盐穗木HcVP1转基因棉花耐盐性的生理生化分析

Physiological and Biochemical Analysis for the Salt Tolerance of Transgenic Cotton Transformed by the Vacuolar H^+-Pyrophosphatase Gene(VP1) from Halostachys caspica

【目的】盐生植物盐穗木的液泡膜氢离子焦磷酸酶(vacuolar H^+-Pyrophosphatase,HcVP1)作为质子泵可有效地形成H^+梯度,促进细胞质中多余Na^+的排除。将HcVP1基因导入棉花有望培育出耐盐性提高的转基因棉花新品种。【方法】研究对已获得的HcVP1转基因棉花经卡那霉素抗性筛选、PCR和RT-PCR检测分析后,对检测阳性的转基因棉花植株进行200 mmol/L NaCl胁迫处理4 wks,检测转HcVP1基因棉花的耐盐相关生理生化指标。【结果】盐胁迫处理的转基因棉花植株长势良好,叶绿素、脯氨酸、可溶性糖含量均显著高于非转基因棉花组,丙二醛(MDA)含量低于非转基因棉花组,而抗氧化物酶SOD、POD、CAT等的活性则显著高于非转基因棉花组。【结论】盐穗木HcVP1基因转化棉花可以有效地提高棉花的耐盐能力。

[ Objective ] Halostachys caspica vacuolar H ＋ - Pyrophosphatase （ HcVP1 ）, as a proton pump, can prompt exclusion of extra Na ＋ from cell plasma by forming H ＋ gradient. It is prospective to enhance the salt tolerance of Xinjiang cotton cuhivars by transforming HcVP1 gene into cotton. [Method]The transgenic cotton plants were firstly screened by kanamycin, PCR and RT- PCR, and then the positive plants were treated with 200 mmol/L NaC1 for 4 wks. The physiological and biochemical indexes related to salt tolerance of these plants were then measured. [ Result ] The results showed that the transgenic cotton plants showed better growth than non - transgenic plants under salt stress. The content of chlorophyll, proline and soluble sugar in the transgenic lines were significantly higher than those of non - transgenic plants, while the malondialdehyde content was lower than non - transgenic cottons. In addition, the activities of antioxidant enzymes, such as SOD, POD and CAT were also higher than those of non - transgenic cottons. [ Conclusion ] Our results demonstrated that the salt tolerance of cotton can be improved by transforming the vacuolar H ~ - Pyrophosphatase gene from the halophyte Halostachys caspica.