A recently conducted study examined how certain genes, called PR genes, were expressed in tomato plants that were infected with two viruses: TMV and CMV. The researchers used a method called RT-qPCR to measure gene expression. They found that both viruses were detected in the plants at six days after infection, and the levels of the viruses increased rapidly until reaching a peak at 15 days.
The researchers used several software tools to analyze the data and found that a gene called β-actin was the most reliable reference gene in the infected tomato tissues. The expression levels of most tested genes changed between activation and repression, especially in the first 12 days after infection.
One particular gene, called PR-1, showed increased expression throughout the study, except at certain time points for CMV and TMV infections. Another gene, PR-2, was highly up-regulated at 8 days after infection for both viruses. The genes PR-3, PR-4, and PR-7 showed increased expression at 4 days after infection.
On the other hand, the gene PR-5 was suppressed in TMV-infected plants from 1 to 9 days after infection but showed increased expression at 10 days. In CMV-infected plants, PR-5 was up-regulated 1 day after infection.
Aseel, Dalia & Sobhy, Sherien & Samy, Marwa & Hamdy, Esraa & Behiry, Said & Abdelkhalek, Ahmed. (2023). Comparative Analysis of the Expression Profiles of Pathogenesis-Related Genes in Tomato Systemically Infected with Tobacco Mosaic and Cucumber Mosaic Viruses. International Journal of Plant Biology. 14. 458-473. 10.3390/ijpb14020035.