Source: TEXAS A&M AGRILIFE RESEARCH submitted to NRP
CAP- ADVANCED TESTING AND COMMERCIALIZATION OF NOVEL DEFENSIN PEPTIDES AND THERAPIES FOR HLB CONTROL
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
1027738
Grant No.
2021-70029-36056
Cumulative Award Amt.
$7,000,000.00
Proposal No.
2021-09241
Multistate No.
(N/A)
Project Start Date
Sep 15, 2021
Project End Date
Sep 14, 2025
Grant Year
2021
Program Code
[ECDRE]- Emergency Citrus Disease Research and Extension Program
Recipient Organization
TEXAS A&M AGRILIFE RESEARCH
2147 TAMU
COLLEGE STATION,TX 77843
Performing Department
Weslaco
Non Technical Summary
Citrus greening or Huanglongbing (HLB) disease, caused by Candidatus Liberibacter asiaticus (CLas) in the U.S. is the most devastating citrus disease today, and has invaded all production areas in the U.S. Developing effective and practical (field deployable and commercially viable) HLB control strategies is critical for the survival of the U.S. citrus industry. In this CAP, by leveraging public-private partnerships between State agencies, Universities, USDA-ARS, regulatory affairs consultants, and the citrus industry, we will pursue advanced testing and commercialization of promising HLB therapies and extend outcomes to stakeholders. Thegoal is to find one or more effective therapies to kill CLas and control HLB. For this, we will utilize high throughput and innovative technologies such as CLas-citrus hairy root system to screen potent anti-CLas peptides and small molecules, followed by rigorous multi-location, multi-year field evaluations of the therapies and delivery systems.Promising therapies will be moved into a commercialization pipeline for regulatory approvals. Economic feasibility studies will be conducted to determine the extent of benefits to the citrus growersand a multi-state extension and outreach team will use diverse multi-media outlets to disseminate project information to the stakeholders.
Animal Health Component
50%
Research Effort Categories
Basic
30%
Applied
50%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21209991160100%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
0999 - Citrus, general/other;

