Table_1_Spore Germination of the Obligate Biotroph Spongospora subterranea: Transcriptome Analysis Reveals Germination Associated Genes.XLSX

For soilborne pathogens, germination of the resting or dormant propagule that enables persistence within the soil environment is a key point in pathogenesis. Spongospora subterranea is an obligate soilborne protozoan that infects the roots and tubers of potato causing root and powdery scab disease for which there are currently no effective controls. A better understanding of the molecular basis of resting spore germination of S. subterranea could be important for development of novel disease interventions. However, as an obligate biotroph and soil dwelling organism, the application of new omics techniques for the study of the pre-infection process in S. subterranea has been problematic. Here, RNA sequencing was used to analyse the reprogramming of S. subterranea resting spores during the transition to zoospores in an in-vitro model. More than 63 million mean high-quality reads per sample were generated from the resting and germinating spores. By using a combination of reference-based and de novo transcriptome assembly, 6,664 unigenes were identified. The identified unigenes were subsequently annotated based on known proteins using BLAST search. Of 5,448 annotated genes, 570 genes were identified to be differentially expressed during the germination of S. subterranea resting spores, with most of the significant genes belonging to transcription and translation, amino acids biosynthesis, transport, energy metabolic processes, fatty acid metabolism, stress response and DNA repair. The datasets generated in this study provide a basic knowledge of the physiological processes associated with spore germination and will facilitate functional predictions of novel genes in S. subterranea and other plasmodiophorids. We introduce several candidate genes related to the germination of an obligate biotrophic soilborne pathogen which could be applied to the development of antimicrobial agents for soil inoculum management.

土壤传播的病原体，休眠或休止状态的繁殖体在土壤环境中的萌发，是实现病原体持久生存的关键环节。Spongospora subterranea是一种严格的土壤传播原生动物，感染马铃薯的根和块茎，导致根腐病和粉状疫病，目前尚无有效的控制措施。对S. subterranea休眠孢子萌发分子机制的理解，对于开发新的病害干预措施可能具有重要意义。然而，作为严格的生物寄主和土壤栖息生物，将新的组学技术应用于研究S. subterranea感染前过程存在一定问题。在本研究中，通过RNA测序技术分析了S. subterranea休眠孢子在体外向游动孢子过渡过程中的重编程。每个样本从休眠和萌发孢子中产生了超过6300万个平均高质量读数。通过结合基于参考序列和新转录组组装的方法，共鉴定出6,664个非冗余基因。这些非冗余基因随后基于已知蛋白质通过BLAST搜索进行注释。在5,448个注释基因中，有570个基因在S. subterranea休眠孢子萌发过程中表现出差异表达，其中大多数显著基因属于转录和翻译、氨基酸生物合成、运输、能量代谢过程、脂肪酸代谢、应激反应和DNA修复。本研究生成的数据集为与孢子萌发相关的生理过程提供了基本知识，并将促进S. subterranea和其他接合菌纲生物中新型基因的功能预测。我们介绍了与严格生物寄主土壤传播病原体萌发相关的候选基因，这些基因可应用于土壤接种物管理的抗菌剂开发。