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Molecular Characterization Of Citrus Tatter Leaf Virus Historically Associated With Meyer Lemon Trees: Complete Genome Sequence And Development Of Biologically Active In Vitro Transcripts, Satyanarayana Tatineni, Mohammad R. Afunian, Mark E. Hilf, Siddarame Gowda, William O. Dawson, Stephen M. Garnsey Jan 2009

Molecular Characterization Of Citrus Tatter Leaf Virus Historically Associated With Meyer Lemon Trees: Complete Genome Sequence And Development Of Biologically Active In Vitro Transcripts, Satyanarayana Tatineni, Mohammad R. Afunian, Mark E. Hilf, Siddarame Gowda, William O. Dawson, Stephen M. Garnsey

Department of Plant Pathology: Faculty Publications

Citrus tatter leaf virus isolated from Meyer lemon trees (CTLV-ML) from California and Florida induces bud union incompatibility of citrus trees grafted on the widely used trifoliate and trifoliate hybrid rootstocks. The complete genome sequence of CTLV-ML was determined to be 6,495 nucleotides (nts), with two overlapping open reading frames (ORFs) and a poly (A) tail at the 3′ end. The genome organization is similar to other capilloviruses, with ORF1 (nts 37 to 6,354) encoding a putative 242-kDa polyprotein which contains replication-associated domains plus a coat protein (CP), and ORF2 (nts 4,788 to 5,750), which is located within ORF1 in …


Preface To Lesser Known Large Dsdna Viruses. Current Topics In Microbiology And Immunology 328, James L. Van Etten Jan 2009

Preface To Lesser Known Large Dsdna Viruses. Current Topics In Microbiology And Immunology 328, James L. Van Etten

Department of Plant Pathology: Faculty Publications

Several large dsDNA-containing viruses such as poxviruses (smallpox) and herpes viruses are well known among the scientific community, as well as the general populace, because they cause human diseases. The large dsDNA insect-infecting baculoviruses are also well known in the scientific community because they are used both as biological control agents and as protein expression systems. However, there are other large dsDNA-containing viruses, including the giant 1.2-Mb mimivirus, which are less well known even though all of them play important roles in everyday life. Seven of these virus families are reviewed in this book.


The Phycodnaviridae: The Story Of How Tiny Giants Rule The World, W. H. Wilson, James L. Van Etten, M. J. Allen Jan 2009

The Phycodnaviridae: The Story Of How Tiny Giants Rule The World, W. H. Wilson, James L. Van Etten, M. J. Allen

Department of Plant Pathology: Faculty Publications

The family Phycodnaviridae encompasses a diverse and rapidly expanding collection of large icosahedral, dsDNA viruses that infect algae. These lytic and lysogenic viruses have genomes ranging from 160 to 560 kb. The family consists of six genera based initially on host range and supported by sequence comparisons. The family is monophyletic with branches for each genus, but the phycodnaviruses have evolutionary roots that connect them with several other families of large DNA viruses, referred to as the nucleocytoplasmic large DNA viruses (NCLDV).The phycodnaviruses have diverse genome structures, some with large regions of noncoding sequence and others with regions of ssDNA. …


Histone H3 Phosphorylation: Universal Code Or Lineage Specific Dialects?, Heriberto Cerutti, J. Armando Casas-Mollano Jan 2009

Histone H3 Phosphorylation: Universal Code Or Lineage Specific Dialects?, Heriberto Cerutti, J. Armando Casas-Mollano

Center for Plant Science Innovation: Faculty and Staff Publications

Post-translational modifications of histones modulate the functional landscape of chromatin and impinge on many DNA-mediated processes. Phosphorylation of histone H3 plays a role in the regulation of gene expression and in chromosome condensation/segregation. Certain evolutionarily conserved residues on histone H3—namely Thr3, Ser10, Thr11, and Ser28—are phosphorylated during interphase or mitosis in both metazoa and plants. However, many of the kinases involved in these events appear to have evolved independently in different lineages. Likewise, the mechanistic function of specific phosphorylated amino acids, although poorly understood, also seems to differ among eukaryotes. Moreover, some modifications, such as phosphorylation of histone H3 Ser10, …


