ABSTRACT
The results of the study of the structure and function of harpin-like peptides (alpha-harpinins) of the EcAMP group from the barnyard grass (E. crusgalli) seeds and the possibility of their involvement in the innate immunity to biotic stresses are presented.
Subject(s)
Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/pharmacology , Echinochloa/chemistry , Phytophthora infestans/growth & development , Plant Proteins/chemistry , Plant Proteins/pharmacology , Protein Structure, Secondary , Structure-Activity RelationshipABSTRACT
The response of Triticum aestivum L. to infection by Septoria nodorum Berk, a pathogen causing speckled leaf blotch, was studied. The effect of salicylic acid (SA) and jasmonic acid (JA) signal molecules, as well as chitooligosaccharides (COSs) with different acetylation degrees (ADs), on the accumulation of hydrogen peroxide (Ð2Ð2) in wheat leaves and the pathogenesis-related (PR) proteins of oxalate oxidase (AJ556991.1), peroxidase (TC 151917), and proteinase inhibitor (EU293132.1) was investigated. Treatment with the signal molecules inhibited S. nodorum growth and stimulated Ð2Ð2 accumulation, as well as PR gene expression. SA and COS with 65% AD are found to be more efficient in Ð2Ð2 induction and elevation of the transcriptional level of the oxalate oxidase and peroxidase genes. At the same time, JA and COS with 30% AD stimulated transcription of the proteinase inhibitor gene. The results suggest the existence of differential means of defense response induction by signal molecules with more prospects for the regulation of plant immunity.
Subject(s)
Actinomyces , Cyclopentanes/pharmacology , Oxylipins/pharmacology , Plant Diseases , Plant Immunity/drug effects , Salicylic Acid/pharmacology , Signal Transduction , Triticum , Actinomyces/growth & development , Actinomyces/immunology , Gene Expression Regulation, Plant/drug effects , Gene Expression Regulation, Plant/immunology , Plant Diseases/immunology , Plant Diseases/microbiology , Plant Proteins/biosynthesis , Plant Proteins/immunology , Signal Transduction/drug effects , Signal Transduction/immunology , Triticum/growth & development , Triticum/immunology , Triticum/microbiologyABSTRACT
A method for determination of oxidation of phenolic compounds by intact wheat seedlings using o-phenylenediamine (OPD) was developed. The reaction is initiated by the addition of oxalic acid to the incubation medium. It is suggested that an endogenous peroxidase and hydrogen peroxide formed during oxidation of oxalic acid by endogenous oxalate oxidase are involved in OPD oxidation. Treatment of plants with chitooligosaccharides (1-10 mg/liter) with acetylation degree of 65% and molecular masses of 5-10 kD significantly activated OPD oxidation by wheat seedlings.