Comprehensive Analysis of the Pectate Lyase Gene Family and the Role of in Strawberry Softening.

Fruit softening is a crucial factor that controls shelf life and commercial value. Pectate lyase (PL) has a major role in strawberry fruit softening. However, the gene family in strawberry has not been comprehensively analyzed. In this study, 65 genes were identified in the octoploid strawberry genome. Subcellular localization prediction indicated that FaPLs are mostly localized to the extracellular and cytoplasmic spaces. Duplication event analysis suggested that gene family expansion is mainly driven by whole genome or segmental duplication. The family members were classified into six groups according to the phylogenetic analysis. Among them, , , , , 25, , and had gradually increased expressions during strawberry fruit development and ripening and higher expression levels in the fruits with less firmness than that in firmer fruit. This result suggested that these members are involved in strawberry softening. Furthermore, overexpression of significantly reduced the fruit firmness, ascorbic acid (AsA), and malondialdehyde (MDA) content but obviously increased the anthocyanins, soluble proteins, and titratable acidity (TA), while it had no apparent effects on flavonoids, phenolics, and soluble sugar content. These findings provide basic information on the gene family for further functional research and indicate that plays a vital role in strawberry fruit softening.