RESUMO
A rice genomic clone (sps1) coding for sucrose phosphate synthase (SPS) was isolated and sequenced. Rice sps1 contains 13 exons and 12 introns, an unusually long 366-bp leader region with a highly organized primary structure and a promoter region with no obvious homology with eukaryotic promoter consensus sequences. Southern blot analysis showed that SPS is encoded by a single-copy gene in the rice genome. Comparison of the rice, maize, potato and spinach SPS deduced amino acid (aa) sequences showed that these enzymes have a well conserved region comprising their first 700 aa, and a variable C-terminal region. Analysis of rice sps1 expression showed that mRNA levels change during leaf development. SPS activity and mRNA were undetectable in roots.
Assuntos
Glucosiltransferases/genética , Oryza/enzimologia , Sequência de Aminoácidos , Sequência de Bases , Southern Blotting , Clonagem Molecular , DNA de Plantas , Expressão Gênica , Genoma de Planta , Dados de Sequência Molecular , Oryza/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Homologia de Sequência de AminoácidosRESUMO
A cDNA library from tomato planta macho viroid (TPMV)-infected tomato was constructed. The library was screened at low stringency with a tobacco PR-R cDNA probe. An 832 bp cDNA from a mRNA present only in infected tissue was isolated. Nucleotide sequence showed high homology with the osmotin from both tobacco and tomato (NP24). This cDNA probably corresponds to the AP24 and P23 proteins previously described in tomato and induced upon fungal and viroid infection.
