Identification of a new tospovirus causing necrotic ringspot on tomato in China

Abstract

BackgroundEmerging tospoviruses cause significant yield losses and quality reduction in vegetables, ornamentals, and legumes throughout the world. So far, eight tospoviruses were reported in China. Tomato fruits displaying necrotic and concentric ringspot symptoms were found in Guizhou province of southwest China.FindingELISA experiments showed that crude saps of the diseased tomato fruit samples reacted with antiserum against Tomato zonate spot virus (TZSV). Electron microscopy detected presence of quasi-spherical, enveloped particles of 80–100 nm in such saps. The putative virus isolate was designated 2009-GZT. Mechanical back-inoculation showed that 2009-GZT could infect systemically some solanaceous crop and non-crop plants including Capiscum annuum, Datura stramonium, Nicotiana benthamiana, N. rustica, N. tabacum and Solanum lycopersicum. The 3012 nt full-length sequence of 2009-GZT S RNA shared 68.2% nt identity with that of Calla lily chlorotic spot virus (CCSV), the highest among all compared viruses. This RNA was predicted to encode a non-structural protein (NSs) (459 aa, 51.7 kDa) and a nucleocapsid protein (N) (278 aa, 30.3 kDa). The N protein shared 85.8% amino acid identity with that of CCSV. The NSs protein shared 82.7% amino acid identity with that of Tomato zonate spot virus(TZSV).ConclusionOur results indicate that the isolate 2009-GZT is a new species of Tospovirus, which is named Tomato necrotic spot virus (TNSV). This finding suggests that a detailed survey in China is warranted to further understand the occurrence and distribution of tospoviruses.

Resistance to Tospoviruses in Vegetable Crops: Epidemiological and Molecular Aspects

“…A phylogenetic tree based on the N-protein coding sequences, one of the ICTV (International Committee on Taxonomy of Viruses) demarcation criteria, is displayed in Figure 1 and includes all the proposed and established tospovirus species, with the main geographically based origin for each clade. In Asia, a number of new potential threats to vegetable crops have been recently discovered infecting tomato, sweet pepper (50,110,150), and ornamental crops (36); particularly worrisome is the recent first report of TSWV in India (97). Meanwhile, Iris yellow spot virus (IYSV) belonging to the Euro-Asian clade has been spreading in Europe (5).…”

Development of a microarray for simultaneous detection and differentiation of different tospoviruses that are serologically related to Tomato spotted wilt virus

“…A threshold of 90% amino acid (aa) identity of the NP is proposed to classify tospoviruses at the species level [6, 18]. Currently, 29 tospovirus species are identified based on the sequence determination of the N gene or S RNA [3, 19–24]. In addition, most of the known tospoviruses are clustered into three major serogroups, which are assigned by the TSWV, Watermelon silver mottle virus (WSMoV) and Iris yellow spot virus (IYSV) due to the serological relatedness of their NPs [25].…”

Occurrence and diversity of Tomato spotted wilt virus isolates breaking the Tsw resistance gene of Capsicum chinense in Yunnan, southwest China

“…In China, symptoms on tomatoes, resembling tomato spotted wilt disease, were first described in Sichuan Province in 1944 (Su et al ., ). After that, tospoviruses were found in many regions of China (Yao, ; Li et al ., ; Ding et al ., ; Dong et al ., ; Xu et al ., , , ; Yin et al ., ; Zheng et al ., ). However, the molecular identification of TSWV was not confirmed until 2011, with the first complete genome sequence of this Tospovirus type species from Yunnan Province, southwest China (Hu et al ., ).…”