. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 52 CJ I T. BJORKMAN Lag time Rise time E o IO 6 Gravistimulate r rVI R 5 niinutea Figure 3. Original trace of current density at upper side of columella. R indicates when the probe was moved away from the root. This figure illustrates the characteristic current shift indicative of gravipercep- tion. Reproduced with permission from Bjorkman and Leopold (1987a). Effect of inhibitors Pretreatment of the roots for 10 min with calmodulin inhibitors calmidazolium (425 fiM) and compound 48/ 80 (100 Mg/ml). at doses that inhibit cur
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 52 CJ I T. BJORKMAN Lag time Rise time E o IO 6 Gravistimulate r rVI R 5 niinutea Figure 3. Original trace of current density at upper side of columella. R indicates when the probe was moved away from the root. This figure illustrates the characteristic current shift indicative of gravipercep- tion. Reproduced with permission from Bjorkman and Leopold (1987a). Effect of inhibitors Pretreatment of the roots for 10 min with calmodulin inhibitors calmidazolium (425 fiM) and compound 48/ 80 (100 Mg/ml). at doses that inhibit curvature but not growth or initial current distribution, completely elimi- nated the characteristic change in current (Fig. 5). Pretreatment of the roots for 10 min with auxin trans- port inhibitors triiodobenzoic acid (10 fiAf) and naph- thylphthalamic acid (NPA; 1 juA/) likewise eliminated curvature but not growth. These treatments did not elim- inate a change in current (Fig. 6). A statistical treatment presented in Bjorkman and Leopold (1987b) indicates that the responses after treatment with these inhibitors was the same as controls except that the response of the NPA-treated roots was delayed by about 3 min. Discussion In exploiting the "geoelectric effect" (Schrank, 1945) for the study of root graviperception. it must be estab-. Time after gravistimulation (min) Current density after gravistimulation at different parts of the root, (a) Adjacent to .'l cap. (b) Adjacent to elongating zone ( mm from tip) which ultimately i-nt to graviperceptive columella. Bars indicate standard deviation. Positive currcni , i current. Redrawn with permission from Bjorkman and Leopold (1987a).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological
Size: 2504px × 998px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
