Calvo A M, Hinze L L, Gardner H W, Keller N P
Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843-2132, USA.
Appl Environ Microbiol. 1999 Aug;65(8):3668-73. doi: 10.1128/AEM.65.8.3668-3673.1999.
Aspergillus spp. are frequently occurring seed-colonizing fungi that complete their disease cycles through the development of asexual spores, which function as inocula, and through the formation of cleistothecia and sclerotia. We found that development of all three of these structures in Aspergillus nidulans, Aspergillus flavus, and Aspergillus parasiticus is affected by linoleic acid and light. The specific morphological effects of linoleic acid include induction of precocious and increased asexual spore development in A. flavus and A. parasiticus strains and altered sclerotium production in some A. flavus strains in which sclerotium production decreases in the light but increases in the dark. In A. nidulans, both asexual spore production and sexual spore production were altered by linoleic acid. Spore development was induced in all three species by hydroperoxylinoleic acids, which are linoleic acid derivatives that are produced during fungal colonization of seeds. The sporogenic effects of these linoleic compounds on A. nidulans are similar to the sporogenic effects of A. nidulans psi factor, an endogenous mixture of hydroxylinoleic acid moieties. Light treatments also significantly increased asexual spore production in all three species. The sporogenic effects of light, linoleic acid, and linoleic acid derivatives on A. nidulans required an intact veA gene. The sporogenic effects of light and linoleic acid on Aspergillus spp., as well as members of other fungal genera, suggest that these factors may be significant environmental signals for fungal development.
曲霉属真菌是常见的种子定殖真菌，它们通过无性孢子（作为接种体）的发育以及闭囊壳和菌核的形成来完成其病害循环。我们发现，构巢曲霉、黄曲霉和寄生曲霉中这三种结构的发育均受亚油酸和光照的影响。亚油酸的具体形态学效应包括诱导黄曲霉和寄生曲霉菌株早熟并增加无性孢子发育，以及改变一些黄曲霉菌株的菌核产生情况，这些菌株在光照条件下菌核产生减少，而在黑暗中增加。在构巢曲霉中，亚油酸改变了无性孢子产生和有性孢子产生。所有三个物种的孢子发育均由氢过氧化亚油酸诱导，氢过氧化亚油酸是亚油酸衍生物，在真菌定殖种子期间产生。这些亚油酸化合物对构巢曲霉的产孢效应类似于构巢曲霉psi因子（一种羟基亚油酸部分的内源性混合物）的产孢效应。光照处理也显著增加了所有三个物种的无性孢子产生。光照、亚油酸和亚油酸衍生物对构巢曲霉的产孢效应需要完整的veA基因。光照和亚油酸对曲霉属真菌以及其他真菌属成员的产孢效应表明，这些因素可能是真菌发育的重要环境信号。
