Cloning and Expression Profiling of Polycomb Gene, Vernalization Insensitive 3 from Tomato Solanum Lycopersicum L

In many plant   species, exposure to a prolonged period of cold during the winter promotes   flowering in the spring, a process termed vernalization. VERNALIZATION   INSENSITIVE 3 (VIN3) is a chromatin remodelling protein that is induced by   low temperatures and is required for the vernalization response in Arabidopsis   thaliana. VIN3 is one of the PcG proteins, which mediates epigenetic   repression of FLOWERING LOCUS C (FLC) in A. thaliana. Here, we present   cloning, characterization and expression of a putative SlVIN3 gene in   tomato (Solanum lycopersicum L.) by isolating cDNA clones   corresponding to SlVIN3 gene using primers designed based on conserved   sequences between PcG genes in A. thaliana and tomato. The SlVIN3   cDNAs were cloned into pBS plasmid and sequenced. Both 5' and 3' RACE were   generated and sequenced. The flcDNA for SlVIN3 gene of 2,823 bp length   was composed of 5'UTR (336 bp), ORF (2,217 bp) and 3'UTR (270 bp). The   translated ORF encodes a polypeptide of 739 amino acids. Alignment of deduced   amino acids indicated that there are highly conserved regions between tomato SlVIN3   predicted protein and plant VIN3 gene family members. Both unrooted   phylogenetic trees constructed using maximum parsimony and maximum likelihood   methods indicated that there is a close relationship between SlVIN3   predicted protein and VIN3 protein of Vitis vinifera. The expression   of SlVIN3 remained high during floral organ differentiation and growth   and decreased to its lowest level when the fruit starts to develop.