TABLE 1.

Occurrence of developmental processes in presence of inhibitors

Inhibitor (concn)% Occurrence of:
Zoospore releasebEfficiency of cleavagecZoospores swimming after 3 hdZoospore encystmenteCyst germinationfDirect germinationg
Controla100100100100100100
Verapamil (40 μM)8 ± 595 ± 5h18 ± 393 ± 3102 ± 8
Verapamil (200 μM)0 ± 211 ± 389 ± 665 ± 22
K-252a (20 nM)88 ± 11101 ± 443 ± 484 ± 1163 ± 10104 ± 10
K-252a (100 nM)47 ± 1495 ± 31 ± 016 ± 59 ± 398 ± 8
K-252a (500 nM)30 ± 1599 ± 20 ± 012 ± 65 ± 0100 ± 7
KN-93 (100 nM)34 ± 399 ± 195 ± 476 ± 757 ± 679 ± 7
KN-93 (500 nM)18 ± 095 ± 592 ± 646 ± 812 ± 551 ± 7
Trifluoroperazine (2.5 μM)78 ± 34 ± 10 ± 08 ± 291 ± 12105 ± 7
Trifluoroperazine (12.5 μM)0 ± 04 ± 088 ± 1091 ± 7
Trifluoroperazine (60 μM)0 ± 02 ± 280 ± 1085 ± 5
Actinomycin D (10 μg/ml)98 ± 3100 ± 2102 ± 497 ± 30 ± 057 ± 10
Actinomycin D (100 μg/ml)96 ± 4102 ± 397 ± 396 ± 50 ± 017 ± 9
  • a Values are standardized to 100% for solvent-only controls.

  • b Percentage was measured 2 h after placing sporangia in water at 10°C. An average of 74% of sporangia released zoospores in controls. These and values in other categories show averages ± range from two experiments, with at least 200 structures counted for each sample.

  • c Percentage of zoospores of fully cleaved, single-unit size; controls averaged 97%.

  • d Scored from samples kept at 10°C, about 1 h after most zoospores were released. Controls averaged 91%.

  • e Inhibitors were added to samples, which were kept at 10°C, 5 min before adding CaCl2 to a concentration of 0.5 mM and vortexing for 20 s. Encystment was scored 10 min later, with controls averaging 87%.

  • f Germination in water at 10°C, scored after 16 h; controls averaged 65%. Germination was first noted after about 2 h, at which time similar results were observed.

  • g Scored after 16 h in rye media at 18°C; controls averaged 62%.

  • h —, too few to accurately count.