کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2836713 | 1570871 | 2007 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Destruxin B produced by Alternaria brassicae does not induce accessibility of host plants to fungal invasion Destruxin B produced by Alternaria brassicae does not induce accessibility of host plants to fungal invasion](/preview/png/2836713.png)
It has been reported that Alternaria brassicae, the causal agent of gray leaf spot in Brassica plants, produces a host-specific or host-selective toxin (HSTs) identified as destruxin B. In this study, the role of destruxin B in infection of the pathogen was investigated. Destruxin B purified from culture filtrates (CFs) of A. brassicae induced chlorosis on host leaves at 50–100 μg ml−1, and chlorosis or necrosis on non-host leaves at 250–500 μg ml−1. Destruxin B was detected in spore germination fluids (SGFs) on host and non-host leaves, but not in a sufficient amount to exert toxicity to host plants. When spores of non-pathogenic A. alternata were combined with destruxin B at 100 μg ml−1 and inoculated on the leaves, destruxin B did not affect the infection behavior of the spores. Interestingly, SGF on host leaves allowed non-pathogenic spores to colonize host leaves. Moreover, a high molecular weight fraction (>5 kDa) without destruxin B obtained by ultrafiltration of SGF had host-specific toxin activity and infection-inducing activity. From these results, we conclude that destruxin B is not a HST and does not induce the accessibility of the host plant which is essential for colonization of the pathogen. In addition, the results with SGF imply that a high molecular weight HST(s) is involved in the host–pathogen interaction.
Journal: Physiological and Molecular Plant Pathology - Volume 71, Issues 1–3, July–September 2007, Pages 48–54