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Li R, Du Y, Zhou Y, Ouyang Z. Identification of HSP70 genes in Diaphorina citri Kuwayama Reveals Their Involvement in Immunity and Development. Mol Biotechnol 2024:10.1007/s12033-024-01232-4. [PMID: 38940979 DOI: 10.1007/s12033-024-01232-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Accepted: 06/13/2024] [Indexed: 06/29/2024]
Abstract
Huanglongbing (HLB), a global citrus threat, is transmitted by Diaphorina citri Kuwayama, a widespread insect pest. The disease's rapid spread and incurability necessitate efficient, sustainable control strategies. This study investigates heat shock protein 70 (HSP70) genes in D. citri, known to play a pivotal role in insect survival and stress response. The genome-wide identification, gene structure analysis, and conserved protein domain analysis of 22 HSP70 genes in D. citri were performed. Furthermore, the expression of these genes during HLB infection or developmental processes was gauged. Phylogenetic analysis revealed the functional categorization of the identified genes, while gene structure and conserved motifs offered insights into gene function. The expression analysis unveiled dynamic profiles in response to infection and across development stages, potentially aiding future targeted pest control strategies. These findings offer promising leads for the design of novel inhibitors or RNAi strategies targeting D. citri and HLB.
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Affiliation(s)
- Ruimin Li
- College of Life Sciences, Gannan Normal University, Ganzhou, 341000, China.
| | - Yimin Du
- College of Life Sciences, Gannan Normal University, Ganzhou, 341000, China
- National Navel Orange Engineering Research Center, Ganzhou, 341000, China
| | - Yan Zhou
- College of Life Sciences, Gannan Normal University, Ganzhou, 341000, China
| | - Zhigang Ouyang
- College of Life Sciences, Gannan Normal University, Ganzhou, 341000, China
- National Navel Orange Engineering Research Center, Ganzhou, 341000, China
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2
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Pandey SS, Li J, Oswalt C, Wang N. Dynamics of ' Candidatus Liberibacter asiaticus' Growth, Concentrations of Reactive Oxygen Species, and Ion Leakage in Huanglongbing-Positive Sweet Orange. PHYTOPATHOLOGY 2024; 114:961-970. [PMID: 38478730 DOI: 10.1094/phyto-08-23-0294-kc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Citrus Huanglongbing (HLB) caused by 'Candidatus Liberibacter asiaticus' (CLas) is the most devastating citrus disease worldwide. CLas induces systemic and chronic reactive oxygen species (ROS) production, which has been suggested to be a primary cause of cell death in phloem tissues and subsequent HLB symptoms. Mitigating oxidative stress caused by CLas using horticultural approaches has been suggested as a useful strategy to reduce HLB damages. To provide information regarding the application timing to mitigate ROS, we investigated monthly dynamics of CLas concentration, CLas-triggered ROS, and phloem cell death in the bark tissues of asymptomatic and symptomatic branches of HLB-positive Hamlin and Valencia sweet orange trees in the field. Healthy branches in the screenhouse were used as controls. CLas concentration exhibited significant variations over the course of the year, with two distinct peaks observed in Florida citrus groves-late spring/early summer and late fall. Within both Hamlin and Valencia asymptomatic tissues, CLas concentration demonstrated a negative correlation with the deviation between the monthly average mean temperature and the optimal temperature for CLas colonization in plants (25.7°C). However, such a correlation was not evident in symptomatic tissues of Hamlin or Valencia sweet oranges. ROS levels were consistently higher in symptomatic or asymptomatic branches than in healthy branches in most months. ROS concentrations were higher in symptomatic branches than in asymptomatic branches in most months. CLas triggered significant increases in ion leakage in most months for asymptomatic and symptomatic branches compared with healthy controls. In asymptomatic branches of Hamlin, a positive correlation was observed between CLas concentration and ROS concentrations, CLas concentration and ion leakage levels, as well as ROS and ion leakage. Intriguingly, such a relationship was not observed in Valencia asymptomatic branches or in the symptomatic branches of Hamlin and Valencia. This study sheds light on the pathogenicity of CLas by providing useful information on the temporal dynamics of ROS production, phloem cell death, and CLas growth, as well as provides useful information in determining the timing for application of antioxidants and antimicrobial agents to control HLB.
