title: Proteome profiling of seed storage proteins reveals the nutritional potential of Salicornia brachiata Roxb., an extreme halophyte.
abstract: Salicornia brachiata  is an extreme halophyte that grows in salty marshes and is considered to be a potential alternative crop for seawater agriculture. Salicornia seeds are rich in protein, and its tender shoots are eaten as salad greens. Seed storage proteins were fractionated by sequential extraction using different solvents, including distilled water for albumins, NaCl (1.0 M) for globulins, NaOH (0.1 N) for glutelins, and ethanol (70% v/v) for prolamins. Globulins accounted for 54.75% of the total seed storage proteins followed by albumins (34.30%) and glutelins (8.70%). The fractionated proteins were characterized using 2D-diagonal SDS-PAGE and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry. The globulin fraction, composed of seven intermolecular disulfide-linked polypeptide pairs of molecular mass 63.5, 62.5, 54.7, 53.0, 43.2, 38.5, and 35.1 kDa, encompassed a basic and an acidic subunit. Two-dimensional gels revealed approximately 32 spots, with isoelectric points and molecular masses ranging from 4.93 to 11.6 and from ∼5.2 to ∼109.4 kDa, respectively. Protein spots were identified by MALDI-TOF MS peptide mass fingerprint analysis and further classified. Homology analysis demonstrated that 19% of the proteins were involved in metabolism, 16% were involved in signaling, and 15% were regulatory proteins. Peptide mass fingerprint analysis confirmed the presence of inter- and intramolecular disulfide linkages in the globulin fraction. Sulfur-rich proteins are of high nutritional value, and disulfides make S. brachiata a potential source of dietary supplementation.
authors.affiliation: Discipline of Marine Biotechnology and Ecology, CSIR-Central Salt and Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India. bjha@csmcri.org
authors.forename: Bhavanath
authors.initials: B
authors.lastname: Jha
authors.forename: Nater Pal
authors.initials: NP
authors.lastname: Singh
authors.forename: Avinash
authors.initials: A
authors.lastname: Mishra
mesh_terms: D005591:Chemical Fractionation; D019663:Chenopodiaceae / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D009753:Nutritive Value; D010940:Plant Proteins / Q000032:analysis*; D055051:Salt-Tolerant Plants / Q000737:chemistry*; D055314:Seed Storage Proteins / Q000032:analysis* / Q000737:chemistry / Q000145:classification; D012639:Seeds / Q000737:chemistry*; D012995:Solubility; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D004220:Disulfides; D010940:Plant Proteins; D055314:Seed Storage Proteins