Analysis of PR-1, PR-2, PR-10, chitinases and chitinase-like proteins genes expression in pea roots under the action of salicylic acid and methyl jasmonate

Stress phytohormones - salicylic and jasmonic acids - participate in the plant defense response. The increase in the content of these compounds during plant infection by pathogens leads to the activation of signaling pathways, ultimately resulting in changes in gene expression and protein synthesis, including a group of pathogenesis-related (PR) proteins. Phytohormone-dependent so-called marker genes, are used to assess the activation of these signaling pathways. In this study, PR-1 genes, which are markers for salicylic acid signaling and expressed in pea roots, were identified and characterized, and the effects of salicylic acid and methyl jasmonate on their expression were analyzed. It was shown that in pea roots, PR-1, encoded by the Psat1g156240 gene, is among the most significantly expressed genes in the control. Salicylic acid did not cause a change in the expression of this gene; however, it was induced by methyl jasmonate after 24 h. Analysis of the expression of other genes encoding PR-1 proteins showed that salicylate had no effect on their expression after 24 and 72 h. Analysis of the expression of genes encoding chitinases and chitinase-like proteins showed that the former do not exhibit specificity in response to the salicylate and methyl jasmonate, except for the Psat1g131280, the expression of which increased after 24 and 72 h of treatment with methyl jasmonate. Genes Psat1g147600, Psat1g147560, Psat1g149120 encoding chitinase-like proteins, were barely expressed in pea roots in control, and were specifically induced by salicylic acid. β-1,3-glucanase genes were not induced in roots by the studied phytohormones. The obtained results allowed to reveal specific genes including chitinase-like proteins, the expression of which is salicylate-inducible. These genes can be used for the assessment of the activation of the salicylate-dependent signaling pathway in pea roots.