Plant and Soil

, Volume 240, Issue 2, pp 343–352

Ecophysiological significance of chlorophyll loss and reduced photochemical efficiency under extreme aridity in Stipa tenacissima L.

  • L. Balaguer
  • F. I. Pugnaire
  • E. Martínez-Ferri
  • C. Armas
  • F. Valladares
  • E. Manrique
Article

DOI: 10.1023/A:1015745118689

Cite this article as:
Balaguer, L., Pugnaire, F.I., Martínez-Ferri, E. et al. Plant and Soil (2002) 240: 343. doi:10.1023/A:1015745118689

Abstract

Stipa tenacissima L., a perennial tussock grass widely found in semi-arid environments of the Iberian Peninsula and North Africa, is subjected to multiple stresses during the extreme summer conditions of south-east Spain. We characterised the photoprotective mechanisms of S. tenacissima during the transition from spring to summer and autumn. S. tenacissima experienced a marked water deficit (Ψ{ pd} < -8.4 MPa) and the complete suppression of CO2 assimilation in August, associated with a 72% reduction of maximal photochemical efficiency of PSII (F{ v}/F{ m}). These reduced F{ v}/F{ m} values were related to the pre-dawn maintenance of high levels of epoxidized forms of xanthophyll-cycle pigments (DPS{ pd}, ca. 42% higher than spring values), and with a 60% reduction in the concentration of total chlorophyll (Chl a+b). These changes were associated with a low capacity of dissipation of the excitation energy non-radiatively (measured as NPQ). Leaves showed a complete recovery of F{ v}/F{ m} and xanthophyll and chlorophyll concentrations after the autumn rainfall, which reached levels similar to that of spring. This poikilohydric-type response of S. tenacissima to stress allows for a greater tolerance of water shortage, high temperature and high light intensity, which are typical in these semi-arid environments and accounts for its distinctive opportunistic growth.

arid environmentsdroughtphotoprotective pigmentspoikilochlorophyllypoikilohydryStipa tenacissima

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • L. Balaguer
    • 1
  • F. I. Pugnaire
    • 2
  • E. Martínez-Ferri
    • 1
    • 3
    • 4
  • C. Armas
    • 2
  • F. Valladares
    • 5
  • E. Manrique
    • 3
  1. 1.Departamento de Biología Vegetal I, Facultad de BiologíaUniversidad ComplutenseMadridSpain
  2. 2.Estación Experimental de Zonas Áridas. Consejo Superior de Investigaciones CientíficasAlmeríaSpain
  3. 3.Departamento de Biología Vegetal II, Facultad de FarmaciaUniversidad ComplutenseMadridSpain
  4. 4.Plant Sciences, Faculty of AgricultureThe University of Western AustraliaCrawleyAustralia
  5. 5.Centro de Ciencias Medioambientales. Consejo Superior de Investigaciones CientíficasMadridSpain