环境胁迫下HOG-MAPK途径对真菌毒素形成的调控机制

Mechanism of HOG-MAPK pathway in regulating mycotoxins formation under environmental stresses

摘要:

真菌为了适应在生长侵染食品、饲料等农产品的过程中所面临的各种环境胁迫的考验,包括热胁迫、氧化胁迫、渗透压胁迫、紫外胁迫等,进化出一套高渗透性甘油促分裂原活化蛋白激酶(high osmolarity glycerol mitogen-activated protein kinase,HOG-MAPK)途径。该途径对真菌的生长发育、真菌毒素的产生和致病性都具有重要影响。HOG-MAPK途径共有两个分支,其中SLN1分支相比另一分支(SHO1分支)具有较为敏感的渗透压胁迫感应能力,能在高渗压和高盐浓度下进行渗透压胁迫反应。SHO1分支参与多种信号感应传导,比如氧化胁迫、热胁迫等。本文综述了真菌HOG-MAPK途径中关键基因sln1、sho1、ste11、ssk2、pbs2和hog1在应对渗透压胁迫、氧化胁迫等不同环境胁迫时所发挥的功能,说明HOG-MAPK途径可以响应多种环境信号,并参与调控黄曲霉、赭曲霉等致病真菌的生长和黄曲霉毒素(aflatoxin)、赭曲霉毒素(ochratoxin)等真菌毒素的产生。在不同环境胁迫下,HOG-MAPK途径对真菌毒素调控机制的研究可为食品和饲料等农产品真菌毒素的防控提供理论基础和指导方向。

Abstract:

In order to adapt to different environmental stresses including heat stress, oxidative stress,osmotic pressure stress and ultraviolet stress in the process of growing and infecting agricultural products,fungi have developed a set of high osmolarity glycerol mitogen-activated protein kinase(HOG-MAPK)pathway to alleviate the environmental stresses. This pathway plays an important role in the growth,development, mycotoxin production and pathogenicity of fungi. There are two branches in the HOG-MAPK pathway, among which the SLN1 branch is more sensitive to osmotic stress than another branch(SHO1 branch), and is able to respond to high osmotic pressure and high salt concentration. The SHO1 branch is involved in a variety of signal transduction in response to oxidative stress and thermal stress. This paper reviews the functions of key genes sln1, sho1, ste11, ssk2, pbs2 and hog1 in the HOG-MAPK pathway of phytopathogenic fungi in responses to different environmental stresses such as osmotic stress and oxidative stress. We show that the HOG-MAPK pathway can respond to a variety of environmental signals and is involved in regulating the growth of phytopathogenic fungi such as Aspergillus flavus and Aspergillus ochraceus, and the production of mycotoxins such as aflatoxins and ochratoxins. Understanding the mechanism of how HOG-MAPK pathway regulates mycotoxins' formation under different environmental stresses that provides a theoretical basis and guidance for the prevention and control of mycotoxins in agricultural products such as food and feed.