茶苗在干旱胁迫下的伤害及其生理原因的探讨

茶苗在PEG溶液中(-1.9bar,-6.7bar,-22.3bar),随着胁迫时间的延长,茶树离体枝条叶片SOD和CAT活性先增后降,并随着胁迫程度的加重其酶活性下降加速;POD活性在处理时间内一直增强,与膜损伤加剧速度相平行.叶片细胞膜透性和膜脂过氧化产物(丙二醛MDA)含量平行地增加,两者呈极显著的正相关(r=0.9938~(**)).茶苗抗旱锻炼后能减轻膜伤害程度和降低膜脂过氧化水平,这与体内的SOD,CAT和POD活性在抗旱锻炼中的增强有关.这一结果为茶树干旱胁迫下活性氧伤害理论提供了又一佐证.

Studies on the drought injury with relation to activated oxygen metabolism in tea plant.

The effects of osmotic stress induced by PEG solutions( - 1. 9 bar,-6. 7 bar ami -22. 3 bar) on permeability of plasma membrane,membrane-lipid peroxidation .activates of endogenous protective enzymes,such as superoxide dismutase (SOD) ,catalase (CAT) .peroxidase (POD) were studied with the aim of understanding the mechanism of drought injury. The results showed that permeability of plasma membrane and maiondiaide-hyde (MDA) contents increased while activities of SOD and CAT increased at first and then decreased sharply, but POD activity increased continuously during the osmotic stress. There was a positive correlation between MDA content and leaked electrolyte level (r= 0. 9933,p<0. 01). The activities of SOD,CAT and POD increased markedly after drought stress,while theincrease of electrolyte leakage and MDA content in drought hardening-treated plants were delayed under water stress. These results suggested that a correlationship might be exist between the drought injury of tea plants and the damage of active oxygen.