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The light growth response of Phycomyces
The Journal of General Physiology
|November 1, 1973
Summary
This study characterizes the transient light growth response in Phycomyces using automated tracking. Key findings include defined latency, oscillatory responses to saturating stimuli, and confirmed growth rate increases at high light intensities.
Area of Science:
- Plant biology
- Photobiology
- Biophysics
Background:
- Phycomyces exhibits complex growth responses to light stimuli.
- Understanding these responses is crucial for elucidating phototropism mechanisms.
Purpose of the Study:
- To characterize the transient light growth response of Phycomyces.
- To investigate the influence of light intensity and spectral properties on growth.
- To analyze the responses of phototropism mutants.
Main Methods:
- Utilized an automated tracking system for precise measurements.
- Applied pulse and sinusoidal light stimuli across various intensities and wavelengths.
- Investigated mutant strains with altered phototropic sensitivity.
Main Results:
- Observed a sharply defined latency in the growth response.
- Identified strong oscillations (1.6 min period) in response to saturating stimuli.
- Confirmed a linear dependence of phase shift on frequency and increased growth rate at high intensities.
- Mutants showed distorted, though sizable, growth responses.
Conclusions:
- The light growth response in Phycomyces is characterized by distinct latency and oscillatory dynamics.
- Response magnitude and steady-state growth are intensity-dependent.
- Mutant analysis suggests a complex genetic basis for phototropism and growth regulation.
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