石榴花发育相关基因PgSPL2 的克隆及功能研究.

This study is aimed to investigate the role of the pomegranate（Punica granatum L.）SPL family gene PgSPL2 （XP_031375027.1）in pomegranate flower development and lay a foundation for further research on the mechanism of pomegranate flower development. Using‘ Tunisian’ soft-seeded pomegranate as experimental material, we used homologous cloning technique to clone the SPL family gene PgSPL2, analyze the physicochemical properties of the gene and the expression differences in different tissues of pomegranate. Then we applied RT-qPCR to analyze the spatio-temporal expression characteristics of the gene upon growth regulator treatment. Finally we transformed Arabidopsis and verified the role of the gene in flower development. The results showed that the gene contained a 591 bp open reading frame encoding 196 amino acids, and multiple sequence alignment revealed that the gene contained a conserved SBP structural domain and nuclear localization signal, belonged to the SBP transcription factor gene family. Phylogenetic tree analysis showed that PgSPL2 clustered with Arabidopsis AtSPL3, AtSPL4 and AtSPL5. The RT-qPCR results showed that the expression of PgSPL2 was relatively high in fruits and flower buds, and the expression of PgSPL2 in complete flowers was significantly down-regulated after spraying with growth regulator, while the ratio of complete flowers significantly increased simultaneously, and the first flowering and blooming periods delayed. Overexpression of PgSPL2 in Arabidopsis presented early flowering and significantly higher expression of inflorescence downstream regulatory genes. These results indicate that PgSPL2 plays a role in regulating flowering time in pomegranate flower development. [ABSTRACT FROM AUTHOR]