Molecular breeding of disease-resistant plants by transforming with lytic enzyme genes.

1. 用水稻β - 1,3 -葡聚糖酶cDNA Gns1 c2转化的烟草植株在R0和R1代对灰霉病表现出较高的抗性。通过农杆菌介导的转化方法，将水稻I类几丁质酶基因Cht-2 （RCC2）或Cht-3 (RCG3)，以及CaMV 35S增强启动子控制的水稻β - 1,3 -葡聚糖酶基因Gns1重新导入到粳稻品种“日本”和“光”中。组成性表达各基因的转基因水稻对稻瘟病病菌007.0和333的抗性均有显著提高。该基因的高水平表达和抗病性都稳定地遗传给了下一代。将CaMV 35S启动子驱动的水稻几丁质酶cDNA （RCC2）导入黄瓜。利用转基因原生植株（R0）自花授粉，获得了200多个具有高抗灰葡萄孢（Botrytis cinerea）的子代（R1）。70%以上的R1植株表现出高水平的转基因表达和抗真菌性。从接合菌属真菌少孢根霉（Rhizopus oligosporus）中分离纯化了3个几丁质酶（ChiI/II/III），并克隆了其编码基因chi1、chi2、chi3。将chi1基因导入烟草、苹果或水稻植株后，发现转基因植株具有抗真菌活性。

1. The transgenic tobacco plants transformed with the rice beta-1, 3-glucanase cDNA Gns1 c2 showed high resistance against Botrytis cinerea in the R0 and R1 generations.2. By an Agrobacterium-mediated transformation method, the rice class I chitinase gene, Cht-2 (RCC2) or Cht-3 (RCG3), or the rice beta-1, 3-glucanase gene Gns1 under the control of the enhanced CaMV 35S promoter was reintroduced into Japonica rice varieties Nipponbare and Koshihikari. The transgenic rice plants which constitutively expressed each transgene showed significantly higher resistance against the rice blast pathogen, Magnaporthe grisea race 007.0 and 333. Both high-level expression of the transgene and blast-resistance were stably inherited by the next generation in several lines.3. A rice chitinase cDNA (RCC2) driven by CaMV 35S promoter was introduced into cucumber. More than 200 filial generation lines (R1) were prepared by self-pollination of a primary transgenic plant (R0) conferred high resistance to Botrytis cinerea. More than 70% of the R1 plants exhibited high-level of the transgene expression and the fungus-resistance.4. Three chitinases (ChiI/II/III) were purified from a Zygomycetes fungus, Rhizopus oligosporus, and the genes encoding them (chi1 chi2 chi3) were cloned. The chi1 gene introduced into tobacco, apple or rice plants revealed to confer antifungal activity to the transgenic plants.