洪水漫溢对塔里木河中游天然胡杨林叶渗透调节物质及抗氧化酶活性的影响  

Effects of flood overtopping on leaf osmotic adjustment substances and antioxidant enzyme activities of natural Populus euphratica forest in the middle reaches of the Tarim River

作　　者：王新英[1,2] 史军辉 刘茂秀[1,2] 白丽丽 艾吉尔·阿不拉[1,2] WANG Xin-ying;SHI Jun-hui;LIU Mao-xiu;BAI Li-li;Aijier Abula(Xinjiang Academy of Forestry Urumqi 830046,Xinjiang,China;Xinjiang Tarim Poplus Riparian Forest Ecosystem National Positioning Observation and Research Station in Tarim River of Xinjiang,Urumqi 830046,Xinjiang,China)

机构地区：[1]新疆林业科学院,新疆乌鲁木齐830046 [2]新疆塔里木河胡杨林生态系统国家定位观测研究站,新疆乌鲁木齐830046

出　　处：《干旱区研究》2020年第6期1544-1551,共8页Arid Zone Research

基　　金：自治区科研机构创新发展专项(2016D0403);自治区公益性科研院所科研业务基本费专项(KY2019047)。

摘　　要：以塔里木河流域中游季节性洪水漫溢的天然胡杨林为研究对象,以野外原位采样的方法研究胡杨林在洪水漫溢条件下叶渗透调节物质及抗氧化酶活性的变化特征,为初步研究天然胡杨林耐水淹生理机制提供科学依据。结果表明:(1)洪水漫溢初期(8 d),胡杨叶中Na^(+)含量、K^(+)含量、游离脯氨酸(Pro)含量、可溶性糖(SS)含量及超氧化物歧化酶(SOD)活性降低,而Cl^(-)含量、可溶性蛋白(SP)含量、过氧化物酶(POD)及过氧化氢酶(CAT)活性提高,说明在洪水漫溢初期,胡杨通过增加Cl^(-)、SP等渗透调节物质含量来维持叶片渗透势,同时通过提高POD和CAT酶活性来清除由水淹胁迫而积累的活性氧,共同提高植物抗性;(2)随着洪水漫溢时间的延长(18 d),胡杨叶中K^(+)含量、Cl^(-)含量、SS含量、SP含量、SOD活性等均增加,而Na^(+)含量、Pro含量、POD活性及CAT活性均降低,说明随着水淹胁迫的加剧,植物通过增加K^(+)、SS、SP含量及提高SOD活性来增强抗逆性;(3)随着洪水漫溢时间的进一步延长(35d),胡杨叶中Na^(+)在叶组织中含量增加,而SS含量、SOD活性、POD活性及CAT活性均降低,但与洪水漫溢前含量相当。综上所述,胡杨在洪水漫溢的水淹逆境下,通过渗透调节物质与抗氧化酶系统共同增强植物抗性。渗透调节物质中,Na^(+)、K^(+)和SP在胡杨整个洪水漫溢过程中发挥了重要的渗透调节作用,而Cl^(-)与SS主要在漫溢初、中期发挥作用,维持叶片液泡渗透势平衡。在抗氧化酶系统中,洪水漫溢前期,POD与CAT在清除胡杨叶中受胁迫而积累的活性氧自由基中发挥重要作用,SOD则在洪水漫溢末期发挥了较强清除作用。In this study,we examined the natural Populus euphratica forest growing along the middle reaches of the Tarim River.We evaluated the characteristics of leaf osmotic adjustment substances and antioxidant enzyme activities of P.euphratica under flooding conditions using in situ sampling methods to elucidate the physiological mechanisms of water-resistant natural forests.In the initial stage of flood overtopping(8 d),Na^(+)content,K^(+)content,free proline(Pro)content,soluble sugar(SS)content,and superoxide dismutase(SOD)activity in the leaves of P.euphratica decreased,and Cl^(-)content,soluble protein(SP)content,peroxidase(POD)activity,and catalase(CAT)activity increased,indicating that leaf osmotic potential was maintained by increasing the content of osmotic adjustment substances such as Cl^(-)and SP.Moreover,plant resistance was enhanced by increasing the activities of POD and CAT enzymes to eliminate reactive oxygen species accumulated as a result of flooding stress.After 18 d of flood overtopping time,K^(+)content,Cl^(-)content,SS content,SP content,and SOD activity in the leaves increased,while Na^(+)content,Pro content,POD activity,and CAT activity all decreased,indicating that the plants enhanced stress resistance by increasing the K^(+),SS,and SP content and improving SOD activity in response to the intensification of flooding stress.After 35 d of flood overtopping time,Na^(+)ions accumulated in the leaves of P.euphratica and SS content,SOD activity,POD activity,and CAT activity decreased to levels comparable to those before the flood.In summary,Populus euphratica strengthens plant resistance through osmotic adjustment substances and antioxidant enzyme systems in response to the stress of flood overtopping.Among the osmotic adjustment substances,Na^(+),K^(+),and SP contributed throughout the flood overtopping,whereas Cl^(-)and SS played a role in the early and middle stages of overtopping to maintain the balance of leaf vacuole infiltration potential.In the antioxidant enzyme system,POD and CAT contributed

关 键 词：胡杨 洪水漫溢 渗透调节物质 抗氧化酶活性 塔里木河 

分 类 号：S792.11[农业科学—林木遗传育种]