盐胁迫下盐角草Na^+/H^+转运基因表达分析

Expression analysis of Salicornia europaea Na^+/H^+ antiporters under salt stress

Na+/H+逆向转运蛋白具有调节细胞内离子浓度及维持pH值稳定的作用,是植物抵御盐胁迫的重要因子。从盐角草RNA-Seq数据中筛选Na+/H+逆向转运蛋白序列,利用生物信息学手段,拼接得到5条Na+/H+逆向转运蛋白完整cDNA序列,通过与NCBI已有序列比对分析,将其命名为SeNHX1、SeNHX3、SeNHX4、SeNHX5和SeNhaD。考察盐角草Na+/H+逆向转运蛋白在两种盐分变化情况下的表达变化:1)从无盐处理转移到200 mM NaCl处理;2)从200 mM NaCl培养基转移到无盐培养基。结果表明:SeNHX4的表达量非常低,在地下部几乎检测不到;SeNhaD在地上部的表达量是地下部的2倍左右,说明NhaD主要在盐角草地上部发挥作用;SeNHX1、SeNHX3和SeNHX5的表达量明显高于其他两个基因,对盐角草的耐盐机制起到更大的作用,并且SeNHX1和SeNHX5受盐分诱导表达,表达量与盐浓度呈正相关,可能在盐角草耐盐调控网络中发挥重要作用。综上,NHX基因家族和NhaD的表达量受到基质中盐分的调控作用,其表达在盐分处理或者盐分去除1~3 d后发生变化。研究结果有助于阐明盐角草NHX基因家族和NhaD对盐分的响应特点。

Na＋/H＋antiporters play important roles in enhancing salt resistance by catalyzing the exchange of Na＋/K＋for H＋and regulating cellular pH.Based on RNA-Seq result, five Na＋/H＋antiporters such as SeNHX1, SeNHX3, SeNHX4, SeNHX5 and SeN-haD from Salicornia europaea were found using bioinformatics.Two treatments（ transfer from 200 mM NaCl solution to no salt culture solution and then transfer from 200 mM NaCl culture solution to no salt solution） were designed for study the response to salt stress of Salicornia europaea.The results showed that SeNHX4 has low expression level especially in root.SeNhaD expresses mainly in shoot of Salicornia europaea as it has twice expression in shoot than in root.SeNHX1/3/5 transcripts were abundant compared to the other genes, and the expression levels of SeNHX1/5 correlated with Na＋concentration indicated that these genes play more important roles in salinity tolerance of Salicornia europaea.Above all, the expression of NHX gene family and NhaD changed in one to three days after treatments and were regulated by salt concentration.