四季桂抗氧化防御系统对干旱、高温及协同胁迫的响应  

Responses of the Antioxidant Defense System of Osmanthus fragrans cv. 'Tian Xiang TaiGe' to Drought,Heat and the Synergistic Stress

作　　者：许馨露 李丹丹[1] 马元丹[1] 翟建云 孙建飞 高岩[1] 张汝民[1] Xinlu Xu;Dandan Li;Yuandan Ma;Jianyun Zhai;Jianfei Sun;Yan Gao;Rumin Zhang(School of Forestry and Biotechnology, Zhejiang A ＆F University, Lin＇an 311300, China)

机构地区：[1]浙江农林大学林业与生物技术学院,临安311300

出　　处：《植物学报》2018年第1期72-81,共10页Chinese Bulletin of Botany

基　　金：国家自然科学基金(No.31470704);浙江省与中国林业科学研究院省院合作林业科技项目(No.2016SY06)

摘　　要：以天香台阁四季桂(Osmanthus fragrans cv.‘Tian Xiang Tai Ge’)为材料,研究干旱(轻度、中度和重度)、高温(40°C)及干旱高温协同胁迫对四季桂叶片抗氧化防御系统的影响。结果显示,干旱胁迫下,四季桂活性氧(ROS)逐渐积累,膜脂过氧化程度加深;轻度和中度干旱胁迫下,抗氧化酶活性显著升高;重度干旱胁迫下,抗坏血酸(As A)及其还原力(As A/DHA)显著降低,谷胱甘肽(GSH)及其还原力(GSH/GSSG)以及抗坏血酸-谷胱甘肽(As A-GSH)循环相关酶活性呈先上升后下降的趋势,在中度干旱胁迫时达到峰值。高温胁迫显著增强ROS积累、抗氧化酶活性、抗氧化剂含量及As A-GSH循环效率。干旱高温协同胁迫下,四季桂所受伤害大于单一胁迫,ROS在抗氧化酶的作用下增幅减缓;随着胁迫强度的加剧,As A-GSH循环效率呈先增加后下降的趋势,重度协同胁迫时显著降低,无法维持氧化还原平衡。四季桂在干旱高温胁迫下能快速启动体内抗氧化防御系统,清除体内过量的ROS,增加机体还原力,以减缓胁迫带来的伤害。In this study,we explored the solo effect of drought stress（control,light,moderate and heavy）,heat stress（control 28°C,heat 40°C） and their dual stresses on the antioxidant defense system of Osmanthus fragrans cv.＇Tian Xiang Tai Ge＇.The experiment data showed that after drought treatment,reactive oxygen species（ROS） accumulated gradually and membrane lipid peroxidation increased;the activity of antioxidant enzymes increased significantly under light and moderate drought stress.Ascorbic acid（AsA） and its reducing power（AsA/DHA） decreased significantly under heavy drought stress,whereas glutathione（GSH） and its reducing power（GSH/GSSG） as well as the activity of enzymes related to ascorbate glutathione cycle（AsA-GSH cycle） showed a trend of first increasing and then decreasing,with the peak reached after moderate drought stress.Unlike drought stress,ROS accumulation,antioxidant enzyme activity,antioxidant content and AsA-GSH cycle efficiency all improved significantly with heat stress.Furthermore,we found that the dual stresses injured the cultivar more severely than either stress alone.ROS level increased slowly via antioxidant enzyme activity,and the AsA-GSH cycle efficiency was enhanced at first and then decreased significantly with increasing dual stresses,especially after severe stress,and was unable to maintain oxidation reduction equilibrium.Under drought and heat stress,the cultivar quickly activated the antioxidant defense system to eliminate ROS,which improved the reducing power of the organism to reduce the environmental damage.

关 键 词：四季桂 干旱 高温 活性氧 抗氧化酶 抗坏血酸-谷胱甘肽循环 

分 类 号：S685.13[农业科学—观赏园艺]