Metagenomic analyses of the soybean root mycobiome and microbiome

Taproot decline (TRD) of soybean is an emerging disease of soybean that has warranted much attention within the past five years. As the name indicates, the taproot is attacked by the pathogen Xylaria necrophora. The lower soybean stem and taproot appear black, dry, and brittle. The inner pith is colonized with robust, white mycelium. Diseased plants snap at the soil line, providing a key diagnostic feature in the field. TRD disease occurrence and yield loss associated with TRD are outstanding issues in soybean production. We applied nuclear ribosomal DNA Internal Transcribed Spacers and 16S rRNA gene taxonomic marker sequencing to define the composition of the fungal and bacterial communities associated with healthy and diseased soybean roots collected from the Mississippi Delta.

大豆根腐衰退病（Taproot decline, TRD）是近五年来备受学界关注的新兴大豆病害。顾名思义，其病原菌为坏死炭角菌（Xylaria necrophora），可侵染大豆主根。罹病植株的下部茎秆与主根会呈现发黑、干枯、脆化的症状，内部髓组织会被粗壮的白色菌丝体定殖。染病植株会在土线处发生折断，这是田间诊断的关键特征。当前，TRD的发生情况及其引发的产量损失仍是大豆生产中亟待解决的突出问题。本研究采用细胞核核糖体DNA内转录间隔区（Internal Transcribed Spacers, ITS）与16S核糖体RNA基因分类标记测序技术，对采自密西西比三角洲的健康与罹病大豆根系的真菌和细菌群落组成进行了解析。