Dissecting the molecular players essential for polar growth in Agrobacterium

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

This project has the potential to change our understanding of growth in bacteria. During bacterial growth the cell wall is typically understood to enlarge by the dispersed generation of new wall material. However, it is now known that some important agricultural and pathogenic bacteria expand their cell walls during growth by adding new material at the ends (poles) of the cells. This project will elucidate the mechanisms of polar growth in Agrobacterium and the manner in which polar growth is integrated with cell division. The project will provide a postdoctoral fellow and graduate student advanced training in plant science, and the PI will engage in public outreach with lectures at museums and during the University's CalDay public open house event. The PI will also teach a course a course on "The Secret Life of Plants" to non-science major undergraduates that emphasizes social, environmental and economic aspects. The project will elucidate the mechanisms of polar growth in bacteria, addressing the following specific issues: 1) Defining the proteins that comprise the Agrobacterium polar growth machinery, using full-length and Agrobacterium specific sub-domains of FtsA, FtsZ, PopZ, PopJ, LDT-0845, and TipN as bait in yeast two hybrid screens to identify novel interacting partners. 2) Genetic depletion of essential Agrobacterium cell cycle factors to determine their primary phenotypes, using riboswitch technology to acutely deplete cells of FtsA, FtsZ, PopZ, PodJ, LDT-0845, and TipN and using time-lapse fluorescence deconvolution and high resolution structured illumination microscopy (SIM). 3) The role of Agrobacterium TipN-At as a potential polar growth organizing center.