Pathogenic Microbiology Commons^™

Prokaryotic Diversity In The Rhizosphere Of Organic, Intensive, And Transitional Coffee Farms In Brazil, Adam Caldwell, Livia Silva, Cynthia Da Silva, Cleber Ouverney

Faculty Publications, Biological Sciences

Despite a continuous rise in consumption of coffee over the past 60 years and recent studies showing positive benefits linked to human health, intensive coffee farming practices have been associated with environmental damage, risks to human health, and reductions in biodiversity. In contrast, organic farming has become an increasingly popular alternative, with both environmental and health benefits. This study aimed to characterize and determine the differences in the prokaryotic soil microbiology of three Brazilian coffee farms: one practicing intensive farming, one practicing organic farming, and one undergoing a transition from intensive to organic practices. Soil samples were collected from 20 …

Diversity Of Bacteria Carried By Pinewood Nematode In Usa And Phylogenetic Comparison With Isolates From Other Countries, Diogo Neves Proença, Luís Fonseca, Thomas Powers, Isabel M.O. Abrantes, Paula V. Morais

Department of Plant Pathology: Faculty Publications

Pine wilt disease (PWD) is native to North America and has spread to Asia and Europe. Lately, mutualistic relationship has been suggested between the pinewood nematode (PWN), Bursaphelenchus xylophilus the causal nematode agent of PWD, and bacteria. In countries where PWN occurs, nematodes from diseased trees were reported to carry bacteria from several genera. However no data exists for the United States. The objective of this study was to evaluate the diversity of the bacterial community carried by B. xylophilus, isolated from different Pinus spp. with PWD in Nebraska, United States. The bacteria carried by PWN belonged to Gammaproteobacteria …

Phages Of Non-Diary Lactococci: Isolation And Characterization Of Phi L47, A Phage Infecting The Grass Isolate Lactococcus Lactis Ssp Cremoris Dpc6860, Daniel Cavanagh, Caitríona M. Guinane, Horst Neve, Aidan Coffey, R. Paul Ross, Gerald F. Fitzgerald, Olivia Mcauliffe

Department of Biological Sciences Publications

Lactococci isolated from non-dairy sources have been found to possess enhanced metabolic activity when compared to dairy strains. These capabilities may be harnessed through the use of these strains as starter or adjunct cultures to produce more diverse flavor profiles in cheese and other dairy products. To understand the interactions between these organisms and the phages that infect them, a number of phages were isolated against lactococcal strains of non-dairy origin. One such phage, ΦL47, was isolated from a sewage sample using the grass isolate L. lactis ssp. cremoris DPC6860 as a host. Visualization of phage virions by transmission electron …

Amelioration Of Root Disease Of Subterranean Clover (Trifolium Subterraneum) By Mineral Nutrients, Tim Scanlon, Tiernan A. O’Rourke, Megan H. Ryan, Martin J. Barbetti, Krishnapillai Sivasithamparam

Journal articles

Subterranean clover (Trifolium subterraneum) is a key pasture legume across southern Australia and elsewhere. Decline in subterranean clover pastures was first recognised in Australia during the 1960s and manifests as an increase in weeds and a decrease in desirable legume species. While both root disease and poor nutrition contribute to subterranean clover pasture decline, the relationships between root disease and nutrition have not been determined. The objective of this study was to define these relationships. Field experiments were undertaken to determine the nutritional and pathogen status of soils and subterranean clover from three Western Australian field sites. Subsequently, …

The Pseudomonas Syringae Type Iii Secretion System: The Translocator Proteins, Their Secretion, And The Restriction Of Translocation By The Plant Immune System, Emerson Crabill

School of Biological Sciences: Dissertations, Theses, and Student Research

Pseudomonas syringae is a Gram-negative plant pathogen whose virulence is dependent upon its type III secretion system (T3SS), a nanosyringe that facilitates translocation, or injection, of type III effector (T3E) proteins into eukaryotic cells. The primary function of P. syringae T3E proteins is suppression of plant immunity. Bacterial proteins called translocators form a translocon that forms a pore in the host plasma membrane which is traversed by T3Es. HrpK1, a putative P. syringae translocator, is a type III-secreted protein important for virulence and T3E injection, but not secretion of T3Es. Harpins are a group of proteins specific to plant pathogens …

Host Pathogen Interactions: Is Arabidopsis Thaliana Remembered By Its Nemesis Pseudomonas Syringae?, Daniel Z. Kreiser

