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以‘贵农5号’刺梨为材料,研究了果实发育过程中主要抗氧化组分对机械伤及UV-B胁迫的响应。结果表明:机械伤和UV-B处理均可诱导刺梨果实中H2O2等自由基的产生,并促使膜脂过氧化水平增加;但抗氧化系统对两种胁迫的响应模式不尽相同:机械伤胁迫下抗氧化酶POD、SOD以及非酶组分AsA、GSH均受快速产生的H2O2等自由基诱导,表现出快速应激响应;之后这两种抗氧化酶呈现出逐渐降低的趋势,而AsA和GSH则一直保持在较高水平。在UV-B处理中,需要较长时间额外增加UV-B辐射才会有效增加成熟果实中SOD、AsA及GSH等组分的活性或积累;而在减弱紫外处理时,SOD、POD和GSH的变化均表现出前期升高后期回落的趋势。机械伤和UV-B胁迫下,CAT和APX等酶只是间或或根本无法检测到活性。总体上看,POD+SOD以及AsA+GSH的共同作用是刺梨果实在这两种胁迫下抗氧化反应的主要机制。
Taking ’Guinong No.5’ prickly pear as material, the responses of main antioxidant components to mechanical injury and UV-B stress during fruit development were studied. The results showed that both mechanical injury and UV-B treatment could induce the generation of free radical such as H2O2 and increase the membrane lipid peroxidation level. However, the response of antioxidant system to both stress was different: mechanical injury Antioxidant enzymes POD, SOD and non-enzymatic components AsA and GSH were all induced by rapid free radicals such as H2O2, which showed a rapid response to stress. Afterwards, the two anti-oxidative enzymes tended to decrease gradually while AsA And GSH has remained at a high level. In the UV-B treatment, it takes a long time to increase UV-B radiation to effectively increase the activity or accumulation of SOD, AsA and GSH in mature fruits. However, in UV-B treatment, the activities of SOD, POD and GSH The changes showed the trend of the late rise of the late period. Under mechanical injury and UV-B stress, enzymes such as CAT and APX could not detect activity either at all or at all. Overall, the combined action of POD + SOD and AsA + GSH is the main mechanism of antioxidative response of Cili pear under these two stresses.