Heterogeneity of chlorophyll fluorescence over thalli of several foliose macrolichens exposed to adverse environmental factors: interspecific differences as related to thallus hydration and high irradiance

Title:

Heterogeneity of chlorophyll fluorescence over thalli of several foliose macrolichens exposed to adverse environmental factors: interspecific differences as related to thallus hydration and high irradiance

Creator:

Barták, M., Hájek, J., and Gloser, J.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:0b0c4b91-cc2a-46a2-9b9a-e30ec4f87b18
uuid:0b0c4b91-cc2a-46a2-9b9a-e30ec4f87b18
issn:0300-3604
doi:10.1023/A:1012405306648

Subject:

chlorophyll fluorescence imaging, desiccation, high irradiance, high light, Hypogymnia physodes, Lasallia pustulata, lichen, photosynthetic parameters, and Umbilicaria hirsuta

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Spatial heterogeneity of chlorophyll (Chl) fluorescence over thalli of three foliose lichen species was studied using Chl fluorescence imaging (CFI) and slow Chl fluorescence kinetics supplemented with quenching analysis. CFI values indicated species-specific differences in location of the most physiologically active zones within fully hydrated thalli: marginal thallus parts (Hypogymnia physodes), central part and close-to-umbilicus spots (Lasallia pustulata), and irregulary-distributed zones within thallus (Umbilicaria hirsuta). During gradual desiccation of lichen thalli, decrease in Chl fluorescence parameters (FO - minimum Chl fluorescence at point O, FP - maximum Chl fluorescence at P point, Φ2 - effective quantum yield of photochemical energy conversion in photosystem 2) was observed. Under severe desiccation (>85 % of water saturation deficit), substantial thalli parts lost their apparent physiological activity and the resting parts exhibited only a small Chl fluorescence. Distribution of these active patches was identical with the most active areas found under full hydration. Thus spatial heterogeneity of Chl fluorescence in foliose lichens may reflect location of growth zones (pseudomeristems) within thalli and adjacent newly produced biomass. When exposed to high irradiance, fully-hydrated thalli of L. pustulata and U. hirsuta showed either an increase or no change in FO, and a decrease in FP. Distribution of Chl fluorescence after the high irradiance treatment, however, remained the same as before the treatment. After 60 min of recovery in the dark, FO and FP did not recover to initial values, which may indicate that the lichen used underwent a photoinhibition. The CFI method is an effective tool in assessing spatial heterogeneity of physiological activity over lichen thalli exposed to a variety of environmental factors. It may be also used to select a representative area at a lichen thallus before application of single-spot fluorometric techniques in lichens. and M. Barták, J. Hájek, J. Gloser.

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

531-537

Source:

Photosynthetica | 2000 Volume:38 | Number:4

Harvested from:

CDK

Metadata only:

false