Résumé
Using RNA extracted from Zantedeschia aethiopica young leaves and primers designed according to the conservative regions of Araceae lectins, the full-length cDNA of Z. aethiopica agglutinin (ZAA) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of zaa was 871 bp and contained a 417 bp open reading frame (ORF) encoding a lectin precursor of 138 amino acids. Through comparative analysis of zaa gene and its deduced amino acid sequence with those of other Araceae species, it was found that zaa encoded a precursor lectin with signal peptide. Secondary and three-dimensional structure analyses showed that ZAA had many common characters of mannose-binding lectin superfamily and ZAA was a mannose-binding lectin with three mannose-binding sites. Southern blot analysis of the genomic DNA revealed that zaa belonged to a multi-copy gene family
Sujets)
Lectine liant le mannose/physiologie , Lectine liant le mannose/génétique , Lectine liant le mannose/composition chimique , Lectine liant le mannose , Protéines végétales/physiologie , Protéines végétales/génétique , Protéines végétales/composition chimique , Gènes de plante/physiologie , Gènes de plante/génétique , Végétaux génétiquement modifiés/physiologie , Végétaux génétiquement modifiés/génétique , Végétaux génétiquement modifiés/composition chimique , Régulation de l'expression des gènes végétaux/physiologie , Régulation de l'expression des gènes végétaux/génétiqueRésumé
Using RNA extracted from Zingiber officinale rhizomes and primers designed according to the conservative regions of monocot mannose-binding lectins, the full-length cDNA of Z. officinale agglutinin (ZOA) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of zoa was 746 bp and contained a 510 bp open reading frame (ORF) encoding a lectin precursor of 169 amino acids with a signal peptide. ZOA was a mannose-binding lectin with three typical mannose-binding sites (QDNY). Semi-quantitative RT-PCR analysis revealed that zoa expressed in all the tested tissues of Z. officinale including leaf, root and rhizome, suggesting it to be a constitutively expressing form. ZOA protein was successfully expressed in Escherichia coli with the molecular weight expected. To our knowledge, this is the first mannose-binding lectin cDNA cloned from the family Zingiberaceae. Our results demonstrate that monocot mannose-binding lectins also occur within the family Zingiberaceae.