玉米瘤黑粉菌的寄生策略及其调控机制

Parasitic strategy and regulation mechanism of Ustilago maydis-A review

摘要:

玉米瘤黑粉病是由担子菌Ustilago maydis对玉米的活体寄生所引起的真菌病害。该病原菌为双相型真菌，需要寄生于玉米植株来完成其有性生殖过程。综合相关研究报道，本文把U. maydis对寄主植物的寄生过程划分为7个阶段，包括形成致病性双核菌丝体、附着寄主植物表面、穿透寄主表皮、消减寄主防御反应、在寄主体内菌丝增殖、使寄主瘤变和生成厚垣孢子等。围绕寄生进程特点和关键基因，分别阐述了各个阶段的相关调控机制以及对寄主植物的致病性；展现了U. maydis为达到有性生殖目的而实施步步为营的寄生策略。本文对U. maydis寄生过程的阶段划分，有助于人们深入了解U. maydis与寄主植物之间互作机制、提供相关病害防控新思路。

关键词:Ustilago maydis;玉米瘤黑粉病;寄生;致病;调控机制

Abstract:

Corn smut is a disease caused by Basidiomycetous fungus Ustilago maydis. This pathogen is a dimorphic fungus that needs to complete its sexual reproduction in living corn. We reviewed recent research reports of this disease, we divided the parasitization course of U. maydis into 7 stages in this paper, including the formation of pathogenic dikaryotic hyphae, attaching to the surface of host plant, penetrating the host epidermis, weakening host defense response, prolifering mycelium in host plant, inducing tumor in host tissue and the formation of chlamydospore. We also reviewed key genes involved in each stage and elaborate their function during pathogenesis. We present the sophisticated parasitic strategy of U. maydis in the process to achieve its sexual reproduction. The division of U. maydis parasitization course in this review will help understanding the interaction mechanisms between the pathogen and host plant, and provide new ideas for the prevention and control of such diseases.

Key words:Ustilago maydis;corn smut;parasitization;pathopoiesia;regulation mechanism