Understanding the mechanisms underlying plant responses to changing environmental conditions is critical to improving agriculture. Plant growth is responsive to seasonal changes in day length, however, our understanding of factors that participate in this photoperiodic control of growth is incomplete. This proposal aims to investigate the function of a newly identified protein that is a key regulator of plant growth in response to photoperiod. The knowledge gained from this work will provide valuable insight into understanding the mechanisms that tie together light sensing, day length measurement, and growth under multiple conditions. This information will contribute to our ability to better anticipate plant responses to the environment. This proposal will also support the development and distribution of a low-cost, open-source plant-imaging platform based on Raspberry-Pi microcomputer systems to high schools as part of an effort to bring science into the local community. A benefit from this Broader Impacts activity is the potential for the public to develop innovative systems for continual, automated monitoring of plant growth. This work will transform our ability to understand plant responses to seasonal changes in the environment, contributing to the long-term goal of improving agriculture.
The objective of this project is to understand the molecular mechanisms that couple light signaling with the circadian clock to regulate growth under changing photoperiodic conditions. This project will investigate the factors that modulate light signaling pathways in association with the circadian clock to regulate growth in response to the environment in a photoperiod-dependent manner. Using affinity purification and mass spectrometry to identify circadian clock-associated components, a new protein was identified that directly binds to both clock and light signaling factors, named MASS SPEC IDENTIFIED MODULATING GROWTH FACTOR 1 (MMF1). MMF1 is a conserved, plant-specific, nuclear-localized factor that regulates hypocotyl elongation in a day-length specific manner. This study aims to determine the mechanisms by which MMF1 modulates growth responses by combining physiology, genetics, biochemistry, mass spectrometry, and expression analysis to gain comprehensive understanding into the role of MMF1 in plants. Preliminary data, based on mass spectrometry results, direct interaction assays, genetics, hypocotyl elongation assays, and gene expression analysis, suggest a key role for MMF1 in modulating growth in a day-length dependent manner. The aims of this proposal are to 1) determine the role of MMF1 in the regulation of growth and physiology in a light- and photoperiod-dependent manner, 2) identify the genetic and biochemical bases underlying MMF1 modulation of light signaling pathways under specific environmental conditions, and 3) determine the role of MMF1 in regulating gene expression networks downstream of light signaling pathways. The knowledge gained from this work will provide valuable insight into understanding the mechanisms that couple light signaling, the circadian clock and growth under multiple conditions. This information will contribute to the ability to better anticipate plant responses to the environment and identify genetic targets to manipulate for increased agricultural productivity. The proposed research will provide scientific training and educational opportunities for students at the secondary school, undergraduate, graduate and post-graduate levels through the PI's participation in on-going science outreach and REU programs at the Danforth Plant Science Center and an appointment at Washington University in St. Louis. Also, an inexpensive time-lapse imaging system will be combined with educational materials for distribution to local high schools to cultivate an interest in plant responses to the environment. Through assembling, programming, and incorporating these low-cost, open-source plant-imaging systems into science projects within the classroom, local students will gain a unique opportunity to participate in STEM activities. Moreover, working with the public has the potential to develop innovative and distributive sensor systems for the non-invasive monitoring of plant growth. Together, the proposed research will have a significant impact on society through a better understanding of circadian clock function in diverse species and increased engagement with the public through participation in education and training programs.
