Majumdar Rajtilak, Rajasekaran Kanniah, Sickler Christine, Lebar Matthew, Musungu Bryan M, Fakhoury Ahmad M, Payne Gary A, Geisler Matt, Carter-Wientjes Carol, Wei Qijian, Bhatnagar Deepak, Cary Jeffrey W
Food and Feed Safety Research Unit, United States Department of Agriculture - Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States.
Department of Plant Biology, Southern Illinois University, Carbondale, IL, United States.
Front Plant Sci. 2017 Oct 17;8:1758. doi: 10.3389/fpls.2017.01758. eCollection 2017.
is an opportunistic plant pathogen that colonizes and produces the toxic and carcinogenic secondary metabolites, aflatoxins, in oil-rich crops such as maize ( L.). Pathogenesis-related (PR) proteins serve as an important defense mechanism against invading pathogens by conferring systemic acquired resistance in plants. Among these, production of the PR maize seed protein, (AC205274.3_FG001), has been speculated to be involved in resistance to infection by and other pathogens. To better understand the relative contribution of to resistance and aflatoxin production, a seed-specific RNA interference (RNAi)-based gene silencing approach was used to develop transgenic maize lines expressing hairpin RNAs to target . Downregulation of in transgenic kernels resulted in a ∼250-350% increase in infection accompanied by a ∼4.5-7.5-fold higher accumulation of aflatoxins than control plants. Gene co-expression network analysis of RNA-seq data during the -maize interaction identified as a network hub possibly responsible for regulating several downstream candidate genes associated with disease resistance and other biochemical functions. Expression analysis of these candidate genes in the -RNAi lines demonstrated downregulation (vs. control) of a majority of these -regulated genes during infection. These results are consistent with a key role of in resistance to infection and aflatoxin accumulation in maize kernels.
是一种机会性植物病原体，它在玉米（L.）等富含油脂的作物中定殖并产生有毒和致癌的次生代谢产物黄曲霉毒素。病程相关（PR）蛋白通过赋予植物系统获得性抗性，作为对抗入侵病原体的重要防御机制。其中，PR玉米种子蛋白（AC205274.3_FG001）的产生被推测与对感染及其他病原体的抗性有关。为了更好地理解其对感染抗性和黄曲霉毒素产生的相对贡献，采用了基于种子特异性RNA干扰（RNAi）的基因沉默方法来培育表达发夹RNA以靶向它的转基因玉米品系。转基因籽粒中该基因的下调导致感染增加约250 - 350%，同时黄曲霉毒素的积累比对照植物高约4.5 - 7.5倍。对玉米相互作用期间RNA-seq数据的基因共表达网络分析确定它为一个网络枢纽，可能负责调节几个与抗病性和其他生化功能相关的下游候选基因。在该基因RNAi品系中对这些候选基因的表达分析表明，在感染期间，这些受该基因调控的基因大多数（与对照相比）下调。这些结果与该基因在玉米籽粒对感染的抗性和黄曲霉毒素积累中的关键作用一致。
