Open Access. Powered by Scholars. Published by Universities.®

Plant Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 10 of 10

Full-Text Articles in Plant Sciences

Mono- And Digalactosyldiacylglycerol Lipids Function Nonredundantly To Regulate Systemic Acquired Resistance In Plants, Qing-Ming Gao, Keshun Yu, Ye Xia, M. B. Shine, Caixia Wang, Duroy Navarre, Aardra Kachroo, Pradeep Kachroo Dec 2014

Mono- And Digalactosyldiacylglycerol Lipids Function Nonredundantly To Regulate Systemic Acquired Resistance In Plants, Qing-Ming Gao, Keshun Yu, Ye Xia, M. B. Shine, Caixia Wang, Duroy Navarre, Aardra Kachroo, Pradeep Kachroo

Plant Pathology Faculty Publications

The plant galactolipids monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) have been linked to the anti-inflammatory and cancer benefits of a green leafy vegetable diet in humans due to their ability to regulate the levels of free radicals like nitric oxide (NO). Here, we show that DGDG contributes to plant NO as well as salicylic acid biosynthesis and is required for the induction of systemic acquired resistance (SAR). In contrast, MGDG regulates the biosynthesis of the SAR signals azelaic acid (AzA) and glycerol-3-phosphate (G3P) that function downstream of NO. Interestingly, DGDG is also required for AzA-induced SAR, but MGDG is not. Notably, …


Co-Opted Oxysterol-Binding Orp And Vap Proteins Channel Sterols To Rna Virus Replication Sites Via Membrane Contact Sites, Daniel Barajas, Kai Xu, Isabel Fernández De Castro Martín, Zsuzsanna Sasvari, Federica Brandizzi, Cristina Risco, Peter D. Nagy Oct 2014

Co-Opted Oxysterol-Binding Orp And Vap Proteins Channel Sterols To Rna Virus Replication Sites Via Membrane Contact Sites, Daniel Barajas, Kai Xu, Isabel Fernández De Castro Martín, Zsuzsanna Sasvari, Federica Brandizzi, Cristina Risco, Peter D. Nagy

Plant Pathology Faculty Publications

Viruses recruit cellular membranes and subvert cellular proteins involved in lipid biosynthesis to build viral replicase complexes and replication organelles. Among the lipids, sterols are important components of membranes, affecting the shape and curvature of membranes. In this paper, the tombusvirus replication protein is shown to co-opt cellular Oxysterol-binding protein related proteins (ORPs), whose deletion in yeast model host leads to decreased tombusvirus replication. In addition, tombusviruses also subvert Scs2p VAP protein to facilitate the formation of membrane contact sites (MCSs), where membranes are juxtaposed, likely channeling lipids to the replication sites. In all, these events result in redistribution and …


A Novel Partitivirus That Confers Hypovirulence On Plant Pathogenic Fungi, Xueqiong Xiao, Jiasen Cheng, Jinghua Tang, Yanping Fu, Daohong Jiang, Timothy S. Baker, Said A. Ghabrial, Jiatao Xie Sep 2014

A Novel Partitivirus That Confers Hypovirulence On Plant Pathogenic Fungi, Xueqiong Xiao, Jiasen Cheng, Jinghua Tang, Yanping Fu, Daohong Jiang, Timothy S. Baker, Said A. Ghabrial, Jiatao Xie

Plant Pathology Faculty Publications

Members of the family Partitiviridae have bisegmented double-stranded RNA (dsRNA) genomes and are not generally known to cause obvious symptoms in their natural hosts. An unusual partitivirus, Sclerotinia sclerotiorum partitivirus 1 (SsPV1/WF-1), conferred hypovirulence on its natural plant-pathogenic fungal host, Sclerotinia sclerotiorum strain WF-1. Cellular organelles, including mitochondria, were severely damaged. Hypovirulence and associated traits of strain WF-1 and SsPV1/WF-1 were readily cotransmitted horizontally via hyphal contact to different vegetative compatibility groups of S. sclerotiorum and interspecifically to Sclerotinia nivalis and Sclerotinia minor. S. sclerotiorum strain 1980 transfected with purified SsPV1/WF-1 virions also exhibited hypovirulence and associated traits similar …


