Understanding DAMP induced innate immunity in tomato and role of cell wall integrity
M. DASGUPTA (1), M. Sahoo (2), N. Prakash (2), S. Ngachan (3) (1) ICAR Research Complex for NEH Region, Manipur Centre, Lamphelpat, Imphal-795 004, India, India; (2) ICAR Research Complex for NEH Region, Manipur Centre, Lamphelpat, Imphal-795 004, India, India; (3) ICAR Research Complex for NEH Region, Umiam, Meghalaya, Pin 793103, India, India

The plant cell wall, being composed of polysaccharides like cellulose, pectin, and hemicelluloses, potentially interlinked in such a way that it becomes difficult to access by the most of the pathogens and hence, represents a unique barrier for most of the invading pathogens. Any breaches of cell wall integrity should alert the host plant to the presence of invaders. Therefore, manipulation of the host, delivery of effectors and suppression of defense responses requires intimate contact between the pathogen and the host. Cell wall degrading enzymes (CWDEs) are the major part of the weaponry used by most of the microbial pathogens. These CWDEs act on plant cell wall and releases plant cell wall degradation products in the form of oligosaccharides, which function as damage-associated molecular patterns (DAMPs). Pattern recognition receptors (PRRs) perceive these DAMPs and induce an early warning system which enables plants to mount defense responses in the form of inducible innate immune responses. Ralstonia solanacearum is a phytopathogenic gram negative bacterium that causes wilt disease of tomato (Lycopersicon esculentum Miller). Like other gram negative bacteria, R. solanacearum, secretes an extensive portfolio of specific CWDEs, which are important for its virulence. However what is the role of theses CWDEs inside the host cell is not yet known. We have studied the role of CWDEs in mounting of innate immunity associated responses like Reactive oxygen species (ROS) production, Programmed cell death (PCD) and Callose deposition in tomato. The infiltration of a CWDE, pectinase in lower concentrations resulted in callose deposition; whereas, the higher concentrations generated ROS followed by hypersensitive response (HR) associated PCD in leaves.  The transcriptional profiling of tomato leaves after infiltrating with a DAMP would also give insights into the molecular mechanisms of the induction of DAMP induced immune response in tomato.

Abstract Number: P15-426
Session Type: Poster