Wu Yan, Shen Hong, Chen Jian-Hong
Department of Plant Nutrition, College of Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Ying Yong Sheng Tai Xue Bao. 2008 May;19(5):1125-30.
As one of the major genes encoding plasma membrane H+ -ATPase, AHA1 gene plays an important role in regulating plant development and resistance to adverse stress. Taking AHA1 transgenic and wild type Arabidopsis thaliana as test plants, the nutrient uptake, resistance to oxidative stress, and organic acid secretion of the plants under aluminum (Al) stress were examined. The results showed that Al decreased the uptake of nitrogen (N), potassium (K), calcium (Ca) and magnesium (Mg), but increased the phosphorus (P) uptake by A. thaliana roots. AHA1 transgenic plant could accumulate more P and less Al than wild type plant. Al stress induced the increase of plant SOD and POD activities, but no significant difference was observed between AHA1 transgenic and wild type A. thaliana. Al triggered the secretion of organic acids significantly, and AHA1 transgenic plant secreted more organic acids than wild type plant. Vanadate, an inhibitor of plasma membrane H+ -ATPase, could inhibit the secretion of organic acids significantly, while Zn2+ and Mg2+ could promote the Al-induced secretion, and partially improve the inhibitory effects triggered by vanadate. It was suggested that AHA1 transgenic A. thaliana could increase its Al resistance via enhanced P uptake and organic acid secretion.
作为编码质膜H⁺-ATPase的主要基因之一，AHA1基因在调控植物发育及抗逆性方面发挥着重要作用。以AHA1转基因拟南芥和野生型拟南芥作为试验植株，检测了铝（Al）胁迫下植株的养分吸收、抗氧化胁迫能力及有机酸分泌情况。结果表明，Al降低了拟南芥根系对氮（N）、钾（K）、钙（Ca）和镁（Mg）的吸收，但增加了对磷（P）的吸收。AHA1转基因植株比野生型植株积累更多的P且积累更少的Al。Al胁迫诱导了植株超氧化物歧化酶（SOD）和过氧化物酶（POD）活性的增加，但AHA1转基因拟南芥和野生型拟南芥之间未观察到显著差异。Al显著触发了有机酸的分泌，且AHA1转基因植株比野生型植株分泌更多的有机酸。钒酸盐作为质膜H⁺-ATPase的抑制剂，可显著抑制有机酸的分泌，而Zn²⁺和Mg²⁺可促进Al诱导的分泌，并部分改善钒酸盐引发的抑制作用。研究表明，AHA1转基因拟南芥可通过增强P吸收和有机酸分泌来提高其对Al的抗性。
