Abstract
Filaments of Griffithsia pacifica replace dead cells by the process of cell repair. When an intercalary cell is killed, but its cell wall remains intact holding the two halves of the plant together, the cell above it produces a repair rhizoid cell; the cell below it produces a specialized, rhizoid-like repair shoot cell. The repair rhizoid and shoot grow towards each other, meet, and fuse to form a single shoot cell. Evidence from observations of cell repair in vivo has indicated that the repair rhizoid produces a hormone or hormones which induce the production of the repair shoot, maintain the rhizoid-like morphology and growth of the repair shoot, and attract it to the repair rhizoid for fusion. This hormone has been named rhodomorphin. Using an artificial cell-fusion system we show that repair rhizoids and normal rhizoids, but no shoot cell, can induce decapitated filaments to form repair shoot cells. Decapitated filaments form repair shoot cells only when they are exposed to the hormone within 4–6 h after decapitation; after this time they lose their sensitivity to the hormone. A method has been developed for isolating, and assaying for, the cell-fusion hormone. Rhodomorphin retains its activity for several days at room temperature and for at least two years at-16° C.
Similar content being viewed by others
References
Barksdale, A.W. (1969) Sexual hormones of Achlya and other fungi. Science 166, 831–837
Duffield, E.C.S., Waaland, S.D., Cleland, R. (1972) Morphogenesis in the red, alga, Griffithsia pacifica: Regeneration from single cells. Planta 105, 185–195
McLachlan, J. (1973) Growth media-marine. In: Handbook of phycological methods, vol. I, pp. 25–51, Stein, J.R., ed., Cambridge Univ. Press, Cambridge
Waaland, S.D. (1975) Evidence for a species-specific cell fusion hormone in red algae. Protoplasma 86, 253–261
Waaland, S.D. (1978) Parasexually produced hybrids between female and male plants of Griffithsia tenuis C. Agardh, a red alga. Planta 138, 65–68
Waaland, S.D., Cleland, R.E. (1974) Cell repair through cell fusion in the red alga Griffithsia pacifica. Protoplasma 79, 185–196
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Waaland, S.D., Watson, B.A. Isolation of a cell-fusion hormone from Griffithsia pacifica kylin, a red alga. Planta 149, 493–497 (1980). https://doi.org/10.1007/BF00385754
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00385754