Relationship between fungus and alga in the lichen Cladonia cristatella Tuck

Ahmadjian, Vernon; Jacobs, Jerome B.

doi:10.1038/289169a0

Cited by 119 publications

(81 citation statements)

References 9 publications

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“…Though not as well characterized as the interactions between mycorrhizal partners, detailed microscopic analysis shows that the lichen mycobiont loses apical dominance and undergoes extensive hyphal branching during its initial interaction with the photobiont (Ahmadjian andJacobs 1981, summarized in Ahmadjian 1993). Several candidates have been suggested for the photobiontderived signal that elicits this response, including plant hormones (IAA, kinetin) and the sugar alcohol, ribitol (Ahmadjian 1993). However, it seems likely that, as with mycorrhizae, a small molecule such as strigolactones will emerge as the lichen ''branching factor.''…”

Section: Mycologiamentioning

confidence: 99%

Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems

2008

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"Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems" (2008 Abstract: The ability of rapidly growing hyphae to generate new polarity axes that result in the formation of a branch represents one of the most important yet least understood aspects of fungal cell biology. Branching is central to the development of mycelial colonies and also appears to play a key role in fungal interactions with other organisms. This review presents a description of the two major patterns of hyphal branching, apical and lateral, and highlights the roles of internal and external factors in the induction of branch formation. In addition, potential mechanisms underlying branch site selection are outlined, and the possible roles of multiple signaling pathways (i.e., G protein alpha, Cdc42, NDR kinases) and subcellular structures (i.e., the Spitzenkorper, septins) are discussed. Finally, other forms of branching in the plant and animal kingdoms are briefly summarized and compared to hyphal branching.

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Section: Mycologiamentioning

confidence: 99%

Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems

2008

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“…They also have allelochemical, antiviral, antibacterial, antiherbivoral, anti-oxidant, and antitumor properties. Although the nature of the relationships in lichens is still the subject of debate, it is widely accepted that it ranges from mutualism to controlled parasitism and changes dynamically over time (e.g., Ahmadjian and Jacobs 1981;Nash 1996;Richardson 1999). The definition of a lichen is further complicated by the presence of diverse, thallus-associated eukaryotic and prokaryotic entities (Zedda and Rambold 2015), including fungi (parasites, saprotrophs, and parasymbionts; Hawksworth 1982Hawksworth , 2015Lawrey and Diederich 2003;Selbmann et al 2013), non-symbiotic algae (diatoms; Lakatos et al 2004), terrestrial and aquatic invertebrates (arthropods, nematodes, Alveolata, Metazoa, Rhizaria; Bates et al 2012), protists (Šatkauskienė 2012), as well as bacterial communities (Bates et al 2011;Aschenbrenner et al 2016).…”

Section: Fungal Associations With Bacteriamentioning

confidence: 99%

The plasticity of fungal interactions

Wrzosek

Ruszkiewicz‐Michalska

Sikora

et al. 2016

Mycol Progress

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Their hyphal structure, the common events of hybridization and horizontal gene transfer, as well as intimate associations with prokaryotes (including endobiotic bacteria) and cooperation with eukaryotes have made fungi very flexible at the genetic, physiological, and ecological levels. It is manifested with the fungal ability to perfectly exploit existing nutrient sources and plastically fit into a changing environment. Although the links between fungi and other ecosystem components are rarely clearly visible and unambiguous, fungi can be ecosystem buffers playing a homeostatic role throughout global ecosystems, reacting to changes in various ways, not only by modifications of gene expression but also by nuclear status and Bextended phenotype^. The goal of this review is to underline some ecological interactions involving fungi and other organisms and to indicate high fungal plasticity in terms of ontogenetic perspective.

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“…This may especially be the case in lichens which are a fungal-algal symbiosis whose status as integrated organisms has been generally recognized only relatively recently (17). Although the nutritional relationships between the symbionts remain in dispute (1), it now appears clear that the lichen symbiosis reflects a long history of coevolution resulting in stable lichen species.…”

mentioning

confidence: 99%

Age Dependence of Photosynthesis in the Caribou Lichen Cladina stellaris

Lechowicz

1983

Plant Physiol.

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The fruticose thailus of the lichen Cladina steflaris (Opiz.) Brodo can be subdivided into individual whorls of branches of known age. Photosynthesis declines steadily with age from a maximum rate of 0.76 milligram CO2 per gram dry weight per hour in 1-year-old whorls to 0.02 milligram CO2 per gram dry weight per hour after 15 years. Conversely, the dry biomass of the whorls increases up to age 9 years and then approximately levels off.Photosynthesis in whorls older than 15 years is less than 0.01 milligram per gram per hour. Progressive changes in thaflus color with age are associated with the observed photosynthetic decline. Whorls aged 6 years and younger together account for 18% of thalHus biomass but 50% of photosynthetic activity. The implications of these results for the idea that the lichen symbiosis results in truly integrated organisms with senescence phenomena akin to those in higher plants is discussed.Many studies of vascular plants have documented physiological changes associated with the aging of both whole plants and individual organs (18,19), but very few comparable data exist for nonvascular plants. The control mechanisms which coordinate developmental processes in higher plants (5) may not function effectively in taxa lacking vascular tissues and having only very simple apical organization. This may especially be the case in lichens which are a fungal-algal symbiosis whose status as integrated organisms has been generally recognized only relatively recently (17). Although the nutritional relationships between the symbionts remain in dispute (1), it now appears clear that the lichen symbiosis reflects a long history of coevolution resulting in stable lichen species.Because of the difficulties in determination of the age of lichen tissue, previous reports of within-thallus variation in Chl concentrations (6, 14), photosynthesis and respiration (3,13,14), and growth rates (7) have not usually been directly related to tissue age differences. Only in the fruticose Cladonia and Cladina lichens which branch once each year can age be readily determined (2).In the abundant caribou lichen, Cladina stellaris, Chl concentration and relative growth rate both decline steadily with increasing thallus age (6, 7). The purpose of this paper is to document the related age dependence of photosynthesis, one of the important measures ofplant senescence (15) air-dried at room temperature, flown to Montreal, and stored dry at -20°C until assayed for photosynthetic activity. These collection and storage procedures do not effect subsequent determinations of lichen gas exchange (10). Fine forceps were used to dissect 10 individual thalli from the collected lichen mats with the lichen lightly wetted by a mist of distilled H20 to avoid loss of branch tips which are very brittle when dry. These 10 thalli were photographed, briefly labeled with '4C02, immediately killed, and then partitioned into annual branch whorls. Each whorl of known age was weighed, combusted to recover 14CO2 in a scintillation cocktail, and co...

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Relationship between fungus and alga in the lichen Cladonia cristatella Tuck

Cited by 119 publications

References 9 publications

Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems

Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems

The plasticity of fungal interactions

Age Dependence of Photosynthesis in the Caribou Lichen Cladina stellaris

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