Good Agricultural And Handling Practices For Grapes And Other Fresh Produce, Pamela L. Brady, Justin R. Morris Jan 2009

Good Agricultural And Handling Practices For Grapes And Other Fresh Produce, Pamela L. Brady, Justin R. Morris

Research Reports and Research Bulletins

In recent years consumption of fresh fruits and vegetables has increased dramatically. This trend has increased the amount of produce being purchased at farmer’s markets, road-side stands, and neighborhood markets since consumers say they feel that the direct contact with growers at these markets makes them better able to assess the quality and safety of the produce. This buying trend has opened new markets to small- and medium-sized farms, which sell at these local outlets.


Role Of P33 In Tombusvirus Replication, Jozsef Stork Jan 2009

Role Of P33 In Tombusvirus Replication, Jozsef Stork

University of Kentucky Doctoral Dissertations

Replication of the nonsegmented, plus-stranded RNA genome of Cucumber necrosis tombusvirus (CNV) requires two essential overlapping viral-coded replication proteins, the p33 replication co-factor and the p92 RNA-dependent RNA polymerase. In my thesis I describe (i) the effect of phosphorylation of p33, (ii) the RNA chaperone-like activity of p33, and (iii) the role of HSP70s a host proteins in the viral replication. To test the effect of phosphorylation on p33 function, I used in vitro phosphorylated p33. I found that phosphorylation inhibited the ability of p33 to bind to the viral RNA. Phosphorylation-mimicking mutations rendered p33 nonfunctional in plant protoplasts and …


Identification And Characterization Of Host Factors Involved In Tombusvirus Replication, Yi Jiang Jan 2009

Identification And Characterization Of Host Factors Involved In Tombusvirus Replication, Yi Jiang

University of Kentucky Doctoral Dissertations

Positive strand RNA viruses are intracellular parasites, and their genome replication and infection involves complex virus-host interactions. Therefore, identification of host factors and dissection of their functions during virus replication could facilitate our understanding of the mechanism of virus infection. Those host factors may also provide new targets for viral disease control. Tomato bushy stunt virus (TBSV) has recently become one of the model viruses to study positive strand RNA virus replication and hostvirus interactions. To identify host factors involved in TBSV replication we used yeast as a model host. Co-expression of the replication proteins and a replicon RNA (DI …


Oxygenase Coordination Is Required For Morphological Transition And The Host-Fungus Interaction Of Aspergillus Flavus, Sigal Horowitz Brown, James B. Scott, Jeyanthi Bhaheetharan, William C. Sharpee, Lane Milde, Richard A. Wilson Jan 2009

Oxygenase Coordination Is Required For Morphological Transition And The Host-Fungus Interaction Of Aspergillus Flavus, Sigal Horowitz Brown, James B. Scott, Jeyanthi Bhaheetharan, William C. Sharpee, Lane Milde, Richard A. Wilson

Fungal Molecular Plant-Microbe Interactions

Oxylipins, a class of oxygenase-derived unsaturated fatty acids, are important signal molecules in many biological systems. Recent characterization of an Aspergillus flavus lipoxygenase gene, lox, revealed its importance in maintaining a density-dependent morphology switch from sclerotia to conidia as population density increased. Here, we present evidence for the involvement of four more oxylipingenerating dioxygenases (PpoA, PpoB, PpoC, and PpoD) in A. flavus density-dependent phenomena and the effects of loss of these genes on aflatoxin production and seed colonization. Although several single mutants showed alterations in the sclerotia-to-conidia switch, the major effect was observed in a strain downregulated for all …


Under Pressure: Investigating The Biology Of Plant Infection By Magnaporthe Oryza, Nicholas J. Talbot, Richard A. Wilson Jan 2009

Under Pressure: Investigating The Biology Of Plant Infection By Magnaporthe Oryza, Nicholas J. Talbot, Richard A. Wilson

Fungal Molecular Plant-Microbe Interactions

The filamentous fungus Magnaporthe oryzae causes rice blast, the most serious disease of cultivated rice. Cellular differentiation of M. oryzae forms an infection structure called the appressorium, which generates enormous cellular turgor that is sufficient to rupture the plant cuticle. Here, we show how functional genomics approaches are providing new insight into the genetic control of plant infection by M. oryzae. We also look ahead to the key questions that need to be addressed to provide a better understanding of the molecular processes that lead to plant disease and the prospects for sustainable control of rice blast.


