title: Life cycle stage and water depth affect flooding-induced adventitious root formation in the terrestrial species Solanum dulcamara.
abstract: OBJECTIVE
  Flooding can occur at any stage of the life cycle of a plant, but often adaptive responses of plants are only studied at a single developmental stage. It may be anticipated that juvenile plants may respond differently from mature plants, as the amount of stored resources may differ and morphological changes can be constrained. Moreover, different water depths may require different strategies to cope with the flooding stress, the expression of which may also depend on developmental stage. This study investigated whether flooding-induced adventitious root formation and plant growth were affected by flooding depth in Solanum dulcamara plants at different developmental stages.
  
  
  METHODS
  Juvenile plants without pre-formed adventitious root primordia and mature plants with primordia were subjected to shallow flooding or deep flooding for 5 weeks. Plant growth and the timing of adventitious root formation were monitored during the flooding treatments.
  
  
  RESULTS
  Adventitious root formation in response to shallow flooding was significantly constrained in juvenile S. dulcamara plants compared with mature plants, and was delayed by deep flooding compared with shallow flooding. Complete submergence suppressed adventitious root formation until up to 2 weeks after shoots restored contact with the atmosphere. Independent of developmental stage, a strong positive correlation was found between adventitious root formation and total biomass accumulation during shallow flooding.
  
  
  CONCLUSIONS
  The potential to deploy an escape strategy (i.e. adventitious root formation) may change throughout a plant's life cycle, and is largely dependent on flooding depth. Adaptive responses at a given stage of the life cycle thus do not necessarily predict how the plant responds to flooding in another growth stage. As variation in adventitious root formation also correlates with finally attained biomass, this variation may form the basis for variation in resistance to shallow flooding among plants.
authors.affiliation: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands qian.zhang@science.ru.nl.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands.
authors.forename: Eric J W
authors.initials: EJ
authors.lastname: Visser
authors.affiliation: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: de Kroon
authors.affiliation: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands.
authors.forename: Heidrun
authors.initials: H
authors.lastname: Huber
mesh_terms: D000704:Analysis of Variance; D018533:Biomass; D017753:Ecosystem; D055868:Floods; D008027:Light; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development* / Q000528:radiation effects; D018520:Plant Shoots / Q000033:anatomy & histology / Q000502:physiology / Q000528:radiation effects; D018547:Plant Stems / Q000033:anatomy & histology / Q000502:physiology; D032322:Solanum / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology / Q000528:radiation effects; D014867:Water
chemical_list: D014867:Water
keywords: Adventitious roots; Solanaceae; Solanum dulcamara; complete submergence; developmental stage; escape strategy; flooding depth; nightshade; pre-formed root primordia; quiescence strategy