Galland P, Pandya A S, Lipson E D
J Gen Physiol. 1984 Nov;84(5):739-51. doi: 10.1085/jgp.84.5.739.
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.
研究了毛霉属中向光性暗适应的波长依赖性，范围在347至545纳米之间。在强度范围为6.2×10⁻²至2×10⁻⁷瓦·米⁻²内，测量了383、409、477和507纳米波长下的暗适应动力学。在这些波长下，暗适应呈现双指数衰减，这与之前用宽带蓝光所发现的情况相同（鲁索，V.E.A.，和P.加兰德，1980年，《结构化学》，41:71；利普森，E.D.，和S.M.布洛克，1983年，《普通生理学杂志》，81:845）。我们发现快速和慢速成分的时间常数严重依赖于波长。在507纳米处，暗适应动力学被发现是单相的。测量了在强度下降500倍后19种不同波长下的向光性潜伏期。在383、477和530纳米处发现最大潜伏期；在409和507纳米处发现最小潜伏期。对于在强度下降前后采用不同波长的照射程序，暗适应动力学严重依赖于两种波长给出的顺序。我们还发现，不仅适应动力学随波长变化，而且在无强度变化的实验中，向光弯曲速率和向光潜伏期也随波长变化。结果表明，不止一种光感受器介导毛霉属中的向光性，并且感觉适应由这些光感受器调节。
