Light-induced Adhesion of Spirogyra Cells to Glass

Abstract

Adhesion ofSpirogyra (tentatively,Spirogyrafluviatilis) cells to glass is described. The cells of an alal filament can adhere to a substrate only when they are located at the end of the hfilment. Rapid Light has a great influence on the life of most organisms and adhesion is another important factor concerned in differentiation. Only one example of light-induced adhesion has been known, that reported by Tanada (13,14). Phytochrome controls the rapid adhesion of excised root tips of barley or mung bean to a glass surface.We isolated a species of Spirogyra, a green alga, which grows in small streams attached to the beds. The filament can adhere to various kinds of substrates. This adhesion which can be induced by light is also a rapid phenomenon. We wondered by what mechanism the adhesion is caused and maintained. MATERIALS AND METHODSAxenic filaments of Spirogyra (tentatively, Spirogyra fluviatilis) were cultured at 20 C under a 12 hr-12 hr light-dark cycle with fluorescent light in Darden's medium (3).2The vessel used for these experiments consisted of a glass ring (1.6 cm in diameter and 1 cm high) sealed above a soda glass slide. It was carefully cleaned with acetone, soap, tap water, and distilled H20. The adhesion rate was calculated as the percentage of end cells which were not released from the substrate by the shaking (under "Results" for reasons for using this method of calculation).All experiments were carried out in a temperature-controlled room kept between 20 and 24 C, + 1 C except where otherwise noted.Further details were previously reported including the isolation (11, 12).All enzymes used here were supplied commercially: pronase from Kaken Chemicals (Japan); trypsin type I and hyaluronidase type I from bovine testes from Sigma Chemical; cellulase from Kyowa Hakko (Japan); RNase from Worthington Biochemical; a-amylase from bacteria from Nagase (Japan). Other chemicals used were reagent grade. RESULTSSpirogyra cells attached to all of the substrates examined: glass, polystyrene, polyethylene, aluminum, wood, filter paper, Teflon, and agar. In the present experiment, a glass slide was chosen as the substrate.All of the cut filaments in the vessel sedimented easily toward the glass bottom to lie there at full length. A cut filament adheres to the glass substrate by its end cell(s), especially by the end cell tip(s), with very few exceptions (Fig. 1)

Saponin-induced release of single cells from filaments and rhizoid differentiation in Spirogyra

“…Light is necessary for initiation of rhizoid differentiation (Nagata 1973b(Nagata , 1977(Nagata , 1979. Filaments were incubated in APW supplemented with 0.1% saponin at 23°C for 1 day under either a light-dark cycle (culture condition) or continuous darkness.…”

“…New terminal cells that result from filament-severing then initiate tip growth at their distal end; they finally form rod-or rosette-shaped rhizoids (Nagata 1973a;Inoue et al 1999). Nagata extensively studied the process of rhizoid differentiation that was induced by filament-severing (Nagata 1973a(Nagata , 1973b(Nagata , 1977(Nagata , 1979. Recently, we revived the study of this fascinating phenomenon and revealed new aspects in rhizoid differentiation:…”

Presence of xyloglucan‐like polysaccharide in Spirogyra and possible involvement in cell–cell attachment

“…Since the outer layer of the cell wall contains pectic substance (Wurdack 1923), antibody cannot have access to the xyloglucan‐like polysaccharides in the cell wall. In addition, the cell wall of rhizoid is coated with transparent material supposed to be lectin‐binding material (Nagata 1977; Inoue et al . 1999).…”

The Role of Electricity in Plant Movements

“…The adhesion of the root tips is associated with a sudden change in surface charge of the epidermal cells of the root cap (Racusen and Etherton, 1975), although measurements of the electrical potential on the root surface have shown only small (about 1 mV) changes in potential (Jaffc, 1968), In addition, phytochrome-mediated adhesion is also associated with an increase in acetylcholine content (Jaffe, 1970), H+ release into the bathing solution, increased Oj consumption and increased ATP consumption (Yunghans and JafTe, 1972), These findings suggest a causal sequence of events which may have some features in common with nerve excitation, although there is no conclusive evidence to support this notion. It would be interesting to see whether the light-induced adhesion of Spirogyra filamentous cells to glass, as reported by Nagata (1977), is also mediated by electrical events similar to those in mung bean root tips. In this connection Fujii.…”