Molad Ori, Leibman Diana, Luria Neta, Sela Noa, Lachman Oded, Smith Elisheva, Reches Meital, Dombrovsky Aviv
Agricultural Research Organization - The Volcani Institute, Plant Pathology Department, Rishon LeZion, Israel.
Hebrew University of Jerusalem Faculty of Science, Institute of Chemistry and The Center for Nanoscience and Nanotechnology , Jerusalem, Jerusalem, Israel;
Plant Dis. 2025 Jul 2. doi: 10.1094/PDIS-07-24-1533-RE.
Tomato brown rugose fruit virus (ToBRFV) is a seed-borne, soil-borne, mechanically transmitted tobamovirus infecting tomato plants worldwide. Tobamovirus-contaminated soil occurring after a growth cycle of infected crops constitutes a primary source of infection for newly planted seedlings, severely affecting crops under the common practice of monoculture farming. For our studies of interrelationships between ToBRFV-infected plants and virus preservation in soil, we have grown ToBRFV-inoculated wild tomato species for five months and analyzed ToBRFV preservation in soil after plant removal. Soil virion RNA subjected to a high throughput sequencing analysis (HTS) revealed the presence of a single isolate with 99.92% similarity to wild-type (WT) ToBRFV. The isolate recovered from the soil contained one nonsynonymous mutation at the movement protein resulting in A134T amino acid substitution. ToBRFV-A134T was stable in -resistant tomato plants (e.g., cv. Ikram), and in co-inoculation experiments with ToBRFV-WT, both isolates were present. The effect of ToBRFV-A134T on tomato plants was studied in comparison to ToBRFV-WT infections. Whereas ToBRFV-WT-infected plants showed mottling-mosaic leaves occasionally associated with shoestring-like symptoms, ToBRFV-A134T-infected plant's leaves showed severe shoestring-like symptoms and unique fern-like leaflets on shoestring-like leaf backbones. Analyses of genes involved in shoestring-like symptoms in -resistant tomato plants by RT-qPCR revealed differential relative expression of RNA-dependent-RNA-polymerase 6b, Dicer-like 4, and Dicer-like 2b in ToBRFV-WT-infected Ikram plants compared to ToBRFV-A134T-infected plants. The results may indicate that different mechanisms are involved in the regulation of severe shoestring-like symptoms induced by ToBRFV-A134T compared to symptoms induced by ToBRFV-WT.
番茄褐色皱纹果病毒（ToBRFV）是一种通过种子、土壤传播以及机械传播的烟草花叶病毒属病毒，可感染全球范围内的番茄植株。受烟草花叶病毒污染的土壤在受感染作物生长周期后出现，这构成了新种植幼苗的主要感染源，在单一栽培种植的常见做法下严重影响作物。为了研究受ToBRFV感染的植物与土壤中病毒保存之间的相互关系，我们种植了接种ToBRFV的野生番茄品种五个月，并在移除植物后分析了土壤中ToBRFV的保存情况。对土壤病毒粒子RNA进行高通量测序分析（HTS）显示存在一个与野生型（WT）ToBRFV相似度为99.92%的单一分离株。从土壤中回收的分离株在运动蛋白处含有一个非同义突变，导致A134T氨基酸取代。ToBRFV - A134T在抗性番茄植株（如品种Ikram）中稳定，并且在与ToBRFV - WT的共接种实验中，两种分离株都存在。与ToBRFV - WT感染相比，研究了ToBRFV - A134T对番茄植株的影响。虽然ToBRFV - WT感染的植株偶尔出现斑驳花叶，有时伴有鞋带状症状，但ToBRFV - A134T感染的植株叶片表现出严重的鞋带状症状，并且在鞋带状叶主脉上有独特的蕨类叶状小叶。通过RT - qPCR分析抗性番茄植株中与鞋带状症状相关的基因，发现与ToBRFV - A134T感染的植株相比，ToBRFV - WT感染的Ikram植株中RNA依赖性RNA聚合酶6b、Dicer样4和Dicer样2b的相对表达存在差异。结果可能表明，与ToBRFV - WT诱导的症状相比，ToBRFV - A134T诱导的严重鞋带状症状的调控涉及不同的机制。
