Rhizoctonia solani is a soilborne pathogen with a broad host range. An anastomosis group (AG) system based on hyphal fusions has been established to distinguish between different R. solani subgroups in this species complex. Members of the AG2-2IIIB subgroup can cause serious problems in sugar beet production, resulting in Rhizoctonia root and crown rot. In this review, we summarize the current molecular advances in the R. solani sugar beet pathosystem. The draft genome of R. solani AG2-2IIIB has an estimated size of 56.02 Mb, larger than any of the R. solani AGs sequenced to date. The genome of AG2-2IIIB has been predicted to harbor 11,897 protein-encoding genes, including a high number of carbohydrate-active enzymes (CAZymes). The highest number of CAZymes was observed for polysaccharide lyase family 1 (PL-1), glycoside hydrolase family 43 (GH-43), and carbohydrate esterase family 12 (CE-12). Eleven single-effector candidates were predicted based on AG2-2IIIB genome data. The RsLysM, RsRlpA, and RsCRP1 genes were highly induced upon early-stage infection of sugar beet seedlings, and heterologous expression in Cercospora beticola and model plant species demonstrated their involvement in virulence. However, despite the progress achieved thus far on the molecular interactions in this pathosystem, many aspects remain to be elucidated, including the development of efficient transformation systems, important for functional studies, and the silencing of undesirable traits in the sugar beet crop.

立枯丝核菌是一种寄主范围广泛的土传病原体。已经建立了基于菌丝融合的吻合群 (AG) 系统，以区分该物种复合体中的不同R. solani亚群。AG2-2IIIB 亚组的成员会导致甜菜生产出现严重问题，导致丝核菌根腐病和冠腐病。在这篇综述中，我们总结了R. solani甜菜病理系统的当前分子进展。R. solani AG2-2IIIB的基因组草图估计大小为 56.02 Mb，大于任何R. solani迄今为止测序的 AG。据预测，AG2-2IIIB 的基因组包含 11,897 个蛋白质编码基因，包括大量碳水化合物活性酶 (CAZymes)。多糖裂解酶家族 1 (PL-1)、糖苷水解酶家族 43 (GH-43) 和碳水化合物酯酶家族 12 (CE-12) 的 CAZyme 数量最多。基于 AG2-2IIIB 基因组数据预测了 11 个单效应候选物。RsLysM、RsRlpA和RsCRP1基因在甜菜幼苗的早期感染中被高度诱导，并在 Cercospora beticola 中异源表达和模型植物物种证明了它们参与毒力。然而，尽管迄今为止在该病理系统中的分子相互作用方面取得了进展，但许多方面仍有待阐明，包括有效转化系统的开发，这对功能研究很重要，以及甜菜作物不良性状的沉默。