Ed Stover

Ed Stover
United States Department of Agriculture | USDA · Agricultural Research Service (ARS)

PhD

About

220
Publications
56,194
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3,227
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Publications

Publications (220)
Article
Full-text available
Plants have a perception system triggered by pathogen and pest signals to initiate defense. These signals include evolutionarily conserved molecules from microbes and insects termed pathogen/herbivore-associated molecular patterns (PAMPs/HAMPs). Here we showed that hexaacetyl-chitohexaose (HC), an oligosaccharide from chitin, a structural component...
Article
Full-text available
Background Citrus Huanglongbing (HLB) is a bacterial disease with high economic significance. The associated agent Candidatus Liberibacter asiaticus is a fastidious, phloem-limited, intracellular bacterium that is transmitted by an insect vector the Asian citrus psyllid (ACP). The genome of Ca. L. asiaticus contains protein secretion machinery that...
Article
Full-text available
Citrus volatiles and their breakdown products, such as formic and acetic acids, guide host finding by Asian citrus psyllids (Diaphorina citri). Formic acid elicits psyllid antennal responses and stimulates probing. This study investigated how exposure to vapor phase formic acid induced changes in plant volatile emissions, expression of plant defens...
Article
The primary objective of this experiment was to determine if the selection of rootstock ( Citrus and hybrids) could enhance the development of huanglongbing (HLB)-related symptoms associated with the pathogen Candidatus Liberibacter asiaticus (CLas) in sweet orange ( Citrus sinensis ). If so, then it may permit more rapid identification of HLB-susc...
Article
Full-text available
Huanglongbing (HLB), or citrus greening, is the most devastating disease in citrus worldwide. Commercial citrus varieties including sweet orange (Citrus sinensis) are highly susceptible to HLB, and trifoliate orange (Poncirus trifoliata, a close Citrus relative) is widely considered resistant or highly tolerant to HLB. In this study, an intergeneri...
Data
Collinear analysis of consensus between genetic linkage maps and reference genome by dot-plot diagram.
Data
Full genetic linkage maps and genome-wide LOD score graphics of QTL mapping of two phenotypic traits.
Data
Summary of Genotyping by Sequencing for 170 F1 progenies and four parental varieties.
Data
Diagnosis of CLas infection by real-time qPCR in 86 F1 progenies and nine control varieties.
Data
Analysis of parental genotypes and distribution of SNP loci on reference genome in four parental varieties.
Data
Phenotypic data of two traits for the evaluation of HLB disease in 86 F1 progenies and nine control varieties.
Preprint
Full-text available
No true resistance to Huanglongbing (HLB), a citrus disease associated with infection of Candidatus Liberibacter asiaticus ( C Las), is found within commercial citrus cultivars, though trifoliate orange ( Poncirus trifoliata ) has been described as resistant or tolerant. Through genotyping an intergeneric F 1 population by Genotyping-by-Sequencing,...
Article
Full-text available
Background and Significance: Foliar trichomes (tiny hair‑like structures) are part of the plant defense mechanisms that may confer resistance to some herbivore pests. Trifoliate orange, Poncirus trifoliata, is a genotype resistant to infestations by the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), vector of the economically importa...
Article
Full-text available
Citrus germplasm is conserved in genebanks at sites around the world to provide genetic resources for breeding and research programs. The value of genebank collections is particularly evident as diseases and climate change threaten citrus production areas. We provide historical, inventory, and maintenance information about national citrus collectio...
Article
Full-text available
Background and Significance Foliar trichomes (tiny hair-like structures) are part of the plant defense mechanisms that may confer resistance to some herbivore pests. Trifoliate orange, Poncirus trifoliata, is a genotype resistant to infestations by the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), vector of the economically importan...
Article
Full-text available
Citrus Huanglongbing (HLB) associated with ‘Candidatus Liberibacter asiaticus’ (Las) and citrus canker disease incited by Xanthomonas citri are the most devastating citrus diseases worldwide. To control citrus HLB and canker disease, we previously screened over forty antimicrobial peptides (AMPs) in vitro for their potential application in genetic...
Data
Las detection from leaves and roots in control plants and transgenic plants of Carrizo expressing D2A21 nine months after grafting with Las-infected rough lemon. (PDF)
Data