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Affiliation(s)
- Sheo Shankar Pandey
- Citrus Research and Education Center (CREC), Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850, U.S.A
- Current affiliation: Life Sciences Division, Institute of Advanced Study in Science and Technology (IASST), Guwahati 781035, India
| | - Jinyun Li
- Citrus Research and Education Center (CREC), Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850, U.S.A
| | - Chris Oswalt
- Institute of Food and Agricultural Sciences, University of Florida, Bartow, FL 33830, U.S.A
| | - Nian Wang
- Citrus Research and Education Center (CREC), Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850, U.S.A
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Li R, Wang X, Hu Y, Huang G. Analysis of huanglongbing-associated RNA-seq data reveals disturbances in biological processes within Citrus spp. triggered by Candidatus Liberibacter asiaticus infection. FRONTIERS IN PLANT SCIENCE 2024; 15:1388163. [PMID: 38660443 PMCID: PMC11039969 DOI: 10.3389/fpls.2024.1388163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 03/27/2024] [Indexed: 04/26/2024]
Abstract
Introduction Huanglongbing (HLB), a disease that's ubiquitous worldwide, wreaks havoc on the citrus industry. The primary culprit of HLB is the gram-negative bacterium Candidatus Liberibacter asiaticus (CLas) that infects the phloem, but its damaging mechanism is yet to be fully understood. Methods and results In this study, a multitude of tools including weighted correlation network analysis (WGCNA), protein-protein interaction (PPI) network analysis and gene expression profiling are employed to unravel the intricacies of its pathogenesis. The investigation pinpoints various central genes, such as the ethylene-responsive transcription factor 9 (ERF9) and thioredoxin reductase 1 (TrxR1), that are associated with CLas invasion and resultant disturbances in numerous biological operations. Additionally, the study uncovers a range of responses through the detection of differential expressed genes (DEGs) across different experiments. The discovery of core DEGs leads to the identification of pivotal genes such as the sieve element occlusion (SEO) and the wall-associated receptor kinase-like 15 (WAKL15). PPI network analysis highlights potential vital proteins, while GO and KEGG pathway enrichment analysis illustrate a significant impact on multiple defensive and metabolic pathways. Gene set enrichment analysis (GSEA) indicates significant alterations in biological processes such as leaf senescence and response to biotic stimuli. Discussion This all-encompassing approach extends valuable understanding into the pathogenesis of CLas, potentially aiding future research and therapeutic strategies for HLB.
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Affiliation(s)
- Ruimin Li
- College of Life Sciences, Gannan Normal University, Ganzhou, China
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Xinyou Wang
- College of Life Sciences, Gannan Normal University, Ganzhou, China
| | - Yanan Hu
- College of Life Sciences, Gannan Normal University, Ganzhou, China
| | - Guiyan Huang
- College of Life Sciences, Gannan Normal University, Ganzhou, China
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
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4
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Galvañ A, Bassanezi RB, Luo W, Vanaclocha P, Vicent A, Lázaro E. Risk-based regionalization approach for area-wide management of HLB vectors in the Mediterranean Basin. FRONTIERS IN PLANT SCIENCE 2023; 14:1256935. [PMID: 38111874 PMCID: PMC10725980 DOI: 10.3389/fpls.2023.1256935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/23/2023] [Indexed: 12/20/2023]
Abstract
Huanglongbing (HLB) is one of the most devastating citrus diseases worldwide. It is associated with the non-culture bacteria Candidatus Liberibacter spp., which can be transmitted by grafting and/or the psyllid vectors Diaphorina citri (ACP) and Trioza erytreae (AfCP). Although HLB has not been reported in the Mediterranean Basin to date, both vectors are present, and thus represent a serious threat to the citrus industry in this region. Resistant citrus cultivars or effective therapeutic treatments are not currently available for HLB. Nevertheless, area-wide pest management via coordinated management efforts over large areas has been implemented in Brazil, China and the USA for HLB control. This study proposes an open access flexible methodology to address area-wide management of both HLB vectors in the Mediterranean Basin. Based on a risk-based approach which considers climatic information and other variables that may influence vector introduction and spread, such as conventional, organic, abandoned and residential citrus areas as well as transportation corridors, an area-wide management division in pest management areas (PMAs) is proposed. The size and location of these PMAs were estimated by means of a hierarchical clustering algorithm with spatial constraints whose performance was assessed under different configuration scenarios. This proposal may assist policymakers and the citrus industry of the citrus-growing areas of the Mediterranean Basin in risk management planning in the case of the spread of HLB vectors or a possible introduction of the disease. Additionally, it may be a valuable resource to inform opinion dynamic models, enabling the identification of pivotal factors for the success of control measures.
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Affiliation(s)
- Anaïs Galvañ
- Centre de Protecció Vegetal i Biotecnologia, Institut Valencià d’Investigacions Agràries (IVIA), Moncada, Spain
| | - Renato Beozzo Bassanezi
- Departamento de Pesquisa e Desenvolvimento, Fundo de Defesa da Citricultura, Araraquara, SP, Brazil
| | - Weiqi Luo
- Agricultural Research Service, U.S. Department of Agriculture, Fort Pierce, FL, United States
- Center for Integrated Pest Management, North Carolina State University, Raleigh, NC, United States
| | - Pilar Vanaclocha
- Centre de Protecció Vegetal i Biotecnologia, Institut Valencià d’Investigacions Agràries (IVIA), Moncada, Spain
| | - Antonio Vicent
- Centre de Protecció Vegetal i Biotecnologia, Institut Valencià d’Investigacions Agràries (IVIA), Moncada, Spain
| | - Elena Lázaro
- Centre de Protecció Vegetal i Biotecnologia, Institut Valencià d’Investigacions Agràries (IVIA), Moncada, Spain
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Carter EW, Peraza OG, Wang N. The protein interactome of the citrus Huanglongbing pathogen Candidatus Liberibacter asiaticus. Nat Commun 2023; 14:7838. [PMID: 38030598 PMCID: PMC10687234 DOI: 10.1038/s41467-023-43648-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 11/15/2023] [Indexed: 12/01/2023] Open
Abstract
The bacterium Candidatus Liberibacter asiaticus (CLas) causes citrus Huanglongbing disease. Our understanding of the pathogenicity and biology of this microorganism remains limited because CLas has not yet been cultivated in artificial media. Its genome is relatively small and encodes approximately 1136 proteins, of which 415 have unknown functions. Here, we use a high-throughput yeast-two-hybrid (Y2H) screen to identify interactions between CLas proteins, thus providing insights into their potential functions. We identify 4245 interactions between 542 proteins, after screening 916 bait and 936 prey proteins. The false positive rate of the Y2H assay is estimated to be 2.9%. Pull-down assays for nine protein-protein interactions (PPIs) likely involved in flagellar function support the robustness of the Y2H results. The average number of PPIs per node in the CLas interactome is 15.6, which is higher than the numbers previously reported for interactomes of free-living bacteria, suggesting that CLas genome reduction has been accompanied by increased protein multi-functionality. We propose potential functions for 171 uncharacterized proteins, based on the PPI results, guilt-by-association analyses, and comparison with data from other bacterial species. We identify 40 hub-node proteins, including quinone oxidoreductase and LysR, which are known to protect other bacteria against oxidative stress and might be important for CLas survival in the phloem. We expect our PPI database to facilitate research on CLas biology and pathogenicity mechanisms.
