title: A novel small heat shock protein gene, vis1, contributes to pectin depolymerization and juice viscosity in tomato fruit.
abstract: We have characterized a novel small heat shock protein gene, viscosity 1 (vis1) from tomato (Lycopersicon esculentum) and provide evidence that it plays a role in pectin depolymerization and juice viscosity in ripening fruits. Expression of vis1 is negatively associated with juice viscosity in diverse tomato genotypes. vis1 exhibits DNA polymorphism among tomato genotypes, and the alleles vis1-hta (high-transcript accumulator; accession no. AY128101) and vis1-lta (low transcript accumulator; accession no. AY128102) are associated with thinner and thicker juice, respectively. Segregation of tomato lines heterogeneous for vis1 alleles indicates that vis1 influences pectin depolymerization and juice viscosity in ripening fruits. vis1 is regulated by fruit ripening and high temperature and exhibits a typical heat shock protein chaperone function when expressed in bacterial cells. We propose that VIS1 contributes to physiochemical properties of juice, including pectin depolymerization, by reducing thermal denaturation of depolymerizing enzymes during daytime elevated temperatures.
authors.affiliation: H.J. Heinz Company, Stockton, California 95201, USA.
authors.forename: Wusirika
authors.initials: W
authors.lastname: Ramakrishna
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Deng
authors.forename: Chang-Kui
authors.initials: CK
authors.lastname: Ding
authors.forename: Avtar K
authors.initials: AK
authors.lastname: Handa
authors.forename: Richard H
authors.initials: RH
authors.lastname: Ozminkowski
mesh_terms: D000064:Acclimatization / Q000235:genetics / Q000502:physiology; D000483:Alleles; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D018744:DNA, Plant / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D005638:Fruit / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D006358:Hot Temperature; D018551:Solanum lycopersicum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010368:Pectins / Q000378:metabolism*; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011096:Polygalacturonase / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide; D011489:Protein Denaturation; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014783:Viscosity
chemical_list: D001426:Bacterial Proteins; D018744:DNA, Plant; D006360:Heat-Shock Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; D010368:Pectins; D011096:Polygalacturonase