First Report Of Sweet Wormwood Leaf Blight Disease In India, Kunal Mandal Jan 2009

First Report Of Sweet Wormwood Leaf Blight Disease In India, Kunal Mandal

Kunal Mandal

Artemisia annua is an important drug plant yielding antimalarial compounds. It was found to be infected by Alternaria alternata in India. The pathogen reduces active leaf area and is also known to produce mycotoxins. Hence, the disease demands serious attention to ensure the availability of a safe drug.


Towards Elimination And Genetic Manipulation Of Ergot Alkaloid Production In Fungal Endophytes, Simona Florea Jan 2009

Towards Elimination And Genetic Manipulation Of Ergot Alkaloid Production In Fungal Endophytes, Simona Florea

University of Kentucky Doctoral Dissertations

Clavicipitaceous fungal endophytes provide several ecological benefits to their hosts. Besides improving host’s growth characteristics, Neotyphodium coenophialum, the endophyte of tall fescue (Lolium arundinaceum), produces ergot alkaloids that have been proposed to be involved in fescue toxicosis. One approach to address the toxicosis problem is to genetically manipulate and modify N. coenophialum by knocking out a pair of homologous genes, (dmaW1 and dmaW2), encoding dimethylallyltryptophan synthase, the enzyme for the first and determinant step in ergot-alkaloid biosynthesis. In this study, disruption of dmaW2 was attempted using several disruption methods. Out of 1522 transformants screened, three …


Plant-Microbes Interactions In Enhanced Fertilizer-Use Efficiency, Anthony O. Adesemoye, Joseph W. Kloepper Jan 2009

Plant-Microbes Interactions In Enhanced Fertilizer-Use Efficiency, Anthony O. Adesemoye, Joseph W. Kloepper

Department of Plant Pathology: Faculty Publications

The continued use of chemical fertilizers and manures for enhanced soil fertility and crop productivity often results in unexpected harmful environmental effects, including leaching of nitrate into groundwater, surface runoff of phosphorus and nitrogen runoff, and eutrophication of aquatic ecosystems. Integrated nutrient management systems are needed to maintain agricultural productivity and protect the environment. Microbial inoculants are promising components of such management systems. This review is a critical summary of the efforts in using microbial inoculants, including plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi for increasing the use efficiency of fertilizers. Studies with microbial inoculants and nutrients have demonstrated that …


Chlorella Virus Atcv-1 Encodes A Functional Potassium Channel Of 82 Amino Acids, Sabrina Gazzarrini, Ming Kang, Alessandra Abenavoli, Giulia Romani, Claudio Olivari, Daniele Gaslini, Giuseppina Ferrara, James L. Van Etten, Michael Kreim, Stefan M. Kast, Gerhard Thiel, Anna Moroni Jan 2009

Chlorella Virus Atcv-1 Encodes A Functional Potassium Channel Of 82 Amino Acids, Sabrina Gazzarrini, Ming Kang, Alessandra Abenavoli, Giulia Romani, Claudio Olivari, Daniele Gaslini, Giuseppina Ferrara, James L. Van Etten, Michael Kreim, Stefan M. Kast, Gerhard Thiel, Anna Moroni

Department of Plant Pathology: Faculty Publications

Chlorella virus PBCV-1 (Paramecium bursaria chlorella virus-1) encodes the smallest protein (94 amino acids, named Kcv) previously known to form a functional K+ channel in heterologous systems. In this paper, we characterize another chlorella virus encoded K+ channel protein (82 amino acids, named ATCV-1 Kcv) that forms a functional channel in Xenopus oocytes and rescues Saccharomyces cerevisiae mutants that lack endogenous K+ uptake systems. Compared with the larger PBCV-1 Kcv, ATCV-1 Kcv lacks a cytoplasmic N-terminus and has a reduced number of charged amino acids in its turret domain. Despite these deficiencies, ATCV-1 Kcv accomplishes all the major features of …