Confirmation of D2A21 insertion in transgenic tobacco plants by PCR. Total DNA from transgenic plants was amplified with primers designed to span from within the D35S promoter through the Nos terminator regions. M: DNA molecular ladder; P: positive control with plasmid carrying D2A21; N: nontransformed control plant; G: negative control with gus am...
Data
PCR confirmation of D2A21 insertion in transgenic Carrizo. Total DNA from transgenic plants was amplified with primers designed to span from within the D35S promoter through the Nos terminator regions. M: DNA molecular ladder; P: positive control with plasmid carrying D2A21; W: water control; N: nontransformed control plant; Lanes 5–29: independent...
Article
The 22-amino acid (flg22) pathogen-associated molecular pattern from the flagellin of Xanthomonas citri subsp. citri has been shown to induce defense responses correlated with citrus canker resistance. Here, flg22 of 'Candidatus Liberibacter asiaticus', the putative causal agent of Huanglongbing (HLB), elicited differential defense responses that w...
Article
Full-text available
Identification of genes with differential transcript abundance (GDTA) in seedless mutants may enhance understanding of seedless citrus development. Transcriptome analysis was conducted at three time points during early fruit development (Phase 1) of three seedy citrus genotypes: Fallglo (Bower citrus hybrid (Citrus reticulata×C. reticulata×C. parad...
Article
Full-text available
The Asian citrus psyllid (Hemiptera: Liviidae) transmits a bacterium responsible for huanglongbing, a serious citrus disease. Insecticidal control of the psyllid is a key tactic used to manage the disease, but host plant resistance may hold some promise and clues in the search for alternative tactics. Results of a field survey revealed that relativ...
Article
Avocado (Persea americana Mill.) is a high-value fruit that continues to increase in consumer demand. A population of ‘Hass’–‘Bacon’ hybrids was planted at USDAARS, Fort Pierce, as part of a study to find selections with good horticultural and postharvest quality traits for Florida. Extensive phenotypic data on quality were collected over 3 years....
Article
Full-text available
Foliar trichomes (tiny hair-like structures) are part of the plant defense mechanisms that may confer resistance to some herbivore pests. Trifoliate orange, Poncirus trifoliata, is a genotype resistant to infestations by the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), vector of the economically important citrus greening (huanglong...
Article
Full-text available
The level of anthocyanins in plants vary widely among cultivars, developmental stages and environmental stimuli. Previous studies have reported that the expression of various MYBs regulate anthocyanin pigmentation during growth and development. Here we examine the activity of three novel R2R3-MYB transcription factor (TF) genes, PamMybA.1, PamMybA....
Article
Full-text available
In a Fort Pierce, FL, field planting, plant growth, and Huanglongbing (HLB) severity were assessed as indicators of HLB tolerance on progenies of 83 seed-source accessions of Citrus and Citrus relatives mainly from the Riverside, CA, genebank. The HLB-associated pathogen [Candidatus Liberibacter asiaticus (CLas)] and vector [asian citrus psyllid (A...
Article
Bloom in individual citrus (Citrus) trees often continues for more than 1 month in south Florida, with even greater bloom duration within most orchard blocks because of variation in bloom timing between trees. Prolonged bloom contributes to variable fruit maturity as harvest approaches and increases severity of postbloom fruit drop (PFD) disease (c...
Article
Plants inoculated with the huanglongbing (HLB)-associated bacterium, Candidatus Liberibacter asiaticus (CLas) typically must be monitored for 8-10 months to identify differences in susceptibility between genotypes. Continuous light is reported to accelerate development of HLB symptoms and field observations suggest that trees girdled by tags or tre...
Article
Full-text available
Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the US citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an economically important disease associated with a bacterial path...
Article
Full-text available
Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the US citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an economically important disease associated with a bacterial path...
Data
Root Las detection using qPCR and HLB symptom in control plants and transgenic plants expressing Mthionin nine months after graft inoculation.
Data
Diagram for Mthionin construct in the binary vector pBinARS/Plus. Designations, LB is left border; Ubi3-p is ubiquitin promoter; NPTII is neomycin phosphotransferase gene (confers kanamycin resistance); Ubi3-t is ubiquitin terminator; D35S-p is double CaMV 35S promoter; Nos-t is nos terminator. RB, right border. Thin arrows indicate position of PCR...
