Inoculum 63(3) - Mycological Society of America

plots in all three exploratory locations (Schwäbische Alb, Hainich-Dün,
Schorfheide-Chorin). Thirteen species of trees whose logs were placed there as
the BeLongDead experiment are now included. A two-year experiment of adding
nitrogen to dead wood was also initiated. We discuss some results of phase 1 and
some planned activities in phase 2. In addition, some current aspects of a related
project, FuPerS, studying leaf litter degradation, are discussed.
LeBlanc, Nicholas, Linda Kinkel, and H Corby Kistler. Department of Plant
Pathology, University of Minnesota, 495 Borlaug Hall 1991 Upper Buford Circle,
St. Paul, MN 55108. Soil fungal lineages respond to host plant identity and
community diversity in a model grassland system
Grassland soils are known to harbor diverse fungal communities but the
effects of host plant identity and the diversity of the surrounding plant community
on these fungi is unknown. We have focused on rhizosphere fungal communities
in a model grassland system using targeted metagenomics and well-annotated
reference material for taxonomic assignment. A total of twenty-four samples
were analyzed from hosts grown in monoculture or polyculture. Hosts included
Big Bluestem, Little Bluestem, Round-Headed Bush Clover, and Sundial Lupine.
We hypothesized that host family (grasses and legumes) and plant community diversity
(monoculture and polyculture) would influence fungal community compositions
and diversity. Amplicon libraries, derived from rhizosphere DNA, were
sequenced using 454 technology. Sequences were aligned to a custom database of
4030 unique accessions published in phylogenetic studies, derived from genome
databases, and obtained from the AFTOL consortium. Initial NCBI taxon IDs
were used to assign reads to higher taxonomies using Perl scripts. Approximately
800 fungal genera were detected from the prairie soils. More diverse fungal
communities were associated with hosts grown in polyculture. Many of the assigned
taxonomies represent slow-growing, poorly- studied fungi, such as
Chaetothyriales and Verrucariales, which were enriched in the grass rhizosphere.
Other taxa, like Helotiales, were preferentially enriched in more diverse plant
communities but also significantly correlated with soil potassium. This work
highlights the first steps towards linking plant host and community diversity with
the abundance of root-associated fungi that likely play important, but poorly understood
roles in plant growth and development.
Lehr, Nina A 1 , Zheng Wang 1 , Francesc Lopez-Giraldez 1 , Ning Li 1 , Frances
Trail 2 , and Jeffrey Townsend 1 . 1 2
Yale University, New Haven, CT, USA,
Michigan State University, East Lansing, MI, USA. The importance of
carotenoids for sexual development of fungi
Carotenoids are terpenes which belong to the most widespread group of
compounds in nature and which are produced by plants, bacteria and fungi. Terpenes
fulfill diverse functions such as protection against reactive oxygen species
(ROS) and are beneficial for the nutrition of humans and animals. The orange pigmentation
of the fungus Neurospora crassa derives from the accumulation of the
xanthophyll neurosporaxanthine and other precursor carotenoids in response to
asexual spore development upon exposure to light. Carotenoid biosynthesis in N.
crassa has been studied intensively and it is known that blue light controls induction
of carotenoid production in the mycelium, formation of protoperithecia as
well as phototropism of perithecial beaks and perithecial polarity. Carotenoid
biosynthesis involves five different enzymes, amongst which are three “albino”
genes al-1, al-2 and al-3, encoding enzymes essential for carotenogenesis but not
for growth. In its life cycle, Neurospora undergoes either an asexual or a sexual
phase depending on environmental conditions. The asexual phase results in hyphal
growth leading to the formation of macro- and microconidia while in the sexual
phase complex, three-dimensional fruiting bodies, perithecia, are formed. So
far there is no information on the linkage between carotenoid biosynthesis and the
sexual life cycle. We have performed Illumina next generation sequencing of
three Neurospora species over the time course of sexual development, followed
by a comparative gene expression analysis with a pipeline we have generated to
measure the levels of gene expression. We have quantified the amount of total
carotenoids present in the mycelium at each individual time point. A screen of
knockout mutants has revealed a linkage of carotenoid biosynthesis to the formation
of perithecia.
Lehr, Nina 1 , Zheng Wang 1 , Usha Sikhakolli 2 , Francesc Lopez-Giraldez 1 , Ning
Li 1 , Frances Trail 2 , and Jeffrey P Townsend 1 . 1 Department of Ecology and
Evolutionary Biology and Program in Computational Biology and Bioinformatics,
Yale University, New Haven, Connecticut 06520, USA., 2 Department of
Plant Biology, Michigan State University, East Lansing, MI 48824. Comparative
transcriptomics reveals new Neurospora crassa genes important to
perithecial development
In recent years, a plethora of genomic sequences have been released for
fungal species, accompanied by functional predictions for genes based on protein
sequence comparisons. However, identification of genes involved in particular
processes has been extremely slow, and new methodologies for identifying genes
involved in a particular process have not kept pace with the exponential increase
28 Inoculum 63(3), June 2012
in genome sequence availability. We have performed transcriptional profiling of
five species of Neurospora and Fusarium during six stages of perithecium development.