Tombusvirus-Yeast Interactions Identify Conserved Cell-Intrinsic Viral Restriction Factors, Zsuzsanna Sasvari, Paulina Alatriste Gonzalez, Peter D. Nagy Aug 2014

Tombusvirus-Yeast Interactions Identify Conserved Cell-Intrinsic Viral Restriction Factors, Zsuzsanna Sasvari, Paulina Alatriste Gonzalez, Peter D. Nagy

Plant Pathology Faculty Publications

To combat viral infections, plants possess innate and adaptive immune pathways, such as RNA silencing, R gene and recessive gene-mediated resistance mechanisms. However, it is likely that additional cell-intrinsic restriction factors (CIRF) are also involved in limiting plant virus replication. This review discusses novel CIRFs with antiviral functions, many of them RNA-binding proteins or affecting the RNA binding activities of viral replication proteins. The CIRFs against tombusviruses have been identified in yeast (Saccharomyces cerevisiae), which is developed as an advanced model organism. Grouping of the identified CIRFs based on their known cellular functions and subcellular localization in yeast …


The Hop-Like Stress-Induced Protein 1 Cochaperone Is A Novel Cell-Intrinsic Restriction Factor For Mitochondrial Tombusvirus Replication, Kai Xu, Jing-Yi Lin, Peter D. Nagy Aug 2014

The Hop-Like Stress-Induced Protein 1 Cochaperone Is A Novel Cell-Intrinsic Restriction Factor For Mitochondrial Tombusvirus Replication, Kai Xu, Jing-Yi Lin, Peter D. Nagy

Plant Pathology Faculty Publications

Recent genome-wide screens reveal that the host cells express an arsenal of proteins that inhibit replication of plus-stranded RNA viruses by functioning as cell-intrinsic restriction factors of viral infections. One group of cell-intrinsic restriction factors against tombusviruses contains tetratricopeptide repeat (TPR) domains that directly interact with the viral replication proteins. In this paper, we find that the TPR domain-containing Hop-like stress-inducible protein 1 (Sti1p) cochaperone selectively inhibits the mitochondrial membrane-based replication of Carnation Italian ringspot tombusvirus (CIRV). In contrast, Sti1/Hop does not inhibit the peroxisome membrane-based replication of the closely related Tomato bushy stunt virus (TBSV) or Cucumber necrosis virus …


Cell Type-Dependent Rna Recombination Frequency In The Japanese Encephalitis Virus, Wei-Wei Chiang, Chingkai Chuang, Mei Chao, Wei-June Chen Jul 2014

Cell Type-Dependent Rna Recombination Frequency In The Japanese Encephalitis Virus, Wei-Wei Chiang, Chingkai Chuang, Mei Chao, Wei-June Chen

Plant Pathology Faculty Publications

Japanese encephalitis virus (JEV) is one of approximately 70 flaviviruses, frequently causing symptoms involving the central nervous system. Mutations of its genomic RNA frequently occur during viral replication, which is believed to be a force contributing to viral evolution. Nevertheless, accumulating evidences show that some JEV strains may have actually arisen from RNA recombination between genetically different populations of the virus. We have demonstrated that RNA recombination in JEV occurs unequally in different cell types. In the present study, viral RNA fragments transfected into as well as viral RNAs synthesized in mosquito cells were shown not to be stable, especially …


Noncanonical Role For The Host Vps4 Aaa+ Atpase Escrt Protein In The Formation Of Tomato Bushy Stunt Virus Replicase, Daniel Barajas, Isabel Fernández De Castro Martín, Judit Pogany, Cristina Risco, Peter D. Nagy Apr 2014

Noncanonical Role For The Host Vps4 Aaa+ Atpase Escrt Protein In The Formation Of Tomato Bushy Stunt Virus Replicase, Daniel Barajas, Isabel Fernández De Castro Martín, Judit Pogany, Cristina Risco, Peter D. Nagy

