水分胁迫诱导平邑甜茶叶片衰老期间内肽酶与活性氧累积的关系

Relationship Between Changes of Endopeptidases Activity and Active Oxygen in Malus hupehensis Leaves During SenescenceInduced by Water Stress

在水分胁迫下,平邑甜茶叶片3种不同底物内肽酶活性的变化可分为缓升期和速升期,分别对应于叶绿素含量的缓降期和速降期。水分胁迫使平邑甜茶叶片SOD活性先升后降, ASA含量大幅度降低, O2-·、H2O2、1O2含量增高,膜脂过氧化产物 MDA含量大幅度增加,且 Chl、O2-·、H2O2、1O2、MDA上升和下降的幅度与内肽酶活性的降低均呈显著相关。表明水分胁迫下活性氧代谢失调而累积的活性氧(O2-·、H2O2、1O2)导致内肽酶活性大幅度上升。

The results showed that the changes of endopeptidases activities included two phases , the relatively steadyphase of low endopeptidases activity and the rapid increase phase of endopeptidases activity, which corresponding to relativelysteady phase and sharp fall phase of chlorophyll content. Under water stress, the contents of chlorophyll decreased. The activitiesof SOD increased in the early period, then decreased. The contents of O2-H2O2 , 1O2, MDA increased and the content of antioxidantsASA decreased. There are high significant correlation between endopeptidases activities and Chl, O2-, H2O2, 1O2, MDA in M.hupehensis pamp Reld. seedlings. The results indicated that the excessive accumulation ofO2-, H2O2, 1O2 induced the increaseof endopeptidases activities with the duration of water stress.