Because we maintained a strictly common medium across experiments,
our transcriptomic data revealed solely evolved differences in the transcriptional
basis of morphological changes. We estimated ancestral gene expression profiles
and transcriptional shifts across this developmental process, facilitating identification
of genes whose transcription had substantially and significantly shifted during
the evolutionary process. We examined one hundred genes whose expression
greatly increased in Neurospora crassa perithecial development compared to
Neurospora tetrasperma, compared to Neurospora discreta, or compared to
Fusarium spp. Phenotypes of knockouts of these genes included substantial
changes in the timing and environmental sensitivity of perithecial development.
These genes were not previously identified as candidates for function in perithecium
development, illustrating the utility of this method for identification of genes
associated with specific functional processes.
Lendemer, James C 1 and Brendan P Hodkinson 2 . 1 Institute of Systematic
Botany, The New York Botanical Garden, Bronx, NY 10458-5126, U.S.A., 2 International
Plant Science Center, The New York Botanical Garden, Bronx, NY
10458-5126, USA. Sterile asexually reproducing crustose lichens: improving
classification, conservation, and communication in the 21st century
Although many lichens reproduce through the dispersal of sexual diaspores,
asexual reproduction is not uncommon and occurs in nearly all of the diverse
lineages that comprise lichen-forming fungi. This type of reproduction can
occur through either purely fungal diaspores or lichenized diaspores. The latter
comprise a morphologically diverse array of structures that have evolved to facilitate
the co-dispersal of the components of the lichen microbiome. The majority
of crustose lichens that reproduce exclusively via lichenized diaspores are poorly
understood, under collected, or undescribed and they represent a large component
of lichen biodiversity that is currently overlooked and underestimated. We present
a conceptual summary of the results of five years of research on this group in
the context of a revision of the sterile crustose genus Lepraria s.l. In addition to
extensive morphological studies of thallus ultrastructure, and integrated studies of
molecular and non-molecular datasets to resolve species boundaries, we show that
Lepraria s.l. is polyphyletic at the ordinal level and contains disparate elements
belonging to four families in three orders, one of which was previously unrecognized.
Drawing upon this body of work we present a standard protocol to improve
our understanding of sterile crustose lichens, communicate this understanding to
a diverse array of interdisciplinary researchers, and translate this understanding
into meaningful applications to promote real-world conservation.
Letcher, Peter M, Satoshi Sekimoto, and Martha J Powell. Department of Biological
Sciences, The University of Alabama, Tuscaloosa, AL 35487. Characterizing
the paracrystalline inclusion in zoospores of members of the
Chytridiales (Chytridiomycota)
Orders within Chytridiomycota (=chytrids) have now been circumscribed
as monophyletic lineages, each with zoospores exhibiting unique suites of character
states. Molecular phylogenetic analyses allow us to hypothesize zoospore
character evolution through tracking modifications, losses, or appearances of
characters along these lineages. The presence of a paracrystalline inclusion is one
zoosporic character within Chytridiomycota that has been reported only among
members of the Chytridiales. We are investigating the structure and function of
the paracrystalline inclusion in zoospores of the Chytridiales. Although the
Chytridiales includes a variety of zoospore sub-types defining the families
Chytridiaceae and Chytriomycetaceae, zoospores of all members studied with
electron microscopy contain a paracrystalline inclusion. Consequently, the presence
of a paracrystalline inclusion unites the Chytridiales and serves as a diagnostic
character for this order within Chytridiomycota. Because paracrystalline inclusions
found in organisms outside the Chytridiomycota are typically associated
with the accumulation of proteins, our hypothesis is that the paracrystalline inclusion
in zoospores of Chytridiales is composed of protein. We have found that
number, size, and complexity of paracrystalline inclusions vary with species. The
long-term aim of this study is to isolate the paracrystalline inclusion and characterize
it biochemically.
Levesque, C Andre, Gregg Robideau, Chen Wen, and Lewis Christopher. Agriculture
& Agri-Food Canada, Ottawa, Canada. Oomycete barcoding and applications
The ITS region is the de facto DNA barcode in oomycetes as in true
Fungi. However, the cytochrome oxidase 1 (COI) region is the NCBI accepted
barcode region and it must be ruled out to pave the way for an alternative marker
such as ITS. COI does not work for the true Fungi, primarily because of numerous
introns, but in oomycetes COI works at least as well as ITS. The prevalence
of ITS in mycology has led to the proposal that it be included as barcode in addi-
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