Genome-Wide Identification of Laccase Gene Family from Punica granatum and Functional Analysis towards Potential Involvement in Lignin Biosynthesis

Laccase (LAC) is the key enzyme responsible for lignin biosynthesis. Here, 57 PgLACs from pomegranate were identified and distributed on eight chromosomes one unplaced scaffold. They divided into six groups containing three typical Cu-oxidase domains. Totally, 51 cis-acting elements in promoter region of are involved response to ABA, GA, light, stress, etc., indicating diverse functions PgLACs. The expression profiles 13 during seed development stage showed that most expressed at a higher level earlier than later two cultivars except PgLAC4. Also, PgLAC1/6/7/16 significantly soft-seed ‘Tunisia’; contrary, PgLAC37 PgLAC50 with hard-seed ‘Taishanhong’. Combined their distinguishing elements, it was concluded PgLAC1/6/7 may respond GA via TATC-box GARE-motif, PgLAC16 repressed promotor activity embryo mid-maturation genes RY-element so as contribute softer formation, whereas PgLAC37/50 participate formation accelerate maturity ABRE G-box elements. Collectively, dramatic gene expressions PgLAC1/6/7/16/37/50 will provide valuable information explore soft- pomegranate.