RII Track-4:NSF:Chloroplast retrograde signaling during plant immunity: integrating signal transduction and cellular dynamics

University Of Arkansas, Fayetteville AR

Investigators

Abstract

Plants are able to fight potential pathogens through a complex defense system that involves multiple compartments inside the cell. One type of compartment is the chloroplast, which in addition to participating in photosynthesis, also generates signaling molecules that turn on genes in the nucleus, a process known as retrograde signaling. This Research Infrastructure Improvement RII Track-4 fellowship will investigate how chloroplast retrograde signaling in living cells operates during plant immunity, and how pathogens interfere with this process. This research requires advanced microscopy instruments available at the host institution, The Donald Danforth Plant Science Center, where the research will be conducted. This research will provide training opportunities for a Hispanic female faculty and a Hispanic graduate student. The knowledge gained from this project will inform the development of strategies to enhance plant defense responses to control plant diseases and reduce their economic and societal impact. Chloroplasts have emerged as important organelles in plant immunity, both as a source of defense signaling molecules, and as major regulators of defense responses. In response to pathogens, chloroplasts re-localize around the nucleus, presumably to facilitate retrograde signaling, a process by which signaling molecules originating in chloroplasts activate gene expression in the nucleus. While retrograde signaling has been recognized, it is not fully understood how it operates during plant immunity. The main goal of this fellowship is to dissect the cellular and regulatory events associated with chloroplast retrograde signaling during plant immunity by 1) delineating how bacterial pathogens with distinct lifestyles impact chloroplast dynamics, 2) characterizing the chloroplast-nuclear communication associated with plant defense responses, and 3) evaluating signal-dependent gene expression in situ. The research proposed requires advanced live-imaging technologies to monitor chloroplast dynamics and chloroplast-mediated responses after infection with bacterial pathogens. This research will provide deeper understanding of the cellular processes associated with plant immunity to enable guided strategies to control plant diseases. Moreover, this research will facilitate advancing live-cell imaging technologies in Arkansas. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.