Salt affected soil inhibits plant growth, development and productivity, especially in case of rice crop. Ion homeostasis is a candidate defense mechanism in the salt tolerant plants or halophyte species, where the salt toxic ions are stored in the vacuoles. The aim of this investigation was to determine the OsNHX1 (a vacuolar Na⁺/H⁺ exchanger) and OsHKT2;1 (Na⁺/K⁺ transporter) regulation by salt stress (200 mM NaCl) in two rice cultivars, i.e. Pokkali (salt tolerant) and IR29 (salt susceptible), the accumulation of Na⁺ in the root and leaf tissues using CoroNa Green^® staining dye and the associated physiological changes in test plants. Na⁺ content was largely increased in the root tissues of rice seedlings cv. Pokkali (15 min after salt stress) due to the higher expression of OsHKT2;1 gene (by 2.5 folds) in the root tissues. The expression of OsNHX1 gene in the leaf tissues was evidently increased in salt stressed seedlings of Pokkali, whereas it was unchanged in salt stressed seedlings of IR29. Na⁺ in the root tissues of both Pokkali and IR29 was enriched, when subjected to 200 mM NaCl for 12 h and easily detected in the leaf tissues of salt stressed plants exposed for 24 h, especially in cv. Pokkali. Moreover, the overexpression of OsNHX1 gene regulated the translocation of Na⁺ from root to leaf tissues, and compartmentation of Na⁺ into vacuoles, thereby maintaining the photosynthetic abilities in cv. Pokkali. Overall growth performance, maximum quantum yield (F_v/F_m), photon yield of PSII (Φ_PSII) and net photosynthetic rate (P_n) was improved in salt stressed leaves of Pokkali than those in salt stressed IR29.

中文翻译：

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Na + / K +转运蛋白OsHKT2; 1和液泡型Na + / H +交换蛋白OsNHX1的表达水平，Na的富集，在盐胁迫下保持in稻幼苗的光合能力和生长性能。

受盐影响的土壤会抑制植物的生长，发育和生产力，特别是在水稻作物的情况下。离子稳态是耐盐植物或盐生植物物种中的候选防御机制，其中盐毒性离子存储在液泡中。本研究的目的是通过盐胁迫（200 mM NaCl）确定两个水稻品种Pokkali（盐）中的OsNHX1（液泡状Na ⁺ / H ⁺交换子）和OsHKT2; 1（Na ⁺ / K ⁺转运蛋白）调节。宽容）和IR29（盐敏感），钠的积累⁺在利用电晕绿色根和叶组织^®染色染料及其相关的生理变化。水稻幼苗cv的根组织中Na ⁺含量大大增加。Pokkali（盐胁迫后15分钟）是由于OsHKT2; 1基因在根组织中的表达较高（2.5倍）。在Pokkali盐胁迫的幼苗中，OsNHX1基因在叶片中的表达明显增加，而在IR29盐胁迫的幼苗中则没有改变。当暴露于200 mM NaCl中12 h后，Pokkali和IR29的根组织中的Na ⁺都会富集，并且在暴露了24 h的盐胁迫植物的叶子组织中尤其是在cv中很容易检测到。Pokkali。此外，OsNHX1的过表达该基因调节了Na ⁺从根到叶组织的转运，以及Na ⁺进入液泡的间隔，从而保持了cv的光合作用能力。Pokkali。Pokkali盐胁迫下的叶片的整体生长性能，最大量子产量（F _v / F _m），PSII的光子产量（_ΦPSII）和净光合速​​率（P _n）比盐胁迫的IR29有所提高。