title: Are winter and summer dormancy symmetrical seasonal adaptive strategies? The case of temperate herbaceous perennials.
abstract: BACKGROUND
  Dormancy in higher plants is an adaptive response enabling plant survival during the harshest seasons and has been more explored in woody species than in herbaceous species. Nevertheless, winter and summer shoot meristem dormancy are adaptive strategies that could play a major role in enhancing seasonal stress tolerance and resilience of widespread herbaceous plant communities.
  
  
  METHODS
  This review outlines the symmetrical aspects of winter and summer dormancy in order to better understand plant adaptation to severe stress, and highlight research priorities in a changing climate. Seasonal dormancy is a good model to explore the growth-stress survival trade-off and unravel the relationships between growth potential and stress hardiness. Although photoperiod and temperature are known to play a crucial, though reversed, role in the induction and release of both types of dormancy, the thresholds and combined effects of these environmental factors remain to be identified. The biochemical compounds involved in induction or release in winter dormancy (abscisic acid, ethylene, sugars, cytokinins and gibberellins) could be a priority research focus for summer dormancy. To address these research priorities, herbaceous species, being more tractable than woody species, are excellent model plants for which both summer and winter dormancy have been clearly identified.
  
  
  CONCLUSIONS
  Summer and winter dormancy, although responding to inverse conditions, share many characteristics. This analogous nature can facilitate research as well as lead to insight into plant adaptations to extreme conditions and the evolution of phenological patterns of species and communities under climate change. The development of phenotypes showing reduced winter and/or enhanced summer dormancy may be expected and could improve adaptation to less predictable environmental stresses correlated with future climates. To this end, it is suggested to explore the inter- and intraspecific genotypic variability of dormancy and its plasticity according to environmental conditions to contribute to predicting and mitigating global warming.
authors.affiliation: CEFE UMR 5175, CNRS.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Gillespie
authors.affiliation: INRA USC 1338, CEFE UMR 5175, CNRS, 1919 Route de Mende, 34293 Montpellier cedex, France florence.volaire@cefe.cnrs.fr.
authors.forename: Florence A
authors.initials: FA
authors.lastname: Volaire
mesh_terms: D004777:Environment; D018519:Meristem / Q000502:physiology; D057445:Plant Dormancy / Q000502:physiology*; D010937:Plant Growth Regulators / Q000502:physiology; D012621:Seasons; D013312:Stress, Physiological / Q000502:physiology
chemical_list: D010937:Plant Growth Regulators
keywords: Summer dormancy; climate change; dehydration tolerance; drought; frost; hormones; induction; perennial herbaceous species; survival; winter dormancy