Sedaghatkish Afsaneh, Kunz Meik, Gossen Bruce D, McDonald Mary Ruth
Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada.
The Bioinformatics CRO, Inc., Sanford, FL, United States.
Front Microbiol. 2025 Apr 22;16:1581233. doi: 10.3389/fmicb.2025.1581233. eCollection 2025.
Clubroot, caused by the obligate Chromist pathogen , is an important disease of brassica crops but little is known about its reproductive biology. We enzymatically removed cell walls from dormant spores to generate protoplasts, enabling the first single-cell sequencing of with DNA free from host and soil microbial contamination. Analysis of 4,000 protoplasts from a single root showed moderate genetic diversity, with 2-5 distinct genotypes. A more detailed analysis of the 500 cells indicated the presence of seven distinct genotypes, accounting for rare haplotypes. This level of genetic diversity in a single root supports other indications that there is a high genetic diversity in field populations of . These results support the hypothesis that balancing selection maintains multiple genotypes within the pathogen population. This level of diversity complicates the use of single-gene resistance sources for clubroot management and explains the short durability of clubroot resistance. The predominance of distinct genotypes in a single root is a strong indication that reproduction of is predominantly clonal. This is the first whole genome DNA sequencing of a single-cell of a plant pathogen.
根肿病由专性色素体病原体引起，是十字花科作物的一种重要病害，但对其生殖生物学了解甚少。我们通过酶法去除休眠孢子的细胞壁以产生原生质体，从而实现了对无宿主和土壤微生物污染的DNA进行首次单细胞测序。对来自单个根的4000个原生质体的分析显示出中等程度的遗传多样性，有2至5种不同的基因型。对500个细胞的更详细分析表明存在7种不同的基因型，这解释了罕见单倍型的存在。单个根中的这种遗传多样性水平支持了其他表明田间病原菌群体存在高遗传多样性的迹象。这些结果支持了平衡选择在病原体群体中维持多种基因型的假设。这种多样性水平使利用单基因抗性资源来管理根肿病变得复杂，并解释了根肿病抗性的短期持久性。单个根中不同基因型的优势强烈表明病原菌的繁殖主要是克隆性的。这是植物病原体单细胞的首次全基因组DNA测序。
