Arabidopsis Thaliana
GENETICS OF DEVELOPMENT.
FLOWER DEVELOPMENT REPORT (ARABIDOPSIS THALIANA)
INTRODUCTION.
Arabidopsis thaliana is the scientific name used to identify a tiny weed whose common name is ‘mouse ear cress’. It is a dicotyledonous angiosperm since its mature embryo carries two leaves (dicotyledonous) and its seeds are contained in an ovary within the flower (angiosperm). Like many other plants, Arabidopsis thaliana is an autotrophic plant capable of producing its own food through photosynthesis. Being firmly rooted to the soil this weed is non-motile and continuously produces new organ systems throughout its life cycle (Masson 2004). Arabidopsis thaliana possesses certain characteristics that make it a suitable experimental plant model. Arabidopsis thaliana is a non-fastidious plant, it has a comparatively shorter generation time than other higher plants, it is able to reproduce by both self-fertilization and cross-pollination and produces abundant seeds which can range from 10 000 to 40 000. Furthermore, Arabidopsis thaliana shares similar patterns of growth, development, flowering and seed production to higher plants. The high germination rate of this plant allows researchers to analyze large populations of seedlings for a specific phenotype. Besides all these characteristics, Arabidopsis thaliana is a small plant, requiring relatively little sunlight within temperatures of 22C to 26C. Thus Arabidopsis thaliana can be grown easily in the laboratory and also in abundant quantity (Masson 2004). A homeotic gene is important for controlling the early development and differentiation of embryonic tissues in eukaryotic organisms which leads to determination of a tissue’s identity during development. The homeotic genes in Arabidopsis thaliana are related with organ identity genes. The development of an organ in the incorrect region of the plant is a homeotic mutation (Fosket 1994). The ABC model was introduced to explain how the organs in the
FLOWER DEVELOPMENT REPORT (ARABIDOPSIS THALIANA)
INTRODUCTION.
Arabidopsis thaliana is the scientific name used to identify a tiny weed whose common name is ‘mouse ear cress’. It is a dicotyledonous angiosperm since its mature embryo carries two leaves (dicotyledonous) and its seeds are contained in an ovary within the flower (angiosperm). Like many other plants, Arabidopsis thaliana is an autotrophic plant capable of producing its own food through photosynthesis. Being firmly rooted to the soil this weed is non-motile and continuously produces new organ systems throughout its life cycle (Masson 2004). Arabidopsis thaliana possesses certain characteristics that make it a suitable experimental plant model. Arabidopsis thaliana is a non-fastidious plant, it has a comparatively shorter generation time than other higher plants, it is able to reproduce by both self-fertilization and cross-pollination and produces abundant seeds which can range from 10 000 to 40 000. Furthermore, Arabidopsis thaliana shares similar patterns of growth, development, flowering and seed production to higher plants. The high germination rate of this plant allows researchers to analyze large populations of seedlings for a specific phenotype. Besides all these characteristics, Arabidopsis thaliana is a small plant, requiring relatively little sunlight within temperatures of 22C to 26C. Thus Arabidopsis thaliana can be grown easily in the laboratory and also in abundant quantity (Masson 2004). A homeotic gene is important for controlling the early development and differentiation of embryonic tissues in eukaryotic organisms which leads to determination of a tissue’s identity during development. The homeotic genes in Arabidopsis thaliana are related with organ identity genes. The development of an organ in the incorrect region of the plant is a homeotic mutation (Fosket 1994). The ABC model was introduced to explain how the organs in the
References: • Access-Science (2002), ‘Genetics of Flower Morophology’ http://www.accessscience.com/server-java/Arknoid/ASResUpdate/2005/. Date Accessed – 19th April 2006. • Fosket, DE 1994, ‘Plant Growth and Development: A Molecular Approach’, Academic Press, United States of America. • Hartwell, LH, Hood, L, Goldberg, ML, Reynolds, AE, Silver, LM & Veres, RC 2004, ‘Genetics: From Genes to Genomes’, Mc-Graw – Hill, New York. • Howell, SH 1998, ‘Molecular Genetics of Plant Development’, Cambridge University Press, United States of America. • Masson, PH 2004, ‘Arabidopsis Thaliana: Genetic Portal of a Model Plant’, Mc-Graw-Hill New York, pp. 759 – 785. • Smyth, DR, Bowman, JL & Meyerowitz, EM 1990, ‘Early Flower Development in Arabidopsis’, The Plant Cell 2, Vol. 8, pp. 755 – 767. • Smyth, D 2006, ‘GEN3030 – Genetics of Development Laboratory Manual’, Monash University, Malaysia. • Weigel, D & Meyerowitz, EM 1994, ‘The ABC’s of Floral Homeotic Genes’, Cell, vol. 79, pp. 203 – 209. APPENDIX. Figure 1 – MADS protein and functional specificities of Arabidopsis genes.