Differential expression of cytochrome oxidase and ALY-family genes in resistant and susceptible tomato cultivars (Solanum lycopersicum) inoculated with Tomato bushy stunt virus

Tomato cultivars (TY20, TY70/84 and TY70/70) were mechanically inoculated with purified virus preparations of Tomato bushy stunt virus (TBSV). Inoculated plant tissues were collected after 1 day, 1 week and 2 weeks post-inoculation. Messenger RNA of the inoculated and healthy plants was scanned using the differential display to discover the up- and down-regulated genes induced or suppressed in the infected plants. Three down-regulated and four up-regulated genes were observed in different molecular weights. Sequence analysis revealed that the 400 bp up-regulated gene of cultivars TY70/84 and TY70/70 was cytochrome oxidase gene. Expression of these genes was higher in the two resistant cultivars more than the control and the susceptible one (TY20). The other four genes belong to the ALY-gene family which possibly function as a chaperone to promote the interaction of DNA-binding proteins.