Relative expression of 15 genes for GMI1000, P673, P597, and UW551 at two temperatures. Positive bars represent higher expression at 30°C and negative bars represent higher expression at 18°C. Quantitative reverse transcription-polymerase chain reaction was performed on equal amounts of total RNA per sample extracted from bacterial suspensions grown in co-culture with in vitro tomato seedlings. 16sRNA was used as reference for the relative expression of each gene. Bars represent standard error of three biological replicates.