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Affiliation(s)
- Erica W Carter
- Citrus Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL, USA
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL, USA
| | - Orlene Guerra Peraza
- Citrus Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL, USA
| | - Nian Wang
- Citrus Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL, USA.
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL, US.
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Ebert TA, Shawer D, Brlansky RH, Rogers ME. Seasonal Patterns in the Frequency of Candidatus Liberibacter Asiaticus in Populations of Diaphorina citri (Hemiptera: Psyllidae) in Florida. INSECTS 2023; 14:756. [PMID: 37754724 PMCID: PMC10532026 DOI: 10.3390/insects14090756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/04/2023] [Accepted: 09/06/2023] [Indexed: 09/28/2023]
Abstract
Candidatus Liberibacter asiaticus (CLas) is one of the putative causal agents of huanglongbing, which is a serious disease in citrus production. The pathogen is transmitted by Diaphorina citri Kuwayama (Hemiptera: Psyllidae). As an observational study, six groves in central Florida and one grove at the southern tip of Florida were sampled monthly from January 2008 through February 2012 (50 months). The collected psyllids were sorted by sex and abdominal color. Disease prevalence in adults peaked in November, with a minor peak in February. Gray/brown females had the highest prevalence, and blue/green individuals of either sex had the lowest prevalence. CLas prevalence in blue/green females was highly correlated with the prevalence in other sexes and colors. Thus, the underlying causes for seasonal fluctuations in prevalence operated in a similar fashion for all psyllids. The pattern was caused by larger nymphs displacing smaller ones from the optimal feeding sites and immunological robustness in different sex-color morphotypes. Alternative hypotheses were also considered. Improving our understanding of biological interactions and how to sample them will improve management decisions. We agree with other authors that psyllid management is critical year-round.
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Affiliation(s)
- Timothy A. Ebert
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Rd., Lake Alfred, FL 33850, USA; (R.H.B.); (M.E.R.)
| | - Dalia Shawer
- Department of Economic Entomology, Faculty of Agriculture, Kafr Elsheikh University, Kafr Elsheikh 33516, Egypt;
| | - Ron H. Brlansky
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Rd., Lake Alfred, FL 33850, USA; (R.H.B.); (M.E.R.)
| | - Michael E. Rogers
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Rd., Lake Alfred, FL 33850, USA; (R.H.B.); (M.E.R.)
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Batarseh TN, Batarseh SN, Morales-Cruz A, Gaut BS. Comparative genomics of the Liberibacter genus reveals widespread diversity in genomic content and positive selection history. Front Microbiol 2023; 14:1206094. [PMID: 37434713 PMCID: PMC10330825 DOI: 10.3389/fmicb.2023.1206094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 06/09/2023] [Indexed: 07/13/2023] Open
Abstract
'Candidatus Liberibacter' is a group of bacterial species that are obligate intracellular plant pathogens and cause Huanglongbing disease of citrus trees and Zebra Chip in potatoes. Here, we examined the extent of intra- and interspecific genetic diversity across the genus using comparative genomics. Our approach examined a wide set of Liberibacter genome sequences including five pathogenic species and one species not known to cause disease. By performing comparative genomics analyses, we sought to understand the evolutionary history of this genus and to identify genes or genome regions that may affect pathogenicity. With a set of 52 genomes, we performed comparative genomics, measured genome rearrangement, and completed statistical tests of positive selection. We explored markers of genetic diversity across the genus, such as average nucleotide identity across the whole genome. These analyses revealed the highest intraspecific diversity amongst the 'Ca. Liberibacter solanacearum' species, which also has the largest plant host range. We identified sets of core and accessory genes across the genus and within each species and measured the ratio of nonsynonymous to synonymous mutations (dN/dS) across genes. We identified ten genes with evidence of a history of positive selection in the Liberibacter genus, including genes in the Tad complex, which have been previously implicated as being highly divergent in the 'Ca. L. capsica' species based on high values of dN.
