UV-C and CHX response in Scots pine needles of 6-week old seedlings

Production of pine stilbenes is known to be strongly induced in response to UV-C treatment but the large scale transcriptional changes in response to the treatment have not been studied before in any coniferous species. The general responses to UV-C in pine were similar than the ones observed in grapevine. Induction of the stilbene pathway as a response to UV-C in pine was fast and not dependent on de novo protein synthesis. Transcriptional changes in response to UV-C and inhibition of translation were further studied with RNA-seq and showed substantial overlap. Activation of the stilbene pathway resembles induction of other defense related genes and involves synergistic effects with the plant hormones ethylene and jasmonate. Protein phosphorylation/dephosphorylation has also role in regulation of the stilbene pathway since inhibition of protein phosphatases were shown to activate fast stilbene synthase gene expression.