Gametophyte Development in Ferns

Abstract

The fern gametophyte has interested plant biologists for the past century because its structure and development is simple and amenable to investigation. Past studies have described many aspects of its development, including germination of the spore, patterns of cell division and differentiation, photomorphogenic or light-regulated responses, sex determination and differentiation of gametangia, hormone and pheromone responses, and fertilization. Several genes that are predicted to regulate some of these processes have been recently cloned, making it possible to analyze how these processes are controlled at a molecular level. The emergence of the fern Ceratopteris richardii as a model organism for readily identifying and characterizing mutations that affect key developmental processes in gametophytes makes it a powerful tool for dissecting the molecular mechanisms underlying these processes. If advances in gene cloning techniques and transformation are forthcoming in Ceratopteris, it is likely that the study of developmental processes in ferns will significantly contribute to our understanding of plant development and evolution beyond that which can be learned solely from studying angiosperms.

Nanoceria and bulk cerium oxide effects on the germination of asplenium adiantum-nigrum spores

“…The rhizoid is a single, elongated, nonphotosynthetic cell that is thought to function in anchoring and absorption of nutrients. The protonemal initial eventually gives rise to the photosynthetic prothallus of the fern gametophyte (Banks, 1999). For many ferns, the whole process is very quick, lasting from some days to several weeks.…”

Effect of Nutrients on Environmental Sex Determination and Size of Gametophytes in Culcita macrocarpa

“…In northwest Spanish populations of C. macrocarpa sporangium dehiscence occurs around the spring equinox, when temperatures are suitable for germination (Quintanilla et al 2000). The fern Culcita macrocarpa produces only one type of spore (i.e., homosporous), yet each Culcita spore has the potential to develop as a free-living haploid green gametophyte with numerous rhizoids on the inferior central surface cushion (Figure 2) which are sexually protandrous (Quintanilla et al 2005) as like as Ceratopteris (Banks 1997(Banks 1999 where the sex of the gametophyte is determined during the development of only sperm or egg or produces both egg and sperm.…”

Theindeterminate gametophyte1Gene of Maize Encodes a LOB Domain Protein Required for Embryo Sac and Leaf Development

“…In primitive land plants, such as the bryophyte Physcomitrella patens, the gametophyte is the dominant phase of the life cycle and contains a leafy-shoot phase called the gametophore with at least superficial similarity to the vegetative shoots of seed plants, whereas the sporophyte is greatly reduced and dependent on the gametophyte (Cove and Knight, 1993). In seedless vascular plants such as ferns, the sporophyte is dominant and grows as a leafy shoot, whereas the gametophyte is free-living but greatly reduced and lacking a leafy-shoot phase (Banks, 1999). The gametophytes are smallest in angiosperms, consisting of only a few cells dependent on the sporophyte for growth and development.…”