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Temporal course of graviperception in intermittently stimulated cress roots
Author(s) -
Hejnowicz Z.,
Sondag C.,
Alt W.,
Sievers A.
Publication year - 1998
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1046/j.1365-3040.1998.00375.x
Subject(s) - stimulation , clinostat , rest (music) , chemistry , biophysics , cytoskeleton , interval (graph theory) , duration (music) , physics , anatomy , neuroscience , mathematics , biology , medicine , cell , biochemistry , combinatorics , acoustics
Gravitropic bending of Lepidium roots caused by intermittent stimulation lasting ≈ 1 h was the same for a particular sum of stimulation intervals and was independent of (i) the length of a single stimulation interval (from 1 to 12·2 s) during which the roots were exposed unilaterally and horizontally, and (ii) rest intervals (from 60 to 300 s) during which roots were horizontally rotated at two revolutions per minute on a clinostat. The same effectiveness of equal sums of short stimulations separated by relatively long rest intervals indicates that the signals into which the stimuli are transduced are: (i) additive; (ii) proportional to the duration of a single stimulation; and (iii) stable for at least 5 min. The perception time is shorter than 1 s, the presentation time is ≈ 10 s. The effects of intermittent stimulation fit the hypothesis that the gravity‐induced movement of statoliths changes asymmetrically the stress in cytoskeletal actin filaments, thereby inducing gravitropic bending.