外源茉莉酸对菜豆和番茄幼苗3种防御酶的诱导效应

为明确外源茉莉酸（JA）对菜豆和番茄化学防御的诱导作用，以鲁阳地豆菜豆和红珍珠番茄为材料，研究4种浓度（0.001、0.01、0.1和1 mmol/L）JA喷施2种植物幼苗后叶片多酚氧化酶(PPO)、过氧化物酶(POD) 和脂氧合酶(LOX)的活性变化。结果表明，JA处理可以提高菜豆和番茄叶片3种防御酶的活性，活性提高与诱导的JA浓度和诱导时间有关。0.001 mmol/L JA对菜豆叶片3种防御酶诱导作用不明显，0.1 mmol/L JA诱导效果均显著。4种JA浓度对番茄叶片POD和PPO均具有显著的诱导作用，但0.001和1 mmol/L JA对LOX诱导效果不明显。0.1 mmol/L JA处理72 h后对番茄叶片LOX诱导作用最强，但处理24 h后对番茄叶片POD和PPO以及菜豆叶片3种防御酶诱导作用最强。

Inductive Effects of Exogenous Jasmonic Acid on Three Defensive Enzymes in Leaves of Kidney Bean and Tomato Seedlings

To clarify the inductive effects of exogenous jasmonic acid (JA) on chemical defense of kidney bean and tomato, the seedlings of kidney bean cultivar Luyang and tomato cultivar Hongzhenzhu were sprayed with JA in four concentrations, and then polyphenol oxidase (PPO), peroxidase (POD) and lipoxygenase (LOX) activities in both plant leaves were measured after application of 0.001,0.01, 0.1 and 1 mmol/L JA. The result showed that exogenous JA treatment resulted in an increase of PPO, POD and LOX activities, but the effect was significantly related to JA concentration and time span of JA treatment. The inductive effect of three defensive enzymes in leaves of kidney bean was not obvious at 0.001 mmol/L JA, but significant at 0.1 mmol/L JA. For activities of PPO and POD in tomato leaves, the inductive effects of four JA concentrations were all significant. However, effect was not significant for LOX at 0.001 and 1 mmol/L JA. In addition, the strongest inductive effect was detected for LOX in tomato leaves after 72 h of 0.1 mmol/L JA treatment, and the strongest inductive effects were detected for POD and PPO in tomato leaves as well as POD, PPO and LOX in kidney bean leaves after 24 h of treatment.