Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan; Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan.
Vegitable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University, College Station, TX, 77843, USA.
Virus Res. 2021 Feb;293:198266. doi: 10.1016/j.virusres.2020.198266. Epub 2020 Dec 24.
Melon is one of the most popular fruits worldwide and has been bred into various cultivars. RNA-sequencing using healthy melon fruit was performed to determine differences in gene expression among cultivars. Unexpected RNA-seq results revealed that viruses asymptomatically infected fruits at a high frequency (16 of 21 fruits examined were infected) and that viral transcripts highly accumulated in comparison with host transcripts (15 %-75 % of total reads). Their nucleotide sequences and phylogenetic analyses indicated that more than 10 novel isolates of tobacco ringspot virus (TRSV) were found in melon fruits. Asymptomatic infection with TRSV on melon fruits was confirmed by both immunoblot and RT-PCR analyses. Numerous isolates of TRSV generated and maintained in melon fields, and this is likely due to their asymptomatic infections. This TRSV melon isolate infected Nicotiana benthamiana plants with stunting and yellowing symptoms. This is the first report of frequent and asymptomatic infection of TRSV in consumable melon fruits.
甜瓜是世界上最受欢迎的水果之一，已经培育出各种品种。本研究利用健康甜瓜果实进行 RNA 测序，以确定品种间基因表达的差异。出乎意料的 RNA-seq 结果表明，病毒以无症状的方式高频感染果实（在 21 个被检测的果实中，有 16 个被感染），与宿主转录本相比，病毒转录本高度积累（总读数的 15%-75%）。它们的核苷酸序列和系统发育分析表明，在甜瓜果实中发现了 10 多种烟草环斑病毒（TRSV）的新分离株。免疫印迹和 RT-PCR 分析均证实了 TRSV 在甜瓜果实上的无症状感染。在甜瓜田中产生和维持的大量 TRSV 分离株可能是由于它们的无症状感染。这种 TRSV 甜瓜分离株感染了本氏烟植物，表现出矮化和黄化症状。这是 TRSV 频繁无症状感染可食用甜瓜果实的首次报道。
