Genome-wide analysis of the Early Flowering 4 (ELF4) gene family in short-juvenile persimmon Deyangshi (Diospyros deyangensis) and its role of DdELF4-8 during flowering control

The species of genus Diospyros are widely distributed in the world, of which D. kaki is one of most important economical fruit crops includes important fruit crops. However, these species have a very long juvenile phase; for example, D. kaki even takes 5-8 years after seeding. Here, we identified a D. kaki related species, Diospyros deyangensis, with a very short juvenile phase, which can flower and then bear fruits even with 3 months after sowing. Because EARLY FLOWERING 4 (ELF4) is involved in photoperiod perception, circadian regulation, and flowering development in model plant Arabidopsis, we herein characterize the 11 EARLY FLOWERING 4 (ELF4) family members in D. deyangensis and investigate molecular function of DdELF4-8 gene. All DdELF4 candidates contained a DUF1313 domain, which was conserved in the ELF4 gene family. Gene duplication analysis showed that segmental duplication mainly caused by polyploidization promoted gene expansion. Similar to other ELF4-ox lines, overexpression of DdELF4-8 delayed flowering and increased rosette leaves in Arabidopsis indicating the functional conservation of ELF4 genes in flowering regulation. It is interesting that the overexpression of DdELF4-8 negatively affected AtGI and AtFT expression levels, which was the likely cause of flowering delay phenotypes. These results suggest that DdELF4 genes may involve in flowering development in D. deyangensis, and provide a new insight on shortening the juvenile phase in Diospyros.

Automated summary

In this study, a species related to Diospyros kaki, Diospyros deyangensis, was discovered to have a short juvenile phase and can flower and bear fruits within 3 months after sowing. The DdELF4-8 gene was found to play an important role in flowering regulation. These findings provide new insights for shortening the juvenile phase in Diospyros.