Sweet potato (Ipomoea batatas) ranks among the most important crops in the world and provides nutritional and economic sustainability for subsistence farmers in sub-Saharan Africa. Its production is mainly constrained by sweet potato virus disease (SPVD) caused by the coinfection of two positive-sense single-stranded RNA viruses, sweet potato chlorotic stunt virus (SPCSV) and sweet potato feathery mottle virus (SPFMV). Current understanding of sweet potato responses to SPCSV and SPFMV at the molecular level remains very limited. In this study, we performed deep sequencing of both messenger RNA (mRNA) and small RNA (sRNA) populations in an SPVD-susceptible cultivar ‘Beauregard’ upon viral infection, to identify biological pathways that contribute to both general and specific host responses to these important viral pathogens. We found that pathways related to stress response and signaling were significantly affected by viral infection. sRNA components of these pathways were predominantly affected in late stages of the coinfection by SPCSV and SPFMV. We identified several novel microRNAs that were responsive to viral infection, some of which were predicted to target nucleotide-binding site leucine-rich repeat (NBS-LRR) disease resistance genes. The downregulation of the salicylic acid-mediated defense response pathway in particular seems to be a result of the viral infection process, and can in part explain the susceptible nature of the ‘Beauregard’ cultivar.

红薯 ( Ipomoea batatas) 是世界上最重要的作物之一，为撒哈拉以南非洲的自给农民提供营养和经济可持续性。其生产主要受到由甘薯褪绿矮化病毒（SPCSV）和甘薯羽毛斑驳病毒（SPFMV）两种正义单链RNA病毒共同感染引起的甘薯病毒病（SPVD）的限制。目前在分子水平上对甘薯对 SPCSV 和 SPFMV 反应的理解仍然非常有限。在这项研究中，我们对 SPVD 易感品种“Beauregard”病毒感染后的信使 RNA (mRNA) 和小 RNA (sRNA) 种群进行了深度测序，以确定有助于宿主对这些病毒的一般和特定反应的生物学途径。重要的病毒病原体。我们发现与压力反应和信号传导相关的途径受到病毒感染的显着影响。这些途径的 sRNA 成分主要在 SPCSV 和 SPFMV 共感染的后期受到影响。我们确定了几种对病毒感染有反应的新型 microRNA，其中一些预测靶向核苷酸结合位点富含亮氨酸重复 (NBS-LRR) 的抗病基因。特别是水杨酸介导的防御反应途径的下调似乎是病毒感染过程的结果，并且可以部分解释“Beauregard”品种的易感性。我们确定了几种对病毒感染有反应的新型 microRNA，其中一些预测靶向核苷酸结合位点富含亮氨酸重复 (NBS-LRR) 的抗病基因。特别是水杨酸介导的防御反应途径的下调似乎是病毒感染过程的结果，并且可以部分解释“Beauregard”品种的易感性。我们确定了几种对病毒感染有反应的新型 microRNA，其中一些预测靶向核苷酸结合位点富含亮氨酸重复 (NBS-LRR) 的抗病基因。特别是水杨酸介导的防御反应途径的下调似乎是病毒感染过程的结果，并且可以部分解释“Beauregard”品种的易感性。