rpoD gene expression as an indicator of bacterial pathogens in host plants

Pseudomonas , Ralstonia , and Xanthomonas are important genera of plant pathogenic bacteria that affect commercially cultivated crops. We developed an assay to assess the viability and development of bacterial pathogens in Arabidopsis thaliana by detecting rpoD mRNA using a quantitative reverse transcription-polymerase chain reaction (qRT-PCR). rpoD is a representative housekeeping gene that encodes the principal RNA polymerase sigma factor. Quantification of rpoD mRNA by qRT-PCR allowed easy detection of viability and development of the pathogens in infected plant tissue. Therefore, qRT-PCR technology provides new research opportunities for investigation of host–pathogen interactions.