Nagata Y
Department of Biology, Faculty of Science, Osaka University, Toyonaka, Osaka 560 Japan.
Plant Physiol. 1979 Jul;64(1):9-12. doi: 10.1104/pp.64.1.9.
Localization of phytochrome which mediates rhizoid differentiation in Spirogyra was investigated. The red-absorbing form of phytochrome (Pr) seems to be distributed all over the cell periphery which remained in the centripetal end part after the centrifugation, as rhizoids formed equally well with red spotlight irradiation of three different parts of an end cell, i.e. distal end, middle, and proximal end, and with irradiation of centrifugal and centripetal end parts of a centrifuged end cell. The Pr distribution was confirmed with an experiment using far red irradiation over the entire cell, centrifugation, and red spotlight irradiation. The Pr-phytochrome molecules appeared to be mobile because no dichroic orientation was shown with polarized red spotlight irradiation. On the contrary, it is suggested that far red-absorbing form of phytochrome molecules are evacuated from the centripetal end part by the centrifugation in an experiment involving red irradiation over the entire cell-centrifugation-far red spot irradiation. Rhizoid formation was repressed markedly by far red irradiation of the centrifugal end part but not of the centripetal end part.
对介导水绵中假根分化的光敏色素定位进行了研究。光敏色素的红光吸收形式（Pr）似乎分布在整个细胞周边，在离心后仍保留在向心端部分，因为用红色聚光灯照射末端细胞的三个不同部分（即远端、中部和近端）以及离心后的末端细胞的离心端和向心端部分时，假根形成情况同样良好。通过在整个细胞上进行远红光照射、离心和红色聚光灯照射的实验证实了Pr的分布。Pr-光敏色素分子似乎是可移动的，因为在偏振红色聚光灯照射下未显示出二向色性取向。相反，在涉及整个细胞红色照射-离心-远红色光斑照射的实验中，表明远红光吸收形式的光敏色素分子通过离心从向心端部分排出。离心端部分的远红光照射显著抑制了假根形成，但向心端部分的远红光照射则没有。
