Background

Abiotic stress effects agricultural production, so research on improving stress tolerance of crop is important. Suaeda salsa is a halophyte with high salt and drought tolerance and ability to desalinate saline soil and improve soil quality.

Objective

To discover and utilize of salt and drought tolerance-related genes, we further investigated the mechanisms of salt and drought tolerance.

Methods

Through screening a salt treated Suaeda salsa cDNA library and further cloning a H subunit of the photosystem I reaction center SsPsaH cDNA, and then the protein domain and phylogenetic analyses of PSI genes was conducted with the NCBI Blast, DNAMAN, and MotifScan programs. The S. salsa seedlings were subjected to various stress treatments and analyze expression of SsPsaH under these treatments by real-time RT-PCR. SsPsaH expression construct was introduced into S. pombe cells by electroporation and transformed into N. tabacum plants by the leaf disc transformation method.

Results

A member of the H subunit of the Photosystem I reaction center (defined as SsPsaH) was obtained. The expression of SsPsaH was up-regulated by abscisic acid (ABA), salt, and drought stress treatments. Over-expressing SsPsaH in recombinant yeasts enhanced high salinity tolerance and increased tolerance to sorbitol during seed germination and seedling root development in tobacco, respectively. Some stress-related mark genes such as a LEA family gene of NtLEA, a binding protein of a drought response element of NtDREB, the ascorbate peroxidase gene (NtAPX) were also up-regulated in SsPsaH overexpressing transgenic tobacco lines.

Conclusions

These results show that SsPsaH may contribute to the salt and osmotic stress response of plants.

中文翻译：

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Suseda salsa光系统I反应中心的H亚基SsPsaH赋予烟草渗透调节功能。

背景

非生物胁迫影响农业生产，因此研究提高作物的抗逆性具有重要意义。Suaeda salsa是一种盐生植物，具有很高的耐盐和耐旱性，能够使盐渍土壤淡化并改善土壤质量。

目的

为了发现和利用盐和干旱耐受性相关基因，我们进一步研究了盐和干旱耐受性的机制。

方法

通过筛选盐处理过的Suaeda salsa cDNA文库，并进一步克隆光系统I反应中心SsPsaH cDNA的H亚基，然后使用NCBI Blast，DNAMAN和MotifScan程序进行PSI基因的蛋白质结构域和系统发育分析。对莎莎幼苗进行了各种胁迫处理，并通过实时RT-PCR分析了这些处理下SsPsaH的表达。通过电穿孔将SsPsaH表达构建体引入粟酒裂殖酵母细胞中，并通过叶盘转化方法将其转化为烟草。

结果

获得了光系统I反应中心的H亚基的成员（定义为SsPsaH）。SsPsaH的表达上调脱落酸（ABA），盐和干旱胁迫处理。重组酵母中过表达的SsPsaH分别增强了烟草的种子发芽和幼苗根发育过程中的高盐分耐受性和对山梨糖醇的耐受性。一些应力相关的标记基因如的LEA家族基因NtLEA，的干旱应答元件的结合蛋白NtDREB中，抗坏血酸过氧化物酶基因（NtAPX）中也被上调SsPsaH过表达的转基因烟草品系。

结论

这些结果表明，SsPsaH可能有助于植物的盐分和渗透胁迫响应。