Data
Las detection from leaves and roots in control plants and transgenic plants expressing Mthionin twelve months after graft inoculation.
Data
PCR amplification of Mthionin gene. Total DNA was amplified with primers designed spanning from within the D35S promoter to the 3′ end of the Nos terminator. M, DNA marker; P, Positive control using plasmid as template; W, Water as negative control; N, Non-transformed plant as negative control; Lane 1–15, Transgenic lines containing Mthionin.
Article
Assessments of the resistance of citrus germplasm to huanglongbing (HLB) can be expedited by inoculating plants under laboratory or greenhouse settings with the HLB bacterium, Candidatus Liberibacter asiaticus (CLas). Consistent rapid screening is critical to efficiently assess disease resistance among plant materials; however, a number of factors...
Article
Full-text available
Three citrus hybrids, containing 50% to 75% sweet orange (Citrus sinensis) genome in their pedigrees and similar to sweet orange in fruit size, color, and taste, were tested for their potential to be classified as new “sweet orange” cultivars. ‘Hamlin’, ‘Midsweet’, and three other early to midseason sweet oranges, along with ‘Dancy’ tangerine (Citr...
Article
Full-text available
Huanglongbing (HLB) is currently the most destructive disease of citrus worldwide. Although there is no immune cultivar, field tolerance to HLB within citrus and citrus relatives has been observed at the USDA Picos farm at Ft. Pierce, Florida, where plants have been exposed to a very high level of HLB pressure since 2006. In this study, we used RNA...
Data
Gene functional classification of DE genes using PageMan.
Data
Differentially expressed transcription factors.
Data
Overview of gene location mapped by RNA-Seq reads.
Data
Boxplot of gene read counts of six samples. (A) Raw data without normalization. (B) Normalization by DESeq.
Data
New gene models predicted from RNA-Seq data using PASA pipeline.
Data
Differentially expressed genes identified by DESeq.
Data
GO enrichment analysis of the DE genes.
Data
DE genes related to disease response identified by MapMan.
Data
DE genes validated using real time PCR.
Data
Differential alternative splicing events identified by rMAST.
Data
Genes with significantly differential isoform usage between HLB tolerant and susceptible citrus trees identified by IUTA.
Article
In vitro axillary shoot proliferation can be used to increase availability of citrus (Citrus) types in high demand, while limiting somaclonal variation. However, established protocols could be improved to increase efficiency. Therefore, this study investigated some factors [plant growth regulators (PGRs), basal media, and successive subculturing] w...
Article
Full-text available
Citrus huanglongbing (HLB) is a destructive disease with no known cure. To identify sources of HLB resistance in the subfamily Aurantioideae to which citrus belongs, we conducted a six-year field trial under natural disease challenge conditions in an HLB endemic region. The study included 65 Citrus accessions and 33 accessions belonging to 20 other...
Research
Full-text available
A test population of Citrus and Citrus Related genotypes were evaluated for cold tolerance in a Florida field planting.
Article
Full-text available
The citrus disease huanglongbing (HLB) has become endemic in Florida, with estimates that greater than 80% of citrus trees are currently infected. Although there are no commercial citrus varieties with strong HLB resistance, some field tolerance has been observed in trees exposed to the disease after they were mature. There is great urgency to iden...
Article
Full-text available
PROJECT SUMMARY Resistance or tolerance to huanglongbing (HLB) and other important traits have been identified in several citrus types and their relatives, and associated markers should be identified soon. What is urgently needed in addition is an accelerated strategy for citrus variety breeding. Identification and use of distant genes and traits i...
Article
The severe citrus (Citrus sp.) disease Huanglongbing (HLB), associated with Candidatus Liberibacter asiaticus, has resulted in widespread tree decline in Florida and overall citrus production is now the lowest it has been in 50 years. More than 80% of Florida citrus trees are HLB affected, and most growers attempt to sustain production on infected...
Article
Full-text available
Overexpression of plant pattern-recognition receptors (PRRs) by genetic engineering provides a novel approach to enhance plant immunity and broad-spectrum disease resistance. Citrus canker disease associated with Xanthomonas citri is one of the most important diseases damaging citrus production worldwide. In this study, we cloned the FLS2 gene from...