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Affiliation(s)
| | - Sarah N. Batarseh
- Department of Plant and Microbial Biology, UC Berkeley, Berkeley, CA, United States
| | - Abraham Morales-Cruz
- U.S. Department of Energy, Joint Genome Institute, Lawrence Berkeley National Lab, Berkeley, CA, United States
| | - Brandon S. Gaut
- Department of Ecology and Evolutionary Biology, UC Irvine, Irvine, CA, United States
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8
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Pandey SS, Xu J, Achor DS, Li J, Wang N. Microscopic and Transcriptomic Analyses of Early Events Triggered by ' Candidatus Liberibacter asiaticus' in Young Flushes of Huanglongbing-Positive Citrus Trees. PHYTOPATHOLOGY 2023; 113:985-997. [PMID: 36449527 DOI: 10.1094/phyto-10-22-0360-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
'Candidatus Liberibacter asiaticus' (CLas) is associated with the devastating citrus disease Huanglongbing (HLB). Young flushes are the center of the HLB pathosystem due to their roles in the psyllid life cycle and in the acquisition and transmission of CLas. However, the early events of CLas infection and how CLas modulates young flush physiology remain poorly understood. Here, transmission electron microscopy analysis showed that the mean diameter of the sieve pores decreased in young leaves of HLB-positive trees after CLas infection, consistent with CLas-triggered callose deposition. RNA-seq-based global expression analysis of young leaves of HLB-positive sweet orange with (CLas-Pos) and without (CLas-Neg) detectable CLas demonstrated a significant impact on gene expression in young leaves, including on the expression of genes involved in host immunity, stress response, and plant hormone biosynthesis and signaling. CLas-Pos and CLas-Neg expression data displayed distinct patterns. The number of upregulated genes was higher than that of the downregulated genes in CLas-Pos for plant-pathogen interactions, glutathione metabolism, peroxisome, and calcium signaling, which are commonly associated with pathogen infections, compared with the healthy control. On the contrary, the number of upregulated genes was lower than that of the downregulated genes in CLas-Neg for genes involved in plant-pathogen interactions and peroxisome biogenesis/metabolism. Additionally, a time-course quantitative reverse transcription-PCR-based expression analysis visualized the induced expression of companion cell-specific genes, phloem protein 2 genes, and sucrose transport genes in young flushes triggered by CLas. This study advances our understanding of early events during CLas infection of citrus young flushes.
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Affiliation(s)
- Sheo Shankar Pandey
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850
| | - Jin Xu
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850
| | - Diann S Achor
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850
| | - Jinyun Li
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850
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Current Epidemic Situation and Control Status of Citrus Huanglongbing in Guangdong China: The Space–Time Pattern Analysis of Specific Orchards. Life (Basel) 2023; 13:life13030749. [PMID: 36983905 PMCID: PMC10055705 DOI: 10.3390/life13030749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/04/2023] [Accepted: 03/05/2023] [Indexed: 03/12/2023] Open
Abstract
Huanglongbing (HLB) is the most harmful bacterial disease in citrus production in the world, and has been seriously ravaging the citrus groves of South China since the 1930s. The surveillance of the epidemiological characteristics of HLB is of utmost priority for citrus production in this region. In order to explore the effects of disease control measures, analyses on the space–time statistical features of the HLB epidemic, from 2019 to 2021, within six orchards in the Guangdong province are presented. Overall, the number of citrus plants in the orchards usually slightly decreased year by year. The reduction was mainly related to the level of plant susceptibility, which is correlated with citrus varieties. The maximum disease severity (incidence and race increment) was correlated with the awareness of this disease and the management intensity applied by the manager. A higher disease index was found in the conventional management orchards than in the comprehensive prevention and control orchards. Proper insect-protective screen houses can effectively prevent the epidemic of HLB, without affecting the fruit quality, and can also aid with higher yields. A high correlation was found between the geometry and topography of orchards and the HLB epidemic due to the wind direction from May to September and the Asia citrus psyllid activity characteristics. For flat orchards, the incidence of HLB in the north and entrance areas was higher than that in the southwest. In the mountain area, the incidence of the windward side in the south was higher than that of the leeward side in the north. Diseased trees tended to have an edge effect in the grove, whereas the trees of the same disease scale were found clustered in their distribution. These results allow a better understanding of HLB epidemiology and provide guidance for the early warning of HLB in new groves in areas that are severely affected by this disease. Furthermore, they also provide a scientific basis for the comprehensive prevention and control of HLB in old groves.