Lawrence University Honors Projects

Plants contain innate immune systems that deter pathogen infection. Pattern recognition receptors bind microbe-associated molecular patterns (MAMPs), triggering immunity. MAMPs are proteins exclusive to pathogens that are typically indispensable for their survival. For this reason, MAMPs cannot be mutated or removed without causing pathogen death. However, this does not necessitate constitutive expression of MAMPs. In this study, the MAMP response of Arabidopsis thaliana was utilized to determine differential detection of MAMPs expressed by Pseudomonas syringe pv. tomato DC3000 when pretreated with A. thaliana. Results demonstrated that more MAMPs are detected when P. syringae had previously encountered A. thaliana, …

Gata-Family Transcription Factors In Magnaporthe Oryzae, Cristian F. Quispe

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The filamentous fungus, Magnaporthe oryzae, responsible for blast rice disease, destroys around 10-30% of the rice crop annually. Infection begins when the specialized infection structure, the appressorium, generates enormous internal turgor pressure through the accumulation of glycerol. This turgor acts on a penetration peg emerging at the base of the cell, causing it to breach the leaf surface allowing its infection.

The enzyme trehalose-6- phosphate synthase (Tps1) is a central regulator of the transition from appressorium development to infectious hyphal growth. In the first chapter we show that initiation of rice blast disease requires a regulatory mechanism involving an …

Letter From The Dean, Lalit Verma

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Root Rot Of Subterranean Clover In W.A, G C. Macnish, M. J. Barbetti, D. Gillespie, K. Hawley

Journal of the Department of Agriculture, Western Australia, Series 4

Root rot of subterranean clover has occurred sporadically in the south west of Western Australia for a number of years.

In most seasons the disease has affected the clover paddocks of only a few farms, but in 1973 there was widespread pasture decline due to root rot in the South-West and south coastal districts.

At present the most promising approaches for minimising the effect of root rot appear to be the use of cultivation techniques and eventually the use of resistant varieties, or other pasture species.

Phomopsis : The Causal Fungus Of Lupinosis, P Mcr Wood, A. G. P. Brown

Journal of the Department of Agriculture, Western Australia, Series 4

It is now well known that lupinosis of sheep and cattle follows ingestion of lupin stubble colonised by the fungus Phomopsis rossiana. The fungus infects green lupins but persists on the stubble and under certain conditions apparently produces a toxin which causes the disease.

As Phomopsis is now widespread on lupins in Western Australia its ecology has been studied in detail as a basis for possible control measures.

This article outlines what is known so far of the disease and its control.

Lupinosis, M R. Gardiner

Journal of the Department of Agriculture, Western Australia, Series 4

In spite of many years of intensive investigation lupinosis remains a remarkably complex and baffling problem. Current research is throwing new light on the disease and it is now much better understood— although far from beaten.

Lupinosis research is co-ordinated by the Department of Agriculture's Lupinosis Committee, on which are represented all groups working on the disease. These include veterinary surgeons and pathologists, chemists, plant pathologists and animal husbandry specialists.

Chairman of the Committee is Dr M. R. Gardiner, Chief of the Department's Animal Division and a veteran of lupinosis research.

In this article Dr Gardiner summarises the current state …

Sturt Pea Hosts Collar Rot Fungus, M D. Marcley

Journal of the Department of Agriculture, Western Australia, Series 4

Evidence that Western Australia's Sturt Pea can be attacked by collar rot fungus suggests a reason for the occurrence of collar rot in places where the fungus should not survive.

At Carnarvon for instance, in spite of the hot, dry conditions, the collar rot fungus has been found on eggplants and Tuart trees.

Pressurised Soil Fumigation Equipment For Control Of Eelworm, C W. Robartson

Journal of the Department of Agriculture, Western Australia, Series 4

THE treatment of soil infested with eelworms involves the use of chemical fumigants usually in the form of volatile liquids.

This article gives details for the construction of a simple pressurised fumigator which could be easily made by most orchardists, vignerons and market gardeners.

Sclerotinia Rot Of Vegetables, S C. Chambers, M. Hardie

Journal of the Department of Agriculture, Western Australia, Series 4

SCLEROTINIA ROT, caused by the fungus Sclerotinia sclerotiorum, is now one of the most serious vegetable diseases in metropolitan market gardens.

Over the past decade it has been steadily increasing in prevalence and if present trends continue, many growers may be forced to abandon certain crops.

Although most vegetables are susceptible, the greatest losses are occurring in the autumn planting of beans, cauliflowers and lettuce and in the production of cauliflower seed.

Sclerotinia Rot Of Beans, S C. Chambers, M. Hardie

Journal of the Department of Agriculture, Western Australia, Series 4

INVESTIGATIONS over the past three years suggest trenching is the most important practice for controlling Sclerotinia rot in market gardens.

None of the remaining measures under test gave satisfactory control of the disease, although some reduced its incidence significantly.