TJ Sullivan

Indiana University Kokomo | IUK · School of Sciences

Epichloë fungi (Ascomycota) live within aboveground tissues of grasses and can have important implications for natural and managed ecosystems through production of alkaloids. Nonetheless, vertebrate herbivores may possess traits, like oral secretions, that mitigate effects of alkaloids. We tested if sheep saliva mitigates effects of Epichloë alkalo...

Premise of the study: Primers were designed to produce short amplicons containing single-nucleotide polymorphisms (SNPs) in β-tubulin (tubB) and translation elongation factor 1-α (tefA) in Epichloë canadensis (Clavicipitaceae), an endophytic fungus of Elymus canadensis (Poaceae). Methods and results: Primers to amplify regions of tubB and tefA c...

Background/Question/Methods Endophytic fungi are common endosymbionts of cool season grasses. Canada wildrye (Elymus canadensis) hosts a variety of endophyte species from the genus Epichloë, including an asexual, vertically transmitted interspecific hybrid and a sexual, potentially horizontally transmitted species. The differing reproductive stra...

The epichloae are ascomycetous fungi in the genera Epichloë and Neotyphodium that live within grasses. Some of these fungi produce alkaloids that can help protect the host from herbivores. The alkaloids may also travel up the food web and affect members of the third trophic level. In this way they can produce trophic cascades which are rippling eff...

• Epichloë spp., fungal endophytes of cool season grasses, produce collars of mycelium (stromata) on host stems that Botanophila flies visit for egg laying. Flies transfer fungal gametes among stromata and thereby serve to cross-fertilize fungi. Hence, the interaction is analogous to insect pollination in angiosperms. While most Epichloë species ar...

Neotyphodium coenophialum is a fungus that commonly grows endosymbiotically within cool season grasses. The fungus can provide protection against biotic stresses to its host through the production of alkaloids. We tested if combinations of two cultivars (Georgia 5 and Jesup) of tall fescue with different isolates of N. coenophialum alter resistance...

Folsomia candida (order Collembola), a common soil arthropod, has recently been described living in a shallow (2.5–5.7 m below surface), unconsolidated aquifer in southwestern Michigan. F. candida was haplotyped from 14 wells using inter-simple sequence repeats (ISSRs) markers, and genetic variation in F. candida was used as a bioindicator to ident...

Neotyphodium coenophialum (Glenn, Bacon, Price & Hanlin) (Ascomycota: Clavicipitaceae) is an endophytic fungus that lives symbiotically within grasses and produces alkaloids that can help protect its hosts from some insect pests. We used laboratory-based experiments to investigate whether fungal genotype influences an herbivore and its parasitoid....

Tall fescue (Lolium arundinaceum) forms a mutualistic relationship with the fungal endophyte Neotyphodium coenophialum. The endophyte provides constitutive resistance to herbivores through its production of alkaloid compounds. Moreover, herbivore attack induces elevated synthesis of loline alkaloids, that is, the fungus also provides wound-inducibl...

Fungal endophyte-grass associations are diverse and complex. Some endophytes (e.g. Neotyphodium spp.) reproduce asexually by growing vegetatively into host seeds and many of these vertically-transmitted endophytes form mutualisms with their hosts by providing high levels of alkaloids, such as lolines, that reduce herbivore performance. Additionally...

Cool-season grasses often harbor obligate fungal symbionts from the genus Neotyphodium, and these symbiota can function as a single ecological unit. Previous studies have shown that gene flow in Neotyphodium in Festuca arizonica is low enough such that populations could diverge and form local adaptations. A reciprocal transplant experiment was perf...

Plants have multiple strategies to deal with herbivory, ranging from chemical or physical defenses to tolerating damage and allocating resources for regrowth. Grasses usually tolerate herbivory, but for some cool-season grasses, their strategy may depend upon their interactions with intracellular symbionts. Neotyphodium endophytes are common symbio...

Plants have evolved a range of responses to herbivory ranging from tolerance to both inducible and constitutive chemical defenses. Previous research has shown lolines produced by Neotyphodium coenophialum are inducible by host damage. In this paper, we examined whether this inducibility can also be caused by damage from an invertebrate herbivore an...

Neotyphodium coenophialum (Ascomycota: Clavicipitaceae) is an endophytic fungus of grasses that produces alkaloids which can have detrimental effects on some insect herbivores, like fall armyworm caterpillars (Spodoptera frugiperda). Alkaloid production can be influenced by fungal genotype. We investigated if endophyte-produced alkaloids might also...

We have been collaborating on a multidisciplinary research programme with undergraduate (baccalaureate) students for the past 3 years, funded by the National Science Foundation in the USA. The project focuses on the ecological interaction between endophytic fungi and the grasses they inhabit and involves students (10-15 annually) and faculty (5 and...

Arizona fescue (Festuca arizonica) often harbours asymptomatic, asexual endophytic fungi from the genus Neotyphodium. In agronomic grasses, Neotyphodium endophytes are often credited with a wide range of mutualistic benefits to its host many of which are related to fungal production of alkaloids for herbivore deterrence. Neotyphodium in the native...

▪ Abstract Endophytic fungi living asymptomatically within plant tissues have been found in virtually all plant species. Endophytes are considered plant mutualists: They receive nutrition and protection from the host plant while the host plant may benefit from enhanced competitive abilities and increased resistance to herbivores, pathogens, and var...

Asexual systemic fungi that live symbiotically within grasses are viewed as strong mutualists on the basis of theory and empirical studies of introduced agronomic grasses. Evolutionary theory predicts that microbial symbionts that lose sexuality and rely on propagules of their hosts for transmission should evolve to benefit their hosts. Fungal endo...

We determined concentrations of peramine, the only alkaloid produced by Neotyphodium-infected (E+) Arizona fescue plants (of the four major types typically assayed in infected grasses), in a long-term field experiment. Four plant genotypes with (E+) and without (experimentally removed, E-) their respective haplotypes (two haplotypes in two plant ge...

Systemic endophytic fungi in agronomic and turf grasses are well known for conferring increased resistance to herbivores and to abiotic stresses, such as drought, and increasing competitive abilities. Many native grasses also harbor high frequencies of the asexual and vertically-transmitted endophyte, Neotyphodium. In Festuca arizonica (Arizona fes...

The discovery of the anti-herbivore properties of Neotyphodium endophytes, most of the available literature suggests that these endophytic fungi are plant defensive mutualists, and ecologists have readily extrapolated it to all endophyte-plant interactions (Breen 1994, Clay 1990). The current understanding of the mutualistic nature of endophytes is...

The goal of this work is to develop a method for the functional analysis of malaria genes using the method of DNA transfection. We have developed a transient transfection vector by constructing a chimeric gene in which the firefly luciferase gene was inserted in frame into the coding region of the pgs28 gene of Plasmodium gallinaceum. This plasmid...