Botany Dept. Univ. of Wyoming, Laramie, WY 82071, USA; Biology Dept. Univ. of Northern Iowa, Cedar Falls. 1A 50614, USA.
Physiol Plant. 1990 Aug;79(4):593-8. doi: 10.1111/j.1399-3054.1990.tb00030.x.
Blue light gradients in the pulvini of soybean (Glycine max var. Northrup King S1346) leaves with different laminar orientations were examined with a fiber optic microprobe. The gradients changed markedly as a function of both incident light angle and leaf position and were determined largely by the amount of light present in the adaxial side of the pulvinus. The steepest gradient for inclined leaves was with light incident at 90° whereas for declined leaves it occurred when the light was incident at 150°. A proposed pulvinar mechanism which allows for the detection of light direction and leaf position by using the blue light gradient as an orientation signal could account for solar tracking by soybean.
利用光纤微探针研究了具有不同叶层取向的大豆（Glycine max var. Northrup King S1346）叶柄中的蓝光梯度。梯度随入射光角度和叶片位置的变化而显著变化，主要由叶柄腹侧的光量决定。对于倾斜叶片，最陡的梯度是在光线以 90°入射时，而对于下降叶片，当光线以 150°入射时发生。一个提出的叶枕机制可以通过使用蓝光梯度作为定向信号来检测光方向和叶片位置，从而解释大豆的太阳跟踪现象。
