Srchi13, a novel early nodulin from Sesbania rostrata, is related to acidic class III chitinases.
On the tropical legume Sesbania rostrata, stem-borne nodules develop after inoculation of adventitious root primordia with the microsymbiont Azorhizobium caulinodans. A cDNA clone, Srchi13, with homology to acidic class III chitinase genes, corresponds to an early nodulin gene with transiently induced expression during nodule ontogeny. Srchi13 transcripts accumulated strongly 2 days after inoculation, decreased from day 7 onward, and disappeared in mature nodules. Induction was dependent on Nod factor-producing bacteria. Srchi13 was expressed around infection pockets, in infection centra, around the developing nodule and its vascular bundles, and in uninfected cells of the central tissue. The specific and transient transcript accumulation together with the lipochitooligosaccharide degradation activity of the recombinant protein hint at a role of Srchi13 in normal nodule ontogeny by limiting the action of Nod factors.
Goormachtig
S
S
Laboratorium voor Genetica, Department of Genetics, Flanders Interuniversity Institute for Biotechnology, Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
Lievens
S
S
Van de Velde
W
W
Van Montagu
M
M
Holsters
M
M
D000595:Amino Acid Sequence; D002688:Chitinases / Q000737:chemistry*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004926:Escherichia coli; D007887:Fabaceae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D010946:Plants, Medicinal; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D018076:DNA, Complementary; D008565:Membrane Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; C113356:Srchi13 protein, Sesbania rostrata; C045625:nodulin; D002688:Chitinases