What is stress?

"Stresses" that impact upon plants can affect agriculture and biodiversity. Together with colleagues from the United Kingdom, South Africa and the Russian Federation we have recently proposed a stress model for plant seeds. Our stress model is based on a biomedical stress concept published in 1936, the "General Adaptation Syndrome" of the endocrinologist Selye. Potential "eustresses" that enhance function are distinguished from "distresses" that have harmful effects. On the molecular level, the "alarm" response is defined by post-translational modifications and stress signalling through cross-talk between reactive oxygen and nitrogen species, and seed hormones, that result in modifications to the transcriptome. Protection, repair, acclimation and adaptation are viewed as the "building blocks" of the "resistance" response, which in seeds are the basis for their longevity over centuries. When protection and repair mechanisms eventually fail, depending on dose and time of exposure to stress, cell death and death of the organism are the result, corresponding to "exhaustion". This proposed seed stress concept may have wider applicability to plants in general. Out main current interest is to test this model and to explore how stress can be quantified on the cellular level.

"When you can measure what you are speaking about and express it in numbers you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind"
Lord Kelvin (1883)


The General Adaptation Syndrome, adapted to describe stress in seeds. Taken from Kranner I, Beckett RP, Minibayeva FV and Seal CE. 2010. What is stress? Concepts, definitions and applications in seed science. New Phytologist 188: 655-673.

The definitive version is available at http://www.blackwell-synergy.com/loi/nph
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