中文摘要：黄曲霉是一种感染玉米和其他富含脂肪酸的食物和饲料作物的腐生真菌，其产生有毒和致癌的次生代谢物即黄曲霉毒素。玉米黄曲霉毒素的污染对人类健康构成严重威胁，其会降低作物价值，从而导致巨大的经济损失。本文设计了一个由TypyPLESIL衍生的合成肽AGM182，并测试其在植物体外和体内的抗真菌活性。体外研究显示，相对于TaqyPLESIN1，AGM182对黄曲霉的抗真菌活性性增加了五倍。本文通过农杆菌介导的转基因方法，生成了在玉米泛素1启动子下表达AGM182的转基因玉米植株。PCR产物证实了AGM182基因的整合，而玉米RNA的RT-PCR证实了AGM182转录本的存在。使用高度黄曲霉产黄曲霉菌株（AF70）的玉米核筛选试验显示，与转基因阴性对照种子相比，AGM182转基因种子中真菌生长减少了72%。AGM182转基因种子中真菌生长的减少会导致黄曲霉毒素水平显著降低（76%-98%）。研究结果表明，抗菌黄曲霉肽的合理设计和合成，对减少经济上重要的食物和饲料作物如玉米的真菌生长和黄曲霉毒素污染是有效的。
外文摘要：Aspergillus fiavus is an opportunistic, saprophytic fungus that infects maize and other fatty acid-rich food and feed crops and produces toxic and carcinogenic secondary metabolites known as aflatoxins. Contamination of maize with aflatoxin poses a serious threat to human health in addition to reducing the crop value leading to a substantial economic loss. Here we report designing a tachyplesinl-derived synthetic peptide AGM182 and testing its antifungal activity both in vitro and in planta. In vitro studies showed a five-fold increase in antifungal activity of AGM182 (vs. tachyplesin1) against A. flavus. Transgenic maize plants expressing AGM182 under maize Ubiquitin-1 promoter were produced through Agrobacterium-mediated transformation. PCR products confirmed integration of the AGM182 gene, while RT-PCR of maize RNA confirmed the presence of AGM182 transcripts. Maize kernel screening assay using a highly aflatoxigenic A. flavus strain (AF70) showed up to 72% reduction in fungal growth in the transgenic AGM182 seeds compared to isogenic negative control seeds. Reduced fungal growth in the AGM182 transgenic seeds resulted in a significant reduction in aflatoxin levels (76-98%). The results presented here show the power of computational and synthetic biology to rationally design and synthesize an antimicrobial peptide against A. fiavus that is effective in reducing fungal growth and aflatoxin contamination in an economically important food and feed crop such as maize.
外文关键词： Aflatoxin, Antimicrobial peptide, Aspergillus flavus, Maize, Synthetic peptide, Tachyplesin
作者： Rajasekaran, Kanniah; Sayler, Ronald J.; Sickler, Christine M.; Majumdar, Rajtilak; Jaynes, Jesse M.; Cary, Jeffrey W.
作者单位：USDA ARS
期刊名称：PLANT SCIENCE
期刊影响因子：3.437
出版年份：2018
出版刊次：5
点击下载：表达AGM182的转基因玉米籽粒中黄曲霉生长和黄曲霉毒素产生的控制研究