Investigating the role of Armadillo-related proteins in early land plants

Mosses evolved approximately 500 million years ago and were among the earliest plants to make the transition from water to land. Mosses are therefore placed at an ideal evolutionary position in which to understand how plant physiology and development has evolved from simple unicellular aquatic organisms to generate the huge diversity of complex modern day flowering plants. The moss Physcomitrella has the unique ability among known land plants to carry out homologous recombination at a similar efficiency to the yeast Saccharyomyces cerevisiae. Armadillo-related proteins play important roles in cellular processes both in animals and plants. In Arabidopsis, ARABIDILLO1 and ARABIDILLO2 control root system architecture. ARABIDILLO-like proteins have been identified extensively throughout the plant kingdom, including early-evolving moss and agriculturally important crops such as rice and maize. Three Physcomitrella ARABIDILLO homologues have been identified; PHYSCODILLO1A, PHYSCODILLO1B and PHYSCODILLO2. Cloning, sequencing and Southern blotting approaches confirmed that PHYSCODILLO2 was a single copy gene, whereas full-length PHYSCODILLO1A and PHYSCODILLO1B genes were 100% identical and exist in a tail-to-tail orientation with 8kb separating their stop codons. A number of physcodillo deletion mutants have been generated. Phenotypic analyses revealed that PHYSCODILLO proteins appear to play important roles during early developmental processes, including growth of filaments from protoplasts and spore germination.EThOS - Electronic Theses Online ServiceGBUnited Kingdo