National Crops Resources Research Institute (NaCRRI), Namulonge, Uganda.
Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
Sci Rep. 2017 Aug 29;7(1):9747. doi: 10.1038/s41598-017-09617-z.
A time-course transcriptome analysis of two cassava varieties that are either resistant or susceptible to cassava brown streak disease (CBSD) was conducted using RNASeq, after graft inoculation with Ugandan cassava brown streak virus (UCBSV). From approximately 1.92 billion short reads, the largest number of differentially expressed genes (DEGs) was obtained in the resistant (Namikonga) variety at 2 days after grafting (dag) (3887 DEGs) and 5 dag (4911 DEGs). At the same time points, several defense response genes (encoding LRR-containing, NBARC-containing, pathogenesis-related, late embryogenesis abundant, selected transcription factors, chaperones, and heat shock proteins) were highly expressed in Namikonga. Also, defense-related GO terms of 'translational elongation', 'translation factor activity', 'ribosomal subunit' and 'phosphorelay signal transduction', were overrepresented in Namikonga at these time points. More reads corresponding to UCBSV sequences were recovered from the susceptible variety (Albert) (733 and 1660 read counts per million (cpm)) at 45 dag and 54 dag compared to Namikonga (10 and 117 cpm respectively). These findings suggest that Namikonga's resistance involves restriction of multiplication of UCBSV within the host. These findings can be used with other sources of evidence to identify candidate genes and biomarkers that would contribute substantially to knowledge-based resistance breeding.
对两种木薯品种进行了时间进程转录组分析,这两种品种对木薯褐色条斑病(CBSD)具有抗性或敏感性,使用 RNASeq 进行分析,然后用乌干达木薯褐色条斑病毒(UCBSV)进行接枝接种。从大约 19.2 亿个短读长中,在接枝后 2 天(3887 个差异表达基因(DEG))和 5 天(4911 个 DEG)获得了最多数量的差异表达基因(DEG)Namikonga 品种(抗性品种)。在同一时间点,Namikonga 中高度表达了几种防御反应基因(编码 LRR 包含、NBARC 包含、病程相关、晚期胚胎发生丰富、选择转录因子、伴侣和热休克蛋白)。此外,在这些时间点,Namikonga 中防御相关的 GO 术语“翻译延伸”、“翻译因子活性”、“核糖体亚基”和“磷酸接力信号转导”也过表达。与 Namikonga 相比,易感品种(Albert)在 45 天和 54 天的 UCBSV 序列的读长数分别为 733 和 1660 个每百万读数(cpm),而 Namikonga 的读长数分别为 10 和 117 个 cpm。这些发现表明,Namikonga 的抗性涉及限制病毒在宿主内的繁殖。这些发现可以与其他证据来源结合使用,以确定候选基因和生物标志物,这将为基于知识的抗性育种做出重大贡献。