Glomalean Fungi from the Ordovician

Redecker, Dirk; Kodner, Robin; Graham, Linda E.

doi:10.1126/science.289.5486.1920

Cited by 987 publications

(603 citation statements)

References 23 publications

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“…While discussing the origin of land plants, Pirozynski and Mallloch (1975) concluded "land plants never had an independence (from fungi); for if they had they could never have colonized land" (italics intentional by Johri for emphasis). The fossil records seem to support this hypothesis (Redecker et al, 2000). Based on the above suggestions and advances in our understanding of metabolic pathways and horizontal gene transfer, it is therefore tempting to suggest that the pathways of phytohormone biosynthesis in green plants are of prokaryotic origin (author's suggestion).…”

Section: Were the Pathways For The Biosynthesis Of Phytohormones In Gmentioning

confidence: 99%

Hormonal regulation in green plant lineage families

Johri

2008

Physiol Mol Biol Plants

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The patterns of phytohormones distribution, their native function and possible origin of hormonal regulation across the green plant lineages (chlorophytes, charophytes, bryophytes and tracheophytes) are discussed. The five classical phytohormonesauxins, cytokinins, gibberellins (GA), abscisic acid (ABA) and ethylene occur ubiquitously in green plants. They are produced as secondary metabolites by microorganisms. Some of the bacterial species use phytohormones to interact with the plant as a part of their colonization strategy. Phytohormone biosynthetic pathways in plants seem to be of microbial origin and furthermore, the origin of high affinity perception mechanism could have preceded the recruitment of a metabolite as a hormone. The bryophytes represent the earliest land plants which respond to the phytohormones with the exception of gibberellins. The regulation by auxin and ABA may have evolved before the separation of green algal lineage. Auxin enhances rhizoid and caulonemal differentiation while cytokinins enhance shoot bud formation in mosses. Ethylene retards cell division but seems to promote cell elongation. The presence of responses specific to cytokinins and ethylene strongly suggest the origin of their regulation in bryophytes. The hormonal role of GAs could have evolved in some of the ferns where antheridiogens (compounds related to GAs) and GAs themselves regulate the formation of antheridia.During migration of life forms to land, the tolerance to desiccation may have evolved and is now observed in some of the microorganisms, animals and plants. Besides plants, sequences coding for late embryogenesis abundant-like proteins occur in the genomes of other anhydrobiotic species of microorganisms and nematodes. ABA acts as a stress signal and increases rapidly upon desiccation or in response to some of the abiotic stresses in green plants. As the salt stress also increases ABA release in the culture medium of cyanobacterium Trichormus variabilis, the recruitment of ABA in the regulation of stress responses could have been derived from prokaryotes and present at the level of common ancestor of green plants. The overall hormonal action mechanisms in mosses are remarkably similar to that of the higher plants. As plants are thought to be monophyletic in origin, the existence of remarkably similar hormonal mechanisms in the mosses and higher plants, suggests that some of the basic elements of regulation cascade could have also evolved at the level of common ancestor of plants. The networking of various steps in a cascade or the crosstalk between different cascades is variable and reflects the dynamic interaction between a species and its specific environment.

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Section: Were the Pathways For The Biosynthesis Of Phytohormones In Gmentioning

confidence: 99%

Hormonal regulation in green plant lineage families

Johri

2008

Physiol Mol Biol Plants

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mentioning

confidence: 99%

“…AM are ancient; the first fossil evidence of this symbiosis dates back 400 million years (33). Several authors have proposed that AM have contributed to the colonization of early land plants (32,38).AM are generally assumed to be nonspecific associations, since Glomeromycota are able to colonize roots of several host plants and are themselves colonized by different AM fungal species (12,14,35,44). Despite this lack of host specificity, the diversity of AM fungi has been shown to affect the plant community composition under field conditions (43), and the genetic structure of the AM fungal community was shown to differ significantly according to the plant species…”

mentioning

confidence: 99%

Identification of Bacterial Groups Preferentially Associated with Mycorrhizal Roots of Medicago truncatula

Offre

Pivato

Siblot

et al. 2007

Appl Environ Microbiol

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Mycorrhizae result from symbiotic associations between soil fungi and the roots of most plants. Mycorrhizae are considered to be classic examples of mutualistic symbioses. The basis for this mutualism relies on the supply of carbon to the fungus by the host plant and, in return, on the supply of mineral nutrients and water to the plant and on the plant's protection against soil-borne diseases by the fungus (41). Among mycorrhizal symbioses, arbuscular mycorrhizae (AM) are the most widespread. AM are recorded in 80% of land plants and are generated by the association of plant roots and fungal populations belonging to the Glomeromycota phylum (37, 41), which includes around 160 species (23,45). AM are ancient; the first fossil evidence of this symbiosis dates back 400 million years (33). Several authors have proposed that AM have contributed to the colonization of early land plants (32,38).AM are generally assumed to be nonspecific associations, since Glomeromycota are able to colonize roots of several host plants and are themselves colonized by different AM fungal species (12,14,35,44). Despite this lack of host specificity, the diversity of AM fungi has been shown to affect the plant community composition under field conditions (43), and the genetic structure of the AM fungal community was shown to differ significantly according to the plant species

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“…Most terrestrial plants have the capacity to establish mutualistic associations with arbuscular mycorrhizal fungi (AMF), a group of ubiquitous soil fungi that belong to the ancient phylum of Glomeromycota (Redecker et al 2000). As in other plantÁmicrobe symbiosis, AMF relationships begin with molecular and chemical dialogs between partners that trigger the events leading to an effective plant tissue colonization by microbes and to the various and complex morphophysiological alterations of the symbiotic partners (Bonfante and Requena 2011;Maillet et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Elicitation of tobacco alkaloid biosynthesis by disrupted spores and filtrate of germinating spores of the arbuscular mycorrhizal fungiGlomus etunicatum

Andrade

Malik

Sawaya

et al. 2013

Journal of Plant Interactions

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Molecules released by soil microorganisms, such as arbuscular mycorrhizal fungi (AMF), trigger plant responses prior to any physical contact. Here, it is shown that disrupted spores (DS) homogenates and exudates from germinating spores (GS) of Glomus etunicatum caused marked alterations in the content of the tobacco alkaloids nicotine, anabasine, and nornicotine and the genes involved in their biosynthesis. GS and DS were applied to the base of Nicotiana tabacum seedling stems, and 3 or 10 days later, the leaves and roots were harvested for analyses. The alkaloid contents were influenced by both elicitors and varied depending on the harvest day. In general, such variations agree with the transcript levels of putrescine N-methyltransferase, oxide reductase Á A622 and nicotine N-demethylase Á CYP82E4. The results are discussed in light of recent insights on chemical signaling processes between plants and AMF able to trigger different elicitation responses and their possible effects on secondary metabolism in plants.

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Glomalean Fungi from the Ordovician

Cited by 987 publications

References 23 publications

Hormonal regulation in green plant lineage families

Hormonal regulation in green plant lineage families

Identification of Bacterial Groups Preferentially Associated with Mycorrhizal Roots of Medicago truncatula

Elicitation of tobacco alkaloid biosynthesis by disrupted spores and filtrate of germinating spores of the arbuscular mycorrhizal fungiGlomus etunicatum

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