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EEB:西北农林科技大学丨MsPIP2; 2提升转基因拟南芥耐盐性(附NMT实验体系)

期刊:Environmental and Experimental Botany(EEB)
主题:MsPIP2; 2提升转基因拟南芥耐盐性
标题:MsPIP2; 2, a novel aquaporin gene from Medicago sativa, confers salt tolerance in transgenic Arabidopsis
检测指标: Na+、K+流速
7日龄拟南芥,150mM NaCl处理24小时

Na+:0.5mMNaCl ,0.3mM MES,pH6.0
K+:0.1mMKCl ,0.3mM MES,pH6.0


Aquaporins (AQPs) are channel proteins that facilitate water transport across cell membranes and play important roles in many biological processes. However, most AQP functions are still poorly understood in the plant kingdom. Here, MsPIP2;2 was isolated and identified from alfalfa (Medicago sativa). MsPIP2;2 was localized to the plasma membrane, and its expression was induced by salt and abscisic acid (ABA) treatment. Overexpression of MsPIP2;2 in Arabidopsis increased the seed germination rate, seedling root length, survival rate, proline content and antioxidant defence activity and decreased cell membrane damage and reactive oxygen species (ROS) accumulation compared to those in WT under salt stress.

The salt tolerance of MsPIP2;2 was affected by Ca2+ and pH in transgenic Arabidopsis plants. MsPIP2;2-overexpressing plants maintained a better K+/Na+ ratio and higher Ca2+ content under salt stress. The higher K+/Na+ maintenance in transgenic plants was mainly achieved by increasing Na+ efflux and K+ retention in roots via regulating the expression of the related ion channel genes. Stress-responsive genes, including P5CS1, RD29A, DREB2 and KIN2, were upregulated in transgenic plants under salt stress.

These results suggest that MsPIP2;2 confers salt tolerance by regulating antioxidant defence system-mediated ROS scavenging, K/Na ion homeostasis and stress-responsive gene expression in plants.


水通道蛋白(AQPs)是促进水跨细胞膜转运的通道蛋白,在许多生物过程中起重要作用。然而,大多数AQP功能在植物界仍然知之甚少。在此,从紫花苜蓿(Medicago sativa)中分离并鉴定了MsPIP2; 2。MsPIP2; 2定位于质膜,其表达由盐和脱落酸(ABA)处理诱导。与盐胁迫下WT相比,拟南芥中MsPIP2; 2的过量表达提高了种子萌发率,幼苗根长,存活率,脯氨酸含量和抗氧化防御活性,降低了细胞膜损伤和活性氧(ROS)积累。

MsPIP2; 2的耐盐性受转基因拟南芥植物中Ca2+和pH的影响。MsPIP2; 2过表达植物在盐胁迫下保持更好的K+ / Na+比率和更高的Ca2+含量。转基因植物中较高的K+ / Na+维持率主要通过调节相关离子通道基因的表达来增加根中的Na+流出和K+保留来实现。应激反应基因,包括P5CS1,RD29A,DREB2和KIN2,在盐胁迫下在转基因植物中上调。

这些结果表明,MsPIP2; 2通过调节抗氧化防御系统介导的ROS清除,K / Na离子稳态和植物中的应激反应基因表达来赋予耐盐性。

Fig. 9. The net flux of Na+ and K+ at the root tip elongation zones of 7-day-old Arabidopsis seedlings. (A) The net Na+ flux under normal conditions (0 mM NaCl). (B) The net Na+ flux after 150 mM NaCl stress. (C) The mean Na+ flux. (D) The net K+ flux under normal conditions (0 mM NaCl). (E) The net K+ flux after 150 mM NaCl stress. (F) The mean K+ flux. Bars represent the mean ± SE (n = 3). Asterisks and double asterisks above the bars indicate significant differences between the transgenic lines and the WT under the same growth conditions: *, P < 0.05; **, P < 0.01.