Cloning, characterization and differential expression of a Bowman-Birk inhibitor during progressive water deficit and subsequent recovery in peanut (Arachis hypogaea) leaves.
Bowman-Birk inhibitor (BBI) genes encode serine protease inhibitors well known for their anticarcinogenic properties and roles in plant defense against insects and pathogens. Here we investigated the expression of a BBI gene in response to water deficit, recovery and phytohormones. A full length cDNA encoding a novel BBI (AhBBI) was isolated from peanut (Arachis hypogaea L.) leaves. The deduced protein is a polypeptide of 11.5kDa containing a signal peptide of 20 amino acids which is missing from peanut seed full-length BBI. Sequence analysis showed that AhBBI presents the characteristic features of BBIs but its first inhibitory loop is unique among the Fabaceae species. Real-time PCR analyses indicated that in peanut leaves, AhBBI is upregulated by water deficit and exogenous jasmonic acid (JA) but repressed by abscissic acid (ABA) after 24h of treatment. The transcripts accumulation patterns during water deficit differed between two cultivars studied in relation to their tolerance levels to drought. AhBBI transcripts accumulated earlier and stronger in the tolerant cultivar (cv. Fleur11) compared to the susceptible one (cv. 73-30) suggesting that BBI genes are involved in drought stress tolerance. Subsequent rehydration reversed the accumulation of AhBBI transcripts in both cultivars but at different levels. The overall role of BBI in abiotic stress tolerance and the possible mechanisms of action are discussed.
Equipe IBIOS, UMR 7618 Bioemco, Université Paris Est - Créteil, 61 avenue du Général de Gaulle, C Créteil cedex, France. k.drame@cgiar.org
Khady Nani
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Dramé
Chantal
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Passaquet
Anne
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Repellin
Yasmine
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Zuily-Fodil
D000222:Adaptation, Physiological / Q000235:genetics*; D000595:Amino Acid Sequence; D010367:Arachis / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D013312:Stress, Physiological; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000235:genetics* / Q000378:metabolism*; D014867:Water / Q000378:metabolism
D010940:Plant Proteins; D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D014867:Water