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Ribeiro C, Xu J, Hendrich C, Pandey SS, Yu Q, Gmitter FG, Wang N. Seasonal Transcriptome Profiling of Susceptible and Tolerant Citrus Cultivars to Citrus Huanglongbing. PHYTOPATHOLOGY 2023; 113:286-298. [PMID: 36001783 DOI: 10.1094/phyto-05-22-0179-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Citrus huanglongbing (HLB) caused by 'Candidatus Liberibacter asiaticus' (CLas) is the most devastating citrus disease worldwide. Most commercial citrus cultivars are susceptible to HLB, with a few more tolerant exceptions such as 'LB8-9' Sugar Belle mandarin. Transcriptomic analyses have been widely used to investigate the potential mechanisms for disease susceptibility, resistance, or tolerance. Previous transcriptomic studies related to HLB mostly focused on single time point data collection. We hypothesize that changes in day length and temperature throughout the seasons have profound effects on citrus-CLas interactions. Here, we conducted RNA-seq analyses on HLB-susceptible Valencia sweet orange and HLB-tolerant mandarin 'LB8-9' in winter, spring, summer, and fall. Significant variations in differentially expressed genes (DEGs) related to HLB were observed among the four seasons. For both cultivars, the highest number of DEGs were found in the spring. CLas infection stimulates the expression of immune-related genes such as NBS-LRR, RLK, RLCK, CDPK, MAPK pathway, reactive oxygen species (ROS), and PR genes in both cultivars, consistent with the model that HLB is a pathogen-triggered immune disease. HLB-positive mandarin 'LB8-9' trees contained higher concentrations of maltose and sucrose, which are known to scavenge ROS. In addition, mandarin 'LB8-9' showed higher expression of genes involved in phloem regeneration, which might contribute to its HLB tolerance. This study shed light on the pathogenicity mechanism of the HLB pathosystem and the tolerance mechanism against HLB, providing valuable insights into HLB management.
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Affiliation(s)
- Camila Ribeiro
- Citrus Research & Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred, FL 33850
| | - Jin Xu
- Citrus Research & Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred, FL 33850
| | - Connor Hendrich
- Citrus Research & Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred, FL 33850
| | - Sheo Shankar Pandey
- Citrus Research & Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred, FL 33850
| | - Qibin Yu
- Citrus Research & Education Center, Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred, FL 33850
| | - Frederick G Gmitter
- Citrus Research & Education Center, Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred, FL 33850
| | - Nian Wang
- Citrus Research & Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred, FL 33850
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11
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Qiu RZ, Chen SP, Chi MX, Wang RB, Huang T, Fan GC, Zhao J, Weng QY. An automatic identification system for citrus greening disease (Huanglongbing) using a YOLO convolutional neural network. FRONTIERS IN PLANT SCIENCE 2022; 13:1002606. [PMID: 36605957 PMCID: PMC9807764 DOI: 10.3389/fpls.2022.1002606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 12/07/2022] [Indexed: 06/01/2023]
Abstract
Huanglongbing (HLB), or citrus greening disease, has complex and variable symptoms, making its diagnosis almost entirely reliant on subjective experience, which results in a low diagnosis efficiency. To overcome this problem, we constructed and validated a deep learning (DL)-based method for detecting citrus HLB using YOLOv5l from digital images. Three models (Yolov5l-HLB1, Yolov5l-HLB2, and Yolov5l-HLB3) were developed using images of healthy and symptomatic citrus leaves acquired under a range of imaging conditions. The micro F1-scores of the Yolov5l-HLB2 model (85.19%) recognising five HLB symptoms (blotchy mottling, "red-nose" fruits, zinc-deficiency, vein yellowing, and uniform yellowing) in the images were higher than those of the other two models. The generalisation performance of Yolov5l-HLB2 was tested using test set images acquired under two photographic conditions (conditions B and C) that were different from that of the model training set condition (condition A). The results suggested that this model performed well at recognising the five HLB symptom images acquired under both conditions B and C, and yielded a micro F1-score of 84.64% and 85.84%, respectively. In addition, the detection performance of the Yolov5l-HLB2 model was better for experienced users than for inexperienced users. The PCR-positive rate of Candidatus Liberibacter asiaticus (CLas) detection (the causative pathogen for HLB) in the samples with five HLB symptoms as classified using the Yolov5l-HLB2 model was also compared with manual classification by experts. This indicated that the model can be employed as a preliminary screening tool before the collection of field samples for subsequent PCR testing. We also developed the 'HLBdetector' app using the Yolov5l-HLB2 model, which allows farmers to complete HLB detection in seconds with only a mobile phone terminal and without expert guidance. Overall, we successfully constructed a reliable automatic HLB identification model and developed the user-friendly 'HLBdetector' app, facilitating the prevention and timely control of HLB transmission in citrus orchards.
