Author/Authors :
Mahmoudi، Esmaeil نويسنده Department of Plant Pathology, Khorasgan (Isfahan) Branch, Islamic Azad University, Isfahan, Iran , , Tarzaban، Safoura نويسنده Department of Plant Pathology, College of Agriculture, Vali-e-Asr University, Rafsanjan, Iran , , khodaygan، Pejman نويسنده Department of Plant Pathology, College of Agriculture, Vali-e-Asr University, Rafsanjan, Iran , , Abed Esfahani، Abbas نويسنده Department of Environmental Chemistry, Faculty Of Basic Sciences, Islamic Azad University, Khorasgan Branch, Isfahan, P.O. Box 81595-158, Iran ,
Abstract :
Quorum sensing is bacterial cell to cell communication with production of diffusible signal molecules such as acyl-homoserine lactones (AHLs) which regulates the virulence of many pathogenic bacteria. Some plants secrete substances that mimic the activity of the N-acyl-l-homoserine lactone signal molecules in bacteria. Among the thirty five plant species that tested in this research, the QS induction activity was observed in the leaves and stem extracts of lettuce (Lactuca sativa), Clover (Trifolium repens), kidney bean (Phaseolus vulgare) and fenugreek (Trigonella foenum-graecum) which induced violacein production in Chromobacterium violaceum CV026. Further, the outcome of the present investigation reveals that fenugreek extract strongly interferes with acyl homoserine lactone (AHL) regulated physiological function in Pectobacterium carotovorum. It promoted production of virulence factors and powerfully increased tissue maceration on potato tubers at low concentration of the bacterium (103 cfu). It is a new finding that fenugreek, kidney bean, clover and lettuce contain substances which mimic the activity of AHL signal molecules and stimulate AHL related quorum sensing in these bacteria. The AHL signal-mimic compounds could prove to be important in determining the outcome of interactions between higher plants and a diversity of pathogenic, symbiotic, and saprophytic bacteria.
