Pinus pinaster Early Hormonal Defence Responses to Pinewood Nematode (Bursaphelenchus xylophilus) Infection

The pinewood nematode (PWN) is the causal agent of pine wilt disease, a pathology that affects conifer forests, mainly Pinus spp. PWN infection can induce expression phytohormone-related genes; however, changes at early phytohormone level have not yet been explored. Phytohormones are low-abundance metabolites, and thus, difficult to quantify. Moreover, most methodologies focus on Arabidopsis or crop species. This work aimed validate fast (run time 6.6 min) liquid chromatography-triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS) analytical method quantify 14 phytohormones in pinaster stem tissues. was further applied evaluate, for first time, susceptible resistant phenotypes P. 24, 48 72 h after inoculation (HAI) with PWN. A significant increase salicylic acid (SA, HAI) jasmonic methyl ester (JA-ME, observed phenotypes. Results indicate higher susceptibility might result from an inefficient trigger hypersensitive responses, involvement JA SA pathways. provides important update forest research, adds current knowledge defence responses infection.