title: Rice glycosyltransferase1 encodes a glycosyltransferase essential for pollen wall formation.
abstract: The pollen wall consists of an exine and an intine. The mechanism underlying its formation is not well understood. Glycosyltransferases catalyze the modification of biological molecules by attaching a single or multiple sugars and play key roles in a wide range of biological processes. We examined the role of GLYCOSYLTRANSFERASE1 (OsGT1) in pollen wall development in rice (Oryza sativa). This gene is highly expressed in mature pollen, and plants containing alleles caused by transfer DNA insertion do not produce homozygous progeny. Reciprocal crosses between OsGT1/osgt1 and the wild type indicated that the mutation leads to a male gametophyte defect. Microscopic analyses revealed that osgt1 pollen developed normally to the pollen mitosis stage but failed to produce mature grains. In osgt1 pollen, intine structure was disrupted. In addition, starch and protein levels were much lower in the mutant grains. Recombinant OsGT1 transferred glucose from UDP-glucose to the third and seventh positions of quercetin, a universal substrate of glycosyltransferases. Consistent with the role of OsGT1, an OsGT1-green fluorescent protein fusion protein was localized to the Golgi apparatus. Taken together, our results suggest that OsGT1 is a Golgi-localized glycosyltransferase essential for intine construction and pollen maturation, providing new insight into male reproductive development.
authors.affiliation: Crop Biotech Institute and Department of Plant Molecular Systems Biotechnology, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Sunok
authors.initials: S
authors.lastname: Moon
authors.forename: Sung-Ryul
authors.initials: SR
authors.lastname: Kim
authors.forename: Guochao
authors.initials: G
authors.lastname: Zhao
authors.forename: Jakyung
authors.initials: J
authors.lastname: Yi
authors.forename: Youngchul
authors.initials: Y
authors.lastname: Yoo
authors.forename: Ping
authors.initials: P
authors.lastname: Jin
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Ki-hong
authors.initials: KH
authors.lastname: Jung
authors.forename: Dabing
authors.initials: D
authors.lastname: Zhang
authors.forename: Gynheung
authors.initials: G
authors.lastname: An
mesh_terms: D055162:Biocatalysis; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D016695:Glycosyltransferases / Q000235:genetics* / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D009154:Mutation; D012275:Oryza / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011058:Pollen / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D011794:Quercetin / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D010940:Plant Proteins; D049452:Green Fluorescent Proteins; D011794:Quercetin; D016695:Glycosyltransferases