Identification and Functional Analysis of the Phosphatidylethanolamine-Binding Protein (PEBP) Gene Family in Liriodendron Hybrids

Abstract

The plant phosphatidylethanolamine-binding protein (PEBP) gene family plays important roles in regulating flowering time and vegetative growth. Compared with its parents, Liriodendron hybrids (Liriodendron chinense (Hemsl.) Sarg. × L. tulipifera L.), have obvious heterosis in terms of higher seed germination, fast growth, bright flower colors, and long growth seasons. However, the genome-wide identification and functional analysis of PEBP genes that contribute to the heterosis of Liriodendron hybrids have not been studied. In this study, we characterized four members of expressed LhPEBP genes in Liriodendron hybrids and divided them into three subfamilies based on their phylogenetic relationships: FT-like (LhFT), TFL1-like (LhTFL1), and MFT-like (LhMFT1 and LhMFT2). A functional analysis of Arabidopsis showed that the overexpression of LhFT significantly promoted flowering, and the LhTFL1 gene induced a wide dispersion of the flowering timing. LhMFTs function differently, with LhMFT2 suppressing flowering, while LhMFT1 accelerates it and had a stronger promoting effect on the early stage of seed germination. Additionally, the seed germination of the LhMFT lines was relatively less influenced by ABA, while the transgenic LhFT and LhTFL1 lines were sensitive to both ABA and GA3. These results provide valuable insights into the functions of LhPEBP genes in flowering and seed germination.