[Effects of exogenous NO on ascorbate-glutathione cycle in loquat leaves under low temperature stress].
Three-year-old 'Zaozhong No. 6' loquat (Eriobotrya japonica Lindl.) seedlings were foliar-sprayed with 0.2, 0.5, 1.0 and 1.5 mmol x L(-1) of sodium nitroprusside (SNP), subjected to low temperature (-3 degrees) stress for 6 hours, and then cultured at 25 degrees C for four days. The antioxidant metabolites and enzymes in the seedling leaves were determined 0, 1, and 4 days after recovery. Comparing with the control (water spraying), all SNP treatments had a decreased H2O2 content but an increased content of glutathione (GSH) and ascorbic acid (AsA) and increased activity of ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDAR) in the seedling leaves. Four days after recovery, the H2O2 content in the seedling leaves treated with 0.5 mmol x L(-1) of SNP decreased by 75.53%, while the GSH and AsA contents and the APX, GR, DHAR and MDAR activities were increased by 29.12%, 23.40%, 50.0%, 44.4%, 49.53%, and 62.68%, respectively. All of these suggested that appropriate dosage of exogenous NO could enhance the activity of antioxidant system in loquat leaves and alleviated the cell injury of loquat leaves under low temperature stress. In this study, the appropriate dosage of NO was 0.5 mmol x L(-1) of SNP.
Department of Environment and Life Science, Putian University, Putian 351100, Fujian, China. wjc2384@163.com
Jin-Cheng
JC
Wu
Jian-Qin
JQ
Chen
Jie
J
Liang
Wei-Bo
WB
Yang
Jing-Jing
JJ
Wu
Li-Qin
LQ
Chen
Mei-Qiong
MQ
Liu
Li-Ping
LP
Chen
D000975:Antioxidants / Q000502:physiology; D001205:Ascorbic Acid / Q000378:metabolism*; D003080:Cold Temperature; D031983:Eriobotrya / Q000187:drug effects / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D009569:Nitric Oxide / Q000494:pharmacology*; D018515:Plant Leaves / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D013312:Stress, Physiological
D000975:Antioxidants; D009569:Nitric Oxide; D005978:Glutathione; D001205:Ascorbic Acid