Molecular Cloning and Expression Analysis of PgLAC in Pomegranate

Abstract

Decreasing the hardness of pomegranate seeds by reducing the content of lignin is an effective way to develop soft-seeded pomegranate. Laccases (LAC) is a key regulatory factor in lignin synthesis. The full-length sequence of PgLAC was obtained from “Punica granatum cv. Hongyushizi”, by using RACE and RT-PCR methods. PgLAC had an open reading frame of 1716 bp and encoded a protein of 571 amino acids. Phylogenetic tree analysis showed that PgLAC was most closely related to the LAC5 ortholog identified in Eucalyptus grandis (EgLAC5). Expression analysis showed that expression of PgLAC was higher in “Hongyushizi”, while lower in “Huiliruanzi” and “Tunisiruanzi”; PgLAC was predominantly expressed in stems; From 20 to 80 days after full bloom, the expression of PgLAC increased and reached a maximum at 80 d, then gradually decreased. These results suggested that PgLAC may be a candidate gene for reducing the hardness of pomegranate seeds.