Tall fescue is thought to have co-evolved with the fungal endophyte Acremonium coenophialum to form a mutualistic relationship. Endophyte-infected (EI) plants can have increased growth and survival when compared with endophyte-free (EF) plants. Responses to endophyte-infection vary and are host-genotype and fungal-biotype specific. Mechanism(s) by which endophyte-infection confers increased growth...
Background: Pseudomonas fluorescens SBW25 has been extensively studied because of its plant growth promoting properties and potential as a biocontrol agent. The genome of SBW25 has been sequenced, and among sequenced strains of pseudomonads, SBW25 appears to be most closely related to P. fluorescens WH6. In the authors' laboratories, WH6...
The Pseudomonas aeruginosa antimetabolite L-2-amino-4-methoxy-trans-3-butenoic acid (AMB) shares biological activities with 4-formylaminooxyvinylglycine, a related molecule produced by Pseudomonas fluorescens WH6. We found that culture filtrates of a P.aeruginosa strain overproducing AMB weakly interfered with seed germination of the grassy weed Poa annua and strongly inhibited growth of Erwinia amylovora, the...
The genetic basis of the biosynthesis of the germination-arrest factor (GAF) produced by Pseudomonas fluorescens WH6, and previously identified as 4-formylaminooxyvinylglycine, has been investigated here. In addition to inhibiting the germination of a wide range of grassy weeds, GAF exhibits a selective antimicrobial activity against the bacterial plant pathogen Erwinia...
Pseudomonas fluorescens WH6 secretes a germination-arrest factor (GAF) that we have
identified previously as 4-formylaminooxyvinylglycine. GAF irreversibly inhibits germination of the
seeds of numerous grassy weeds and selectively inhibits growth of the bacterial plant pathogen
Erwinia amylovora. WH6-3, a mutant that has lost the ability to produce GAF, contains a...
Knowledge of post-dispersal seed fates and other regeneration characteristics is
crucial for predicting abundances and distributions of populations and, ultimately,
community species composition and diversity. Seed fate studies, however, are rare
primarily due to the difficulty of determining seed fates and causes of mortality.
This thesis investigated post-dispersal seed fates...
Many species have complex life cycles in which a dispersive larval stage is
followed by a relatively sedentary adult stage. For such species, reproductive output
is often high and large variation in survivorship throughout early life-history phases
(eggs and larvae) can lead to dramatic fluctuations in recruitment which may in...
The first part of the dissertation is to evaluate the use of proposed and established equations for area under the plasma concentration versus time (AUC) for molecules undergoing nonlinear Michaelis–Menten pharmacokinetic elimination. The effects of varying Michaelis-Menten parameters, rate of drug absorption, or bioavailability on the predictability of drug exposure...
Acid whey is the largest byproduct of the dairy industry but to date has few useful applications and is frequently discarded as a result. However, acid whey has a high carbon content, making it a suitable co-substrate for anaerobic co-digestion with raw sewage sludge. The synergistic effect of co-digestion has...
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Mark E. Dolan, Committee Member, representing Chemical, Biological, and Environmental
The epistemic practices that make up engineering are poorly understood and there is a lack of empirical research on this topic. Characterizing the epistemic practices of engineering students, faculty, and professionals is critical to creating effective curriculum that aids in developing student’s epistemic practices. Doing so allows us to better...
