Systems Biology of Abiotic Stress: The Elephant and the Blind Men

Summary

The study of plant stress responses is fragmented into many separate domains by the type of stress used, the response measured, and the disciplinary perspective of the investigation. Thus, light, salt, drought, and ozone stress are commonly investigated separately. End-point measures vary from changes in stomatal aperture and cellular electrophysiology to signaling and transcriptional changes and, ultimately, cell death. Furthermore, investigations of the same system and end-point are often carried out from very different disciplinary perspectives, such as signaling, cell structure, or expression of genes and protein trafficking. In the present review, I use the old Hindu parable of the elephant and the blind men as a metaphor for the study of the stress response. Taking the well-studied environmental response of guard cells, I first assemble a “parts” list, briefly overviewing the literature on signaling, cytoskeletal changes and vesicular trafficking that mediate changes in the stomatal aperture. I then attempt to synthesize a “systems” view of stomatal responses by integrating the various perspectives. Finally, I briefly explore the relevance of guard cell responses to the more general issues of plant stress responses and comment on future areas of interest.