Symbiotic Effects Of The Fungus Glomus Sp. On Chromium(Iii), Chromium(Vi), And Lead(Ii) Uptake By Mesquite (Prosopis Sp.): A Novel Method To Remediate Heavy Metals, Jack A. Arias Jan 2009

Symbiotic Effects Of The Fungus Glomus Sp. On Chromium(Iii), Chromium(Vi), And Lead(Ii) Uptake By Mesquite (Prosopis Sp.): A Novel Method To Remediate Heavy Metals, Jack A. Arias

Open Access Theses & Dissertations

The indiscriminate disposal of lead (Pb) and chromium (Cr) containing wastes has resulted in a detrimental impact on environmental health. Lead and Cr are in the EPA priority list due to their degree of toxicity on humans, animals, plants, and other living organisms. The removal of toxic wastes involves technologies that are expensive, sometimes incomplete, and could represent health hazards. In addition, site restoration after contaminant removal encompasses time and technological resources. Phytoremediation, the use of plants alone or associated with microorganisms, represents a potentially cost-effective option in the long term management of contaminated sites. Various plants known as "hyperaccumulators" …


Choline-Utilizing Microblal Strains For Biologically Controlling Fusarium Head Blight, David A. Schisler, Naseem I. Khan, Michael J. Boehm, Patricia J. Slininger Jan 2009

Choline-Utilizing Microblal Strains For Biologically Controlling Fusarium Head Blight, David A. Schisler, Naseem I. Khan, Michael J. Boehm, Patricia J. Slininger

Department of Plant Pathology: Faculty Publications

Three choline utilizing strains of microorganisms isolated from the anthers of wheat, Aureobasidium pullulans strainAS 55.2, Arthrobacter species strain OH 221.3, and Pseudomonas species strain AS 64.4, are superior antagonists of F. graminearum. These microorganisms are effective for suppression and control of FHB in cereals, particularly in wheat and barley.


Intergenic Transcription By Rna Polymerase Ii Coordinates Pol Iv And Pol V In Sirna-Directed Transcriptional Gene Silencing In Arabidopsis, Binglian Zheng, Zhengming Wang, Shengben Li, Bin Yu, Jin -Yuan Liu, Xuemei Chen Jan 2009

Intergenic Transcription By Rna Polymerase Ii Coordinates Pol Iv And Pol V In Sirna-Directed Transcriptional Gene Silencing In Arabidopsis, Binglian Zheng, Zhengming Wang, Shengben Li, Bin Yu, Jin -Yuan Liu, Xuemei Chen

Center for Plant Science Innovation: Faculty and Staff Publications

Intergenic transcription by RNA Polymerase II (Pol II) is widespread in plant and animal genomes, but the functions of intergenic transcription or the resulting noncoding transcripts are poorly understood. Here, we show that Arabidopsis Pol II is indispensable for endogenous siRNA-mediated transcriptional gene silencing (TGS) at intergenic low-copy-number loci, despite the presence of two other polymerases—Pol IV and Pol V—that specialize in TGS through siRNAs. We show that Pol II produces noncoding scaffold transcripts that originate outside of heterochromatic, siRNA-generating loci. Through these transcripts and physical interactions with the siRNA effector protein ARGONAUTE4 (AGO4), Pol II recruits AGO4/siRNAs to homologous …


Roadmap For Future Research On Plant Pathogen Effectors, James R. Alfano Jan 2009

Roadmap For Future Research On Plant Pathogen Effectors, James R. Alfano

Center for Plant Science Innovation: Faculty and Staff Publications

Bacterial and eukaryotic plant pathogens deliver effector proteins into plant cells to promote pathogenesis. Bacterial pathogens containing type III protein secretion systems are known to inject many of these effectors into plant cells. More recently, oomycete pathogens have been shown to possess a large family of effectors containing the RXLR motif, and many effectors are also being discovered in fungal pathogens. Although effector activities are largely unknown, at least a subset suppress plant immunity. A plethora of new plant pathogen genomes that will soon be available thanks to next-generation sequencing technologies will allow the identification of many more effectors. This …


