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Poster: Biology & Disease Mgmt: Biological Control


Characterization and Expression of the Potent Antimicrobial Peptide LsGRP1C Originated from Lilium
C. CHEN (1), C. Lin (1), Y. Pan (2), M. Chang (2), F. Liu (2) (1) National Taiwan University, Taiwan; (2) National Taiwan University, Taiwan

LsGRP1 is a plant defense-related gene increasingly expressed in lily leaves exhibiting salicylic acid-induced systemic resistance against pathogenic fungus Botrytis elliptica. In vitro antimicrobial assay applied with synthetic peptides revealed that the 38-a.a. cysteine-rich C-terminal portion (LsGRP1C) of LsGRP1 inhibited kinds of bacterial and fungal species via the mechanisms of alteration of microbial membrane permeability and induction of fungal programmed cell death (PCD) as investigated by SYTOX Green staining and 4′,6′-diamidino-2-phenylindole staining/terminal deoxynucleotidyl transferase dUTP nick end labeling assays. Then the expression system for recombinant LsGRP1C production was established using an optimized Escherichia coli strain and an N-terminal fusion partner of small ubiquitin-like modifier protein (SUMO) Smt3 originated from yeast, conducting a high yield of SUMO-LsGRP1C fusion protein. According to the half inhibitory concentrations for spore germination and PCD occurrence of the assayed fungal species, SUMO-LsGRP1C was proven to exhibit higher antifungal activity and identical fungal PCD-inducibility as compared with synthetic LsGRP1C. Thus, we proposed that LsGRP1C would play a role in antimicrobial function of LsGRP1; moreover, efficient and effective E. coli expression strategy would enable the convenient production of antimicrobial LsGRP1C for practical use.