title: Molecular cloning and characterization of the MsHSP17.7 gene from Medicago sativa L.
abstract: Heat shock proteins (HSPs) are ubiquitous protective proteins that play crucial roles in plant development and adaptation to stress, and the aim of this study is to characterize the HSP gene in alfalfa. Here we isolated a small heat shock protein gene (MsHSP17.7) from alfalfa by homology-based cloning. MsHSP17.7 contains a 477-bp open reading frame and encodes a protein of 17.70-kDa. The amino acid sequence shares high identity with MtHSP (93.98 %), PsHSP17.1 (83.13 %), GmHSP17.9 (74.10 %) and SlHSP17.6 (79.25 %). Phylogenetic analysis revealed that MsHSP17.7 belongs to the group of cytosolic class II small heat shock proteins (sHSP), and likely localizes to the cytoplasm. Quantitative RT-PCR indicated that MsHSP17.7 was induced by heat shock, high salinity, peroxide and drought stress. Prokaryotic expression indicated that the salt and peroxide tolerance of Escherichia coli was remarkably enhanced. Transgenic Arabidopsis plants overexpressing MsHSP17.7 exhibited increased root length of transgenic Arabidopsis lines under salt stress compared to the wild-type line. The malondialdehyde (MDA) levels in the transgenic lines were significantly lower than in wild-type, although proline levels were similar between transgenic and wild-type lines. MsHSP17.7 was induced by heat shock, high salinity, oxidative stress and drought stress. Overexpression analysis suggests that MsHSP17.7 might play a key role in response to high salinity stress.
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
authors.forename: Zhen-Yi
authors.initials: ZY
authors.lastname: Li
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
authors.forename: Rui-Cai
authors.initials: RC
authors.lastname: Long
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
authors.forename: Tie-Jun
authors.initials: TJ
authors.lastname: Zhang
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
authors.forename: Qing-Chuan
authors.initials: QC
authors.lastname: Yang
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China. kangjmei@126.com.
authors.forename: Jun-Mei
authors.initials: JM
authors.lastname: Kang
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D003001:Cloning, Molecular; D017124:Conserved Sequence; D003593:Cytoplasm / Q000378:metabolism; D004926:Escherichia coli; D015870:Gene Expression; D050888:Heat-Shock Proteins, Small / Q000235:genetics* / Q000378:metabolism; D000455:Medicago sativa / Q000235:genetics* / Q000378:metabolism; D019697:Onions; D009928:Organ Specificity; D018384:Oxidative Stress; D010802:Phylogeny; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018547:Plant Stems / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics; D055049:Salt Tolerance
chemical_list: D050888:Heat-Shock Proteins, Small; D010940:Plant Proteins
keywords: Heat shock protein; Homology cloning; Medicago sativa; RT-qPCR; Salt stress