Faculty of Agriculture, Tottori University, Tottori 680, Japan.
Plant Physiol. 1989 Mar;89(3):925-31. doi: 10.1104/pp.89.3.925.
Host-specific toxin from the rough lemon (Citrus jambhiri Lush) pathotype of Alternaria alternata (ACR toxin) was tested for effects on mitochondria isolated from several citrus species. The toxin caused uncoupling of oxidative phosphorylation and changes in membrane potential in mitochondria from leaves of the susceptible host (rough lemon); the effects differed from those of carbonylcyanide-m-chlorophenylhydrazone, a typical protonophore. ACR toxin also inhibited malate oxidation, apparently because of lack of NAD(+) in the matrix. In contrast, the toxin had no effect on mitochondria from citrus species (Dancy tangerine and Emperor mandarin [Citrus reticulata Blanco], and grapefruit [Citrus paradisi Macf.]) that are not hosts of the fungus. The effects of the toxin on mitochondria from rough lemon are similar to the effects of a host-specific toxin from Helminthosporium maydis (HMT) on mitochondria from T-cytoplasm maize. Both ACR and HMT toxins are highly selective for the respective host plants. HMT toxin and methomyl had no effect (toxic or protective) on the activity of ACR toxin against mitochondria from rough lemon.
从 rough lemon（Citrus jambhiri Lush）Alternaria alternata（ACR 毒素）的专化型中分离出的宿主特异性毒素被测试对几种柑橘属植物分离的线粒体的影响。该毒素引起易感宿主（rough lemon）叶片中线粒体的氧化磷酸化解偶联和膜电位变化；其作用与典型的质子载体羰基氰化物 m-氯苯腙的作用不同。ACR 毒素还抑制苹果酸氧化，显然是由于基质中缺乏 NAD(+)。相比之下，该毒素对柑橘属植物（Dancy 橘和帝王橘[Citrus reticulata Blanco]和葡萄柚[Citrus paradisi Macf.])的线粒体没有影响，这些植物不是真菌的宿主。毒素对 rough lemon 线粒体的影响类似于 Helminthosporium maydis（HMT）从 T-细胞质玉米分离的宿主特异性毒素对 T-细胞质玉米线粒体的影响。ACR 和 HMT 毒素均对各自的宿主植物具有高度选择性。HMT 毒素和灭多威对 ACR 毒素对 rough lemon 线粒体的活性没有影响（毒性或保护）。
