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Dr Keara Franklin

Plant Environmental Signalling

My group's research investigates the molecular mechanisms through which plants integrate light and temperature signals to regulate growth and development.

Shade Avoidance

Light signals, perceived by the red/ far-red (R/FR) light– absorbing phytochrome family of plant photoreceptors are amongst the most important environmental cues regulating plant development. A particularly important role of the phytochromes involves detection of the presence of neighbouring vegetation by sensing changes in the quality of reflected/transmitted light. The interaction of daylight with living vegetation leads to a relative depletion in red (R) wavelengths and a relative enrichment in far-red light (FR) wavelengths. These changes in light quality (reduced R:FR ratio) are detected by the phytochromes and, in many plant species, lead to dramatic elongation growth of stems and alterations in leaf morphology. Such responses (termed the shade avoidance syndrome) serve to elevate leaves towards unfiltered daylight and provide an essential survival strategy in rapidly growing populations. We are currently investigating how shade avoidance responses are affected by other environmental stresses.

Shade Avoidance

Light and Temperature Signal Integration

A primary research interest of the group is the interaction between light quality and temperature signalling pathways in the regulation of plant architecture. We have shown that some shade avoidance responses of the model species, Arabidopsis thaliana, are modulated by ambient growth temperature and have identified a number of genes which are regulated by phytochrome in a temperature-dependent manner. These include the CBF regulon of genes involved in cold acclimation and freezing tolerance. We have also established that the phytochrome-interacting factor PIF4 functions as a key regulator of plant architectural responses to elevated temperature, thereby operating as a central hub of light and temperature signal integration. We are currently investigating the parallels between shade avoidance and high temperature signalling and the fitness costs/benefits of such plasticity.

Thermal image of Arabidopsis

Research keywords

  • Plant Photomorphogenesis
  • Phytochrome
  • Shade avoidance
  • Temperature Signalling
  • PIF4

Research methods

  • Plant Physiology
  • Gene expression
  • Protein expression