Accumulation Of A 5′ Proximal Subgenomic Rna Of Citrus Tristeza Virus Is Correlated With Encapsidation By The Minor Coat Protein, Siddarame Gowda, Satyanarayana Tatineni, Svetlana Y. Folimonova, Mark E. Hilf, William O. Dawson Jan 2009

Accumulation Of A 5′ Proximal Subgenomic Rna Of Citrus Tristeza Virus Is Correlated With Encapsidation By The Minor Coat Protein, Siddarame Gowda, Satyanarayana Tatineni, Svetlana Y. Folimonova, Mark E. Hilf, William O. Dawson

Department of Plant Pathology: Faculty Publications

During replication, Citrus tristeza virus (CTV) produces large amounts of two unusual subgenomic (sg) RNAs that are positive-stranded and 5′ coterminal. Although these RNAs are produced in similar amounts and are similar in size, with LMT1 (~750 nt) only slightly larger than LMT2 (~650), we found that the similar sgRNAs are produced differently. We previously showed that the LMT1 RNA is produced by premature termination during genomic RNA synthesis. However, LMT2 production was found to correlate with virion assembly instead of RNA replication. The time course of accumulation of the LMT2 RNA occurred late, coinciding with virion accumulation. The long …


Protein-Protein Interactions Of Tandem Affinity Purified Protein Kinases From Rice, Jai S. Rohila, Mei Chen, Shuo Chen, Johann Chen, Ronald L. Cerny, Christopher Dardick, Patrick Canlas, Hiroaki Fujii, Michael Gribskov, Siddhartha Kanrar, Lucas Knoflicek, Becky Stevenson, Mingtang Xie, Xia Xu, Xianwu Zheng, Jing-Kang Zhu, Pamela Ronald, Michael E. Fromm Jan 2009

Protein-Protein Interactions Of Tandem Affinity Purified Protein Kinases From Rice, Jai S. Rohila, Mei Chen, Shuo Chen, Johann Chen, Ronald L. Cerny, Christopher Dardick, Patrick Canlas, Hiroaki Fujii, Michael Gribskov, Siddhartha Kanrar, Lucas Knoflicek, Becky Stevenson, Mingtang Xie, Xia Xu, Xianwu Zheng, Jing-Kang Zhu, Pamela Ronald, Michael E. Fromm

Center for Plant Science Innovation: Faculty and Staff Publications

Eighty-eight rice (Oryza sativa) cDNAs encoding rice leaf expressed protein kinases (PKs) were fused to a Tandem Affinity Purification tag (TAP-tag) and expressed in transgenic rice plants. The TAP-tagged PKs and interacting proteins were purified from the T1 progeny of the transgenic rice plants and identified by tandem mass spectrometry. Forty-five TAPtagged PKs were recovered in this study and thirteen of these were found to interact with other rice proteins with a high probability score. In vivo phosphorylated sites were found for three of the PKs. A comparison of the TAP-tagged data from a combined analysis of 129 …


Fungal Physiology: A Future Perspective, Richard A. Wilson, Nicholas J. Talbot Jan 2009

Fungal Physiology: A Future Perspective, Richard A. Wilson, Nicholas J. Talbot

Fungal Molecular Plant-Microbe Interactions

The study of fungal physiology is set to change dramatically in the next few years as highly scalable technologies are deployed allowing accurate measurement and identification of metabolites, proteins and transcripts within cells. The advent of next-generation DNA-sequencing technologies will also provide genome sequence information from large numbers of industrially relevant and pathogenic fungal species, and allow comparative genome analysis between strains and populations of fungi. When coupled with advances in gene functional analysis, protein-protein interaction studies, live cell imaging and mathematical modelling, this promises a step-change in our understanding of how fungal cells operate as integrated dynamic living systems