| Autor: |
Hart, James W., Gordon, Dennis C., MacDonald, Ian R. |
| Předmět: |
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| Zdroj: |
Plant, Cell & Environment; Oct1982, Vol. 5 Issue 5, p361-366, 6p |
| Abstrakt: |
Growth rates throughout an organ curving phototropically under continuous, unilateral white light were monitored by time-lapse photography of cress hypocotyls marked into 1 mm sections by two rows of ion-exchange beads. Curvature resulted from an integrated sequence of changes in growth rate on each side of organ, but the actual patterns of change and, therefore rates of curvature, differed within even this one species, depending upon the immediate pretreatment of the seedlings. Transference of seedlings from darkness to unilateral irradiation gave immediate growth inhibition of both sides of the organ. Curvature resulted from differential recovery of growth rate, being seen first on the shaded side, most prominently in the apical regions, on the lit (lower) side. On the other hand, transfer of seedlings from omnilateral to unilateral irradiation of the same intensity resulted in simultaneous growth inhibition on the irradiated side and stimulated growth on the shaded side; this growth stimulation of the shaded side was greater than occurred in totally darkened control plants. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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