PEG胁迫对偏关苜蓿脯氨酸代谢途径关键酶的影响  

Effect of PEG Stress on Key Enzymes Involved in Proline Metabolism of Medicago sativa cv.Pianguan

作　　者：朱慧森[1] 刘艳香[1] 董宽虎[1] 杨武德[2] 

机构地区：[1]山西农业大学动物科技学院,山西太谷030801 [2]山西农业大学农学院,山西太谷030801

出　　处：《草地学报》2011年第6期1000-1004,1024,共6页Acta Agrestia Sinica

基　　金：国家"十一五"科技支撑计划课题(2007BAD56B01);国家农业科技成果转化资金项目(2009GB2A300043);山西省青年基金项目(2006021036);农业部草地农业生态系统学重点开放实验室开放课题基金资助

摘　　要：以山西地方品种偏关苜蓿(Medicago sativa cv.Pianguan)为试验材料,采用20%聚乙二醇(PEG-6000)分别处理不同时间(0,8,16,24,32,48和72h),研究偏关苜蓿地上部及地下部的脯氨酸(proline,Pro)含量、鸟氨酸δ-氨基转移酶(ornithine-oxo-acidtransaminase,δ-OAT)、吡咯啉-5-羧酸合成酶(pyrroline-5-carboxylate synthetase,P5CS)、脯氨酸脱氢酶(proline dehydragenase,ProDH)活性的动态变化。结果表明:PEG胁迫下,地上部Pro含量显著高于地下部,PEG处理40h时,地上部Pro含量最高(3230.4μg.g-1 FW)。地上部和地下部P5CS活性呈"升-降-升-降"的变化趋势。δ-OAT活性则在胁迫8h时升高,之后下降。ProDH活性受PEG胁迫显著降低,呈时间依赖性。PEG胁迫前期,偏关苜蓿的Pro积累以鸟氨酸-脯氨酸途径为主,随胁迫时间的延长,逐渐转为以谷氨酸-脯氨酸途径为主。Medicago sativa cv.Pianguan is an important local variety in Pianguan of Shanxi province.This study focuses on the dynamic changes og proline（Pro） content and the activities of pyrroline-5-carboxylate synthetase（P5CS）,ornithine-oxo-acid transaminase（δ-OAT） and proline dehydragenase（ProDH） in both aboveground and underground parts of Medicago sativa cv.Pianguan under PEG-6000 stress for 0,8,16,24,32,48 and 72 h,respectively.The proline content of aboveground parts was the highest（3230.4 μg·g-1 FW） when stressed for 40 h,which is significantly greater than that of underground parts.P5CS activity showed a tendency of rising-declining-rising-declining,while the δ-OAT activity was rising initially when stressed for 8 h,then declining.ProDH activity significantly declined for both aboveground and underground parts with increasing PEG-6000 stress time.In the earlier stage of PEG stress,the ornithine-proline pathway is the main style for Medicago sativa cv.Pianguan responding to PEG stress,but the glutamate-proline pathway would gradually take over the predominant role with the time extending of PEG stress.

关 键 词：偏关苜蓿 脯氨酸 鸟氨酸δ-氨基转移酶 吡咯啉-5-羧酸合成酶 脯氨酸脱氢酶 

分 类 号：Q945.78[生物学—植物学]