剪叶及昆虫取食对兴安落叶松蛋白酶抑制剂的影响

植物蛋白酶抑制剂是植物重要的防御物质之一。为了研究不同程度剪叶及昆虫取食诱导与兴安落叶松Larix gmelinii针叶内蛋白酶抑制剂活性变化的关系，分别以剪叶及落叶松毛虫Dendrolimus superans取食处理兴安落叶松幼苗，用紫外分光光度法测定不同处理后针叶内胰蛋白酶抑制剂(TI)和胰凝乳蛋白酶抑制剂(CI)活性变化。结果表明：落叶松毛虫取食及剪叶可诱导兴安落叶松产生系统性防御反应，处理后的1～20天，苗木针叶内TI和CI两种抑制剂活性产生显著变化，诱导产生的TI和CI的活性与损伤程度无显著相关性。相同损伤程度下，虫害诱导的TI活性高于剪叶损伤诱导的活性，但二者差异不显著；3种取食程度诱导的CI活性，只在第5天同时显著高于剪叶损伤诱导的抑制剂的活性。由此可见，可以通过适当的损伤处理取得与昆虫取食相似的植物抗性反应，这为林木病虫防治提供了新的思路。

Activities of proteinase inhibitors in Larix gmelinii seedlings under the stresses of cutting needles and herbivore feeding

Plant proteinase inhibitors(PPIs) are important defensive substances.In order to understand the effects of damage degrees on the activities of PPIs,the activities of trypsin inhibitors(TI) and chymotrypsin inhibitors(CI) in Larix gmelinii seedling needles after being cut with scissors or fed by the larvae of Dendrolimus superans at three various degrees,respectively,were assayed with UV-spectrometry.The results showed that both TI and CI activities in the seedling needles increased significantly after the two treatments from 1 to 20 days,compared with the control.However,there was no significant relationship between PI activities and the damage degrees.TI activities induced by insect feeding were higher than those by needle cutting under the same injured degree whereas the differences were not significant.CI activities induced by larva feeding were all higher than those by needle cutting only on the 5th day no matter what damage degrees.Our research clearly demonstrated that making appropriate injury intentionally to mimic well the effects of herbivory feeding could increase larch defence,which can be used as a new method to control the larch pests.