Disease resistance gene transcription in transgenic potato is unaltered by temperature extremes and plant physiological age

To date, several dozen plant disease resistance genes have been cloned from a variety of species. Despite successful efforts to isolate functional disease resistance genes and understand their roles in defence responses, surprisingly little is known about their transcriptional regulation. Global climate changes are expected to impact crop plant production, plant physiology and plant-microbe interactions. Understanding the impact of varying environmental and physiological factors on disease resistance gene transcript levels may be key to successful deployment. In this study we analyzed the expression patterns of the Phytophthora infestans resistance gene RB in transgenic potato plants across a broad range of temperatures and key physiological stages. Our results demonstrate that while temperature extremes have an obvious effect on plant morphology and development, RB is transcribed at all ages and temperatures in all genetic backgrounds. Quantitative analyses demonstrate that the RB transcript accumulates comparably throughout plant development, including at the tuber initiation stage. Implications for successful deployment of RB are discussed.