Title - Arabidopsis transcriptomics reveals late Lipoxygenase2  (AtLOX2)-specific gene expression in wounded plants
In wounded Arabidopsis thaliana leaves, four 13S-lipoxygenases (AtLOX2, AtLOX3, AtLOX4, AtLOX6) act in a hierarchical manner to contribute to the jasmonate burst leading to downstream defense responses. In this study, we sought to differentiate the impact of LOX2 compared to the other LOXs to the wound-induced phytohormone and transcriptional response to foliar mechanical damage using wildtype (WT) and lox2 mutant plants. Compared to WT, the lox2 mutant had higher constitutive expression of the phytohormone salicylic acid (SA) and expression of SA-responsive genes, implying that AtLOX2 may be involved in constitutive jasmonate biosynthesis that is involved in the crosstalk with the salicylic acid pathway. As expected, the jasmonate burst in response to wounding was dampened in lox2 plants. In general, early wound-induced genes included those involved in jasmonate biosynthesis, jasmonate signaling attenuation and abscisic acid-responsive genes primarily involved in wound sealing and healing. Late wound-induced genes that showed genotype-specific patterns where wounded WT plants had stronger expression of genes associated with plant protection against insect herbivory. This study highlights the dynamic nature of jasmonate-responsive gene expression and the potential contribution of AtLOX2 to this pathway.