灰飞虱胁迫对水稻叶片中防御酶活性及细胞超微结构的影响

为探讨灰飞虱为害对水稻叶片的防御酶及细胞结构的影响，利用透射电镜观察了灰飞虱取食不同时间后叶片细胞超微结构的变化并测定了防御酶的活性。灰飞虱为害后，透射电子显微镜观察显示，随着灰飞虱取食时间延长，感虫水稻‘Kittake’的叶片细胞逐渐出现质壁分离，叶绿体发育异常，结构趋于模糊，72h后叶绿体膜破裂，叶绿体基粒片层完全溶解或断裂；抗虫品种‘Mudgo’叶绿体结构完整，基粒及片层结构完好，抗虫水稻的厚壁组织细胞内聚集了大量电子致密物，细胞内结晶状物质可能为酚类化合物。抗感水稻植株体内的苯丙氨酸解氨酶（PAL）和过氧化物酶（POD）的活性随灰飞虱取食时间延长而显著升高，多酚氧化酶（PPO）活性则表现出先上升后下降的趋势，且‘Mudgo’中的3种防御酶活性明显高于‘Kit—take’的，表明3种酶的活性均受灰飞虱为害诱导升高，但‘Mudgo’中3种酶活性上升的速度和幅度均高于‘Kittake’。

Effect of Small Brown Planthopper Stress on Defense Enzyme Activities and Cell Ultrastructure in Rice Leaf

In order to study the effect of small brown planthopper （SBPH）, Laodelphax striatellus Fallen, stress on defense enzymes and cell structure in rice leaf, the enzyme activities were tested and ultrastructure of rice leaf cells was observed with transmission electron microscope （TEM） at different feeding time. With the prolonging of SBPH feeding time, plasmolysis separation appeared in the leaf cell of ＇Kittake＇. Chloroplast structure became gradually abnormal and tended to be obscure, moreover, chloroplast membrane ruptured and grana thylakoid and lamellar structure dissolved or fractured in ＇Kittake＇ after 72 h-SBPH feeding. However, the chloroplast structure was integrate, whose grana thylakoid and lamellar structure were intact in resistant rice ＇Mudgo＇ infested by SBPH. A lot of electron-dense materials accumulated in sclerenchyma cells in ＇Mudgo＇. The crystalline substances in the cell maybe phenolic compounds. The activities ofphenylalanine ammonialyase （PAL） and peroxidase （POD） increased significantly with the SBPH feeding time going. The polyphenol oxidase （PPO） activity increased at first and then tended to decrease. The activity of three defense enzymes was significantly higher in ＇Mudgo＇ than in ＇Kittake＇. The above results indicated that three defense enzyme activities were induced to increase by SBPH feeding but increase speed and extent of enzyme activities was higher in ＇Mudgo＇ than in ＇Kittake＇.