Development of Biotechnology-oriented Plant Disease Control Measures

利用生物技术建立了一些新的植物病害防治策略。1. 通过在土壤中应用植物病原真菌与其拮抗剂之间的抗生素，建立了一种控制真菌疾病的措施。从几丁质降解菌中纯化出几丁质酶，对其作用方式进行了鉴定，并将其生产基因克隆到大肠杆菌中进行了测序。在甲壳素和沸石改性土壤中添加含有这些细菌的藻酸盐微球，对番茄和草莓镰刀菌病有较好的防治效果。2. 构建了镰刀菌和白粉病菌转化载体，并通过显微注射或电穿孔等方法分析了与载体相关的报告基因的表达。这两种真菌都被转化为在其染色体中含有外源基因。3. 采用显微注射技术确定了外源基因在真菌细胞中的导入和表达条件。采用原位杂交分析转录本，刺入相应的检测剂后用细胞化学或免疫化学反应检测翻译产物。4.从酶化学水平探讨了腐木真菌降解木质素的分子机制。研究了木材腐烂过程中微生物的演替特征，以选择与木材腐烂真菌竞争的有效微生物。5. 从侵染土壤中分离到番茄假单胞菌（Pseudomonas solanacearum）噬菌体，并测定了其对不同菌株的感染性。作为决定其宿主特异性的一个因素，编码衣壳蛋白的基因被克隆并部分测序。6. 利用组织培养过程中诱导的体细胞无性系变异，获得了番茄抗枯萎系和草莓抗枯萎、抗炭疽病系。7. 通过根状农杆菌侵染甜瓜叶片，获得了抗cmv转基因甜瓜。少

Some novel strategies of plant disease control was established by the use of biotechnology techniques. 1. A measure of fungal disease control was established by the use of antibiosis in soil between plant pathogenic fungi and their antagonists. Chitinases were purified from chitinolytic bacteria and characterized in terms of mode of action,and genes for their production was cloned into E.coli and sequenced. Alginate beads containing these bacteria were effective in controlling Fusarium diseases of tomato and strawberry, provided they were added in chition and Zeolite-amended soils. 2. Vectors for the transformation of Fusarium species and powdery mildew fungi were constructed and expression of reporter genes connected to these vectors were analyzed after microinjection or electroporation into fungal structures. Both fungi were transformed to contain foreign genes in their chromosome. 3. Conditions for introduction and expression of foreign genes in fungal cells were specified by microi … More njection technique. Transcripts were analyzed by in situ hybridization and translation products were detected by cytochemical or immunochemical reaction after pricking introduction of respective detecting agents. 4.Molecular mechanisms of lignin degradation by wood-decay fungi were elucidated at the level of enzyme chemistry. Microbial succession of microbes during wood-decay was also characterized to select effective microbes which compete with wood decay fungi. 5. Bacteriophages of Pseudomonas solanacearum were isolated from infested soils and characterized of their infectivities to different stains of the bacterium. As a factor detrminign their host speficities, genes encoding capsid proteins were cloned and partly sequenced. 6. Baterial wilt-resistant tomato lines and Fusarial wilt and Anthrachose resistant strawberry lines were obtained by the use of somaclonal variation induced during tissue culture. 7. CMV-resistant transgenic melon was produced through infection of melon leaf discs by Agrobacterium rhizogenes. Less