Food and Feed Safety Research Unit, Southern Regional Research Center, United States Department of Agriculture, Agricultural Research Service, New Orleans, LA 70124, USA.
Int J Mol Sci. 2021 Apr 3;22(7):3747. doi: 10.3390/ijms22073747.
()-mediated aflatoxin contamination in maize is a major global economic and health concern. As is an opportunistic seed pathogen, the identification of factors contributing to kernel resistance will be of great importance in the development of novel mitigation strategies. Using V3-V4 bacterial rRNA sequencing and seeds of -resistant maize breeding lines TZAR102 and MI82 and a susceptible line, SC212, we investigated kernel-specific changes in bacterial endophytes during infection. A total of 81 bacterial genera belonging to 10 phyla were detected. Bacteria belonging to the phylum comprised 86-99% of the detected phyla, followed by (14%) and others (<5%) that changed with treatments and/or genotypes. Higher basal levels (without infection) of and in TZAR102 and increases in the abundance of and in MI82 following infection may suggest their role in resistance. Functional profiling of bacteria using 16S rRNA sequencing data revealed the presence of bacteria associated with the production of putative type II polyketides and sesquiterpenoids in the resistant vs. susceptible lines. Future characterization of endophytes predicted to possess antifungal/ anti-aflatoxigenic properties will aid in their development as effective biocontrol agents or microbiome markers for maize aflatoxin resistance.
黄曲霉毒素污染是一个主要的全球经济和健康问题。由于 是一种机会性种子病原体，因此确定导致籽粒抗性的因素对于开发新的缓解策略将非常重要。本研究使用 V3-V4 细菌 rRNA 测序和抗 - 的玉米育种系 TZAR102 和 MI82 以及易感系 SC212 的种子，研究了感染过程中内生细菌在籽粒中的特异性变化。共检测到 81 个细菌属，属于 10 个门。门 的细菌占检测到的门的 86-99%，其次是 （14%）和其他门（<5%），它们随处理和/或基因型而变化。在 TZAR102 中，基础水平（无感染）下 和 的含量较高，感染后 MI82 中 和 的丰度增加，这可能表明它们在抗性中的作用。使用 16S rRNA 测序数据对细菌进行功能分析表明，在抗性与易感系中存在与产生假定的 II 型聚酮和倍半萜有关的细菌。对预测具有抗真菌/抗黄曲霉毒素特性的内生菌进行特征描述，将有助于将其开发为有效的生物防治剂或玉米抗黄曲霉毒素的微生物组标记。
