Photosynthetic response of transgenic soybean plants, containing an Arabidopsis P5CR gene, during heat and drought stress
Photosynthetic response of transgenic soybean plants, containing an Arabidopsis P5CR gene, during heat and drought stress
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DOI：
10.1016/j.jplph.2004.01.014
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发表时间：
2004-11-01
影响因子：
4.3
通讯作者：
Van Staden, J
中科院分区：
文献类型：
--
作者：
De Ronde, JA;Cress, WA;Van Staden, J
通过比较反义和正义转基因大豆植物（含有L-δ（1）-吡咯啉-5-羧酸还原酶基因）与非转基因野生型植物的反应来研究耐热/耐旱性的生化基础。使植物同时经受2天的干旱和热胁迫，然后在25 ℃下再浇水。在此期间，与严重胁迫的反义植物相比，正义植物仅显示出轻微的胁迫症状。在胁迫下，反义白色植物的烟酰胺腺嘌呤二核苷酸磷酸（NADP（+））水平降低，而正义植物的NADP（+）水平升高。恢复NADP（+）水平是最好的有意义的植物。有意义的植物有最高的能力积累脯氨酸在胁迫期间和复水后脯氨酸的代谢。快相叶绿素-a荧光瞬变的分析表明，在所有的压力下，氧释放复合物（OEC）的解离。植物测试在最能抵抗胁迫的有意义植物中，OEC解离被脯氨酸供给电子进入光系统2（PSII）绕过，维持可接受的烟酰胺腺嘌呤二核苷酸磷酸氢盐（NADPH）水平，防止进一步的损害。在恢复时，NADPH在积累的脯氨酸的氧化过程中被消耗，提供高水平的NADP（+）以充当PSII的电子受体，这间接地可以改善OEC的抑制和/或解偶联的效果。(C)2004年Elsevier GmbH。All rights reserved.
The biochemical basis of heat/drought tolerance was investigated by comparing the response of antisense and sense transgenic soybean plants (containing the L-Delta(1)-pyrroline-5-carboxylate reductase gene) with non-transgenic wild-type plants. The plants were subjected to a simultaneous drought and heat stress of 2 days, whereafter they were rewatered at 25degreesC. During this time the sense plants only showed mild symptoms of stress compared to the antisense plants which were severely stressed. Upon stress, nicotinamide adenine dinucleotide phosphate (NADP(+)) levels decreased in antisense white it increased in sense plants. Recovery with respect to NADP(+) levels was best in sense plants. Sense plants had the highest ability to accumulate proline during stress and to metabolise proline after rewatering. Analyses of the fast phase chlorophyll-a fluorescence transients showed dissociation of the oxygen-evolving complex (OEC) upon stress in all. plants tested. In the sense plants, which best resisted the stress, OEC dissociation was bypassed by proline feeding electrons into photosystem 2 (PSII), maintaining an acceptable nicotinamide adenine dinucleotide hydrogen phosphate (NADPH) Level, preventing further damage. Upon recovery, NADPH is consumed during oxidation of accumulated proline providing high levels of NADP(+) to act as electron acceptor to PSII, which indirectly may ameliorate the inhibition and/or the effect of uncoupling of the OEC. (C) 2004 Elsevier GmbH. All rights reserved.