H2O2胁迫对山黧豆生理生化指标的影响
Effects of H2O2 Stress on Physiological and Biochemical Indexes of Grass Pea

用不同浓度H2O2的水培液处理7 d山黧豆幼苗24 h，分析山黧豆叶片鲜质量、H2O2和O·2组织化学定位、丙二醛（MDA）与抗坏血酸（ASA）质量摩尔浓度和过氧化氢酶（CAT）、过氧化物酶（POD）及抗坏血酸过氧化物酶（APX）的活性变化，研究H2O2诱导氧化胁迫下山黧豆叶片的生理应答特征，揭示山黧豆叶片对氧化胁迫的耐受机制。结果显示：与对照组相比，5 mmol·L-1 和10 mmol·L-1 H2O2处理组叶片鲜质量无显著变化，20 mmol·L-1 H2O2处理叶片鲜质量显著降低。山黧豆叶绿素a、叶绿素b和类胡萝卜素的质量分数并无显著变化。随外源H2O2处理浓度不断增加，叶片组织内源O·2染色范围和程度呈明显减少趋势，H2O2染色范围和程度呈先增加后减少趋势。H2O2与MDA积累水平也呈现先增加后减少的趋势；山黧豆叶片中CAT、POD与APX的活性均表现先升高后降低的趋势，而ASA质量摩尔浓度则呈现先降低后上升的趋势。研究表明，叶片内H2O2和MDA水平变化与抗氧化酶的活性变化均处于动态平衡中并呈现一致变化趋势，低浓度H2O2处理可以提高山黧豆抗氧化酶的活性。
Grass pea（Lathyrus satirus L.） seedlings cultured in hydroponic solution for 7 days were used as experimental materials, and suffered stress for 24 h in the different concentrations of H2O2. The fresh mass of leaf, tissue localization of H2O2 and O·2, H2O2, molality of malondialdehyde(MDA) and ascorbic acid(ASA),as well as activities of catalase(CAT), peroxidase(POD) and ascorbate peroxidase(APX) in leaves of grass pea were analyzed, in order to reveal the tolerance mechanisms of oxidative stress induced by H2O2, and characterize physiological response to oxidative stress in grass pea leaves. Results showed that, compared with the control group, fresh mass of leaves treated with 5 and 10 mmol·L-1 H2O2 had no significant changes, and fresh mass of leaves showed an obvious decrease when the H2O2 concentration increased to 20 mmol·L-1.There was no significant changes in the mass fractions of chlorophyll a,chlorophyll b and carotenoid. The scope and extent of O·2 staining were significantly reduced with H2O2 concentration increasing. The scope and extent of H2O2 staining was significantly increased firstly and then decreased. While the levels of MDA and H2O2 accumulation also significantly increased firstly and then decreased. The activities of CAT, POD and APX all exhibited a decrease trend after an initial increase in grass pea leaves. However, the molality of ASA had been showing an opposite trend decreasing firstly and then increasing. These results confirmed that changes of H2O2 and MDA were in the same consistent trend with activities of antioxidant enzymes in grass pea leaves and they were all in dynamic equilibrium. And low concentrations of H2O2 treatment could improve the activities of antioxidant enzymes in grass pea leaves.