Digitale Bibliotheek
Sluiten Bladeren door artikelen uit een tijdschrift
 
<< vorige    volgende >>
     Tijdschrift beschrijving
       Alle jaargangen van het bijbehorende tijdschrift
         Alle afleveringen van het bijbehorende jaargang
           Alle artikelen van de bijbehorende aflevering
                                       Details van artikel 4 van 10 gevonden artikelen
 
 
  Circadian Rhythms of Leaf and Stomatal Movements in Gymnosperm Species
 
 
Titel: Circadian Rhythms of Leaf and Stomatal Movements in Gymnosperm Species
Auteur: Brinker, Monika
Engelmann, Wolfgang
Kellmann, Jan W.
Piechulla, Birgit
Verschenen in: Biological rhythm research
Paginering: Jaargang 32 (2001) nr. 4 pagina's 471-478
Jaar: 2001-10
Inhoud: It is generally accepted that various physiological, morphological and gene expression phenomena are under the control of a circadian clock, and that this time keeping mechanism is universally present. Although such endogenously regulated phenomena have first been documented in plants more than 250 years ago and much work has been accumulated particularly in the past 70 years, it was not obvious from the literature whether such time keeping mechanisms exist in gymnosperms. Two prominent parameters were investigated in several gymnosperm species which have been demonstrated to be under the control of a circadian clock in many plants: (i) leaf movement and (ii) stomata movement. In young plants of Pinus sylvestris, Picea abies, Taxus baccata, Araucaria angustifolia, Araucaria heterophylla and Ginkgo biloba leaf oscillations could be recorded for about 5 days. However, compared to angiosperm plants, the amplitude was small. The period length under free running conditions (constant temperature and continuous light) was characteristic for the species. Stomatal movement was observed in Ginkgo biloba leaves by electron microscopy. Stomata were open at noon and closed at midnight under normal day/night conditions (LD) as well as under constant light conditions (LL), indicating that stomatal aperture is under circadian control in the gymnosperm Ginkgo biloba. Online recordings of stomata conductance however, exhibited diurnal but not circadian oscillations of net CO2-exchange in G. biloba leaves. Our results show that a circadian clock controls leaf and stomatal movements in gymnosperm species indicating that endogenous time keeping mechanisms are present.
Uitgever: Taylor & Francis
Bronbestand: Elektronische Wetenschappelijke Tijdschriften
 
 

                             Details van artikel 4 van 10 gevonden artikelen
 
<< vorige    volgende >>
 
 Koninklijke Bibliotheek - Nationale Bibliotheek van Nederland