Molecular characterization and pathogenicity of an infectious cDNA clone of tomato brown rugose fruit virus

Ziyue Ma,Xueping Zhou,Zhongkai Zhang,Xiuling Yang,Hui Zhang,Ming Ding

doi:10.1186/s42483-021-00091-0

Abstract

Tomato brown rugose fruit virus (ToBRFV) is a new member of the genus Tobamovirus, and has the potential to affect the production and marketability of tomatoes and peppers. In this study, we sequenced and analyzed the complete genome of ToBRFV isolates from tomato plants showing mosaic and mottling symptoms in Yunnan Province of China. We constructed a full-length infectious cDNA clone of ToBRFV, which could induce systemic infection with typical symptoms in tomato, Nicotiana benthamiana, and N. tabacum cv. Samsun nn plants through Agrobacterium-mediated inoculation. Further experimental evidence demonstrated that the rod-shaped virions accumulating in agroinfiltrated plants are sap-transmissible. This is the first report on the construction of a biologically active, full-length infectious cDNA clone of ToBRFV. The system developed herein will facilitate further research on functions of ToBRFV-encoded proteins and plant-ToBRFV interactions through reverse genetic approaches.

Highlights

Tomato is one of the world’s most cultivated and extensively consumed vegetable crops, with an annual production of about 180 million tons in 2019 (FAOSTAT 2020, http://www.fao.org/faostat/en/#data)
Thereafter, seven samples were collected and tested for Tomato brown rugose fruit virus (ToBRFV) infection by Reverse transcriptionpolymerase chain reaction (RT-polymerase chain reaction (PCR)) using ToBRFV-specific primers based on the genomic sequences of tobacco mosaic virus (TMV), tomato mosaic virus (ToMV), and ToBRFV
Sequence comparisons were performed subsequently, and the alignment result showed 100% of nucleotide sequence identities among the five isolates, suggesting that they all belong to the same virus species

Summary

Introduction

Tomato is one of the world’s most cultivated and extensively consumed vegetable crops, with an annual production of about 180 million tons in 2019 (FAOSTAT 2020, http://www.fao.org/faostat/en/#data). Despite the increased annual production of tomatoes over the past 5 years, the yield and fruit quality of tomato plants are largely affected by an array of pests and diseases during their growing season in the field or postharvest period. As with other members of the genus Tobamovirus, ToBRFV has a positive singlestranded RNA genome that is encapsidated into a rodshaped particle of about 300 nm in length and 18 nm in diameter. It can be transmitted by contact, propagation materials, seeds, and bumblebees (Levitzky et al 2019; Davino et al 2020). While ToBRFV (2021) 3:14 has spread worldwide in only a few years, its incidence has been reported in Mexico, the United States of America, Germany, Italy, Palestine, Turkey, United Kingdom, Greece, China, Spain, Holland, France, Czech Republic, and Cyprus (Alkowni et al 2019; Camacho-Beltran et al 2019; Fidan et al 2019; Panno et al 2019; Skelton et al 2019; Yan et al 2019; Amer and Mahmoud 2020; Beris et al 2020; van de Vossenberg et al 2020; AlfaroFernández et al 2021)

Methods

Results

Conclusion