褐飞虱刺吸诱导的水稻一些防御性酶活性的变化

褐飞虱刺吸导致稻株体内丙二醛含量迅速上升,表明褐飞虱刺吸引起了水稻植株膜脂的过氧化;抗虫和感虫品种植株体内脂氧合酶(LOX)、脂氢过氧化物裂解酶(HPL)、苯丙氨酸解氨酶(PAL)的活性均显著升高;而过氧化氢酶(CAT)活性在抗虫品种稻株体内明显受抑制,H2O2含量提高,但在感虫品种植株体内CAT的活性略有提高,H2O2含量略有下降.对抗虫品种植株不同器官的测定结果表明,褐飞虱刺吸对PAL和H2O2的影响是系统性的,而对LOX的影响则仅局限于褐飞虱刺吸部位的茎杆中.

Changes in Some Defensive Enzyme Activity Induced by the Piercing-Sucking of Brown Planthopper in Rice

The effects of brown planthopper on the activities of some key enzymes involved in defense response and the H2O2 content were investigated in rice. From the fact that after piercing-sucking of brown planthopper, malondialdehyde (MDA) con- tent of rice plant was increased rapidly (Fig.3), one can conclude that it induced lipid peroxidation; lipoxygenase (LOX), hydroperoxide lyase (HPL) and phenylalanine ammonia-lyase (PAL) activities were increased significantly in plants of resistant and susceptible varieties by piercing-sucking of brown planthopper (Figs.1, 2, 4); whereas the catalase activity and the H2O2 content were significantly dif- ferent between resistant and susceptible plants by piercing-sucking of brown planthopper, the former being decreased and the latter increased in resis- tance plants of variety RH (Oryza sativa L. cv.Rathu Heenati), while the reverse was true in the susceptible plants of variety TN1 (Oryza sotiva L. cv. Taichung Native 1) (Figs.5, 6). The effect of brown planthopper on the PAL activity and the H2O2 content were systemic (Figs.4, 6), but the effect on the LOX activity occurred only in stem, the organ which brown planthopper sucking (Fig.1).