0000000000303632
AUTHOR
Russell L. Reagan
showing 8 related works from this author
Stress responses in citrus peel: Comparative analysis of host responses to Huanglongbing disease and puffing disorder
2015
Abstract A comparison between transcriptomic responses to puffing disorder and Huanglongbing disease was conducted to decipher differences and similarities in gene and pathway regulation induced by abiotic (puffing) and biotic stresses (Huanglongbing) in citrus peel tissues. We functionally analyzed two previously published datasets: the first obtained for the study of puffing disorder using an Affymetrix citrus microarray and the second consisting of a deep sequencing analysis of symptomatic responses to Huanglongbing disease. Transcriptomic data were mined using bioinformatic tools to highlight genes and pathways playing a key role in modulating responses to different types of stress in c…
Proteomic analysis highlights the role of detoxification pathways in increased tolerance to Huanglongbing disease.
2016
Background Huanglongbing (HLB) disease is still the greatest threat to citriculture worldwide. Although there is not any resistance source in the Citrus germplasm, a certain level of moderated tolerance is present. A large-scale analysis of proteomic responses of Citrus may help: 1) clarifying physiological and molecular effects of disease progression, 2) validating previous data at transcriptomic level, and 3) identifying biomarkers for development of early diagnostics, short-term therapeutics and long-term genetic resistance. Results In this work we have conducted a proteomic analysis of mature leaves of two Citrus genotypes with well-known differing tolerances to HLB: Navel orange (highl…
Analysis of Early Host Responses for Asymptomatic Disease Detection and Management of Specialty Crops
2010
The rapid and unabated spread of vector-borne diseases within US specialty crops threatens our agriculture, our economy, and the livelihood of growers and farm workers. Early detection of vector-borne pathogens is an essential step for the accurate surveillance and management of vector-borne diseases of specialty crops. Currently, we lack the tools that would detect the infectious agent at early (primary) stages of infection with a high degree of sensitivity and specificity. In this paper, we outline a strategy for developing an integrated suite of platform technologies to enable rapid, early disease detection and diagnosis of huanglongbing (HLB), the most destructive citrus disease. The re…
Transcriptome profiling of citrus fruit response to huanglongbing disease.
2010
Huanglongbing (HLB) or "citrus greening" is the most destructive citrus disease worldwide. In this work, we studied host responses of citrus to infection with Candidatus Liberibacter asiaticus (CaLas) using next-generation sequencing technologies. A deep mRNA profile was obtained from peel of healthy and HLB- affected fruit. It was followed by pathway and protein-protein network analysis and quantitative real time PCR analysis of highly regulated genes. We identified differentially regulated pathways and constructed networks that provide a deep insight into the metabolism of affected fruit. Data mining revealed that HLB enhanced transcription of genes involved in the light reactions of phot…
Molecular Responses to Small Regulating Molecules against Huanglongbing Disease
2016
Huanglongbing (HLB; citrus greening) is the most devastating disease of citrus worldwide. No cure is yet available for this disease and infected trees generally decline after several months. Disease management depends on early detection of symptoms and chemical control of insect vectors. In this work, different combinations of organic compounds were tested for the ability to modulate citrus molecular responses to HLB disease beneficially. Three small-molecule regulating compounds were tested: 1) L-arginine, 2) 6-benzyl-adenine combined with gibberellins, and 3) sucrose combined with atrazine. Each treatment contained K-phite mineral solution and was tested at two different concentrations. T…
Transcriptome and metabolome analysis of citrus fruit to elucidate puffing disorder.
2014
a b s t r a c t A systems-level analysis reveals details of molecular mechanisms underlying puffing disorder in Citrus fruit. Flavedo, albedo and juice sac tissues of normal fruits and fruits displaying symptoms of puffing disorder were studied using metabolomics at three developmental stages. Microarrays were used to compare normal and puffed fruits for each of the three tissues. A protein-protein interaction network inferred from previous work on Arabidopsis identified hub proteins whose transcripts show significant changes in expression. Glycolysis, the backbone of primary metabolism, appeared to be severely affected by the disorder, based on both transcriptomic and metabolomic results. …
Gene regulation in parthenocarpic tomato fruit.
2009
Parthenocarpy is potentially a desirable trait for many commercially grown fruits if undesirable changes to structure, flavour, or nutrition can be avoided. Parthenocarpic transgenic tomato plants (cv MicroTom) were obtained by the regulation of genes for auxin synthesis (iaaM) or responsiveness (rolB) driven by DefH9 or the INNER NO OUTER (INO) promoter from Arabidopsis thaliana. Fruits at a breaker stage were analysed at a transcriptomic and metabolomic level using microarrays, real-time reverse transcription-polymerase chain reaction (RT-PCR) and a Pegasus III TOF (time of flight) mass spectrometer. Although differences were observed in the shape of fully ripe fruits, no clear correlatio…
Gene regulatory networks elucidating Huanglongbing disease mechanisms
2013
Next-generation sequencing was exploited to gain deeper insight into the response to infection by Candidatus liberibacter asiaticus (CaLas), especially the immune disregulation and metabolic dysfunction caused by source-sink disruption. Previous fruit transcriptome data were compared with additional RNA-Seq data in three tissues: immature fruit, and young and mature leaves. Four categories of orchard trees were studied: symptomatic, asymptomatic, apparently healthy, and healthy. Principal component analysis found distinct expression patterns between immature and mature fruits and leaf samples for all four categories of trees. A predicted protein - protein interaction network identified HLB-…