紫花苜蓿叶片对硒胁迫的生理响应研究

Study on Selenium Stress on Physiological Responses of Medicago sativa Leaves

以紫花苜蓿"大叶苜蓿""维多利亚""阿尔冈金"为试材,采用土培法,研究了硒胁迫对3种紫花苜蓿叶片酶促防御系统的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性及丙二醛(MDA)、可溶性蛋白质含量的影响。结果表明:在100μmol·L-1Se时,硒胁迫显著提高了3种紫花苜蓿叶片SOD、APX、POD、CAT活性和可溶性蛋白质含量。Se为900μmol·L-1时,SOD、APX活性和可溶性蛋白质、MDA含量显著增加,而CAT、POD活性显著降低。不同品种间抗氧化酶活性相比,"大叶苜蓿"抗氧化酶SOD、APX、POD、CAT活性显著高于其它2个苜蓿品种,且差异显著。综合评价表明,"大叶苜蓿"的抗氧化能力最强,其次为"阿尔冈金","维多利亚"苜蓿的抗氧化能力最差。

Taking Medicago sativassp.,‘Vitoria＇alfalfa and Medicago sativacv.as materials,effects of Se stress on the activities of antioxidant enzymes and the contents of soluble protein and MDA in three Medicageo staival L.were studied with soil culture.The results indicated that the activities of SOD,APX,POD and CAT and the content of soluble protein in the leaves of three Medicageo staival L.was increased under 100μmol·L-1 Se.After exposure to 900μmol·L-1 Se,Se stress markedly increased the activities of SOD and APX,and the contents of soluble protein and MDA in the leaves of three Medicageo staival L..However,Se stress markedly decreased the activities of CAT and POD in the leaves of three Medicageo staival L..Under different levels of Se stress,Medicago sativa ssp.had the highest activities of SOD,CAT,APX and POD,compared with other species.Above results suggested that the order of antioxidant capacity of the three Medicageo staival L.species was Medicago sativassp.,‘Vitoria＇alfalfa and Medicago sativacv.