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dc.contributor.authorHenskens, Frieda L.
dc.contributor.authorGreen, T.G. Allan
dc.contributor.authorWilkins, Alistair L.
dc.date.accessioned2013-04-09T02:51:14Z
dc.date.available2013-04-09T02:51:14Z
dc.date.copyright2012-07-19
dc.date.issued2012
dc.identifier.citationHenskens, F. L., Green, T. G. A., & Wilkins, A. (2012). Cyanolichens can have both cyanobacteria and green algae in a common layer as major contributors to photosynthesis. Annals of Botany, 110(3), 555-563.en_NZ
dc.identifier.issn0305-7364
dc.identifier.urihttps://hdl.handle.net/10289/7429
dc.description.abstractBACKGROUND AND AIMS: Cyanolichens are usually stated to be bipartite (mycobiont plus cyanobacterial photobiont). Analyses revealed green algal carbohydrates in supposedly cyanobacterial lichens (in the genera Pseudocyphellaria, Sticta and Peltigera). Investigations were carried out to determine if both cyanobacteria and green algae were present in these lichens and, if so, what were their roles. METHODS: The types of photobiont present were determined by light and fluorescence microscopy. Small carbohydrates were analysed to detect the presence of green algal metabolites. Thalli were treated with selected strengths of Zn²⁺ solutions that stop cyanobacterial but not green algal photosynthesis. CO₂ exchange was measured before and after treatment to determine the contribution of each photobiont to total thallus photosynthesis. Heterocyst frequencies were determined to clarify whether the cyanobacteria were modified for increased nitrogen fixation (high heterocyst frequencies) or were normal, vegetative cells. KEY RESULTS: Several cyanobacterial lichens had green algae present in the photosynthetic layer of the thallus. The presence of the green algal transfer carbohydrate (ribitol) and the incomplete inhibition of thallus photosynthesis upon treatment with Zn²⁺ solutions showed that both photobionts contributed to the photosynthesis of the lichen thallus. Low heterocyst frequencies showed that, despite the presence of adjacent green algae, the cyanobacteria were not altered to increase nitrogen fixation. CONCLUSIONS: These cyanobacterial lichens are a tripartite lichen symbiont combination in which the mycobiont has two primarily photosynthetic photobionts, 'co-primary photobionts', a cyanobacterium (dominant) and a green alga. This demonstrates high flexibility in photobiont choice by the mycobiont in the Peltigerales. Overall thallus appearance does not change whether one or two photobionts are present in the cyanobacterial thallus. This suggests that, if there is a photobiont effect on thallus structure, it is not specific to one or the other photobiont.en_NZ
dc.language.isoen
dc.publisherOxford University Pressen_NZ
dc.relation.ispartofAnnals of Botany
dc.subjectgreen algaeen_NZ
dc.subjectCyanolichensen_NZ
dc.titleCyanolichens can have both cyanobacteria and green algae in a common layer as major contributors to photosynthesisen_NZ
dc.typeJournal Articleen_NZ
dc.identifier.doi10.1093/aob/mcs108en_NZ
dc.relation.isPartOfAnnals of Botanyen_NZ
pubs.begin-page555en_NZ
pubs.elements-id37813
pubs.end-page563en_NZ
pubs.issue3en_NZ
pubs.volume110en_NZ


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