Biochemical and molecular characterization of three barley seed proteins with antifungal properties.
We have purified three proteins from barley (Hordeum vulgare L.) seeds which synergistically inhibit the growth of fungi measured in a microtiter well assay. The proteins are a 26-kDa chitinase, a 30-kDa ribosome-inactivating protein, and a 32-kDa (1-3)-beta-glucanase. Full-length cDNAs encoding them were isolated and sequenced to determine the complete primary structures of the proteins. Northern hybridizations with the cDNAs as probes showed that the corresponding mRNAs accumulate differentially during seed development and germination. Chitinase mRNA accumulates to high levels in aleurone cells during late seed development and early germination, while high levels of mRNA encoding the ribosome-inactivating protein accumulate only in the starchy endosperm during late seed development. The glucanase mRNA accumulates to low levels during seed development and to higher levels in aleurone and seedling tissues during germination. Southern hybridizations showed that the three proteins are encoded by small families of three to eight genes. Their biological roles and potential use in genetic engineering studies are discussed.
Leah
R
R
Carlsberg Research Laboratory, Copenhagen, Denmark.
Tommerup
H
H
Svendsen
I
I
Mundy
J
J
D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000302:isolation & purification; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002688:Chitinases / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D017343:Genes, Plant; D043326:Glucan 1,3-beta-Glucosidase; D001467:Hordeum / Q000235:genetics; D008969:Molecular Sequence Data; D009699:N-Glycosyl Hydrolases; D010940:Plant Proteins / Q000235:genetics* / Q000302:isolation & purification* / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D054789:Ribosome Inactivating Proteins, Type 1; D012270:Ribosomes / Q000187:drug effects; D012639:Seeds / Q000737:chemistry; D014118:Toxins, Biological; D001617:beta-Glucosidase / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology
D000935:Antifungal Agents; D010940:Plant Proteins; D012333:RNA, Messenger; D054789:Ribosome Inactivating Proteins, Type 1; D014118:Toxins, Biological; D004247:DNA; D002688:Chitinases; D001617:beta-Glucosidase; D043326:Glucan 1,3-beta-Glucosidase; D009699:N-Glycosyl Hydrolases; C487943:ribosome-inactivating protein, Hordeum vulgare