This study aims to assess the photoprotective potential of desiccation-induced curling in the light-susceptible old forest lichen Lobaria pulmonaria by using chlorophyll fluorescence imaging. Naturally curled thalli showed less photoinhibition-induced limitations in primary processes of photosynthesis than artificially flattened specimens during exposures to 450 micromol m-2 s-1 in the laboratory after both 12- (medium dose treatment) and 62-h duration (high dose treatment). Thallus areas shaded by curled lobes during light exposure showed unchanged values of measured chlorophyll fluorescence parameters (FV/FM, PhiPS II), whereas non-shaded parts of curled thalli, as well as the mean for the entire flattened thalli, showed photoinhibitory limitation after light treatments. Furthermore, the chlorophyll fluorescence imaging showed that the typical small-scale reticulated ridges on the upper side of L. pulmonaria caused a spatial, small-scale reduction in damage due to minor shading. Severe dry-state photoinhibition readily occurred in flattened and light-treated L. pulmonaria, although the mechanisms for such damage in a desiccated and inactive stage are not well known. Natural curling is one strategy to reduce the chance for serious photoinhibition in desiccated L. pulmonaria thalli during high light exposures.

Department of Plant Physiology and Anatomy Masaryk University Kotlarska 2 61137 Brno Czech Republic

See more in PubMed

Oecologia. 1997 Aug;111(4):523-528 PubMed

Plant Biol (Stuttg). 2004 May;6(3):333-41 PubMed

Planta. 1990 Feb;180(3):400-9 PubMed

Oecologia. 2006 Mar;147(3):406-16 PubMed

Planta. 2000 Nov;211(6):770-80 PubMed

J Photochem Photobiol B. 2006 May 1;83(2):151-62 PubMed

Planta. 2004 May;219(1):110-20 PubMed

Oecologia. 2001 Feb;126(4):462-471 PubMed

J Exp Bot. 2001 Oct;52(363):1999-2006 PubMed

Oecologia. 1996 Nov;108(3):412-418 PubMed

Oecologia. 1990 Oct;84(4):451-456 PubMed