Genome-wide identification and characterization of the abiotic-stress-responsive lipoxygenase gene family in diploid woodland strawberry (Fragaria vesca)

Lipoxygenase (LOXs) is a kind of dioxygenase without heme and iron, which plays an important role in the development and adaptation of many plants to the environment. However, the study of strawberry LOX gene family has not been reported. In this study, 14 LOX genes were identified from the diploid woodland strawberry genome. The phylogenetic tree divides the FvLOX gene into two subfamilies: 9-LOX and 13-LOX. Gene duplication event analysis showed that whole-genome duplication (WGD)/segmental duplication and dispersed duplication effectively promoted the expansion of strawberry LOX family. QRT-PCR analysis showed that FvLOX genes were expressed in different tissues. Expression profile analysis showed that FvLOX1 and FvLOX8 were up-regulated under low temperature stress, FvLOX3 and FvLOX7 were up-regulated under drought stress, FvLOX6 and FvLOX9 were up-regulated under salt stress, FvLOX2, FvLOX3 and FvLOX6 were up-regulated under salicylic acid (SA) treatment, FvLOX3, FvLOX11 and FvLOX14 were up-regulated under methyl jasmonate (MeJA) treatment, FvLOX4 and FvLOX14 were up-regulated under abscisic acid (ABA) treatment. Promoter analysis showed that FvLOX genes were involved in plant growth and development and stress response. We analyzed and identified the whole genome of strawberry FvLOX family and characterized a variety of FvLOX candidate genes involved in abiotic stress response. This study laid a theoretical and empirical foundation for the response mechanism of strawberry to abiotic stress.