Seasonal variations in UV-absorbing compounds and physiological characteristics in the aquatic liverwort Jungermannia exsertifolia subsp. cordifolia over a three-year period

  1. Núñez-Olivera, E. 1
  2. Otero, S. 1
  3. Tomás, R. 1
  4. Martínez-Abaigar, J. 1
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

Revista:
Physiologia Plantarum

ISSN: 0031-9317

Año de publicación: 2009

Volumen: 136

Número: 1

Páginas: 73-85

Tipo: Artículo

DOI: 10.1111/J.1399-3054.2009.01215.X PMID: 19374718 SCOPUS: 2-s2.0-65249108198 WoS: WOS:000265233700007 GOOGLE SCHOLAR

Otras publicaciones en: Physiologia Plantarum

Repositorio institucional: lock_openAcceso abierto Editor

Resumen

Temporal physiological variations in relation to environmental factors, in particular to ultraviolet (UV) radiation, have been studied in bryophytes from circumpolar latitudes, but not in mid-latitudes with longer growing seasons. In addition, seasonal and interannual changes in individual UV-absorbing compounds (UVAC) have not been previously studied in bryophytes. To fill these gaps, samples of the aquatic liverwort Jungermannia exsertifolia subsp. cordifolia were collected on a monthly basis during 3 years from a mountain stream in northern Spain. Sclerophylly index, chlorophyll fluorescence, DNA damage, the bulk UV absorbance of methanolic extracts and the concentration of five UVAC (hydroxycinnamic acid derivatives) were measured. Interannual changes were little marked, probably because the 3 years studied were environmentally similar. In summer-autumn, with respect to seasonal variations, newly grown tender young shoots with high Fv/Fm accumulated higher amounts of several hydroxycinnamic acid derivatives than in winter-spring. DNA damage was not detected in any of the samples analyzed. p-Coumaroylmalic acid was the compound best associated with radiation changes, and the best model explaining UV-B took into consideration the concentration of this compound and the ozone level. The specific effects of UV radiation could not be separated from the effects caused by other environmental factors, such as global radiation or temperature, because all these variables were correlated. However, indirect evidence strongly suggests that seasonal changes in bulk UV absorbance and p-coumaroylmalic acid are mainly driven by UV radiation. This compound may be a promising physiological variable to be used for UV bioindication. Copyright © 2009 Physiologia Plantarum.