title: Cloning and characterization of the Gossypium hirsutum major latex protein gene and functional analysis in Arabidopsis thaliana.
abstract: The major latex protein (MLP) gene in Gossypium hirsutum was cloned and designated Gh-MLP. Expression in cotton root was induced by salt stress and Verticillium dahliae toxin, and bioinformatic analysis showed that Gh-MLP encodes a 157-amino acid protein that is similar to members of the MLP subfamily in the Bet v 1 family. Although the structure of MLP is similar to Bet v 1 family proteins, the sequence identity to other subfamilies of Bet v 1 proteins is less than 20%. The Gh-MLP promoter contains potential cis-acting elements for response to salt stress and fungal elicitor. RT-PCR analysis showed that Gh-MLP expression was rapidly induced by NaCl and V. dahliae toxin, and induction was maintained over 72 h. However, Gh-MLP transgenic Arabidopsis thaliana did not show resistance to V. dahiae, salt tolerance was significantly enhanced. In contrast to the wild type, the Gh-MLP transgene allowed plants to germinate normally after treatment with 75 mM NaCl. Total flavonoid was twofold higher in transgenic Arabidopsis than in the control, suggesting that Gh-MLP might be involved in altering flavonoid content. We hypothesize Gh-MLP, like other Bet v 1 family proteins, participates in the binding or transport of ligands through its specific three-dimensional structure, and takes part in defensive responses to biotic and abiotic stresses.
authors.affiliation: Institute of Crop Science, Chinese Academy of Agricultural Sciences, 100081 Beijing, People's Republic of China.
authors.forename: Jie-Yin
authors.initials: JY
authors.lastname: Chen
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Dai
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D019295:Computational Biology; D005419:Flavonoids / Q000378:metabolism; D003368:Gossypium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D017433:Protein Structure, Secondary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D005419:Flavonoids; D010940:Plant Proteins; D012965:Sodium Chloride