title: Isolation and functional characterization of a Medicago sativa L. gene, MsLEA3-1.
abstract: A full-length cDNA of 1,728 nt, called MsLEA3-1, was cloned from alfalfa by rapid amplification of cDNA ends from an expressed sequence tag homologous to soybean pGmPM10 (accession No. AAA91965.1). MsLEA3-1, encodes a deduced protein of 436 amino acids, a calculated molecular weight of 47.0 kDa, a theoretical isoelectric point of 5.18, and closest homology with late embryogenesis abundant proteins in soybean. Sequence homology suggested a signal peptide in the N terminus, and subcellular localization with GFP revealed that MsLEA3-1 was localized preferentially to the nucleolus. The transcript titre of MsLEA3-1 was strongly enriched in leaves compared with roots and stems of mature alfalfa plants. Gene expression of MsLEA3-1 was strongly induced when seedlings were treated with NaCl and ABA. Expression of the MsLEA3-1 transgenic was detected in transgenic tobacco. Malondialdehyde content and, electrical conductivity content were reduced and electrical conductivity and proline content were increased in transgenic tobacco compared with non-transgenic tobacco under salt stress. The results showed that accumulation of the MsLEA3-1 protein in the vegetative tissues of transgenic plants enhanced their tolerance to salt stress. These results demonstrate a role for the MsLEA3-1 protein in stress protection and suggest the potential of the MsLEA3-1 gene for genetic engineering of salt tolerance.
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China.
authors.forename: Yongqin
authors.initials: Y
authors.lastname: Bai
authors.forename: Qingchuan
authors.initials: Q
authors.lastname: Yang
authors.forename: Junmei
authors.initials: J
authors.lastname: Kang
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.forename: Margaret
authors.initials: M
authors.lastname: Gruber
authors.forename: Yuehui
authors.initials: Y
authors.lastname: Chao
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D001483:Base Sequence; D002466:Cell Nucleolus / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004553:Electric Conductivity; D020224:Expressed Sequence Tags; D000455:Medicago sativa / Q000235:genetics*; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011392:Proline / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054712:Salinity; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014026:Nicotiana / Q000378:metabolism
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D010940:Plant Proteins; C066246:late embryogenesis abundant protein, plant; D011392:Proline