title: A stress-associated protein containing A20/AN1 zing-finger domains expressed in Medicago truncatula seeds.
abstract: MtSAP1 (Medicago truncatula stress-associated protein 1) was revealed as a down-regulated gene by suppressive subtractive hybridization between two mRNA populations of embryo axes harvested before and after radicle emergence. MtSAP1 is the first gene encoding a SAP with A20 and AN1 zinc-finger domains characterized in M. truncatula. MtSAP1 protein shares 54% and 62% homology with AtSAP7 (Arabidopsis thaliana) and OsiSAP8 (Oryza sativa) respectively, with in particular a strong homology in the A20 and AN1 conserved domains. MtSAP1 gene expression increased in the embryos during the acquisition of tolerance to desiccation, reached its maximum in dry seed and decreased dramatically during the first hours of imbibition. Abiotic stresses (cold and hypoxia), abscisic acid and desiccation treatments induced MtSAP1 gene expression and protein accumulation in embryo axis, while mild drought stress did not affect significantly its expression. This profile of expression along with the presence of anaerobic response elements and ABRE sequences in the upstream region of the gene is consistent with a role of MtSAP1 in the tolerance of low oxygen availability and desiccation during late stages of seed maturation. Silencing of MtSAP1 by RNA interference (RNAi) showed that the function of the encoded protein is required for adequate accumulation of storage globulin proteins, vicilin and legumin, and for the development of embryos able to achieve successful germination.
authors.affiliation: University of Angers, UMR-1191 Physiologie Moléculaire des Semences, IFR 149 Quasav, 2 Boulevard Lavoisier, Angers Cedex 01, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Gimeno-Gilles
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Gervais
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Planchet
authors.forename: Pascale
authors.initials: P
authors.lastname: Satour
authors.forename: Anis M
authors.initials: AM
authors.lastname: Limami
authors.forename: Eric
authors.initials: E
authors.lastname: Lelievre
mesh_terms: D000040:Abscisic Acid; D000222:Adaptation, Physiological / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D055864:Droughts; D015870:Gene Expression; D020868:Gene Silencing; D017343:Genes, Plant; D018525:Germination / Q000235:genetics / Q000502:physiology; D005916:Globulins / Q000378:metabolism; D046913:Medicago truncatula / Q000235:genetics / Q000378:metabolism*; D015394:Molecular Structure; D012275:Oryza / Q000235:genetics; D010100:Oxygen; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D055314:Seed Storage Proteins / Q000378:metabolism; D012639:Seeds / Q000254:growth & development / Q000378:metabolism*; D017385:Sequence Homology; D013312:Stress, Physiological / Q000235:genetics*; D016335:Zinc Fingers
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D002352:Carrier Proteins; D005916:Globulins; D010940:Plant Proteins; D055314:Seed Storage Proteins; D000040:Abscisic Acid; C015575:vicilin protein, plant; D010100:Oxygen