Plant Pathology Faculty Publications

Assembling of the membrane-bound viral replicase complexes (VRCs) consisting of viral- and host-encoded proteins is a key step during the replication of positive-stranded RNA viruses in the infected cells. Previous genome-wide screens with Tomato bushy stunt tombusvirus (TBSV) in a yeast model host have revealed the involvement of eleven cellular ESCRT (endosomal sorting complexes required for transport) proteins in viral replication. The ESCRT proteins are involved in endosomal sorting of cellular membrane proteins by forming multiprotein complexes, deforming membranes away from the cytosol and, ultimately, pinching off vesicles into the lumen of the endosomes. In this paper, we show an …


The Expanding Functions Of Cellular Helicases: The Tombusvirus Rna Replication Enhancer Co-Opts The Plant Eif4aiii-Like Atrh2 And The Ddx5-Like Atrh5 Dead-Box Rna Helicases To Promote Viral Asymmetric Rna Replication, Nikolay Kovalev, Peter D. Nagy Apr 2014

The Expanding Functions Of Cellular Helicases: The Tombusvirus Rna Replication Enhancer Co-Opts The Plant Eif4aiii-Like Atrh2 And The Ddx5-Like Atrh5 Dead-Box Rna Helicases To Promote Viral Asymmetric Rna Replication, Nikolay Kovalev, Peter D. Nagy

Plant Pathology Faculty Publications

Replication of plus-strand RNA viruses depends on recruited host factors that aid several critical steps during replication. Several of the co-opted host factors bind to the viral RNA, which plays multiple roles, including mRNA function, as an assembly platform for the viral replicase (VRC), template for RNA synthesis, and encapsidation during infection. It is likely that remodeling of the viral RNAs and RNA-protein complexes during the switch from one step to another requires RNA helicases. In this paper, we have discovered a second group of cellular RNA helicases, including the eIF4AIII-like yeast Fal1p and the DDX5-like Dbp3p and the orthologous …


Characterization Of Glomerella Strains Recovered From Anthracnose Lesions On Common Bean Plants In Brazil, Quélen L. Barcelos, Joyce M.A. Pinto, Lisa J. Vaillancourt, Elaine A. Souza Mar 2014

Characterization Of Glomerella Strains Recovered From Anthracnose Lesions On Common Bean Plants In Brazil, Quélen L. Barcelos, Joyce M.A. Pinto, Lisa J. Vaillancourt, Elaine A. Souza

Plant Pathology Faculty Publications

Anthracnose caused by Colletotrichum lindemuthianum is an important disease of common bean, resulting in major economic losses worldwide. Genetic diversity of the C. lindemuthianum population contributes to its ability to adapt rapidly to new sources of host resistance. The origin of this diversity is unknown, but sexual recombination, via the Glomerella teleomorph, is one possibility. This study tested the hypothesis that Glomerella strains that are frequently recovered from bean anthracnose lesions represent the teleomorph of C. lindemuthianum. A large collection of Glomerella isolates could be separated into two groups based on phylogenetic analysis, morphology, and pathogenicity to beans. Both …


Inactivation Of The Host Lipin Gene Accelerates Rna Virus Replication Through Viral Exploitation Of The Expanded Endoplasmic Reticulum Membrane, Chingkai Chuang, Daniel Barajas, Jun Qin, Peter D. Nagy Feb 2014

Inactivation Of The Host Lipin Gene Accelerates Rna Virus Replication Through Viral Exploitation Of The Expanded Endoplasmic Reticulum Membrane, Chingkai Chuang, Daniel Barajas, Jun Qin, Peter D. Nagy

Plant Pathology Faculty Publications

RNA viruses take advantage of cellular resources, such as membranes and lipids, to assemble viral replicase complexes (VRCs) that drive viral replication. The host lipins (phosphatidate phosphatases) are particularly interesting because these proteins play key roles in cellular decisions about membrane biogenesis versus lipid storage. Therefore, we examined the relationship between host lipins and tombusviruses, based on yeast model host. We show that deletion of PAH1 (phosphatidic acid phosphohydrolase), which is the single yeast homolog of the lipin gene family of phosphatidate phosphatases, whose inactivation is responsible for proliferation and expansion of the endoplasmic reticulum (ER) membrane, facilitates robust RNA …