Study On The Resistance Of Peanut To Aspergillus Flavus

Peamil(Arachis hypogaea L.Shanyou523)seeds were chosen as materials in this thesis to study the general characteristics of the natural proteinaceous protease inhibitors from them, and the effect of MJ and elicitor on the activities of some enzymes about resistance were investigated.the crude PI and 2S fraction was separated from peanut seeds and purificated by Sephadex G-100 and DEAE cellulose(DE-32) chromatography . the properties of purified PI and 2S was determinded. The result showed that the content of PI and 2S in peanut seeds is very low and their last quantity is 6% and 1.2%seperately. PAGE, SDS-PAGE and HPLC analysis showed that the PI we gained are pure, which is a single polypetide with a molecular weight of 7.07kDa by SDS-PAGE and laser mass spectrum and a isoelectric point at pH5.8; The 2S protein is consist of five polypeptides with low molecular weight and the approximate isoelectric point at pH4.1and partly hang together, one of which has the same molecular weight as PI(named 2S-1).PI and 2S were stable below 100℃and between pH2.0-ll. PI can inhibite strongly proteinaceous protease,endopeptidase and A.flavus, while 2S before treatment had little inhibition on proteinaceous protease,endopeptidase and A.flavus, but after treatment, it had strong inhibition on proteinaceous protease,endopeptidase and A.flavus. Some of 2S had inhibiton on proteinaceous protease, which had the same properties as PI, but amino acid sequence and amino acid content analysis showed that it is different from PI.Suspension cells of peanut were treated with MJ and elicitor to determine the activities of phenylalanine ammonialyase (PAL), # 1,3-glucanase, polyphenol oxidase, chitinase, lipoxygenase(LOX-l,LOX-3), catalase(CAT), inhibition activity and active oxygene. The result showed that MJ largely increased the activities of PAL, LOX-1, inhibition activity, chitinase and slightly increased the activities of # 1,3-glucanase and LOX-3 while it slightly inhibited the activity of CAT and had no effect on the activities of inhibition; while elicitor largely increased the activities of PAL, inhibition activity, chitinase and slightly increased the activities of active oxygene, while it slightly inhibited the activity of LOX-land CAT and have no effect on the activities of LOX-3 and # 1,3-glucanase .Treatment with MJ and elicitor had different effect on different substance about resistance. It is inferred that there were various pathways in different substances on resistance induced by MJ and elicitor,which are both relateted and indenpendent...