Download or read book Pathogenesis and Modelling of Infection Dynamics in Ralstonia Solanacearum written by Gaofei Jiang and published by . This book was released on 2016 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bacterial wilt caused by Ralstonia solanacearum limits the global production of many crops. The extensive genetic diversity of the bacterium has in recent years led to the concept of a R. solanacearum Species Complex (RSSC). Genome sequencing of over 30 representative strains of the each phylogenetic groups has broadened our knowledge of the evolution and speciation of RSSC. This enabled the identification of novel virulence-associated functions. Furthermore, a large number of studies have been carried on plants-R. solanacearum interactions and shed light on the genetics, molecular biology, and disease development. These studies have documented the infection strategies of R. solanacearum employed to cope with plant immune defenses. Although these qualitative investigations are a basis to understand the pathogenesis of R. solanacearum, they are insufficient to know whether or not plants will be diseased. These fundamental questions require a quantitative understanding of the processes responsible for the rise, dissemination and fall of the infection populations of R. solanacearum. This work pioneered the quantitative study in plant bacterial pathogens by addressing the following question: "How many R. solanacearum individuals enter from the root to establish the bacterial wilt disease in plant?" It allowed us to determine what factors control the infection dynamics of R. solanacearum within the host plant. This scientific question requires a re-examination on the life cycle of R. solanacearum and the precise characterization of the whole infection process in plant. Seven dynamical parameters were refined from five subsequent infection steps of R. solanacearum in host plant. Then, we established a mathematical model of within-host dynamics of the bacterium by the integration of these parameters. The model suggests that the whole population dynamics influences the founding population/bottleneck size of R. solanacearum. The in vivo assessment of parameters and their interactions predicted a small founding population size, around four hundred bacterial cells, which was confirmed by experimental measurements with a probabilistic approach. To understand mechanisms restricting R. solanacearum population, we further investigated impacts of bacterial virulence, plant barriers and environmental factor on the infection founding population. We showed that infection bottleneck is mainly modulated by the pathogen (virulence arsenal), the host (physical and immunity traits) and the environmental conditions (temperature).