Comparison of the serological relationships among the NSs proteins of different tospoviruses

• Main Authors: Yu-Chi Chen, 陳羽騏
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/19586063377187631687

碩士 === 朝陽科技大學 === 應用化學系生化科技碩士班 === 101 === Tospoviruses is a group of plant viruses characterized in their distinct thrips-borne transmissibility. There have been more than 30 different tospoviruses reported globally and most of them induce very severe symptoms on their host plant that result evident loss in yield and quality. Among the three tospoviruses known to infect Phalaenopsis, Capsicum chlorosis virus (CaCV) was currently endemic in Taiwan. The other two including Tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus (INSV) have not yet been found in Taiwan to infect Phalaenopsis. Therefore the latter two tospoviruses are considered as quarantine pathogens for Taiwan’s Phalaenopsis industry. Therefore, the accuracy of the techniques applied to the detection and diagnosis is a major concern on the surveillance and control of the these virus diseases of orchids. Traditionally, the nuclear capsid protein (NP) was used as the major target of detection and taxonomic criteria for tospoviruses. While recently there was literature suggesting the non-structure protein (NSs) encoded in the S-RNA of tospoviruses could be used an alternative target. This study was therefore aiming at clarification of the feasibility of using NSs as a target for quick differentiation of those Phalaenopsis-infecting tospoviruses. In addition, serological relationship of NSs proteins among tospoviruses was also studied due to its importance in application of NSs for virus detection. Our study took the approach of using bacteria expressed protein system to obtain purified NSs protein encoded by the three Phalaenopsis infecting tospoviruses for their antibody production. We also included Watermelon silver mottle virus (WSMoV), the type species of the 4th NP serogroup in tospoviruses, to study the serological variation among NSs proteins of tospoviruses. The study started by the design of primer pairs specific respectively to these tospoviruses to amplify their NSs genes, which were then cloned in pGEM-T Easy (Promega, USA) or pCRII-TOPO (Quiagen, USA) plasmids and sequenced. Analyses of these NSs gene sequences found that those viruses in the same NP serogroup were also closely related among their NSs proteins. The nucleotide and amino acid sequence identities within the same NP serogroup were 70-79