and ion compartmentalisation) changed to combat salinity. We found significant downregulation of proteins related to photosynthetic electron transport in IR29, indicating that photosynthesis was influenced, probably increasing the risk of reactive oxygen species formation. The sensitivity of IR29 might be related to its inability to exclude salt from its transpiration stream, to compartmentalise excess ions and to maintain a healthy photosynthetic apparatus during salt stress, or might be because of the leakiness of its roots, allowing excess salt to enter apoplastically. In FL478, superoxide dismutase, ferredoxin thioredoxin reductase, fibre protein and inorganic pyrophosphatase, which may participate in salt tolerance, increased in abundance. Our analyses provide novel insights into the mechanisms behind salt tolerance and sensitivity in genotypes with close genetic backgrounds.
盐度是影响作物生长的一个限制因素。我们评估了耐盐重组自交水稻（Oryza sativa L.）品系FL478和盐敏感品系IR29的反应。将幼苗置于盐胁迫下，并监测其生长速率，以解读长期胁迫的影响。在第16天，IR29的地上部生物量低于FL478。在不同基因型之间，根和地上部的Na+和K+浓度以及Na+∶K+比率存在显著差异。分析了对照和盐胁迫植株的蛋白质组变化，分别在根和叶中鉴定出59个和39个盐响应蛋白。蛋白质组分析表明，IR29中蛋白质的下调幅度更大。在IR29中，与耐盐相关途径（如氧化应激反应、氨基酸生物合成、多胺生物合成、肌动蛋白细胞骨架和离子区室化）相关的蛋白质发生变化以应对盐度。我们发现IR29中与光合电子传递相关的蛋白质显著下调，这表明光合作用受到影响，可能增加了活性氧形成的风险。IR29的敏感性可能与其在蒸腾流中无法排除盐分、无法将过量离子区室化以及在盐胁迫期间无法维持健康的光合器官有关，或者可能是因为其根部渗漏，使得过量盐分通过质外体进入。在FL478中，可能参与耐盐的超氧化物歧化酶、铁氧还蛋白硫氧还蛋白还原酶、纤维蛋白和无机焦磷酸酶丰度增加。我们的分析为具有相近遗传背景的基因型中耐盐性和敏感性背后的机制提供了新的见解。
