Photomorphogenesis and nucleic acid metabolism in fern gametophytes.

Abstract

Publisher Summary Sporophytes, which are recognizable fern plants, have been utilized in morphogenetic studies and have yielded important results bearing on apical organization, cellular totipotency, phyllotactic pattern, stelar morphology, vascular tissue initiation, leaf and bud development, and embryogenesis. Gametophytes (prothalli) are morphologically insignificant in comparison to the sporophyte, they have not been utilized for experimental studies. However, the simplicity of prothallial development and organization make these plants ideal for studying certain aspects of cellular differentiation. The transition from a simple filamentous prothallus to a gametophyte with biplanar morphology provides a useful experimental system for investigating mechanisms controlling the planes of cell division, which contribute to the development of form. The chapter reviews the literature on the control of growth in the filamentous prothalli and the causal factors promoting the transition to the two-dimensional gametophyte. It focuses on the effects of light quality and nucleic acid metabolism; the survey includes not only recent accomplishments in these areas but also provides a critical assessment of the outstanding problems.