Satter R L, Geballe G T, Galston A W
J Gen Physiol. 1974 Oct;64(4):431-42. doi: 10.1085/jgp.64.4.431.
Phytochrome, a membrane-localized biliprotein whose conformation is shifted reversibly by brief red or far-red light treatments, interacts with the rhythmic oscillator to regulate leaflet movement and potassium flux in pulvinal motor cells of Samanea. Darkened pinnae exposed briefly to red light (high P(fr) level) have less potassium in motor cells in the extensor region, more potassium in motor cells in the flexor region, and smaller angles than those exposed to far-red light (low P(fr) level). Increase in temperature from 24 degrees to 37 degrees increases the differential effect of the light treatments during opening (the energetic phase) but not during closure, implying that phytochrome controls an energetic process. It seems likely that phytochrome interacts with rhythmically controlled potassium pumps in flexor and extensor cells. During nyctinastic closure of white-illuminated pinnae, exposure to far-red light before darkening results in larger angles than does exposure to red. As in rhythmic opening, the angles of all pinnae and the differential effect of the light treatments increases with increasing temperature.
光敏色素是一种定位于膜上的双蛋白，其构象可通过短暂的红光或远红光处理而发生可逆变化，它与节律振荡器相互作用，以调节雨树小叶运动和叶枕运动细胞中的钾通量。短暂暴露于红光（高P(fr)水平）下的变黑羽片，其伸肌区域运动细胞中的钾含量较少，屈肌区域运动细胞中的钾含量较多，且角度比暴露于远红光（低P(fr)水平）下的羽片小。温度从24摄氏度升高到37摄氏度会增加光处理在打开（能量阶段）期间的差异效应，但在关闭期间则不会，这意味着光敏色素控制着一个能量过程。光敏色素似乎与屈肌和伸肌细胞中有节律控制的钾泵相互作用。在白色光照下羽片的感夜性关闭过程中，变黑前暴露于远红光下的角度比暴露于红光下的角度大。与节律性打开一样，所有羽片的角度以及光处理的差异效应都随温度升高而增加。
