BACKGROUND Kochia scoparia is a dicotyledonous annual herb and belongs to the Amaranthaceae family. Genetic diversity and resistance to drought stress of this plant has made it widely scattered in different regions which contains highly genetic diversity and great potential as fodder and can grow on salty, drought affected areas. Since the soil salinity has become widely spread, environmental concern has sparked so many debates. An important limiting factor in agricultural production worldwide is the sensitivity of most of the crop to salinity caused by high concentration of salts soil. Plants use three different strategies to prevent and adapt to high Na+ concentrations. Antiporters are important category of genes that play a pivotal role in ion homeostasis in plants. Na+/H+ antiporters (NHX1 and SOS1) are located in tonoplasts and reduce cytosolic Na+ concentration by pumping in the vacuole whereas SOS1 is localized at the plasma membrane and extrudes Na+ in apoplasts. RESULTS Coding sequence of plasma membrane Na+/H+ antiporter (SOS1) and vacuole membrane Na+/H+ antiporter (NHX) in Kochia scoparia were isolated using conserved sequences of SOS1 and NHX. Also, expression profile under salinity stress was studied in this study. The amino acid sequences (aa) of the isolated region of K.SSOS1 and K.SNHX showed the maximum identity up to 84% and 90% to its orthologous in salicornia brachiate and suede maritime, respectively. The results of semi-quantitative RT-PCR revealed that salinization has affected positively on SOS1 transcription level. The expression of K.SSOS1 and K.SNHX in leaves and roots of Kochia scoparia were progressively increased under all salinity levels compared to control. CONCLUSION The results suggest that K.SSOS1 and K.SNHX play an essential role in salt tolerance of K.scoparia and they can be useful to improve salt tolerance in other crops.

中文翻译：

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地肤盐胁迫下 Na+/H+ 逆向转运蛋白（SOS1 和 NHX）基因的分离和半定量 PCR。

背景技术地肤是一种双子叶一年生草本植物，属于苋科。该植物的遗传多样性和对干旱胁迫的抗性使其广泛分布于不同地区，具有高度的遗传多样性和作为饲料的巨大潜力，可在盐碱地、干旱地区生长。由于土壤盐分已经广泛传播，环境问题引发了如此多的争论。世界范围内农业生产的一个重要限制因素是大多数作物对高浓度盐土引起的盐分敏感。植物使用三种不同的策略来预防和适应高 Na+ 浓度。反转运蛋白是一类重要的基因，在植物的离子稳态中起关键作用。Na+/H+ 逆向转运蛋白（NHX1 和 SOS1）位于液泡内，通过在液泡中泵送降低细胞溶质 Na+ 浓度，而 SOS1 位于质膜上并在质外体中挤出 Na+。结果利用保守的SOS1和NHX序列分离出地肤中质膜Na+/H+逆向转运蛋白(SOS1)和液泡膜Na+/H+逆向转运蛋白(NHX)的编码序列。此外，本研究还研究了盐分胁迫下的表达谱。K.SSOS1 和K.SNHX 的分离区域的氨基酸序列(aa) 与其在salicornia brachiate 和suede marine 中的直系同源物分别显示出高达84% 和90% 的最大同一性。半定量RT-PCR结果表明盐渍化对SOS1转录水平有正向影响。K.SSOS1 和 K 的表达。与对照相比，在所有盐度水平下，地肤子叶和根中的 SNHX 均逐渐增加。结论结果表明K.SSOS1和K.SNHX在K.scoparia的耐盐性中起重要作用，它们可用于提高其他作物的耐盐性。