Department of Genetics, University of Leeds, LS2 9JT, Leeds, UK.
Planta. 1983 Aug;158(4):357-64. doi: 10.1007/BF00397338.
Primary chloronemata growing from germinated spores of the moss Physcomitrella patens adopt one of two preferred polarotropic orientations depending on the wavelength and photon fluence rate of monochromatic light. Growth is mainly parallel to the electrical vector of plane polarised light in blue light and higher fluence rates of red light, and perpendicular to the electrical vector in the green and far-red regions of the spectrum and in low fluence rates of red light. The transition between the two polarotropic orientations, at wavelengths where it can be observed, usually occurs over a narrow range of fluence rates, and at this point the filaments do not grow randomly but tend to adopt in approximately equal numbers one of the preferred directions of growth. The primary chloronemata are positively phototropic in far-red light and in red light of low fluence rates, but tend to grow at right angles to the incident light in high fluence rates of red light. Simultaneous illumination with a high fluence rate of red light and a low fluence rate of far-red light causes a marked increase in the percentage of filaments growing towards the red light source at the expense of those growing at right angles to it, supporting the hypothesis that in red and far-red light, at least, the responses are controlled by the photoequilibrium of a phytochrome pool.
从藓类植物Physcomitrella patens 的萌发孢子中生长出来的初生原绿体根据单色光的波长和光子通量率，采用两种优先的极向性取向之一。在蓝光和较高的红光通量率下，生长主要与平面偏振光的电矢量平行，而在绿光和远红光区域以及红光的低通量率下，则与电矢量垂直。在可以观察到的波长范围内，两种极向性取向之间的转变通常发生在一个狭窄的通量率范围内，此时，丝状体能随机地生长，而是倾向于以大约相等的数量采用其中一种生长的优选方向。初生原绿体在远红光和低通量率的红光中具有正向光向性，但在红光通量率较高时，往往会垂直于入射光生长。同时用高通量率的红光和低通量率的远红光照射会导致向红光光源生长的丝状体的百分比显著增加，而垂直于它生长的丝状体的百分比则减少，这支持了这样一种假设，即在红光和远红光中，至少这些反应是由一个光敏色素库的光平衡控制的。
