| The pine wilt disease caused by the pine wood nematode (Bursaphelenchus xylophilus) is one of the most devasting diseases of pine trees. This disease has been found in Japan, U.S.A., Canada, Korea and so on, but the degree of harm is different in different countries. It is the most severe in Japan and China. It resulted not only in losses of forest industry, but also in damage of landscape. Therefore, the studies of pathogenesis of Bursaphelenchus xylophilus will provide with theoretic and practical significance.Along with study of plant-parasitic nematode pathogenesis, The effect of esophageal secretions of Bursaphelenchus xylophilus to host cell and its metobolization is a hot point of current research. In this study, secretory-excretory proteins, secretory proteins of subcellular granules and cellulase between Bursaphelenchus xylophilus and B. mucronatus were compared by electrophoresis, enzyme stain, topical application etc. The main results are as follows:1. Nematode reactions varied in different populations in staining with six biological dyes. In present study, secretion-excretions from stylets, amphids, valva and anus of Bursaphelenchus xylophilus were observed. Secretions from stylets and amphids of Bursaphelenchus mucronatus were observed. Only secretion from stylets of Fl population was observed. So secretion-excretions of Bursaphelenchus xylophilus are very different from that of Bursaphelenchus mucronatus. The differences are possibly related to pathogenesis of Bursaphelenchus xylophilus. Stylet-secretions were observed in all nematode populations in this experiment, the quantity of the secretions from Bursaphelenchus xylophilus, however, is more than that from Bursaphelenchus mucronatus. Because stylet-secretions come from esophageal gland, the results indicated secretory activity of Bursaphelenchus xylophilus is stronger than that of Bursaphelenchus mucronatus. Stylet-secretions from esophageal gland of Bursaphelenchus xylophilus maybeplay important role in pathogenesis. All stylet-secretions can be stained with coomassie brilliant blue G-250 which specially dye protein, therefore, stylet-secretions must contain proteins.2. In the cellullase analyzing examinations, there are no difference of cellulase of secretion-excretions and secretion granules among inter- or intra-species both adults and juveniles. Only the mass nematode homogenates have difference in populations. All cellulase patters contain one quickest band and two slowest band. The results revealed that both Bursaphelenchus xylophilus and Bursaphelenchus mucronatus secret cellullase. There is no difference in activity and moleculer weights. So cellullase secreted by pine wood nematode is able to loose plant-host cell, which faver the reduction of mechanical intensity of cellullose net but is not important in inducing pine wilt diease.3. The proteins of secretion-excretions and subcellular secretory granules are axamined by PAGE and SDS-PAGE. The results indicate , there are clear difference interspecies in PAGE. The molecular weights of major protein bands range from 10KD to 100KD. There are more protein bands in SDS-PAGE than in PAGE, so secretion-excretions and subcellular secretion granules contain the multimeric proteins. The results from the PAGE analysis showed there are more bands in secretion-excretions than subcellular granules. It indicated that other secretion-excretions were involved except stylet-secretions which include many special protein bands. In all protein bands, the bands with molecular weights 37KD and 23KD stand out in Bursaphelenchus xylophilus. 37KD protein come from esophageal gland and 23KD come from secretion-excretions except for stylet-secretions. These proteins maybe have tight relation with pathogenesis. Subcellular secretion granules protein of Bursaphelenchus xylophilus have more special proteins in SDS-PAGE than in PAGE. The results revealed subcellular granules contain many multimeric protein. Fl population is always disputed in classify, our results indicate that... |
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