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Affiliation(s)
| | | | | | | | | | | | - Jian Zhao
- *Correspondence: Jian Zhao, ; Qi-Yong Weng,
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Huang Y, Zhu F, Koh J, Stanton D, Chen S, Wang N. Proteomic and bioinformatic analyses of proteins in the outer membrane and extracellular compartments and outer membrane vesicles of Candidatus Liberibacter species. Front Microbiol 2022; 13:977710. [PMID: 36225379 PMCID: PMC9548881 DOI: 10.3389/fmicb.2022.977710] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 09/02/2022] [Indexed: 11/23/2022] Open
Abstract
Citrus Huanglongbing (HLB) is the most devastating citrus disease in the world. Candidatus Liberibacter asiaticus (Las) is the prevalent HLB pathogen, which is yet to be cultivated. A recent study demonstrates that Las does not contain pathogenicity factors that are directly responsible for HLB symptoms. Instead, Las triggers systemic and chronic immune responses, representing a pathogen-triggered immune disease. Importantly, overproduction of reactive oxygen species (ROS) causes systemic cell death of phloem tissues, thus causing HLB symptoms. Because Las resides in the phloem tissues, it is expected that phloem cell might recognize outer membrane proteins, outer membrane vesicle (OMV) proteins and extracellular proteins of Las to contribute to the immune responses. Because Las has not been cultivated, we used Liberibacter crescens (Lcr) as a surrogate to identify proteins in the OM fraction, OMV proteins and extracellular proteins by liquid chromatography with tandem mass spectrometry (LC–MS/MS). We observed OMVs of Lcr under scanning electron microscope, representing the first experimental evidence that Liberibacter can deliver proteins to the extracellular compartment. In addition, we also further analyzed LC–MS/MS data using bioinformatic tools. Our study provides valuable information regarding the biology of Ca. Liberibacter species and identifies many putative proteins that may interact with host proteins in the phloem tissues.
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Affiliation(s)
- Yixiao Huang
- Department of Plant Pathology, Citrus Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL, United States
| | - Fanchao Zhu
- Proteomics and Mass Spectrometry, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, United States
| | - Jin Koh
- Proteomics and Mass Spectrometry, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, United States
| | - Daniel Stanton
- Department of Plant Pathology, Citrus Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL, United States
| | - Sixue Chen
- Proteomics and Mass Spectrometry, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, United States
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL, United States
- *Correspondence: Nian Wang,
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13
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Aidoo OF, Souza PGC, da Silva RS, Júnior PAS, Picanço MC, Osei-Owusu J, Sétamou M, Ekesi S, Borgemeister C. A machine learning algorithm-based approach (MaxEnt) for predicting invasive potential of Trioza erytreae on a global scale. ECOL INFORM 2022. [DOI: 10.1016/j.ecoinf.2022.101792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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14
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Yang C, Ancona V. An Overview of the Mechanisms Against " Candidatus Liberibacter asiaticus": Virulence Targets, Citrus Defenses, and Microbiome. Front Microbiol 2022; 13:850588. [PMID: 35391740 PMCID: PMC8982080 DOI: 10.3389/fmicb.2022.850588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 02/18/2022] [Indexed: 12/01/2022] Open
Abstract
Citrus Huanglongbing (HLB) or citrus greening, is the most destructive disease for citrus worldwide. It is caused by the psyllid-transmitted, phloem-limited bacteria "Candidatus Liberibacter asiaticus" (CLas). To date, there are still no effective practical strategies for curing citrus HLB. Understanding the mechanisms against CLas can contribute to the development of effective approaches for combatting HLB. However, the unculturable nature of CLas has hindered elucidating mechanisms against CLas. In this review, we summarize the main aspects that contribute to the understanding about the mechanisms against CLas, including (1) CLas virulence targets, focusing on inhibition of virulence genes; (2) activation of citrus host defense genes and metabolites of HLB-tolerant citrus triggered by CLas, and by agents; and (3) we also review the role of citrus microbiome in combatting CLas. Finally, we discuss novel strategies to continue studying mechanisms against CLas and the relationship of above aspects.
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Affiliation(s)
- Chuanyu Yang
- Department of Agriculture, Agribusiness, and Environmental Sciences, Citrus Center, Texas A&M University-Kingsville, Weslaco, TX, United States
| | - Veronica Ancona
- Department of Agriculture, Agribusiness, and Environmental Sciences, Citrus Center, Texas A&M University-Kingsville, Weslaco, TX, United States
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15
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Ma W, Pang Z, Huang X, Xu J, Pandey SS, Li J, Achor DS, Vasconcelos FNC, Hendrich C, Huang Y, Wang W, Lee D, Stanton D, Wang N. Citrus Huanglongbing is a pathogen-triggered immune disease that can be mitigated with antioxidants and gibberellin. Nat Commun 2022; 13:529. [PMID: 35082290 PMCID: PMC8791970 DOI: 10.1038/s41467-022-28189-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/04/2022] [Indexed: 12/17/2022] Open
Abstract
Huanglongbing (HLB) is a devastating disease of citrus, caused by the phloem-colonizing bacterium Candidatus Liberibacter asiaticus (CLas). Here, we present evidence that HLB is an immune-mediated disease. We show that CLas infection of Citrus sinensis stimulates systemic and chronic immune responses in phloem tissue, including callose deposition, production of reactive oxygen species (ROS) such as H2O2, and induction of immunity-related genes. The infection also upregulates genes encoding ROS-producing NADPH oxidases, and downregulates antioxidant enzyme genes, supporting that CLas causes oxidative stress. CLas-triggered ROS production localizes in phloem-enriched bark tissue and is followed by systemic cell death of companion and sieve element cells. Inhibition of ROS levels in CLas-positive stems by NADPH oxidase inhibitor diphenyleneiodonium (DPI) indicates that NADPH oxidases contribute to CLas-triggered ROS production. To investigate potential treatments, we show that addition of the growth hormone gibberellin (known to have immunoregulatory activities) upregulates genes encoding H2O2-scavenging enzymes and downregulates NADPH oxidases. Furthermore, foliar spray of HLB-affected citrus with gibberellin or antioxidants (uric acid, rutin) reduces H2O2 concentrations and cell death in phloem tissues and reduces HLB symptoms. Thus, our results indicate that HLB is an immune-mediated disease that can be mitigated with antioxidants and gibberellin.
