Yunhao Liu
Doctor of Philosophy, (Genetics)
Study Completed: 2015
College of Sciences
Citation
Thesis Title
Molecular mechanism of xylose utilization in a plant growth-promoting bacterium Pseudomonas fluorescens SBW25
Read article at Massey Research Online: 
Xylose is a five-carbon sugar prevalent in the hemicellulose fraction of plants and can be used by bacteria as nutrient and energy sources. When a plant growth-promoting bacteriumPseudomonas fluorescens SBW25 colonises sugar beet seedlings, xylose utilisation genes in SBW25 are expressed at elevated levels, suggesting that SBW25 colonisation may be critically dependent on the presence and catabolism of plant-derived xylose. Mr Liu used genetic and biochemical approaches to elucidate novel mechanisms of xylose utilisation in terms of not only the catabolic genes but also the modes of their regulation, and moreover, the complexity and redundancy of regulators involved in carbon catabolite repression of xylose utilisation genes. In addition, the results indicate that xylose assimilation is an important trait for P. fluorescensSBW25 and xylose utilisation genes contribute to the competitiveness of this bacterium in the plant environment.
Supervisors
Distinguished Professor Paul Rainey
Associate Professor Xue-Xian Zhang