Stress is a common aspect in the life cycle of a plant. However, the principles of ‘plant stress’ remain poorly de-
fined, and key terminology can be interpreted in more than one way. This ambiguity can potentially impede sci-
entific progress. Several theoretical frameworks detailing the principles of plant stress have been conceived, based
on analogies with human stress, mechanics and thermodynamic states. Particularly important are the concepts
of eustress and distress (good and bad stress), and how these are affected by stressor dose and duration. Using
these concepts can help place experimental data in a conceptual framework, and avoid generation of seemingly
contradictory data.