ARS | Publication request: Gene expression profiling reveals insight into how distinct viruses induce symptoms

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 22, 2006
Publication Date: N/A

Technical Abstract: Plant viruses induce a wide array of disease symptoms and cytopathic effects including alterations of chloroplasts, ribosomes, and cellular architecture. While some of these changes are virus specific, many are common even among diverse viruses, and in most cases, the molecular determinants responsible are unknown. To identify gene expression changes that are concomitant with virus symptoms, we performed microarray expression profiling experiments on Nicotiana benthamiana leaves infected with one of three different fruit tree viruses that produce distinct symptoms: plum pox potyvirus (PPV- stunting, changes in leaf morphology, severe mottling), tomato ringspot nepovirus (ToRSV- necrosis, yellowing, stunting, and severe mottling), and prunus necrotic ringspot ilarvirus (PNRSV- very mild mottling). The expression profiles were compared with both visual observations of symptoms and electron microscopic examinations of cytopathic effects. The number of significant genes identified in each case was consistent with the severity of the observed symptoms: 1,423 (ToRSV), 897 (PPV), and 121 (PNRSV). Forty six percent of the gene expression changes caused by PPV were also altered by ToRSV, 88% of which changed in the same direction. Both PPV and ToRSV infected leaves showed repression of large numbers of genes controlling chloroplast function and photosynthesis. In contrast, PPV uniquely induced the expression of over 50 nuclear ribosomal genes (53% of all ribosome subunits). How these expression changes might contribute to both symptom development and cytopathic effects are discussed.