Interactions between red light, abscisic acid, and calcium in gravitropism

Leopold, A. C.; LaFavre, A. K.

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NASA NTRS · 20040112083

Interactions between red light, abscisic acid, and calcium in gravitropism

Leopold, A. C.·LaFavre, A. K.

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Abstract

The effect of red light on orthogravitropism of Merit corn (Zea mays L.) roots has been attributed to its effects on the transduction phase of gravitropism (AC Leopold, SH Wettlaufer [1988] Plant Physiol 87:803-805). In an effort to characterize the orthogravitropic transduction system, comparative experiments have been carried out on the effects of red light, calcium, and abscisic acid (ABA). The red light effect can be completely satisfied with added ABA (100 micromolar) or with osmotic shock, which is presumed to increase endogenous ABA. The decay of the red light effect is closely paralleled by the decay of the ABA effect. ABA and exogenous calcium show strong additive effects when applied to either Merit or a line of corn which does not require red light for orthogravitropism. Measurements of the ABA content show marked increases in endogenous ABA in the growing region of the roots after red light. The interpretation is offered that red light or ABA may serve to increase the cytoplasmic concentrations of calcium, and that this may be an integral part of orthogravitropic transduction.

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NASA Program Space Biology Non-NASA Center NASA Discipline Plant Biology NASA Discipline Number 29-20 Light Gravitropism/drug effects/physiology/radiation effects Calcium/metabolism/pharmacology/physiology Zea mays/growth & development/physiology/radiation effects Abscisic Acid/metabolism/pharmacology/physiology Support, U.S. Gov't, P.H.S Support, U.S. Gov't, Non-P.H.S Signal Transduction/physiology Osmotic Pressure Plant Root Cap/growth & development/physiology/radiation effects

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Leopold, A. C., LaFavre, A. K.. 1989-01-01. Interactions between red light, abscisic acid, and calcium in gravitropism. https://ntrs.nasa.gov/citations/20040112083

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