The Irreversible Loss of a Decomposition Pathway Marks the Single Origin of an Ectomycorrhizal Symbiosis

Microbial symbioses have evolved repeatedly across the tree of life, but the genetic changes underlying transitions to symbiosis are largely unknown, especially for eukaryotic microbial symbionts. We used the genus Amanita, an iconic group of mushroom-forming fungi engaged in ectomycorrhizal symbioses with plants, to identify both the origins and potential genetic changes maintaining the stability of this mutualism. A multi-gene phylogeny reveals one origin of the symbiosis within Amanita, with a single transition from saprotrophic decomposition of dead organic matter to biotrophic dependence on host plants for carbon. Associated with this transition are the losses of two cellulase genes, each of which plays a critical role in extracellular decomposition of organic matter. However a third gene, which acts at later stages in cellulose decomposition, is retained by many, but not all, ectomycorrhizal species. Experiments confirm that symbiotic Amanita species have lost the ability to grow on complex organic matter and have therefore lost the capacity to live in forest soils without carbon supplied by a host plant. Irreversible losses of decomposition pathways are likely to play key roles in the evolutionary stability of these ubiquitous mutualisms.Organismic and Evolutionary Biolog

A kitchen and its furnishings

Citation: Tulloss, Elsie May. A kitchen and its furnishings. Senior thesis, Kansas State Agricultural College, 1908.Introduction: A kitchen is that portion of a dwelling to which the preparation of pure, wholesome food is confined for the nourishment of our bodies. When it is realized how necessary it is that food be pure and wholesome and properly prepared, the first thing to look to, is a suitable place for its preparation

The Idol, 1965

In this issue: new writers appearing in this issue are Donald Abood and Harold Neunder, both of Professor Gado\u27s Creative Writing Class. Professor Gado\u27s notes comment on them as well as other pieces appearing in this Idol. Paul Sherwin contributes two poems showing the profound influence of Dylan Thomas, Gerard Manley Hopkins, and the folk singer-poet, Bob Dylan. Jeffrey Hedquist and Douglass Allen contribute two pieces of verse in conventional style. And Martin Jay returns after a year in Europe with two precise pieces. Lawrence Weitz is the present Counsellor to Students and an instructor in psychology; he contributes the record of an intriguing dream.https://digitalworks.union.edu/idol/1051/thumbnail.jp

The Idol, 1964

In this issue: Eight of our contributors appear in the Idol for the first time: Daniel F. McLister, winner of honorable mention in last spring\u27s Academy of American Poets contest, is represented by two intricate pieces of verse. A. Rutherford justifies his existence admirably. Stephen Granger contributes with a simple pastoral. Robert Milder contributes an essay on existentialism which won some praise from Prof. Kurtz. Peter Blue, a member of Prof. Gado\u27s Creative Writing course, makes his first appearance with an untitled poem. Charles Nunzio and Ken R. Wilkes make good representatives of the new freshman class with two poems and an entertaining sketch respectively. And Wayne Franklin submits a poem on one of the major problems of any age - communication.https://digitalworks.union.edu/idol/1052/thumbnail.jp

Multi-locus phylogeny of lethal amanitas: Implications for species diversity and historical biogeography

BACKGROUND: Lethal amanitas (Amanita section Phalloideae) are a group of wild, fatal mushrooms causing many poisoning cases worldwide. However, the diversity and evolutionary history of these lethal mushrooms remain poorly known due to the limited sampling and insufficient gene fragments employed for phylogenetic analyses. In this study, five gene loci (nrLSU, ITS, rpb2, ef1-α and β-tubulin) with a widely geographic sampling from East and South Asia, Europe, North and Central America, South Africa and Australia were analysed with maximum-likelihood, maximum-parsimony and Bayesian inference methods. Biochemical analyses were also conducted with intention to detect amatoxins and phalloidin in 14 representative samples. RESULT: Lethal amanitas were robustly supported to be a monophyletic group after excluding five species that were provisionally defined as lethal amanitas based on morphological studies. In lethal amanitas, 28 phylogenetic species were recognised by integrating molecular phylogenetic analyses with morphological studies, and 14 of them represented putatively new species. The biochemical analyses indicated a single origin of cyclic peptide toxins (amatoxins and phalloidin) within Amanita and suggested that this kind of toxins seemed to be a synapomorphy of lethal amanitas. Molecular dating through BEAST and biogeographic analyses with LAGRANGE and RASP indicated that lethal amanitas most likely originated in the Palaeotropics with the present crown group dated around 64.92 Mya in the early Paleocene, and the East Asia–eastern North America or Eurasia–North America–Central America disjunct distribution patterns were primarily established during the middle Oligocene to Miocene. CONCLUSION: The cryptic diversity found in this study indicates that the species diversity of lethal amanitas is strongly underestimated under the current taxonomy. The intercontinental sister species or sister groups relationships among East Asia and eastern North America or Eurasia–North America–Central America within lethal amanitas are best explained by the diversification model of Palaeotropical origin, dispersal via the Bering Land Bridge, followed by regional vicariance speciation resulting from climate change during the middle Oligocene to the present. These findings indicate the importance of both dispersal and vicariance in shaping the intercontinental distributions of these ectomycorrhizal fungi