HvSAMS (Hordeum vulgare S-AdenosylMethionine Synthetase) that expressed differentially in the seed development of extra early maturity barley was isolated and characterized. SAM acted as a major methyl group donor and was involved in numerous highly specific transmethylations of secondary metabolites. In plants, SAM also served as a precursor for the synthesis of ethylene and polyamine. In order to examine the localization of HvSAMS protein, green fluorescent protein (GFP) was fused in-frame to the C-terminus of HvSAMS, and the fusion protein was allowed to express in the epidermal cell of onion. Expression of HvSAMS recognized by GFP expression of 35S::HvSAMS::GFP was detected in the nucleus, but the 35S::GFP (control vector) was detected in cytosol, nucleus, and cell wall. HvSAMS (Ubiqutin::HvSAMS) was transformed and allowed to be over-expressed in the Arabidopsis. HvSAMS-over-expressed plants showed slightly higher early germination ratio in the MS medium. The growth of the transgenic plants was compared with that of wild-type plants at 4 weeks after sowing. Over-expression of transformed HvSAMS was observed in a kernel development of reproductive stage than wild-type. A T-DNA insertion mutant (Signal Salk 052289) was screened using GSP1 (gene specific primer) and Lb1, 2 (left board primer). PCR products of 485 bp and 345 bp were obtained in T-DNA insertion mutant. Absence of PCR products using GSP1 and GSP2 (Gene specific primer, T-DNA reside between GSP1 and GSP2). Delay of maturity at T-DNA insertion Arabidopsis mutant indicated that SAM has a role in early stage of plant reproductive development.

This work was supported by a grant (20050301-034-432-006-01-00) from BioGreen 21 Program, Rural Development Administration, Republic of Korea.