title: Plant responsiveness to root-root communication of stress cues.
abstract: OBJECTIVE
  Phenotypic plasticity is based on the organism's ability to perceive, integrate and respond to multiple signals and cues informative of environmental opportunities and perils. A growing body of evidence demonstrates that plants are able to adapt to imminent threats by perceiving cues emitted from their damaged neighbours. Here, the hypothesis was tested that unstressed plants are able to perceive and respond to stress cues emitted from their drought- and osmotically stressed neighbours and to induce stress responses in additional unstressed plants.
  
  
  METHODS
  Split-root Pisum sativum, Cynodon dactylon, Digitaria sanguinalis and Stenotaphrum secundatum plants were subjected to osmotic stress or drought while sharing one of their rooting volumes with an unstressed neighbour, which in turn shared its other rooting volume with additional unstressed neighbours. Following the kinetics of stomatal aperture allowed testing for stress responses in both the stressed plants and their unstressed neighbours.
  
  
  RESULTS
  In both P. sativum plants and the three wild clonal grasses, infliction of osmotic stress or drought caused stomatal closure in both the stressed plants and in their unstressed neighbours. While both continuous osmotic stress and drought induced prolonged stomatal closure and limited acclimation in stressed plants, their unstressed neighbours habituated to the stress cues and opened their stomata 3-24 h after the beginning of stress induction.
  
  
  CONCLUSIONS
  The results demonstrate a novel type of plant communication, by which plants might be able to increase their readiness to probable future osmotic and drought stresses. Further work is underway to decipher the identity and mode of operation of the involved communication vectors and to assess the potential ecological costs and benefits of emitting and perceiving drought and osmotic stress cues under various ecological scenarios.
authors.affiliation: Mitrani Department of Desert Ecology, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 84990, Israel.
authors.forename: Omer
authors.initials: O
authors.lastname: Falik
authors.forename: Yonat
authors.initials: Y
authors.lastname: Mordoch
authors.forename: Daniel
authors.initials: D
authors.lastname: Ben-Natan
authors.forename: Miriam
authors.initials: M
authors.lastname: Vanunu
authors.forename: Oron
authors.initials: O
authors.lastname: Goldstein
authors.forename: Ariel
authors.initials: A
authors.lastname: Novoplansky
mesh_terms: D000222:Adaptation, Physiological; D031744:Cynodon / Q000502:physiology*; D031746:Digitaria / Q000502:physiology*; D055864:Droughts; D009997:Osmotic Pressure; D018532:Pisum sativum / Q000502:physiology*; D018517:Plant Roots / Q000502:physiology*; D054046:Plant Stomata / Q000502:physiology; D015398:Signal Transduction; D012965:Sodium Chloride / Q000378:metabolism*; D013312:Stress, Physiological; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water; D012965:Sodium Chloride