100. Itoh, T., O'Neil, R. M., and R. M. Brown, Jr. 1984 Interference of cell wall regeneration of Boergesenia forbesii protoplasts by Tinopal LPW, a fluorescent brightening agent. Protoplasma 123:174-183.

100. Summary

Wounding cells of Boergesenia forbesii (Harvey) Feldmann induces the synchronous formation of numerous protoplasts which synthesize large cellulose microfibrils within 2-3 hours after wounding. The microfibrils appear to be assembled by linear terminal synthesizing complexes (TCs). TC subunits appear on both E- and P-faces of the plasma membrane, thus suggesting the occurrence of a transmembrane complex. The direction of microfibril synthesis is random during primary wall assembly and becomes ordered during secondary wall assembly. The average density of TCs during secondary wall deposition is 1.7/m2, and the average length of the TC is 510 nm. TC organization is similar to that of Valonia macrophysa, however, the larger TCs of Boergesenia (510 nm vs. 350 nm) produce correspondingly larger microfibrils (30 nm vs. 20 nm). The effects of a fluorescent brightening agent (FBA), Tinopal LPW, on cell wall regeneration of Boergesenia protoplasts was investigated. The threshold level of Tinopal LPW for interfering with microfibril assembly is 1.5 M. At 95 M Tinopal (for short periods up to 15 minutes), microfibril impressions have atypical spherical impressions at their termini. At longer incubations (24 hours), TCs and microfibril impressions are absent. When washed free of Tinopal, the protoplasts eventually resume normal wall assembly; however, TCs do not reappear until at least 30 minutes after the removal of Tinopal. In consideration of the presence of ordered TCs before FBA treatment, their random distribution upon recovery implies an intermediate stage of assembly or possibly de novo synthesis.

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Last modified 27 October 2005.
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