干旱胁迫及复水对大豆抗坏血酸-谷胱甘肽循环的影响

摘要

为明确大豆耐旱机制,以黑农44(耐旱型品种)和黑农65(敏感型品种)为试验材料,采用盆栽方式,于大豆初花期作胁迫处理,而后复水.研究不同土壤含水率及复水后抗坏血酸-谷胱甘肽(ASA-GSH)循环中抗氧化物质含量及抗氧化酶活性变化.结果表明,土壤含水率降低改变ASA-GSH循环非酶和酶成分,诱导丙二醛(MDA)积累.ASA-GSH循环中,干旱胁迫处理下还原型抗坏血酸(ASA)、还原型谷胱甘肽(GSH)含量先升后降,脱氢抗坏血酸(DHA)、氧化型谷胱甘肽(GSSG)含量呈升高趋势,ASA/DHA呈先升后降趋势,GSH/GSSG呈高-低-高-低变化趋势,复水后ASA、DHA、GSH含量升高,GSSG含量下降.抗坏血酸过氧化物酶(APX)、单脱氢抗坏血酸还原酶(MDHAR)、脱氢抗坏血酸还原酶(DHAR)、谷胱甘肽还原酶(GR)活性呈先升后降趋势,复水后APX、GR、MDHAR、DHAR活性升高.黑农44抗氧化物质含量和抗氧化酶活性高于黑农65,MDA含量低于黑农65.研究为大豆抗旱筛选及抗氧化机制探究提供理论基础.%In order to clarify the mechanism ofdrought tolerance in soybean,Heinong44 (drought-resistant soybean) and Heinong 65 (sensitive soybean) were selectedas test materials,drought stress treatment begunwith flowering stage,and then re-watering.The changes of antioxidantsubstances and antioxidase activities in the ascorbate-glutathione cycle underdifferent soil water contentswere investigated.Theresults showed that the decrease of soil water content transforms non-enzymeand enzyme components of the ascorbate-glutathione cycle,and induces theaccumulation of MDA.In the ascorbate-glutathione cycle,contents of ASA andGSH increased at first and then decreased,contents of DHA and GSSG were rising,contents of ASA/DHA increased at first and then decreased,contents of GSH/GSSGwere in the upward-downward-upward-downward trends,after re-watering,thecontent of ASA,DHA and GSH increased,and the content of GSSG decreased.At thesame time,activities of APX,MDHAR,DHAR,and GR increased at first and thendecreased,after re-watering,activities of APX,GR,MDHAR and DHAR increased.Antioxidantcontent and antioxidant enzyme activities for Heinong44 were higher than thoseof Heinong65,and MDA content was lower than HN65.The study provided atheoretical basis for drought resistance screening and antioxidant mechanism ofsoybean.