Role of Sw5 gene cluster in the fight against plant viruses

2022 ◽  
Author(s):  
Namisha Sharma ◽  
Ashish Prasad ◽  
Manoj Prasad

The Sw5 gene cluster furnishes robust resistance to Tomato spotted wilt virus in tomato, which has led to its widespread applicability in agriculture. Among the five orthologs, Sw5b functions as a resistance gene against a broad-spectrum Tospovirus and is linked with Tospovirus resistance. However, its paralog, Sw5a, has been recently implicated in providing resistance against Tomato leaf curl New Delhi virus , broadening the relevance of the Sw5 gene cluster in promoting defense against plant viruses. We propose that plants have established modifications within the homologs of R genes that permit identification of different effector proteins and provide broad and robust resistance against different pathogens through activation of hypersensitive response and cell death.

2021 ◽  
Author(s):  
Kaiqiang Hao ◽  
Ming Gu ◽  
Miaoren Yang ◽  
Xinran Gao ◽  
Zihao Xia ◽  
...  

Abstract Tomato spotted wilt virus (TSWV) is one of the most economically destructive and scientifically challenging plant viruses, which has seriously affected the production of commercial crops. At present, there is no effective strategy to control this virus. Therefore, there is an urgent need for a rapid and simple method to detect TSWV, which is of great significance to prevent its spread. In this study, an isolate of TSWV (TSWV-LNTL) infecting pepper from Liaoning Province of northeast China was obtained. A phylogenetic tree based on neighbor-joining using coat protein (CP) gene was established. A rapid method for detecting TSWV by recombinase polymerase amplification (RPA) was established. The phylogenetic tree based on the nucleotide sequences of coat protein (CP) genes of different TSWV isolates showed that the genetic relationship of TSWV-LNTL was most closely related to that of TSWV-LX-Lettuce-12 (Yunnan) and TSWV-TSHL (Shandong) isolates in China. It can be finished at 39 °C for 20 min and then purified by heating at 65 °C for 10 min. The RPA primers were highly specific and no cross-reactivity was detected with other selected viruses infecting pepper. The results of sensitivity test revealed that the detection limit of RPA is 1.0 × 103 copies/μL, which was tenfold lower than that of PCR method. In addition, the RPA method was successfully applied to detect TSWV in field samples. These results reported the occurrence of TSWV on crop in Liaoning Province of northeast China and demonstrated that the established RPA assay provided an effective molecular diagnostic tool for the accurate and rapid detection of TSWV to prevent its spread.


2020 ◽  
Vol 117 (42) ◽  
pp. 26237-26244
Author(s):  
Yoav Bahat ◽  
Joel Alter ◽  
Moshe Dessau

Tospoviridaeis a family of enveloped RNA plant viruses that infect many field crops, inflicting a heavy global economic burden. These tripartite, single-stranded, negative-sense RNA viruses are transmitted from plant to plant by thrips as the insect vector. The medium (M) segment of the viral genome encodes two envelope glycoproteins, GNand GC, which together form the envelope spikes. GCis considered the virus fusogen, while the accompanying GNprotein serves as an attachment protein that binds to a yet unknown receptor, mediating the virus acquisition by the thrips carrier. Here we present the crystal structure of glycoprotein N (GN) from the tomato spotted wilt virus (TSWV), a representative member of theTospoviridaefamily. The structure suggests that GNis organized as dimers on TSWV’s outer shell. Our structural data also suggest that this dimerization is required for maintaining GNstructural integrity. Although the structure of the TSWV GNis different from other bunyavirus GNproteins, they all share similar domain connectivity that resembles glycoproteins from unrelated animal-infecting viruses, suggesting a common ancestor for these accompanying proteins.


Biljni lekar ◽  
2021 ◽  
Vol 49 (2) ◽  
pp. 148-157
Author(s):  
Marina Ćuk ◽  
Zagorka Savić ◽  
Renata Iličić ◽  
Ferenc Bagi

Tomato spotted wilt virus (TSWV) is the most economically important plant viruses from genus Tospovirus. It has a polyphagous character and infects a wide range of very significant agricultural crops. Vectors of viruses are insects from order Thysanoptera (Thripidae) and till know eight species are known to transmit tospoviruses of which Frankliniella occidentalis is considered to be economically most important vector. TSWV is transmitted by thrips in a persistent and propagative manner. Relationship between vector and TSWV is very specific because vectors acquire the virus in the larval stages, while imago plays a key role in transmission of the virus. TSWV causes wide range of symptoms depending on host plant, external environmental conditions and type of viruses. In addition to affecting the fruit quality of cultivated crops, greatly reduces the yield to agricultural producers. Tomato is the most commonly attacked by TSWV, and after the symptoms manifested on leaves in the form of a bronze color, the virus was name. Protection of agricultural crops is very challenging and difficult due to wide distribution of viruse vectors, their hidden way of life as well as wide range of TSWV hosts.


Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 442-442 ◽  
Author(s):  
R. Pourrahim ◽  
Sh. Farzadfar ◽  
A. A. Moini ◽  
N. Shahraeen ◽  
A. Ahoonmanesh

Severe leaf and stem necrosis before flowering was observed in potato (Solanum tuberosum) fields of Firouzkoh Province, Iran, during the summer of 1998. Infected plants died before the end of the growing season. Necrosis was more severe in cv. Agria than in cvs. Ajaxs and Arinda. A high population of Thrips tabaci was observed in August and September. Tomato spotted wilt virus (TSWV) (1) was detected in affected potatoes by using specific TSWV-IgG (from Bioreba) in double-antibody sandwich enzyme linked immunosorbent assay and by indicator plant reactions. Mechanical inoculation of indicator plants with leaf extracts of symptomatic potatoes produce necrotic local lesions in Chenopodium quinoa, C. amaranticolor, Gomphrena globosa, Vicia faba, Vigna sinensis, Phaseolus aureus var. Gohar, P. vulgaris, and Petunia hybrida. The virus caused systemic necrosis in Capsicum frutescens, Datura stramonium, D. metel, Nicotiana glutinosa, N. rustica, and Trapaeolum majus, preceded by systemic chlorotic spots. TSWV was reported from ornamental crops in Tehran and Absard areas near to Firouzkoh province (2), but this is the first report of TSWV occurrence on potatoes in Iran. References: (1) T. S. Ie. Descriptions of Plant Viruses. No. 39, 1970. (2) A. A. Moeini, et al. Iran. J. Plant Pathol. (In press.)


Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 647 ◽  
Author(s):  
Xin Qian ◽  
Qing Xiang ◽  
Tongqing Yang ◽  
Hongyu Ma ◽  
Xin Ding ◽  
...  

Tospovirus is a tripartite negative stranded RNA virus and is considered as one of the most devastating plant viruses. Successful virus infection in plant requires many host factors. To date, very few host factors have been identified as important in Tospovirus infection in plants. We reported earlier that NSm protein encoded by Tomato spotted wilt virus (TSWV), a type species of the genus Orthotospovirus, plays critical roles in viral cell-to-cell and long-distance movement. In this study, we determined that molecular co-chaperone NbSGT1 interacted with TSWV NSm in Nicotiana benthamiana. TSWV infection significantly upregulated the expression of NbSGT1 gene and transient overexpression of NbSGT1 in N. benthamiana leaves accelerated TSWV infection. In contrast, silencing the NbSGT1 gene expression using a virus-induced gene silencing (VIGS) approach strongly inhibited TSWV NSm cell-to-cell movement, as well as TSWV local and systemic infection in N. benthamiana plants. Furthermore, NbSGT1 was found to regulate the infection of both American and Euro/Asia type tospoviruses in N. benthamiana plant. Collectively, our findings presented in this paper and the results published previously indicated that molecular co-chaperone NbSGT1 plays important roles in modulating both positive stranded and tripartite negative stranded RNA virus infection in plants.


Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1042 ◽  
Author(s):  
Roberta Spanò ◽  
Massimo Ferrara ◽  
Donato Gallitelli ◽  
Tiziana Mascia

Grafting is routinely implemented in modern agriculture to manage soilborne pathogens such as fungi, oomycetes, bacteria, and viruses of solanaceous crops in a sustainable and environmentally friendly approach. Some rootstock/scion combinations use specific genetic resistance mechanisms to impact also some foliar and airborne pathogens, including arthropod or contact-transmitted viruses. These approaches resulted in poor efficiency in the management of plant viruses with superior virulence such as the strains of tomato spotted wilt virus breaking the Sw5 resistance, strains of cucumber mosaic virus carrying necrogenic satellite RNAs, and necrogenic strains of potato virus Y. Three different studies from our lab documented that suitable levels of resistance/tolerance can be obtained by grafting commercial tomato varieties onto the tomato ecotype Manduria (Ma) rescued in the framework of an Apulian (southern Italy) regional program on biodiversity. Here we review the main approaches, methods, and results of the three case studies and propose some mechanisms leading to the tolerance/resistance observed in susceptible tomato varieties grafted onto Ma as well as in self-grafted plants. The proposed mechanisms include virus movement in plants, RNA interference, genes involved in graft wound response, resilience, and tolerance to virus infection.


2007 ◽  
Vol 100 (4) ◽  
pp. 1241-1247 ◽  
Author(s):  
D. Ames Herbert ◽  
S. Malone ◽  
S. Aref ◽  
R. L. Brandenburg ◽  
D. L. Jordan ◽  
...  

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