Melon ascorbate oxidase: cloning of a multigene family, induction during fruit development and repression by wounding

Plant Mol Biol. 1997 Jul;34(5):759-70. doi: 10.1023/a:1005851527227.

Abstract

A small family of at least four genes encoding melon ascorbate oxidase (AO) has been identified and three members of it have been cloned. Preliminary DNA sequence determination suggested that melon AO genes code for enzymes homologous to ascorbate oxidases from other plants and similar to other multicopper oxidases. We describe detailed molecular studies addressing melon AO expression during organ specific differentiation, fruit development and ripening, and in response to wounding. In particular, AO transcript accumulation was induced in ovaries and the outer mesocarp of mature preclimacteric melon fruits, before the expression of genes encoding the necessary enzymatic activities for ethylene biosynthesis. On the other hand, AO was not expressed in late stages of fruit ripening and was repressed in wounded fruits. The role of ethylene in transcriptional regulation of AO is discussed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Ascorbate Oxidase / biosynthesis
  • Ascorbate Oxidase / genetics*
  • Cloning, Molecular
  • Enzyme Repression / genetics
  • Ethylenes / biosynthesis
  • Fruit / enzymology*
  • Fruit / genetics*
  • Fruit / growth & development
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Plant*
  • Genes, Plant*
  • Molecular Sequence Data
  • Multigene Family*
  • Substrate Specificity
  • Transcription, Genetic

Substances

  • Ethylenes
  • ethylene
  • Ascorbate Oxidase