Real time quantitative pcr system

The gene expression analysis was performed according to our previous study (Qu et al., 2016). Briefly, overnight cultures were grown to an A630 nm of 0.5–0.8 (37°C, 150 rpm) in LB broth with (15.63 μg/ml) or without (but 2% DMSO was added) Melo. And the total RNA was extracted using a E.Z.N.A. Total RNA Kit II (Omega Bio‐tek, Norcross, GA). RNA purity and concentration were determined by the absorbance at 260 and 280 nm, and 1 μl RNA was used for cDNA synthesis by the TransScript All‐in‐One First‐Strand cDNA Synthesis SuperMix for qPCR (Transgene, Beijing, China). A qPCR was performed with TransStartTM Green qPCR SuperMix UDG (Transgene, Beijing, China) using a real‐time quantitative PCR system (Eppendorf, Germany). The oligonucleotide primers used to amplify the QS‐related genes (lasR, rhlR, mvfR, and pqsC/D) and EPS‐related genes (pslA, pelA, and alg44) were referred to Qu et al. (2016) and Kim, Park, and Lee (2015), respectively.

Gene expression was detected by qRT‐PCR according to our previous study (Qu et al., 2016). Briefly, overnight cultures of PA47 grown in LB broth in the presence or absence of 2% glucose were collected at the A630 of 0.5–0.8. Total RNA was extracted using an E.Z.N.A. Total RNA Kit II (Omega Bio‐tek). The RNA purity and concentration was determined by the absorbance at 260/280 nm, and 1 μl of RNA was used for cDNA synthesis by TransScript All‐in‐One First‐Strand cDNA Synthesis SuperMix (Transgene). qPCR was performed using TransStartTM Green qPCR SuperMix UDG (Transgene) using a real‐time quantitative PCR system (Eppendorf). The oligonucleotide primers used to amplify the housekeeping gene 16S rRNA and EPS‐related genes (pelA, pslA, and alg44) (Kim, Park, & Lee, 2015) are shown in Table A1.