The Affect of Ultra Violet Radiation on Sex Determination in Ceratopteris Richardii: a Comparison Between Wild-Type and Her1
Abstract:
Ultraviolet (UV) radiation and its detrimental effects on plant life have been widely researched. This research studies the effects of UV radiation on sex-determination in Ceratopteris richardii. Sex determination in Ceratopteris richardii is determined by antheridiogen, a pheromone that promotes maleness. In this experiment, UV radiation was used on the wild type and mutants Her1, which are insensitive to the male-inducing pheromone (does not form male gametophytes). Ceratopteris richardii spores were exposed to UV radiation at different stages during their life cycle. Wild type gametophytes treated with UV radiation until germination and sexual maturity showed an increase of hermaphrodites as compared to wild type gametophytes only exposed to white light. Her1 mutants treated with UV radiation until germination showed no change in expected sex ratios. However, her1 mutants exposed to UV radiation until sexual maturity showed a large discrepancy in normal sex ratios and produced a huge increase of males. These results show that UV radiation does have an effect on sex determination in Ceratopteris richardii, and perhaps other plants as well.
Introduction Ceratopteris richardii, also known as C-Fern, start out as haploid spores. After four to six days, germination takes place and rhizoids, a root-like filament which absorbs nutrition, appear. It begins to develop into a sexually mature gametophyte, an ameristic male or hermaphrodite with a well-defined meristic region.
Figure 1: C-Fern Life Cycle
Source: D. Maxwell. “C-Fern Genetics”
The sexual fate of the gametophyte depends if the pheromone antheridiogen (ACE) is present in the early stages of development, approximately three to four days after spore inoculation. ACE, which is thought to be a form of gibberellin, promotes maleness in Ceratopteris richardii gametophytes and must be present during the entire duration of cell division to allow the production of antheridia. ACE is responsible
Ultraviolet (UV) radiation and its detrimental effects on plant life have been widely researched. This research studies the effects of UV radiation on sex-determination in Ceratopteris richardii. Sex determination in Ceratopteris richardii is determined by antheridiogen, a pheromone that promotes maleness. In this experiment, UV radiation was used on the wild type and mutants Her1, which are insensitive to the male-inducing pheromone (does not form male gametophytes). Ceratopteris richardii spores were exposed to UV radiation at different stages during their life cycle. Wild type gametophytes treated with UV radiation until germination and sexual maturity showed an increase of hermaphrodites as compared to wild type gametophytes only exposed to white light. Her1 mutants treated with UV radiation until germination showed no change in expected sex ratios. However, her1 mutants exposed to UV radiation until sexual maturity showed a large discrepancy in normal sex ratios and produced a huge increase of males. These results show that UV radiation does have an effect on sex determination in Ceratopteris richardii, and perhaps other plants as well.
Introduction Ceratopteris richardii, also known as C-Fern, start out as haploid spores. After four to six days, germination takes place and rhizoids, a root-like filament which absorbs nutrition, appear. It begins to develop into a sexually mature gametophyte, an ameristic male or hermaphrodite with a well-defined meristic region.
Figure 1: C-Fern Life Cycle
Source: D. Maxwell. “C-Fern Genetics”
The sexual fate of the gametophyte depends if the pheromone antheridiogen (ACE) is present in the early stages of development, approximately three to four days after spore inoculation. ACE, which is thought to be a form of gibberellin, promotes maleness in Ceratopteris richardii gametophytes and must be present during the entire duration of cell division to allow the production of antheridia. ACE is responsible
Bibliography: 2. Stapleton, Ann E. "Ultraviolet Radiation and Plants: Burning Questions." Plantcell.org. Department of Biological Sciences, Stanford University, Nov. 1992. Web. 4. Eberle, James R., and Jo Ann Banks. "Genetic Interactions Among Sex-Determining Genes in the Fern Ceratopteris Richardii." Genetics.org. Department on Botany and Plant Pathology, 1996. Web. <http://www.genetics.org/content/142/3/973.full.pdf>. 5. Hickok, Leslie G., and Thomas R. Warne. "C-Fern Web Manual." Marginscience.com. University of Tennessee Research Foundation, 2008. Web. < http://www.magrinscience.com/images/biology/ferns/C-Fern_Manual.pdf 7. Banks, Jo Ann. "The Programming of Sexual Phenotype in the Homosporous Fern Ceratopteris Richardii." JSTOR. N.p., 1993. Web.