PHYLOGENETIC CONNECTIONS AND COMPARISONS OF THE AMINO ACID SEQUENCES OF SEVERAL PEPTIDE INDUCERS OF MICROBIAL ORIGIN- A FOUNDATION STUDY FOR DEVELOPMENT OF NOVEL BIOPESTICIDES

Abstract

Peptides of microbial origin stand out as one of theprominent tools to elicit plant immunity. These peptides comprise one of thekey strategies of integrated pest management and are considered as candidatesto develop novel biopesticides. Manyresearch investigations have proved their potential in fending off plantpathogens and were described as sustainable plant protection strategies. Thepresent study was attempted to discover phylogenetic relationships and compareamino acid sequence alignments of various peptide elicitors of microbialorigin. Phylogenetic analysis of 33 microbial peptide elicitors resulted in twoclusters, one cluster contained 19 flagellin sequences, which is furtherdivided into one major (15 peptide sequences) and one (4 peptide sequences)minor subclusters. Further amino acid sequence alignments were carried outbased on the evolutionary relationships among the peptides. The amino acidsequence alignment of flagellin sequences using Clustal W did not present conservativeamino acid sequences except Serine (S), Alanine (A) and Aspartic acid (D).These conserved amino acids (SAxD) that are positioned in the protruding loopmay play a vital role in recognition by plant surface receptors. Alignment ofamino acid sequences of cold shock protein, xylanase, elongation factor andharpin from various sources did not present conservative amino acid sequencesexcept glycine. These investigations lay a theoretical foundation for exploringmany more microbial peptides for inducing plant resistance.