Abstract: 【Objective】 The objective of this study is to clone Solanumlycopersicum SYTA (S.l SYTA), to analyze its bioinformatic characteristics, tissue expression and subcellular localization, the effect of green fluorescence protein (GFP) labeled Tobacco mosaic virus (TMV) on the expression level of S.l SYTA, its effect on the infection and movement of TMV and to provide a theoretical basis for further investigation of the S.l SYTA influence on the process of the infection and movement of the plant viruses. 【Method】The primer pairs of S.l SYTA were designed using Primer Premier 5.0 software based on the sequence of homologous SYTA in the genome ofthe S. lycopersicum. A complete coding sequence of S.l SYTAwas isolated and obtained by RT-PCR method. The sequence characteristics ofS.l SYTA was analyzed by bioinformatics tools. Multiple sequence alignments between S.l SYTAand its homologous ones from other species and a phylogenetic tree of homologous species were made by MEGA 7.0. The subcellular localization of S.l SYTA was analyzed through fusing with GFP protein. The real-time fluorescent quantitative PCR (qRT-PCR) was used to analyze the expression of S.l SYTAin different tissues and the change of its expression level in the TMV-GFP infected S. lycopersicum. The S.l SYTA was transiently expressed in the Nicotiana benthamiana by agroinfiltration, and then ELISA was used to detect the accumulation and movement of TMV-GFP. 【Result】A full-length SYTA of 1 620 bp was cloned from S. lycopersicum. Sequence alignment and bioinformatics analysis revealed that the deduced amino acids ofS.l SYTA had common characteristics of SYTs family with an N-terminal transmembrane region, a linker of variable size, and two C-terminal C2 domains. Furthermore, SYTA has the closest phylogenetic relationship to that of the N. sylvestris and N. tomentosiformis in amino acids sequences, and distanced from that of Cucumis sativus. Subcellular localization results showed that S.l SYTA was distributed at plasma membrane. The expression level of S.l SYTAin different tissues of S. lycopersicum was root＞leaf＞stem. The expression of S.l SYTAin S. lycopersicum obviously increased on the 1st day and decreased to the normal level on the 7th day after inoculation of TMV-GFP.Following the transient expression of S.l SYTA in N. benthamiana, TMV-GFP was inoculated. After 5 days, TMV-GFP had moved to the new leaf of the N. benthamiana. But no TMV-GFP was found in the new leaf of the control N. benthamiana in which the empty vectors were transiently expressed. ELISA assay results showed that the accumulation of the TMV-GFP in the samples under treatment was obviously higher than that in the control group after 5 days of TMV-GFP inoculation.【Conclusion】S.l SYTAhas the typicalcharacteristics of the SYTs family. S.l SYTAlocated on the plasma membrane of epidermal cell of N. benthamiana. The S.l SYTA expressed highest in root of S. lycopersicum. Under the stress of TMV-GFP, the expression of S.l SYTA in S. lycopersicum obviously increased firstly and then decreased to the normal level. In the S.l SYTA transient expression of N. benthamiana, the S.l SYTA could promote the initial accumulation and movement of TMV-GFP.

Key words: Solanum lycopersicum, S.l SYTA, gene cloning, expression and analysis, TMV-GFP