Ultrastructure of Compatible and Incompatible Interactions of Pumpkin Stems Infected with Phytophthora capsici

  • Lee, Byung-Kook (Molecular Plant Pathology Laboratory, Collge of Life, Environmental Sciences, Korea University) ;
  • Hong, Jeum-Kyu (Molecular Plant Pathology Laboratory, Collge of Life, Environmental Sciences, Korea University) ;
  • Hwang, Byung-Kook (Molecular Plant Pathology Laboratory, Collge of Life, Environmental Sciences, Korea University)
  • Published : 2001.02.01

Abstract

Early infection process of Phytophthora capsici in pumpkin stems was similar in the compatible and incompatible interactions 24 h after inoculation. Intercellularly growing hyphae penetrated host parenchyma cells by growing hyphae penetrated host parenchyma cells by forming haustoria. An extrahaustorial matrix was found around the haustoria in both compatible and incompatible interactions. No wall appositions were observed at the infection sites in the parenchyma cells. In the compatible interaction, infecting hyphae grew well in the intercellular spaces between xylem vessels in stem tissues. Degraded host cell wall, plasmolysis of plasma membrane, and degenerated chloroplasts were pathological features of pumpkin stem tissues in both compatible and incompatible interactions. A characteristic host response in the resistant pumkin cultivar Danmatmaetdol was rapid cytoplasmic movement of host cells toward the oomycete haustoria.