Investigation of gibberellin signalling and the effect of n-acyl homoserine lactones on germination in Physcomitrella patens and an investigation of the interaction between PGE2 and Phospholipase B1 in a Cryptococcus/Macrophage Infection Model

Abstract

This project consists of two separate research projects each covering 4 months. The first project studies the role of gibberellin signalling and the impact of bacterial quorum sensing molecules, AHLs, in $Physcomitrella$. $Physcomitrella$ patens is a model organism of early land plants and is a useful tool for studying plant evolution. By studying the germination rates of wild type spores and spores that lack the enzyme to produce gibberellins and spores in the presence of AHLs it was found that a gibberellin precursor is important in controlling germination signals in the model moss system. It was also found that long chain AHLs in all substitution states, oxo and hydroxyl and non-substituted, significantly promoted germination in $Physcomitrella$. The second project looked at the role of PGE2 during $Cryptococcus$ infection using a murine macrophage like cell line to study infection. $Cryptococcus$ $neoformans$ is an intracellular opportunistic fungal pathogen that can cause fatal infections in individuals with compromised immune systems. By studying the intracellular proliferation rates and cell viability counts of the wild type fungi with a mutant that did not produce PGE2 it was found that PGE2 produced by the fungi was important for intracellular survival and growth