H_2O_2对抗旱性不同玉米品种愈伤组织抗氧化系统的影响

EFFECT OF EXOGENOUS H 2O 2 ON THE ANTIOXIDANT SYSTEM IN CALLI OF TWO MAIZE CULTIVARS WITH DIFFERENT DROUGHT RESISTANCE

两个玉米品种愈伤组织经１０－４ｍｏｌＬ－１、１０－３ｍｏｌＬ－１和１０－２ｍｏｌＬ－１Ｈ２Ｏ２处理３ｈ后，电解质泄漏率加大；Ｈ２Ｏ２和ＭＤＡ含量增加；ＡｓＡ和ＣＡＲ含量的减少．１０－４ｍｏｌＬ－１的Ｈ２Ｏ２处理对愈伤组织产生的氧化伤害较小．抗旱性较强品种ＰＡＮ６０４３愈伤组织的抗氧化酶（ＳＯＤ、ＰＯＤ、ＡＰ和ＧＲ）活性高于抗旱性较弱品种ＳＣ７０１，ＡｓＡ和ＣＡＲ含量的下降程度低于ＳＣ７０１．ＰＡＮ６０４３愈伤组织具有较强的抗Ｈ２Ｏ２能力。

The effect of exogenous H 2O 2 on antioxidant system was studied in callus tissues of drought-resistant (PAN 6043) and drought-sensitive (SC 701) cultivars of maize ( Zea mays L.). Eight day old calli were harvested and soaked with hydrogen peroxide solution (10 -4 , 10 -3 and 10 -2 mol L -1 ) for 3 h. Hydrogen peroxide damaged the calli, as indicated by the increase in leakage of electrolytes, the contents of H 2O 2 and malondiadehyde, as well as the reduction in ascorbate and carotenoid contents in the calli of the both cultivars. Hydrogen peroxide (10 -4 mol/L ) had small oxidant effect. When calli were treated by hydrogen peroxide, the activities of SOD, POD, AP and GR, and the levels of AsA and CAR remained higher in the calli of the drought resistant cultivar than those of the drought sensitive one. The results showed that the higher activity of the antioxidant system had a greater protective effect against oxidative stress caused by hydrogen peroxide in drough resistant cultivar than in the drought sensitive cultivar.