Effect of foliar application of salicylic acid, hydrogen peroxide and a xyloglucan oligosaccharide on capsiate content and gene expression associatedwith capsinoids synthesis in Capsicum annuum L.
Capsinoids are non-pungent analogues of capsaicinoids in pepper (Capsicum spp). The absence of pungency, inaddition to their biological activities similar to that of capsaicinoids such as anti-inflammatory, antimicrobial, andantioxidant properties, makes capsinoids an excellent option for increasing use in human and animal nutrition, as wellas health and pharmaceutical industries. There are only few sources of pepper producing capsinoids, and one of them(accession 509–45-1), Capsicum annuum L., is a potential source for increasing capsinoids content using strategies ascontrolled elicitation during plant production in the greenhouse. In this research we evaluated the effect of weekly andone-day-before-harvest foliar applications of hydrogen peroxide, salicylic acid and a xyloglucan oligosaccharide onthe concentration of capsiate in fruits of this pepper accession, as well as the gene expression of phenylalanineammonia-lyase (pal), putative aminotransferase (pamt), capsaicin synthase (at3) and β-keto acyl synthase (kas).Results showed that the two tested concentrations of H2O2 significantly increased capsiate content and geneexpression associated with capsaicinoids (pamt, at3 and kas) and the phenylpropanoids (pal) pathways. Plant yieldwas not affected using this induction strategy. Our results indicated that the pre-harvest and weekly application ofhydrogen peroxide and xyloglucan oligosaccharide improved production of capsiate in C. annuum L.