A second edition has been published of Sergey Shabala’s popular book on plant stress physiology. The revised text contains, amongst others, chapters on heavy metal toxicity (White & Pongrac), salinity stress (Shabala and Munns), flooding stress (Pucciariello & Perata), drought stress (Manavalan & Nguyen), chilling stress (Ruelland) and reactive oxygen species (Demidchik).
Plant stress terminology
Prof Marcel Jansen and Dr Geert Potters contributed an introductory chapter on the terminology of plant stress response, citing Hans Selye who stated “everybody knows what stress is and nobody knows what it is”. The authors state that “there is too much variation in the way in which plant stress researchers use and understand terminology such as stress, stressor, acclimation and adaptation. This causes ambiguity, and impedes scientific progress.
Moreover, there is a lack of recognition that plant stress responses comprise a mixture of eustress and distress, and that this mixture depends on the dose of the stressor, as well as on exposure kinetics. Thus, without appropriate calibration of stress-conditions, contradictory data can be produced that are of limited use for the understanding of plant stress responses. Selye, Levitt, Lichtenthaler and Tsimilli-Michael have provided theoretical frameworks defining stress, and these frameworks can be used to place molecular, biochemical or physiological data in the appropriate context. The theoretical stress frameworks have demonstrated that in the plant-world stress is more than just a clinical condition. Rather, stress-conditions are important drivers that help a plant to perceive the outside environment, to harmonise itself with it and thus to optimise growth and development”
Prof Jansen contributed a further chapter on plant UV-responses, summarising how “following the discovery of ozone layer depletion in the late 1980s, large numbers of studies investigated the effects of ambient and/or enhanced levels of ultraviolet-B (UV-B) radiation on plants, animals, humans and micro-organisms.
Initial studies reported severe, inhibitory UV effects on plant growth and development, and these were associated with damage to genetic material and the photosynthetic machinery. This led to a strong perception that UV-radiation is harmful for plants. Since that time, a conceptual U-turn has taken place in the way that UV-B effects are perceived. Under realistic UV-B exposure conditions, accumulation of UV-mediated damage is a relatively rare event.
Instead, it is now recognized that UV-B is predominantly an environmental regulator that controls cellular, metabolic, developmental and stress-protection processes in plants through a dedicated UV-B photoreceptor. UV-B regulated signalling pathways control, amongst others, expression of 100’s of genes, the biochemical make-up and the morphology of plants and this, in turn, can alter the nutritional value, pest and disease tolerance, sexual reproduction, and hardiness of plants and plant tissues. As a consequence, UV-B radiation can impact on trophic relationships and ecosystem function, but is also a potentially valuable tool for sustainable agriculture”.
Plant Stress Physiology, 2017, Edited by S Shabala, CABI publishers; ISBN-13:978 1 78064 729 6