Wavelength dependence of dark adaptation in Phycomyces phototropism.
Wavelength dependence of dark adaptation in Phycomyces phototropism.
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DOI：
10.1085/jgp.84.5.739
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发表时间：
1984-11
期刊：
影响因子：
--
通讯作者：
Lipson ED
中科院分区：
文献类型：
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作者：
Galland P;Pandya AS;Lipson ED
在347~545 nm波长范围内研究了藻视光暗适应的波长依赖性。在6.2 × 10~（-2）~2 × 10~（-7）W × m~（-2）的强度范围内，对383、409、477和507 nm波长的暗适应动力学进行了测量。在这些波长下，暗适应遵循双指数衰减，如先前在宽带蓝光下发现的那样（Russo，V.E.一、和P.Galland，1980，Struct.Bonding.，41：71; Lipson，E. D、和s. M. Block，1983，J. Gen. Physiol.，81：845）。我们已经发现，快速和慢速组件的时间常数依赖于波长的关键。在507 nm处，暗适应动力学被发现是双相的。对19种不同波长测量了500倍递减后的向光性潜伏期。在383、477和530 nm处观察到最大光通量;在409和507 nm处观察到最小光通量。在降压前后采用不同波长的照射程序，暗适应动力学关键取决于给定两个波长的顺序。我们还发现，不仅适应动力学随波长而变化，而且在没有强度变化的实验中，向光弯曲速率和向光弯曲率也随波长而变化。这些结果表明，在Phycomerma中，不止一个光感受器介导向光性，并且感觉适应受这些光感受器的调节。
The wavelength dependence of phototropic dark adaptation in Phycomyces was studied between 347 and 545 nm. Dark adaptation kinetics were measured for wavelengths of 383, 409, 477, and 507 nm in the intensity range from 6.2 X 10(-2) to 2 X 10(-7) W X m-2. At these wavelengths, dark adaptation follows a biexponential decay as found previously with broadband blue light (Russo, V. E. A., and P. Galland, 1980, Struct. Bonding., 41:71; Lipson, E. D., and S. M. Block, 1983, J. Gen. Physiol., 81:845). We have found that the time constants of the fast and slow components depend critically on the wavelength. At 507 nm, dark adaptation kinetics were found to be monophasic. The phototropic latency after a step down by a factor of 500 was measured for 19 different wavelengths. Maximal latencies were found at 383, 477, and 530 nm; minimal latencies were found at 409 and 507 nm. With irradiation programs that employ different wavelengths before and after the step down, the dark adaptation kinetics depend critically on the sequence in which the two wavelengths are given. We have found too that not only do the adaptation kinetics vary with wavelength, but so also do the phototropic bending rate and the phototropic latencies in experiments without intensity change. The results imply that more than one photoreceptor is mediating phototropism in Phycomyces and that sensory adaptation is regulated by these photoreceptors.