禾谷炭疽菌CgRAB4的功能研究

Functional Analysis on CgRAB4 of Colletotrichum graminicola

【目的】阐明禾谷炭疽菌(Colletotrichum graminicola)中CgRAB4的功能,为探究Rab蛋白在禾谷炭疽病菌中的保守性和特殊功能奠定理论基础。【方法】通过同源重组的方法对CgRAB4进行基因敲除,经潮霉素抗性筛选和PCR验证后获得缺失突变体,进而分析其在禾谷炭疽菌生长发育和侵染致病过程中的作用。【结果】成功获得CgRAB4基因的3个缺失突变体和1个异位整合突变体,对其表型分析发现CgRAB4基因缺失后促进了菌丝的生长,但不影响菌丝的形态,且不参与调控外界胁迫的响应过程,产孢量、孢子形态、附着胞的产生以及对玉米的致病性都没有明显变化。【结论】通过对CgRAB4基因进行敲除,表型分析后发现该基因可能参与调控禾谷炭疽菌的生长过程,为揭示Rab蛋白在禾谷炭疽菌生长发育和侵染致病过程的作用奠定理论基础,为防治玉米炭疽病提供理论指导。

【Objective】Conserve and special functions of Rab4 protein of Colletotrichum graminicola(Cg)were studied.【Method】Based upon the principle of homologous recombination,CgRAB4 was knocked out from the DNA of Cg to obtain mutants with the target gene deleted.A hygromycin-resistance screening and PCR verification were performed on the mutants prior to a functional analysis on Cg development and pathogenesis.【Result】Three CgRAB4-deleted and one ectopic mutants were secured by the designed process.The phenotypic analysis revealed that the deletion promoted the hypha growth but did not affect the mycelial morphology,nor regulate the response to external stress or significant change in the spore production and morphology,appressorium germination or the pathogenicity on the mutants.【Conclusion】CgRAB4 was successfully removed from Cg to unveil the involvement of the gene in regulating the mycelial growth.Understanding on the roles of Rab proteins played in the development and pathogenesis of Cg provided a guiding direction for further research on the prevention and treatment of corn anthrax.