Manipulation of Photosensory and Circadian Signalling Restricts Developmental Plasticity in Arabidopsis

Abstract Plants exploit developmental plasticity to adapt their growth and development to prevailing environmental cues. This developmental plasticity provides a selective and competitive advantage in nature but is obstructive during large-scale, intensive agricultural practices since economically important traits (including vegetative growth and flowering time) can widely vary depending on local environmental conditions. This prevents accurate prediction of harvesting times and produces a variable crop. We sought to restrict developmental plasticity by manipulating signalling systems that govern plants’ responses to environmental signals. Mathematical modelling of plant growth and development predicted a reduction in plant responses to changing environments when circadian and light signaling pathways were manipulated. We tested this hypothesis by utilising a constitutively-active allele of the plant photoreceptor phytochromeB, along with disruption of the circadian system via mutation of EARLY FLOWERING3. We found that the combination of these manipulations produced plants that are less responsive to light and temperature cues. These engineered plants have uniform vegetative growth and flowering time and demonstrate how developmental plasticity can be limited whilst maintaining plant productivity. This has significant implications for future agriculture in both open fields and controlled environments.