title: Differential expression of two galactinol synthase isoforms LcGolS1 and LcGolS2 in developing lentil (Lens culinaris Medik. cv CDC Redberry) seeds.
abstract: Galactinol synthase (GS, EC 2.4.1.123) catalyzes the transfer of a galactosyl residue from UDP-galactose to myo-inositol to synthesize galactinol, a precursor for raffinose family oligosaccharides (RFO) biosynthesis. Screening, a cDNA library constructed with RNA isolated from developing lentil seeds, with partial GS genes resulted in identification of cDNA clones for two isoforms of GS, LcGolS1 (1336 bp, ORF-1002 bp, 334 amino acids) and LcGolS2 (1324bp, ORF-975bp, 325 amino acids) with predicted molecular weights of 38.7 kDa and 37.6 kDa, respectively. During lentil seed development, LcGolS1 transcripts showed higher accumulation during 26-32 days after flowering (DAF) corresponding to seed desiccation, while LcGolS2 showed maximum accumulation at 24 DAF, prior to increase in LcGolS1 transcripts. GS enzyme activity was maximum at 26 and 28 DAF and corresponded to galactinol accumulation, which also increased rapidly at 22 DAF with maximum accumulation at 26 DAF. Substrates for GS activity, myo-inositol and glucose/galactose were present in high concentrations during early stages of seed development but gradually decreased from 20 DAF to 32 DAF when galactinol concentration increased coinciding with increased GS enzyme activity.
authors.affiliation: Department of Plant Sciences, College of Agriculture & Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N 5A8, Canada.
authors.forename: Udhaya
authors.initials: U
authors.lastname: Kannan
authors.affiliation: Department of Plant Sciences, College of Agriculture & Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N 5A8, Canada.
authors.forename: Roopam
authors.initials: R
authors.lastname: Sharma
authors.affiliation: Department of Plant Sciences, College of Agriculture & Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N 5A8, Canada.
authors.forename: Yogendra
authors.initials: Y
authors.lastname: Khedikar
authors.affiliation: Department of Plant Sciences, College of Agriculture & Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N 5A8, Canada.
authors.forename: Manu P
authors.initials: MP
authors.lastname: Gangola
authors.affiliation: Department of Plant Sciences, College of Agriculture & Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N 5A8, Canada.
authors.forename: Seedhabadee
authors.initials: S
authors.lastname: Ganeshan
authors.affiliation: Department of Plant Sciences, College of Agriculture & Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N 5A8, Canada.
authors.forename: Monica
authors.initials: M
authors.lastname: Båga
authors.affiliation: Department of Plant Sciences, College of Agriculture & Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N 5A8, Canada. Electronic address: ravi.chibbar@usask.ca.
authors.forename: Ravindra N
authors.initials: RN
authors.lastname: Chibbar
mesh_terms: D003001:Cloning, Molecular; D018076:DNA, Complementary; D004187:Disaccharides / Q000378:metabolism; D005700:Galactosyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D027806:Lens Plant / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods / Q000592:standards; D011487:Protein Conformation; D012015:Reference Standards; D015203:Reproducibility of Results; D012639:Seeds / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*
chemical_list: D018076:DNA, Complementary; D004187:Disaccharides; D007527:Isoenzymes; D010940:Plant Proteins; C013536:6 beta-galactinol; D005700:Galactosyltransferases; C096645:inositol 1-alpha-galactosyltransferase
keywords: Galactinol; Lentil; Oligosaccharides; Raffinose