Format

Send to

Choose Destination
See comment in PubMed Commons below
Photosynth Res. 2006 Oct;90(1):29-43. Epub 2006 Nov 17.

Rapid light-response curves of chlorophyll fluorescence in microalgae: relationship to steady-state light curves and non-photochemical quenching in benthic diatom-dominated assemblages.

Author information

1
Departamento de Biologia & CESAM, Universidade de Aveiro, Campus de Santiago, 3810-193, Aveiro, Portugal. jserodio@bio.ua.pt

Abstract

Rapid light-response curves (RLC) of variable chlorophyll fluorescence were measured on estuarine benthic microalgae with the purpose of characterising its response to changes in ambient light, and of investigating the relationship to steady-state light-response curves (LC). The response of RLCs to changes in ambient light (E, defined as the irradiance level to which a sample is acclimated to prior to the start of the RLC) was characterised by constructing light-response curves for the RLC parameters alpha (RLC), the initial slope, ETR(m,RLC), the maximum relative electron transport rate, and E (k,RLC), the light-saturation parameter. Measurements were carried out on diatom-dominated suspensions of benthic microalgae and RLC and LC parameters were compared for a wide range of ambient light conditions, time of day, season and sample taxonomic composition. The photoresponse of RLC parameters was typically bi-phasic, consisting of an initial increase of all parameters under low ambient light (E < 21-181 micromol m(-2) s(-1)), and of a phase during which alpha (RLC) decreased significantly with E, and the increase of ETR(m,RLC) and E (k,RLC) was attenuated. The relationship between RLC and LC parameters was dependent on ambient irradiance, with significant correlations being found between alpha (RLC) and alpha, and between ETR(m,RLC) and ETR(m), for samples acclimated to low and to high ambient irradiances, respectively. The decline of alpha (RLC) under high light (Deltaalpha (RLC)) was strongly correlated (P < 0.001 in all cases) with the level of non-photochemical quenching (NPQ) measured before each RLC. These results indicate the possibility of using RLCs to characterise the steady-state photoacclimation status of a sample, by estimating the LC parameter E (k), and to trace short-term changes in NPQ levels without dark incubation.

PMID:
17111236
DOI:
10.1007/s11120-006-9105-5
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Springer
    Loading ...
    Support Center