毕业论文-模拟干旱胁迫对水稻根三种抗氧化酶的影响讲述.docxVIP

模拟干旱胁迫对水稻根三种抗氧化酶的影响 摘 要 干旱胁迫是影响植物生长的重要因素之一，是世界农业生产的主要自然灾害。水稻是世界上最重要的粮食作物之一，是禾本科的代表植物，也是单子叶植物的模式植物，具有对环境的变化做出响应的机制，这种机制是在长期进化中建立起来的。对各种生物和非生物胁迫的共同响应均表现出预先指示现象，即通过预处理能够提高水稻对未来这种胁迫的抗性。在此背景下，研究并提高水稻抵抗干旱胁迫的机制已经成为急需解决的关键问题之一。 本实验对中花11水稻苗期进行不同聚乙二醇（PEG6000）浓度的模拟干旱胁迫处理，研究了在5％、12.5％、20％PEG6000模拟干旱胁迫下对水稻幼苗根系形态指标的影响、Pro含量的影响及超氧化物歧化酶(SODs，superoxide dismutase)、过氧化氢酶(CAT，catalase)、过氧化物酶(POD，non-specificperoxidase)同功酶活性的影响 。主要结论如下： 在PEG模拟干旱的情况下，高强度的干旱胁迫对最长根长有抑制作用，低强度的干旱胁迫对最长根长有促进作用；SOD活性和CAT活性都随PEG浓度增加而增加，随处理时间增加表现出先急剧增加，SOD活性在处理的第2天达到最大值， CAT活性在处理的第3天达到最大值，然后再急剧下降。处理的浓度越高，上升的速度越快，下降的速度也越快。本实验也发现干旱胁迫时水稻幼苗根系POD活性随PEG浓度的增加而增加，因此可以通过测定相同环境下POD的活性来比较干旱胁迫的程度。 关键词：干旱胁迫，抗氧化酶，水稻 The Effects of Simulated Drought Stress on Three Antioxidant Enzymes in the Rice Root ABSTRACT Drought stress is one of the important factors that influence the growth of plants , is the worlds agricultural production is mainly natural disasters. Rice is one of the worlds most important crops , is representative of gramineous plants, monocot plants are also single mode , with a mechanism to respond to changes in the environment , such a mechanism is established in the long term evolution. Common response to various biotic and abiotic stress exhibited the phenomenon of advance directives , which can increase by pretreatment of rice for the future of this stress resistance. In this context , research and improve rice resistance mechanisms to drought stress has become one of the key issues need to be resolved . The experiments carried out in the flower 11 different rice seedling polyethylene glycol (PEG6000) concentrations simulated drought stress , the effects of under 5%, 12.5%, 20% PEG6000 simulated drought stress on rice seedling root morphology indicators, contents of Pro and superoxide dismutase (SODs, superoxide dismutase), catalase (CAT, catalase), peroxidase (POD, non-specificperoxidase) isoenzyme activity impact. The main conclusions are as follows : In the case of PEG simulated drought , high intensity