Dynamic expression analysis of early response genes induced by potato virus Y in PVY-resistant Nicotiana tabacum.

KEY MESSAGE: Dynamic transcriptional changes of the host early responses genes were detected in PVY-resistant tobacco varieties infected with Potato virus Y; PVY resistance is a complex process that needs series of stress responses. Potato virus Y (PVY) causes a severe viral disease in cultivated crops, especially in Solanum plants. To understand the molecular basis of plant responses to the PVY stress, suppression subtractive hybridization (SSH) and microarray approaches were combined to identify the potentially important or novel genes that were involved in early stages (12 h, 1, 2, 3, 5, 8 days) of tobacco response to PVY infection. Dynamic changes of the host plant early responses to PVY infection on a transcriptional level were detected. In total, 167 different expressed ESTs were identified. The majority of genes involved in the metabolic process were found to be down-regulated at 12 h and 1 day, and then up-regulated at least one later period. Genes related to signaling and transcriptions were almost up-regulated at 12 h, 1 or 2 days, while stress response genes were almost up-regulated at a later stage. Genes involved in transcription, transport, cell wall, and several stress responses were found to have changed expression during the PVY infection stage, and numbers of these genes have not been previously reported to be associated with tobacco PVY infection. The diversity expression of these genes indicated that PVY resistance is a complex process that needs a series of stress responses. To resist the PVY infection, the tobacco plant has numerous active and silent responses.