稻纵卷叶螟为害对水稻防御化合物及信号分子含量的影响

Influence of infestation by rice leaf folder Cnaphalocrocis medinalis on levels of defense chemicals and signal molecules in rice

测定稻纵卷叶螟Cnaphalocrocis medinalis(Guen啨e)为害后水稻体内过氧化氢、水杨酸、茉莉酸3种信号分子以及防御相关化合物含量的变化.结果表明,稻纵卷叶螟为害后0.5、24 h能显著提高水稻体内过氧化氢浓度,为害后0.5、1、24 h显著增加水杨酸浓度,但不影响茉莉酸浓度.稻纵卷叶螟为害能导致水稻叶片中胰蛋白酶抑制剂和6种未知防御化合物含量上升,在叶鞘中只引起6种未知物中的3种含量上升,其他的3种未知物与胰蛋白酶抑制剂没有明显变化.外用水杨酸或过氧化氢处理水稻只在叶鞘中增加6种未知物中1种化合物的含量.说明稻纵卷叶螟为害诱导的防御化合物的变化部分是系统性的,而另一部分则是局部性的;并且稻纵卷叶螟为害诱导的防御反应是多种信号分子相互作用的结果.

The change.s in levels of hydrogen peroxide, salicylic acid and jasmonic acid, and defenserelated chemicals were investigated in rice plants infested by the rice leaf folder Cnaphalocrocis medinalis. The results show that C. medinalis infestation enhanced significantly the levels of hydrogen peroxide （0.5 and 24 h after infestation） and salicylic acid （0.5, 1 and 24 h after infestation） but not of jasmonic acid in plants. Compared to the control, C. rnedinalis infestation resulted in increases in concentrations of trypsin inhihitors and six unknown defense chemicals in infested leaves, but only three of the six unknown chemicals were enhanced in leaf sheaths of the infested plants. Exogenous application of hydrogen peroxide or salicylic acid only increased level of one of the six unknown chemicals in plants. This suggests that some defense chemicals in rice plants are systematically induced by C. medinalis infestation, whereas some are locally induced, and C. rnedinalis-induced rice defense response is a result of crosstalk among a number of signaling pathways.