Comparative transcriptome analysis of susceptible and resistant sesame against charcoal rot

Sesame (Sesamum indicum L.) is an important oilseed crop with a unique property of regulating hypercholesterolemia. However, its vulnerability to Macrophomina phaseolina (Mp) Tassi (Goid) infection is a serious concern for the sesame growers worldwide. This destructive soil-borne pathogen causes charcoal rot of sesame, leading to high (>50%) yield losses, and most high yielding sesame cultivars of India are susceptible to charcoal rot. Traditionally, agricultural and chemical prevention measures are utilized to reduce the damage caused by M. phaseolina, it has become more important to develop disease-resistant varieties. However, wild type sesame (Sesamum mulayanum) shows a high degree of resistance against many pathogens. To better understand the resistance, exploration of the resistance gene pool through transcriptomics is a key approach.To find out potential defence-related genes, we have performed transcriptome analyses of three sesame genotypes in control and infected state. The founder sesame genotypes are susceptible Indian cultivar S. indicum and wild type S. mulyanum. Further, these contrasting lines were used as female and male parents of a recombinant line respectively. This study will help us to analyze the global gene expression and the molecular basis of interactions between sesame and Mp, particularly with respect to mechanisms of resistance and the basal defence response.

芝麻（Sesamum indicum L.）作为一种重要的油料作物，具有调节高胆固醇血症的独特属性。然而，其对Macrophomina phaseolina (Mp) Tassi (Goid)感染的易感性，成为全球芝麻种植者面临的一大严重问题。这种具有毁灭性的土传病原体导致芝麻炭疽病，造成高达50%以上的产量损失，而印度多数高产量芝麻品种均对炭疽病敏感。传统上，农业化学预防措施被用来减轻M. phaseolina造成的损害，但发展抗病品种的重要性日益凸显。野生型芝麻（Sesamum mulayanum）对多种病原体表现出高度的抗性。为更好地理解这种抗性，通过转录组学方法探索抗性基因库是关键途径。为发现潜在的防御相关基因，我们对三种芝麻基因型在未感染和感染状态下的转录组进行了分析。创始芝麻基因型为易感的印度栽培种S. indicum和野生型S. mulyanum。进一步地，这些对比系分别作为重组线杂交的雌性和雄性亲本。本研究有助于我们分析芝麻的全局基因表达以及与Mp相互作用，特别是关于抗性机制和基础防御反应的分子基础。