Combined biochemical and ultrastructural analysis of aflatoxin B1 action on the endomembrane system of plant cells

SummaryAflatoxin B1 inhibits bean germination, elongation of both attached and excised, cultured roots and the latter's ability to intraccllularize 14C-leucine. Thus, B1 may alter plamalemma structure and, or, function. To determine whether 18h incubation of excised roots in B1—containing medium could affect membrane chemical content, endomembranes were isolated at 1 000 (1), 40 000 (40) and 80 000 (80) xg and characterized chemically. Statistically significant differences (SD) in acid-insoluble protein between treated (T) and non-treated (NT) roots were observed for both 40 and 80 xg pellets (P). Protein and sterol recoveries were 81 (T) and 84 (NT)% for the former and 77 (T) and 79 (NT)% for the latter. Lipid phosphorus recoveries were 87, 3 (T) and 136 (NT) with and 96 (T) and 83 (NT) without membrane stabilization.Protein: sterol: lipid phosphorus were: - 35, 7: 4, 5: 1 (1 xg); 18, 9: 3, 6: 1 (40 xg); 26, 3: 4, 6: 1 (80 xg); 1, 010: 29: 1 (80 supernatant S) for NT.- 36, 9: 3, 3: 1 (1 xg); 23, 1: 3, 8:...