The Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
J Sci Food Agric. 2010 Jul;90(9):1410-6. doi: 10.1002/jsfa.3951.
Proton (H(+)) and aluminium (Al(3+)) toxicities are major factors limiting crop production on acid soils, while gamma-aminobutyric acid (GABA) is a non-protein amino acid involved in various stress tolerances in plants. In this study, to determine whether exogenous GABA is functional in alleviating oxidative stress induced by H(+) and Al(3+) toxicities, the antioxidant defence response regulated by GABA was investigated in barley (Hordeum vulgare L.).
After 24 h treatments of seedlings under H(+), Al(3+) and combined stresses with and without GABA, morphological and biochemical assays were conducted. It was observed that the inhibition of seedling root elongation caused by Al(3+) and H(+) toxicities was significantly mitigated by GABA. The amount of carbonylated proteins with molecular masses of 14.4-97 kDa was decreased. The activities of antioxidant enzymes were enhanced, the content of malondialdehyde was reduced and the accumulation of reactive oxygen species (ROS), as shown by staining roots with nitroblue tetrazolium, declined in GABA-treated seedlings.
GABA can alleviate oxidative damage caused by H(+) and Al(3+) toxicities in barley seedlings by activating antioxidant defence responses and reducing the elevated levels of carbonylated proteins caused by ROS.
质子（H(+)）和铝（Al(3+)）毒性是限制酸性土壤上作物产量的主要因素，而γ-氨基丁酸（GABA）是一种参与植物各种胁迫耐受的非蛋白氨基酸。在这项研究中，为了确定外源 GABA 是否能有效缓解 H(+)和 Al(3+)毒性引起的氧化应激，研究了 GABA 调节的大麦（Hordeum vulgare L.）的抗氧化防御反应。
在 H(+)、Al(3+)和 H(+)与 Al(3+)联合胁迫以及有无 GABA 处理 24 小时后，对幼苗进行了形态和生化测定。结果表明，GABA 显著减轻了 Al(3+)和 H(+)毒性对幼苗根伸长的抑制作用。分子量为 14.4-97 kDa 的羰基化蛋白的含量减少。抗氧化酶的活性增强，丙二醛的含量降低，用硝普钠染色根后，活性氧（ROS）的积累减少。
GABA 通过激活抗氧化防御反应和降低 ROS 引起的羰基化蛋白水平升高，减轻大麦幼苗中由 H(+)和 Al(3+)毒性引起的氧化损伤。
