Effect of the host-specific toxin from Alternaria kikuchiana on the ultrastructure of plasma membranes of cells in leaves of Japanese pear

Ultrastructural analysis of responses of host and fungal cells during plant infection

“…The slightly damaged subtype is typical of susceptible genotypes treated with AF-toxin (Park et al 1981a(Park et al , 1992aPark and Unno 1999), AM-toxin (Park et al , 1981bShimomura et al 1992Shimomura et al , 1993, and alternaric acid (Langsdorf et al 1991). The severely damaged subtype was found in host tissues treated with AK-toxin (Park 1977a(Park , b, c, d, e, f, 1991(Park , 1998Park et al 1976Park et al , 1981aPark et al , b, 1989Park et al , 1992bPark et al , 1994Shimizu et al 2005a;Shinogi et al 2001;Suzuki et al 2002), AFtoxins (Park et al 1981(Park et al , 1992aPark and Unno 1999), SVtoxin (Singh et al 2000) and ACT-toxin (Itoh et al 1993). AK-toxin I is the HST produced from A. alternata Japanese pear pathotype and is the causal fungus of black spot disease of pear plants (Tanaka 1933); AF-toxin I is from A. alternata strawberry pathotype (the causal fungus of black spot disease of strawberry) (Maekawa et al 1984); AM-toxin I is from A. alternata apple pathotype (the causal fungus of Alternaria blotch in apple plants) (Sawamura 1965); and SV-toxin is from S. vesicarium (the causal fungus of brown spot disease in European pear plants) (Signh et al 2000).…”

“…The permeability dysfunction was probably associated with the modifications because the modifications were observed specifically at plasma membranes near the plasmodesmata of the toxin-treated host cells ( Fig. 1) (Park et al 1976). This result suggested that the toxin receptor is on plasmodesmatal plasma membranes (Park 1991).…”

“…The severely damaged subtype of plasma membrane modification is typical in susceptible genotypes of Japanese pear plants treated with the toxin. The toxin caused permeability changes in host cells but not in fungal cells within 2 min of toxin exposure (Park et al 1976) and caused changes in the plasma membrane within 5 min of exposure (Park et al 1987b). The permeability dysfunction was probably associated with the modifications because the modifications were observed specifically at plasma membranes near the plasmodesmata of the toxin-treated host cells ( Fig.…”

Ultrastructural Changes in Cells of Susceptible Leaves of Japanese Pear Inoculated with Spores of Alternaria kikuchiana Tanaka

“…The author10, 11,13) reported that the effect of AK-toxin appeared in the intefaces between the cell walls and plasma membrane of leaf cells of susceptible pears. The mycelial mats were removed from the test tubes, rinsed with tap water for 6hr continually, and anchored to a glass plate at 20C for 16hr in a moist chamber.…”

Activation of carbohydrate-containing golgi vesicles in susceptible leaf cells of Japanese pear responding with AK-toxin.

“…Chojuro are unaffected4). Park et al 8,10) examined the primary action sites of the toxin in susceptible cells by electron microscopy. They reported that the effect of the toxin in susceptible cells firstly was detected as occurrence of plasmalemmal invaginations near plasmodesmata at 5min after toxin exposure10).…”