Identification of differential expressed proteins and establishing a defense proteome of sugarcane in response to Colletotrichum falcatum infection

Abstract

Defense proteome of sugarcane in response to red rot pathogen Colletotrichum falcatum was established for the first time upon analyzing the differentially expressed proteins of resistant and susceptible cultivars through two dimensional gel electrophoresis (2-DE) and mass spectrometry. The proteomes of red rot resistant (Co 93009) and susceptible varieties (CoC 671) showed significant differences in their protein expression after pathogen inoculation. The resistant variety showed a dynamic activation and regulation of cellular components upon infection from the pathogen, whereas the response was submissive in the susceptible variety. A total of 136 differentially expressed proteins were characterized by MALDI-TOF and the identified proteins were grouped into seven broad categories based on their putative functions. The major portion of the up-regulated proteins belonged to signal transduction, transcription/ transcription factors, metabolism, defense/ stress and retroelements. Among the down-regulated proteins, majority belonged to metabolism, cell growth and development, followed by signal transduction and transcription factors. The important proteins identified by MALDI-TOF analyses were of those involved in various defense/ cellular functions such as cyclic nucleotide gated ion channel protein, callose synthase, R2R3-MYB transcription factor MYB6, WRKY transcription factor, putative p-coumarate 3-hydroxylase, PISTILLATA-like protein, flagellar associated protein, class III HD-Zip protein HDZ34, calcium dependent protein kinase, DNAJ heat shock protein, polyphenoloxidase, cytokinin oxidase 3, NB-ARC domain containing protein, NADH dehydrogenase, UDP glucose:flavonoid 3-O-glucosyltransferase, ACC synthase and putative disease resistance protein. The isolation and characterization of differentially expressed proteins would help us to understand the complex host-pathogen interaction at molecular level during the course of disease development/ progression.