Journal of Microbial & Biochemical Technology

Interkingdom signaling: Interference of plant derived small molecules with bacterial communication and virulence

Joint Event on 4^th World Congress and Expo on Applied Microbiology & 2^nd International Conference on Food Microbiology

November 29-December 01, 2017 Madrid, Spain

Iris Yedidia

Plant Sciences â?? Agricultural Research Organization, Volcani Center, Israel

Scientific Tracks Abstracts: J Microb Biochem Technol

Abstract:

Plants produce a diverse array of low molecular-mass compounds, with more than 8,000 phenolics. Phenolic compounds play a pivotal role in plant defense and fitness. Here, we provide an example of the interference of plant small molecules (phenolics) with bacterial virulence, via inhibition of the quorum sensing (QS) machinery of the soft rot bacterium P. carotovorum. Interestingly, biofilm formation and exoenzymes activity were significantly impaired, at compounds concentrations that did not affect bacterial cell growth or membrane integrity. Since biofilm production and exoenzymes are virulence determinants known to be under the strict control of QS, the effect of specific molecules on QS was studied. Common volatile and soluble phenolic compounds were tested for their influence on the expression of central QS system and QS-controlled genes. The N-acyl-homoserine lactone (AHL) reporter strains (CV026 and pSB401) demonstrated a prominent reduction in the level of QS signal molecules accumulation, following exposure to the compounds. Moreover, infection capabilities were strongly impaired on potato, cabbage, and calla-lily; but fully recovered upon external application of AHL. To further confirm the interaction of the plant compounds with bacterial QS targets, drug discovery tools were occupied using the schrodinger® molecular docking suit. Pectobacterium central QS proteins ExpI/ExpR were used as targets for salicylic acid and carvacrol (plant phenolics). Finally using isothermal calorimetry (ITC), SA and CAR were directly bound to cloned and purified ExpI, by this, experimentally supporting the computational docking results. True binding of plant-derived phenolics to bacterial QS synthase protein as a target was demonstrated. The importance of plant-bacteria chemical signaling shown here supports a rising field of research endeavoring interkingdom communication between plants and bacterial pathogens.

Biography :

Iris Yedidia is the Head of the Ornamental Plants and Agricultural Biotechnology Department at the Agricultural Research Organization (ARO), Volcani center, Israel. Since 2004, She is a Scientist and a Team Leader focusing on applying biotechnological tools to improve ornamental bulbs resistance to bacterial pathogens and studying the involvement of natural products in bacterial pathogenesis.