Reduced contamination by the Fusarium mycotoxin zearalenone in maize kernels through genetic modification with a detoxification gene
Reduced contamination by the Fusarium mycotoxin zearalenone in maize kernels through genetic modification with a detoxification gene
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DOI：
10.1128/aem.01077-06
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发表时间：
2007-03-01
影响因子：
4.4
通讯作者：
Kimura, Makoto
中科院分区：
文献类型：
--
作者：
Igawa, Tomoko;Takahashi-Ando, Naoko;Kimura, Makoto
玉米的穗腐病是由产毒曲霉和镰刀菌引起的，导致黄曲霉毒素、伏马菌素、毛霉烯和玉米赤霉烯酮(Zen)的污染。毛霉烯类和禅宗真菌毒素是由谷物病原菌禾谷镰刀菌产生的。先前利用EGFP：：zhd101基因(Gfzhd101)开发了一种用于消除Zen的转基因解毒系统，该基因编码一种融合到Zen降解酶上的增强型绿色荧光蛋白。在本研究中，我们获得了一个表达完整gfzhd101拷贝的转基因玉米品系，并研究了转基因在籽粒中解毒的可行性。在种子成熟过程中(授粉后6周)，转基因籽粒中检测到了ZEN降解活性。在6℃下延长16周的贮藏时间后，种子的解毒活性水平没有变化。用Zen溶液在WC中浸泡48h，转基因种子中的真菌毒素总量被均匀地降低到野生型的1/10以下。在较低的水分活度和温度条件下，转基因玉米籽粒中的ZEN也得到了有效的净化；例如，在48h内每克种子在a=16.9mgZen的情况下被去除，在20℃时每克种子的Zen被去除0.90。转基因解毒可能为解决玉米中的真菌毒素污染问题提供简单的解决方案。
Maize is subject to ear rot caused by toxigenic Aspergillus and Fusarium species, resulting in contamination with aflatoxins, fumonisins, trichothecenes, and zearalenone (ZEN). The trichothecene group and ZEN mycotoxins are produced by the cereal pathogen Fusarium gramineartun. A transgenic detoxification system for the elimination of ZEN was previously developed using an egfp::zhd101 gene (gfzhd101), encoding an enhanced green fluorescent protein fused to a ZEN-degrading enzyme. In this study, we produced a transgenic maize line expressing an intact copy of gfzhd101 and examined the feasibility of transgene-mediated detoxification in the kernels. ZEN-degrading activity has been detected in transgenic kernels during seed maturation (for a period of 6 weeks after pollination). The level of detoxification activity was unaltered after an additional storage period of 16 weeks at 6 degrees C. When the seeds were artificially contaminated by immersion in a ZEN solution for 48 h at WC the total amount of the mycotoxin in the transgenic seeds was uniformly reduced to less than 1/10 of that in the wild type. The ZEN in the transgenic maize kernels was also efficiently decontaminated under conditions of lower water activity (a,) and temperature; e.g., 16.9 mu g of ZEN was removed per gram of seed within 48 h at an a, of 0.90 at 20 degrees C. F. gramineartun infection assays demonstrated an absence of ZEN in the transgenic maize seeds, while the mycotoxin accumulated in wild-type kernels under the same conditions. Transgene-mediated detoxitication may offer simple solutions to the problems of mycotoxin contamination in maize.