REDUCED VIRULENCE OF GIBBERELLA-ZEAE CAUSED BY DISRUPTION OF A TRICHOTHECENE TOXIN BIOSYNTHETIC GENE
REDUCED VIRULENCE OF GIBBERELLA-ZEAE CAUSED BY DISRUPTION OF A TRICHOTHECENE TOXIN BIOSYNTHETIC GENE
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DOI：
10.1094/mpmi-8-0593
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发表时间：
1995-07-01
影响因子：
3.5
通讯作者：
MCCORMICK, SP
中科院分区：
文献类型：
--
作者：
PROCTOR, RH;HOHN, TM;MCCORMICK, SP
一些植物病原镰刀菌产生的多孢霉素毒素被认为是其毒力的原因，如玉米赤霉菌（Gibbsrella zeae）（F.禾谷镰刀菌（G. graminearum）是一种重要的禾谷类病原菌，它能产生脱氧雪腐镰刀菌烯醇（deoxynivalenol）。zeae，我们通过基因破坏产生了该真菌的二孢噻吩缺陷型突变体。被破坏的基因，Tri 5，编码的酶，β-二烯合酶，催化的第一步，在β-二烯生物合成。为了破坏Tri 5，G.用携带被潮霉素B抗性基因中断的TRi 5编码区的双截短拷贝的质粒转化玉米。通过筛选不能产生三烯并通过Southern印迹分析来选择Tri 5（-）转化体。Tri 5（-）菌株对普通小麦和冬黑麦幼苗的毒力降低，但对金矮脚鸡玉米幼苗的毒力为野生型。在考德威尔和马歇尔小麦和波特燕麦幼苗上，Tri 5（-）菌株在引起比它们的野生型祖先菌株更少的疾病方面不一致，当用Tri 5（-）突变体接种时，小麦上的赤霉病比用野生型菌株接种时发展得更慢。这些结果表明，G.在一些主机上。
The production of trichothecene mycotoxins by some plant pathogenic species of Fusarium is thought to contribute to their virulence, Gibbsrella zeae (F. graminearum) is an important cereal pathogen that produces the trichothecene deoxynivalenol, To determine if trichothecene production contributes to the virulence of G. zeae, we generated trichothecene-deficient mutants of the fungus by gene disruption. The disrupted gene, Tri5, encodes the enzyme trichodiene synthase, which catalyzes the first step in trichothecene biosynthesis. To disrupt Tri5, G. zeae was transformed with a plasmid carrying a doubly truncated copy of the TRi5 coding region interrupted by a hygromycin B resistance gene. Tri5(-) transformants were selected by screening for the inability to produce trichothecenes and by Southern blot analysis. Tri5(-) strains exhibited reduced virulence on seedlings of Wheaten wheat and common winter rye, but wild-type virulence on seedlings of Golden Bantam maize. On Caldwell and Marshall wheat and Porter oat seedlings, Tri5(-) strains were inconsistent in causing less disease than their wild-type progenitor strain, Head blight developed more slowly on Wheaten when inoculated with Tri5(-) mutants than when inoculated with wild-type strains. These results suggest that trichothecene production contributes to the virulence of G. zeae on some hosts.