中文摘要：据广泛报道，植物组织释放的乙烯（ET）在植物发育、对环境胁迫的反应和对某些病原体的防御中起到重要作用。从暴露于ET的体外真菌培养物中获得的最新证据表明外源ET可以通过曲霉控制黄曲霉毒素的产生。然而，种子内源ET的功能尚未有人探究过。本研究发现以前报道的易受曲霉菌感染的玉米脂氧合酶lox3突变体，受黄曲霉感染后释放了更高水平的ET，表明内源性ET对玉米中黄曲霉的敏感性具有潜在影响。研究结果表明，受感染的种子释放的ET促进了黄曲霉的定植，但不能促进黄曲霉毒素的产生。
 
外文摘要： Ethylene (ET) emitted by plant tissues has been broadly reported to play important roles in plant development, response to environmental stresses and defense against certain pathogens. Recent evidence obtained from using in vitro fungal cultures exposed to ET suggested that exogenous ET may regulate the production of aflatoxin by Aspergilli. However, the function of endogenous, seed-derived ET has not been explored. In this study, we found that the maize lipoxygenase lox3 mutant, previously reported to be susceptible to Aspergillus spp., emitted greater levels of ET upon A. flavus infection, suggesting the potential involvement of endogenous ET in the susceptibility of maize to A. flavus. Supporting this idea, both colonization and conidiation of A. flavus were reduced in wild-type (WT) kernels treated with AgNO3, an ET synthesis inhibitor. There was no ET emission from non-viable kernels colonized by A. flavus, suggesting that living seed but not the fungus itself was the primary source of ET released upon infection with A. flavus. The kernels of acs2 and acs6, two ET biosynthetic mutants carrying Mutator transposons in the ACC synthase genes, ACS2 and ACS6, respectively, displayed enhanced seed colonization and conidiation, but not the levels of aflatoxin, upon infection with A. flavus. Surprisingly, both acs2 and acs6 mutant kernels emitted greater levels of ET in response to infection by A. flavus as compared with WT seed. The increased ET in single mutants was found to be due to overexpression of functional ACS genes in response to A. flavus infection. Collectively, these findings suggested that ET emitted by infected seed facilitates colonization by A. flavus but not aflatoxin production.
外文关键词：Aspergillus flavus；ethylene；maize；colonization；aflatoxin
作者：Wang, S；Park, YS；Yang, Y；Borrego, EJ；Isakeit, T；Gao, XQ； Kolomiets,MV
作者单位：Nanjing Agr Univ
期刊名称：FRONTIERS IN PLANT SCIENCE
期刊影响因子：4.495
出版年份：2017
出版刊次：3
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