A tomato kinesin-like protein is associated with Tobacco mosaic virus infection

Tobacco mosaic virus (TMV) causes severe damage and economic losses of tomato in crop yield production and quality worldwide. Tomato plants infected with TMV usually show a mosaic pattern and chlorosis symptoms that result from affected chloroplasts. To elucidate tomato–TMV interactions, the transcriptional profiles of tomato tissues at different time intervals were analysed using a differential display-polymerase chain reaction technique. Compared to mock-inoculated plants, and based on gene expression changes in tomato plants, the representative down- and up-regulated genes were selected for further analysis. The Basic Local Alignment Search Tool at the National Center for Biotechnology Information (NCBI-BLAST) analysis revealed that the three up-regulated gene transcripts at 15 days post-inoculation were coding for chloroplast (MG565980 and MG565979) and kinesin-like proteins (MG565981). Additionally, the down-regulated gene was a chloroplast-related gene (MG565978). Interestingly, the two chloroplast genes, MG565978 and MG565980, shared more than 96% sequence identity, and their transmembrane profiles were nearly identical. On the other hand, many protein kinase C phosphorylation, casein kinase II phosphorylation and N-myristoylation sites were detected within the MG565981 gene. Moreover, the high similarity between the kinesin gene and many Arabidopsis defensin genes indicated that it might play an important role in the plant defence system against TMV infection. It should be stressed that studies of the pathways in which chloroplast and kinesin-like protein genes are involved may elucidate the mechanisms of tomato tolerance to viral infection and can lead us to a more comprehensive understanding of tomato–TMV interactions.