文献类型： 外文期刊

作者： Omolehin, Olanike ¹ ; Raruang, Yenjit ¹ ; Hu, Dongfang ¹ ; Han, Zhu-Qiang ² ; Wei, Qijian ³ ; Wang, Kan ⁴ ; Rajasekaran, Kanniah ³ ; Cary, Jeffrey W. ³ ; Chen, Zhi-Yuan ¹ ;

作者机构： 1.Louisiana State Univ, Ctr Agr, Dept Plant Pathol & Crop Physiol, Baton Rouge, LA 70803 USA

2.Guangxi Acad Agr Sci, Cash Crops Res Inst, Nanning 530007, Peoples R China

3.USDA ARS, Food & Feed Safety Res Unit, Southern Reg Res Ctr, New Orleans, LA 70124 USA

4.Iowa State Univ, Dept Agron, Ames, IA 50011 USA

关键词： Aspergillus flavus; host induced gene silencing; alkaline protease (alk); aflatoxin resistance; transgenic maize; small RNA; breeding; RNA interference

期刊名称：JOURNAL OF FUNGI （ 影响因子：5.724； 五年影响因子：6.413 ）

ISSN：

年卷期： 2021 年 7 卷 11 期

页码：

收录情况： SCI

摘要： Aspergillus flavus is a fungal pathogen that infects maize and produces aflatoxins. Host-Induced Gene Silencing (HIGS) has been shown to reduce host infection by various fungal pathogens. Here, the A. flavus alkaline protease (alk) gene was targeted for silencing through HIGS. An RNAi vector carrying a portion of the alk gene was incorporated into the B104 maize genome. Four out of eight transformation events containing the alk gene, Alk-3, Alk-4, Alk-7 and Alk-9, were self-pollinated to T4/T6 generations. At T3, the Alk-transgenic lines showed up to 87% reduction in aflatoxin accumulation under laboratory conditions. T4 transgenic Alk-3 and Alk-7 lines, and T5 and T6 Alk-4 and Alk-9 showed an average of 84% reduction in aflatoxin accumulation compared to their null controls under field inoculations (p < 0.05). F-1 hybrids of three elite maize inbred lines and the transgenic lines also showed significant improvement in aflatoxin resistance (p < 0.006 to p < 0.045). Reduced A. flavus growth and levels of fungal ss-tubulin DNA were observed in transgenic kernels during in vitro inoculation. Alk-4 transgenic leaf and immature kernel tissues also contained about 1000-fold higher levels of alk-specific small RNAs compared to null controls, indicating that the enhanced aflatoxin resistance in the transgenic maize kernels is due to suppression of A. flavus infection through HIGS of alk gene.