外源茉莉酸诱导对油菜防御酶活性和4种物质含量及植株生长的影响

Effects of exogenous jasmonic acid on the activities of defense enzymes,the contents of four substances and the growth of rape

油菜是我国重要的油料作物。近10年来油菜虫害呈重发态势,而茉莉酸可以诱导植物产生抗虫性。本研究测定了外源茉莉酸处理对‘大黄’油菜幼苗中防御酶活性以及可溶性蛋白、可溶性糖、叶绿素、单宁含量及植株生长状况的影响。结果显示,以100μmol/L茉莉酸处理后,油菜叶片中过氧化物酶(POD)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)和苯丙氨酸解氨酶(PAL)活性较对照均有提高。其中对PAL影响最大,48 h时上升为对照的2.36倍;POD和PPO活性均在12 h后达到最高,分别比对照增加了73.46%和49.21%;对SOD活性在处理后24 h比对照增加了14.93%;胰蛋白酶抑制剂(TI)活性在茉莉酸处理后48 h达到最大,比对照提高了38.37%,之后逐渐下降,至120 h时与对照无显著差异;胰凝乳蛋白酶抑制剂(CI)活性在茉莉酸诱导后一直增加,120 h时是对照的1.78倍。可溶性糖和叶绿素含量在处理120 h均降到最低,分别比对照降低了38.70%和17.83%。可溶性蛋白含量则先降低后升高,在处理48 h后最低,比对照降低47.98%。可溶性单宁在茉莉酸诱导后含量持续升高,在120 h时上升为对照的2.03倍。油菜根长在茉莉酸处理后28 d和35 d显著长于对照;株高和干重均与对照无显著差异。上述结果说明适当剂量的外源茉莉酸诱导可激活油菜的防御体系,增强其抗虫性,且不影响油菜的生长。

Rape is one of the most important oil crops in China,and the insect pests of rape have been recurring in recent decades.Jasmonic acid(JA)plays an important role in plant resistance to insects.The changes in the activities of four defense enzymes and the contents of soluble protein,sugar,chlorophyll and tannin in‘Dahuang’rape subjected to exogenous JA treatment were measured in this study.The results showed that the activities of peroxidase(POD),polyphenol oxidase(PPO),superoxide dismutase(SOD)and phenylalanine ammonia lyase(PAL)increased significantly in rape seedling leaves treated with 100μmol/L of JA compared with those of the control.The effect of JA on PAL activity was the strongest among four defense enzymes,2.36 times of the control at 48 h.POD and PPO activities reached the peak 12 h after JA treatment,which increased by 73.46%and 49.21%compared with the control,respectively.SOD activity increased by 14.93%compared to the control at 24 h.The activity of trypsin inhibitors(TI)reached its maximum 48 h after JA treatment,which increased by 38.37%,and then decreased gradually.There was no significant difference from the control in 120 h.The activity of chymotrypsin inhibitors(CI)increased after JA treatment,reaching 1.78 times of the control at 120 h.The content of soluble sugar and chlorophyll decreased to the lowest at 120 h,38.70%and 17.83%lower than those of the controls.The soluble protein content decreased first and then increased,reaching the lowest value 48 h after JA treatment,47.98%lower than that of the control.The soluble tannin content increased after JA treatment,reaching 2.03 times of the control at 120 h.The root length was significantly different from control after JA treatment for 28 d and 35 d,and there were no significant difference in the stem length and dry weight.The results suggested that appropriate exogenous JA dose could induce defense response and enhance resistance of rape,and there was no significant effect on the growth of rape.