Involvement Of Gcr1, GCR2 In Response To The Bacterial Signal Molecules

N-acyl-homoserine lactones (AHLs) belong to a class of bacterial quorum-sensing signals important for bacterial cell-to-cell communication. In recent years, we found that AHLs is perceived not only by the bacteria, but also perceived by their host plants, in order to regulate eukaryotic gene expression and cellular responses. According to previous studies, we boldly speculate that plant cells may transduct AHLs through heterotrimeric G protein signaling transduction system, and then it can activate plant gene expression of intracellular and a series of reactions.Addition of 1μmol·L-1 3OC6-HSL or 10μmol·L-1 3OC8-HSL in the medium significantly promoted the root growth of wild type Arabidopsis thaliana. However, the two Arabidopsis mutants gcr1-1 and gcr2-2 lacking GCR1 and GCR2 respectively showed insensitive to these two signals; Real Time PCR analysis showed that the expression levels of GCR1 and GCR2 are increased 2~4 times by the treatment of these two AHLs. These results indicated that GCR1 and GCR2 might be involved in the signal transduction in Arabidopsis root response to bacterial quorum-sensing signals.Carrying GCR1, GCR2 recombinant Agrobacterium EHA105 (pCAMBIA1301-gcr1) and EHA105 (pCAMBIA1301-gcr2) were constructed. We construct transgenic plants through Agrobacterium infection method.The GCR1, GCR2 gene were cloned into express vector pET28a to recombinate E.coli BL21(pET-28a-gcr1) and BL21(pET-28a-gcr2). Express the recombinant protein under IPTG inducing condition. SDS-PAGE and Western Blot analysis showed that recombinant GCR2 protein was successfully expressed.