Coordinate accumulation of antifungal proteins and hexoses constitutes a developmentally controlled defense response during fruit ripening in grape

Plant Physiol. 1998 Jun;117(2):465-72. doi: 10.1104/pp.117.2.465.

Abstract

During ripening of grape (Vitis labruscana L. cv Concord) berries, abundance of several proteins increased, coordinately with hexoses, to the extent that these became the predominant proteins in the ovary. These proteins have been identified by N-terminal amino acid-sequence analysis and/or function to be a thaumatin-like protein (grape osmotin), a lipid-transfer protein, and a basic and an acidic chitinase. The basic chitinase and grape osmotin exhibited activities against the principal grape fungal pathogens Guignardia bidwellii and Botrytis cinerea based on in vitro growth assays. The growth-inhibiting activity of the antifungal proteins was substantial at levels comparable to those that accumulate in the ripening fruit, and these activities were enhanced by as much as 70% in the presence of 1 m glucose, a physiological hexose concentration in berries. The simultaneous accumulation of the antifungal proteins and sugars during berry ripening was correlated with the characteristic development of pathogen resistance that occurs in fruits during ripening. Taken together, accumulation of these proteins, in combination with sugars, appears to constitute a novel, developmentally regulated defense mechanism against phytopathogens in the maturing fruit.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antifungal Agents / chemistry*
  • Antifungal Agents / pharmacology
  • Antigens, Plant
  • Carrier Proteins / chemistry
  • Fruit / microbiology*
  • Fruit / physiology*
  • Hexoses / biosynthesis*
  • Hexoses / pharmacology
  • Microbial Sensitivity Tests
  • Mitosporic Fungi / drug effects*
  • Mitosporic Fungi / growth & development
  • Molecular Sequence Data
  • Plant Proteins / biosynthesis*
  • Plant Proteins / chemistry
  • Plant Proteins / pharmacology
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Sweetening Agents*
  • Xylariales / drug effects*
  • Xylariales / growth & development

Substances

  • Antifungal Agents
  • Antigens, Plant
  • Carrier Proteins
  • Hexoses
  • Plant Proteins
  • Sweetening Agents
  • lipid transfer proteins, plant
  • thaumatin protein, plant