title: Isolation and characterization of a gene from Medicago sativa L., encoding a bZIP transcription factor.
abstract: A full-length cDNA of 1,537 nucleotides was cloned from Medicago sativa L. cv. "Zhongmu No. 1" by rapid amplification of cDNA ends. It was designated as MsZIP, encoding a protein of 340 amino acids. The protein molecular weight was 36.43 kDa, and the theoretical isoelectric point was 5.72. The MsZIP preferentially localized in nucleus and have signal peptide. Blast analysis revealed that MsZIP shared the highest homology with some bZIP proteins of M. truncatula. The transcript of MsZIP was strongly enriched in leaf compared with root and stem of mature alfalfa plants. MsZIP was strongly induced by 15 % PEG6000 (polyethylene glycol), 50 μM abscisic acid, 200 mM NaCl, 70 μM gibberellic acid, 5 mM salicylic acid and 200 μM methyl jasmonate. Physiological resistance parameters were measured in the transgenic tobacco. Malondialdehyde content, relative water content, soluble sugar content, soluble protein content and proline content in transgenic tobacco increased compared with non-transgenic tobacco under salt stress or drought stress. The results showed that accumulation of the MsZIP protein in the vegetative tissues of transgenic plants enhanced their tolerance to osmotic pressure stress. These results demonstrate a role for the MsZIP protein in stress protection and suggest the potential of the MsZIP gene for genetic engineering of salt tolerance and drought tolerance.
authors.affiliation: Institute of Animal Science, Chinese Academy of Agricultural Sciences, No. 2 Yuanmingyuan West Road, Haidian, Beijing, 100193, People's Republic of China. caasliyan@yahoo.com.cn
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.forename: Qingchuan
authors.initials: Q
authors.lastname: Yang
authors.forename: Feng
authors.initials: F
authors.lastname: Fang
authors.forename: Junmei
authors.initials: J
authors.lastname: Kang
authors.forename: Tiejun
authors.initials: T
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D005818:Genetic Engineering; D007526:Isoelectric Point; D000455:Medicago sativa / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D019697:Onions / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000502:physiology; D021381:Protein Transport; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055049:Salt Tolerance; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological; D014026:Nicotiana / Q000235:genetics / Q000502:physiology; D014158:Transcription, Genetic
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D018076:DNA, Complementary; D010940:Plant Proteins; D011994:Recombinant Proteins