深淹下三峡库区狗牙根脯氨酸积累代谢途径的响应  

Responses of Proline Accumulation Metabolic Pathways of Bermudagrass (Cynodon dactylon(L. ) Pers. ) on Deep Submergence Stress in Three Gorges Reservoir Area

作　　者：周大祥[1,2] 刘仁华[1] 李彦杰[1] 杨俊年[1] 

机构地区：[1]重庆三峡学院生命科学与工程学院,重庆404100 [2]三峡库区可持续发展研究中心,重庆404100

出　　处：《西南农业学报》2012年第5期1629-1632,共4页Southwest China Journal of Agricultural Sciences

基　　金：重庆市教委项目"三峡库区消落带治理植物抗涝胁迫生理生化机理研究"(KJ091102);重庆高校创新团队建设计划(201040);国家水体污染控制与治理科技重大专项(2009ZX07104-003-04-02);国务院三峡工程建设委员会项目"三峡水库消落区植被重建试验示范研究"(sx2008-005)

摘　　要：以三峡库区自然消落带野生狗牙根为研究对象,进行自然条件下不同深度(0、5、10、15、20、25和30 m)的深淹胁迫以及胁迫后恢复实验,研究了脯氨酸及其积累代谢途径的关键酶活性的变化规律。结果表明,深淹胁迫能诱导脯氨酸的积累,顺序上调脯氨酸合成关键酶精氨酸、鸟氨酸转氨酶(OAT)、谷氨酸脱氢酶(GDH)和吡咯啉-5-羧酸合成酶(P5CS)的活性,降低脯氨酸降解关键酶脯氨酸脱氢酶(PDH)的活性。因此,深淹胁迫导致脯氨酸积累是脯氨酸合成的鸟氨酸途径和谷氨酸途径顺序激活、而脯氨酸降解途径显著抑制的综合结果。深淹恢复生长30 d后,狗牙根脯氨酸及其积累代谢途径的关键酶活性恢复至未淹对照水平。从植物对深淹胁迫下脯氨酸积累代谢途径的响应上,表明狗牙根作为禾本科植物在遗传上具有较强的耐淹能力,可以作为三峡水库消落带植被恢复的物种之一。A submergence experiment was conducted on Bermudagrasses originally distributed in the water-level-fluctuation zone of the Three Gorges Reservoir Area.The deep submergence stress and after recovery were carried out in respective submerged depth of 0,5,10,15,20,25,30 m.The proline and the key enzymes of its biosynthesis were studied.The results showed that,the deep submergence stress induced proline accumulation in Bermudagrasses,sequential up-regulation of activities of the key enzymes（arginase,ornithine aminotransferase,glutamate dehydrogenase pyroline-5-carboxylate synthetase） for proline biosynthesis and inhibition of activity of the key enzyme proline dehydrogenase for proline degradation.So the deep submergence stress-induced proline accumulation might be a combined result of the orderly activation of the ornithine pathway and the glutamate pathway of proline biosynthesis,and inhibition of proline degradation pathway.Proline accumulation protected oxidative damage induced by deep submergence stress.After deep submergence stress recovery growth 30 days,the content of proline and activities of arginase,ornithine aminotransferase,glutamate dehydrogenase pyroline-5-carboxylate synthetase were recovered to un-submerged control.From physiological response of Bermudagrass to deep submergence stress,the results implied that Bermudagrass had submergence-tolerant instinct.It could be a promising species for revegetation of the water-level-fluctuation zone in the Three Gorges Reservoir Area.

关 键 词：狗牙根 深淹胁迫 脯氨酸 谷氨酸途径 鸟氨酸途径 

分 类 号：Q945[生物学—植物学]