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Affiliation(s)
- Wenxiu Ma
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Zhiqian Pang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Xiaoen Huang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Jin Xu
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Sheo Shankar Pandey
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Jinyun Li
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Diann S Achor
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Fernanda N C Vasconcelos
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Connor Hendrich
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Yixiao Huang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Wenting Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Donghwan Lee
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Daniel Stanton
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA.
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16
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Huang X, Wang Y, Wang N. Highly Efficient Generation of Canker-Resistant Sweet Orange Enabled by an Improved CRISPR/Cas9 System. FRONTIERS IN PLANT SCIENCE 2022; 12:769907. [PMID: 35087548 PMCID: PMC8787272 DOI: 10.3389/fpls.2021.769907] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 12/09/2021] [Indexed: 06/02/2023]
Abstract
Sweet orange (Citrus sinensis) is the most economically important species for the citrus industry. However, it is susceptible to many diseases including citrus bacterial canker caused by Xanthomonas citri subsp. citri (Xcc) that triggers devastating effects on citrus production. Conventional breeding has not met the challenge to improve disease resistance of sweet orange due to the long juvenility and other limitations. CRISPR-mediated genome editing has shown promising potentials for genetic improvements of plants. Generation of biallelic/homozygous mutants remains difficult for sweet orange due to low transformation rate, existence of heterozygous alleles for target genes, and low biallelic editing efficacy using the CRISPR technology. Here, we report improvements in the CRISPR/Cas9 system for citrus gene editing. Based on the improvements we made previously [dicot codon optimized Cas9, tRNA for multiplexing, a modified sgRNA scaffold with high efficiency, citrus U6 (CsU6) to drive sgRNA expression], we further improved our CRISPR/Cas9 system by choosing superior promoters [Cestrum yellow leaf curling virus (CmYLCV) or Citrus sinensis ubiquitin (CsUbi) promoter] to drive Cas9 and optimizing culture temperature. This system was able to generate a biallelic mutation rate of up to 89% for Carrizo citrange and 79% for Hamlin sweet orange. Consequently, this system was used to generate canker-resistant Hamlin sweet orange by mutating the effector binding element (EBE) of canker susceptibility gene CsLOB1, which is required for causing canker symptoms by Xcc. Six biallelic Hamlin sweet orange mutant lines in the EBE were generated. The biallelic mutants are resistant to Xcc. Biallelic mutation of the EBE region abolishes the induction of CsLOB1 by Xcc. This study represents a significant improvement in sweet orange gene editing efficacy and generating disease-resistant varieties via CRISPR-mediated genome editing. This improvement in citrus genome editing makes genetic studies and manipulations of sweet orange more feasible.
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17
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Alquézar B, Carmona L, Bennici S, Miranda MP, Bassanezi RB, Peña L. Cultural Management of Huanglongbing: Current Status and Ongoing Research. PHYTOPATHOLOGY 2022; 112:11-25. [PMID: 34645319 DOI: 10.1094/phyto-08-21-0358-ia] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Huanglongbing (HLB), formerly known as greening, is a bacterial disease restricted to some Asian and African regions until two decades ago. Nowadays, associated bacteria and their vectors have spread to almost all citrus-producing regions, and it is currently considered the most devastating citrus disease. HLB management can be approached in terms of prevention, limiting or avoiding pathogen and associated vectors to reach an area, or in terms of control, trying to reduce the impact of the disease by adopting different cultural strategies depending on infestation/infection levels. In both cases, control of psyllid populations is currently the best way to stop HLB spread. Best cultural actions (CHMAs, TPS system) to attain this goal and, thus, able to limit HLB spread, and ongoing research in this regard is summarized in this review.
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Affiliation(s)
- Berta Alquézar
- Laboratório de Biotecnologia Vegetal, Pesquisa & Desenvolvimento, Fundo de Defesa da Citricultura (Fundecitrus), Vila Melhado, 14807-040 Araraquara, São Paulo, Brazil
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC) Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain
| | - Lourdes Carmona
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC) Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain
| | - Stefania Bennici
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC) Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain
| | - Marcelo P Miranda
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC) Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain
| | - Renato B Bassanezi
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC) Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain
| | - Leandro Peña
- Laboratório de Biotecnologia Vegetal, Pesquisa & Desenvolvimento, Fundo de Defesa da Citricultura (Fundecitrus), Vila Melhado, 14807-040 Araraquara, São Paulo, Brazil
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC) Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain
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18
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Menger RF, Rehberg RA, Trivedi P, Henry CS, Borch T. High Spatial Resolution Fluorescence Imagery for Optimized Pest Management in a Huanglongbing-Infected Citrus Grove. PHYTOPATHOLOGY 2022; 112:173-179. [PMID: 34524882 DOI: 10.1094/phyto-05-21-0211-fi] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Huanglongbing (HLB), or citrus greening disease, has significantly decreased citrus production all over the world. The disease management currently depends on the efficient application and adequate distribution of insecticides to reduce the density of the disease vector, the Asian citrus psyllid. Here, we use a novel fluorescent-based method to evaluate insecticide distribution in an HLB-infected citrus grove in Florida. Specifically, we evaluated six different locations within citrus trees, the top and bottom sides of leaves, the effect of application approach (tractor versus airplane), and different application rates. We found that despite the insecticide distribution being highly variable among the different locations within a tree, the top of the leaves received an average increase of 21 times more than the bottom of the leaves. Application by tractor also resulted in a 4- to 87-fold increase in insecticide coverage compared with aerial application, depending on the location in the tree and side of the leaf. When taken to context with the type of insecticide that is applied (systemic vs. contact), these results can be used to optimize a pest management strategy to effectively target psyllids and other pests while minimizing the time and money spent on insecticide application and reducing risk to the environment.
