外源NO对低温胁迫下仁用杏花器官AsA-GSH循环的影响

Effects of exogenous nitric oxide on AsA-GSH cycle of kernel apricot floral organs under low temperature stress

为探讨低温胁迫下不同浓度外源一氧化氮(NO)对仁用杏花器官AsA-GSH循环的影响,本试验选用3个品种的仁用杏花器官作为试验材料,喷施0(CK)、0.1、0.2、0.3、0.4、0.5 mmol/L的外源NO供体硝普钠(Sodium nitroprusside,SNP)处理,研究经低温胁迫4 h后仁用杏花器官活性氧水平及AsA-GSH循环的变化。结果表明,与CK相比,不同浓度的外源NO均降低了3种仁用杏花器官过氧化氢(H2O2)含量和超氧阴离子(O2-)产生速率;‘优一’(‘Youyi’)在0.4 mmol/L SNP处理下H2O2含量和O2-产生速率分别比CK降低了13.71%、65.20%;‘龙王帽’(‘Longwangmao’)在0.4 mmol/L SNP处理下分别比CK降低了25.17%、85.62%;‘围选1号’(‘Weixuan 1’)在0.5 mmol/L SNP处理下分别比CK降低了25.17%、77.11%。不同浓度的外源NO可以提高3种仁用杏花器官抗坏血酸(AsA)含量、谷胱甘肽(GSH)含量、AsA+DHA含量、GSH+GSSG含量和AsA/DHA、GSH/GSSG;降低脱氢抗坏血酸(DHA)含量、氧化型谷胱甘肽(GSSG)含量;同时增强抗坏血酸过氧化物酶(APX)活性、谷胱甘肽过氧化物酶(GPX)活性和脱氢抗坏血酸还原酶(DHAR)活性,以提高AsA-GSH循环的速率,减少活性氧的累积,降低膜脂过氧化作用,缓解低温对花器官的伤害,提高其抗寒性。本研究结果表明,0.4 mmol/L SNP对‘优一’和‘龙王帽’2品种花器官抗寒性提高效果最佳,而‘围选1号’在SNP浓度为0.5 mmol/L时效果最佳。

In order to investigate the effects of different concentrations of exogenous nitric oxide(NO)on the AsA-GSH cycle of kernel apricot floral organs under low temperature stress,three varieties of kernel apricot floral organs were selected as experimental materials.The apricot floral organs were sprayed with 0(CK),0.1,0.2,0.3,0.4 and 0.5 mmol/L exogenous NO donor sodium nitroprusside(SNP),and the changes of active oxygen level and AsA-GSH cycle of kernel apricot floral organs were studied after low temperature stress for 4 hours.The results showed that exogenous NO decreased the hydrogen peroxide(H2O2)content and superoxide anion(O2-)production rate of the three kernel apricot floral organs compared with the CK.The H2O2 content and-O2 production rate of‘Youyi’reduced by 13.71%and 65.20%respectively under the treatment of 0.4 mmol/L SNP,and that of‘Longwangmao’reduced by 25.17%and 85.62%respectively under the treatment of 0.4 mmol/L SNP.The H2O2 content and-O2 production rate of‘Weixuan1’reduced by 25.17%and 77.11%respectively under the treatment of 0.5 mmol/L SNP.Exogenous NO at different concentrations could increase AsA content,GSH content,AsA+DHA content,GSH+GSSG content,AsA/DHA and GSH/GSSG of the three kernel apricot floral organs.While exogenous NO decreased DHA and GSSG content.Meanwhile,the APX,GPX and DHAR activities were enhanced resulting in increased rate of AsA-GSH cycle,reduced accumulation of reactive oxygen species,reduced membrane peroxidation,and thus the damage of low temperature on kernel apricot floral organs was alleviated,and the cold resistance was improved.The results showed that 0.4 mmol/L SNP had the best effect on the improvement of cold resistance of floral organs of‘Youyi’and‘Longwangmao’,while‘Weixuan 1’preferred to 0.5 mmol/L SNP treatment.