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Affiliation(s)
- Ruth F Menger
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523
| | - Rachelle A Rehberg
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523
| | - Pankaj Trivedi
- Microbiome Cluster and Department of Agricultural Biology, Colorado State University, Fort Collins, CO 80523
| | - Charles S Henry
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523
| | - Thomas Borch
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523
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19
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Merfa MV, Naranjo E, Shantharaj D, De La Fuente L. Growth of ' Candidatus Liberibacter asiaticus' in Commercial Grapefruit Juice-Based Media Formulations Reveals Common Cell Density-Dependent Transient Behaviors. PHYTOPATHOLOGY 2022; 112:131-144. [PMID: 34340531 DOI: 10.1094/phyto-06-21-0228-fi] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The phloem-restricted, insect-transmitted bacterium 'Candidatus Liberibacter asiaticus' (CLas) is associated with huanglongbing (HLB), the most devastating disease of citrus worldwide. The inability to culture CLas impairs the understanding of its virulence mechanisms and the development of effective management strategies to control this incurable disease. Previously, our research group used commercial grapefruit juice (GJ) to prolong the viability of CLas in vitro. In the present study, GJ was amended with a wide range of compounds and incubated under different conditions to optimize CLas growth. Remarkably, results showed that CLas growth ratios were inversely proportional to the initial inoculum concentration. This correlation is probably regulated by a cell density-dependent mechanism, because diluting samples between subcultures allowed CLas to resume growth. Moreover, strategies to reduce the cell density of CLas, such as subculturing at short intervals and incubating samples under flow conditions, allowed this bacterium to multiply and reach maximum growth as early as 3 days after inoculation, although no sustained exponential growth was observed under any tested condition. Unfortunately, cultures were only transient, because CLas lost viability over time; nevertheless, we obtained populations of about 105 genome equivalents/ml repeatedly. Finally, we established an ex vivo system to grow CLas within periwinkle calli that could be used to propagate bacterial inoculum in the lab. In this study we determined the influence of a comprehensive set of conditions and compounds on CLas growth in culture. We hope our results will help guide future efforts toward the long-sought goal of culturing CLas axenically.
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Affiliation(s)
- Marcus V Merfa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| | - Eber Naranjo
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| | - Deepak Shantharaj
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
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20
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Pandey SS, Hendrich C, Andrade MO, Wang N. Candidatus Liberibacter: From Movement, Host Responses, to Symptom Development of Citrus Huanglongbing. PHYTOPATHOLOGY 2022; 112:55-68. [PMID: 34609203 DOI: 10.1094/phyto-08-21-0354-fi] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Candidatus Liberibacter spp. are fastidious α-proteobacteria that cause multiple diseases on plant hosts of economic importance, including the most devastating citrus disease: Huanglongbing (HLB). HLB was reported in Asia a century ago but has since spread worldwide. Understanding the pathogenesis of Candidatus Liberibacter spp. remains challenging as they are yet to be cultured in artificial media and infect the phloem, a sophisticated environment that is difficult to manipulate. Despite those challenges, tremendous progress has been made on Ca. Liberibacter pathosystems. Here, we first reviewed recent studies on genetic information of flagellar and type IV pili biosynthesis, their expression profiles, and movement of Ca. Liberibacter spp. inside the plant and insect hosts. Next, we reviewed the transcriptomic, proteomic, and metabolomic studies of susceptible and tolerant plant genotypes to Ca. Liberibacter spp. infection and how Ca. Liberibacter spp. adapt in plants. Analyses of the interactions between plants and Ca. Liberibacter spp. imply the involvement of immune response in the Ca. Liberibacter pathosystems. Lastly, we reviewed how Ca. Liberibacter spp. movement inside and interactions with plants lead to symptom development.
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Affiliation(s)
- Sheo Shankar Pandey
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, Lake Alfred, FL 33850, U.S.A
| | - Connor Hendrich
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, Lake Alfred, FL 33850, U.S.A
| | - Maxuel O Andrade
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Centre for Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, Lake Alfred, FL 33850, U.S.A
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21
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A promising plant defense peptide against citrus Huanglongbing disease. Proc Natl Acad Sci U S A 2021; 118:2026483118. [PMID: 33526706 DOI: 10.1073/pnas.2026483118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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