Field Of Science
1160 - Pathology;
Goals / Objectives
The overall goal of thisproject is topursue advanced research and commercialization of promising HLB therapies and extend outcomes to stakeholders. To achieve this, we propose thefollowing objectives/aims:1. High throughput hairy root pre-screening and selection of effective HLB therapies.2. Evaluation of antimicrobial peptides using CTV vectorin citrus trees.3. Evaluation ofsmall molecule therapies in citrus trees.4.Pursue data collection for regulatory approvals of the new therapies.5.Evaluate the economic feasibility of deploying new HLB therapies.6. Extension and outreach to inform stakeholders.
Project Methods
Obj. 1. High throughput hairy root pre-screening. Two classes of therapies will be evaluated: a) defensins/antimicrobial peptide (AMP) and b) small molecules/chemistries. Each AMP and small molecule will be evaluated using established methods of hairy root bioassays. Hairy roots will be subjected to multiple QC diagnostics followed by relative CLas titer estimation using qPCR and CLas-specific primers, to determine effectiveness of the treatments when compared to untreated controls (vector-alone or mock). Statistical analysis will be performed using ANOVA/Post hoc and/or Student's t-test as appropriate to determine significant differences. Promising therapies will be moved to the in-planta evaluation using the Citrus tristeza virus (CTV) viral vector delivery system (Obj. 2) and vascular injection/delivery systems (Obj. 3).Obj. 2. Evaluation of antimicrobial peptides using CTV vectors. AMPs will be cloned into the CTV viral vectors and used to inoculate citrus trees in the greenhouse. After confirmation of systemic spread of the CTV-AMP in the trees, the material will be used as a source for inoculum to graft field-grown citrus trees. The field trials will be conducted in FL under an EPA EUP and USDA APHIS/BRS permits. The trials will be in a randomized complete block design under natural HLB/ACP pressure. Standard grove caretaking procedures are used to manage the plots. Multiple tree health traits will be assessed semi-annually. These include quantifying CLas incidence/titers and HLB disease symptoms, CTV titer (by ELISA), AMP stability (by RT-PCR), canopy volume and density (by measuring photosynthetically active radiation [PAR] penetrating the canopy), canopy volume, and flushing ratio. We will employ both ground truthing and high-throughput technologies (e.g., UAS) for data collection. CLas titers within the leaves and fine root samples will be estimated semi-annually by qPCR. Pre-harvest fruit drop will be assessed monthly starting in October. Finally, fruit yield (boxes/tree) and quality traits (e.g., fruit size and color, % juice, brix, acid, etc.) will be determined using standard procedures annually during harvest season. All fruits will be destroyed after harvest as per crop destruct and APHIS/EUP permit protocols. Statistical analyses will be performed using ANOVA/post hoc tests and/or Student t-test, as appropriate, to determine significant differences.Obj. 3. Evaluation of small molecule therapies. For the potential new anti-CLas candidates, first we will evaluate: i) systemic translocation in the plants, ii) suitable adjuvant/carrier combinations, iii) potential phytotoxicity, and iv) residual levels in plant tissues. The goal is to optimize effective delivery dosages, adjuvant combinations, and obtain information on residual levels and phytotoxicity to optimize approaches for field trials in FL and TX. For field trials, we will use a randomized block design. Briefly, we will compare efficacy of new compounds, alongside antibiotic controls, mock (e.g., solvent/adjuvant) and untreated plants as negative controls. All injections will be performed with Chemjet injectors above the graft union, two per tree on opposite sides. Multiple tree health traits will be assessed biannually or annually as described in Obj. 2 such as disease ratings, canopy volume and density, CLas titers biannually, pre-harvest fruit drop, fruit yield (boxes/tree), and quality traits annually during harvest season. All fruits will be destroyed after harvest as per crop destruct protocols. Statistical analyses will be performed using ANOVA/post hoc tests and/or Student t-test, as appropriate, to determine significant differences. Selected compounds with highest efficacy in year 1 will be evaluated in the second year.Obj. 4. Pursue data collection for regulatory approvals of the therapies. This work is NOT funded by this project; however, it will be complementary to the R&D activities and pursued in close collaboration with the citrus industry and a dedicated regulatory affairs team. We will initiate various required data collections and waivers to seek EPA approvals for promising therapies. A suite of good laboratory practice (GLP) data collection will be pursued, using agency guidelines, and included in a registration application package to support pesticide registration regulatory requirements for approval. Including, but not limited to, market basket study, health/dietary risk assessment, non-target effects on beneficials, pollinator/honeybee toxicity, and product characterization.Obj. 5. Evaluate the economic feasibility of deploying new HLB therapies and stakeholder surveys. To evaluate the profitability of adopting new HLB therapies on new and existing groves we will use investment analysis, which is used to assess the profitability of long-term capital investment, such as a citrus grove. The Net Present Value (NPV) is the preferred method for such evaluation because it considers the time value of money as well as the size of the stream of cash flows. In general, investments that yield a positive net present value should be accepted, otherwise rejected. For our purposes, therapies with higher NPVs will be preferred over alternatives with lower NPV because it would mean they are more profitable. The data generated from the project's trials will be inputs to the economic model along with the relevant market prices. The enterprise citrus budgets developed by FL, TX and CA University systems will serve as the baseline to estimate the cost of production in each citrus production region. We will also engage collaborating growers and other citrus growers in FL, TX, and CA, as needed, to seek various farm-level input data. In addition to determining the economic feasibility data, we will garner grower/industry feedback via surveys to understand the potential use/adoption rates. We will poll citrus growers using paper and electronic questionnaires as described before, to assess their willingness to adopt the novel HLB management strategies presented. Gathered data will be subjected to parametric and non-parametric econometric valuation models to examine the factors that could affect the adoption of the proposed HLB therapies by growers.Obj. 6. Extension and outreach to inform stakeholders. We will leverage every possible means to engage the stakeholders in the project by selecting multiple growers, industry, and commodity group members in our project advisory board, who will be directly informed of the project findings. Furthermore, our extension team is affiliated with regional citrus research and extension centers in TX, FL, and CA, and have continuous interactions with citrus growers, industry, and other stakeholders. They will interact with growers in TX, FL, and CA to provide HLB disease management recommendations resulting from this study and will organize extension programs and/or workshops to disseminate the results and economic benefits. Multiple engagement/outreach streams will be pursued such as: a) direct stakeholder engagement at industry and advisory board meetings, workshops, and field days. b) dissemination of project results via. presentations and talks. c) dissemination of project results via. factsheets, brochures, and research/extension flyers. d) dissemination of project results via. online websites related citrus research and HLB, and Facebook and twitter handles.

Progress 09/15/23 to 09/14/24

Outputs
Target Audience:The following target audience was reached by the efforts and activities of this reporting period. • Plant pathology, microbiology, and biotechnology scientific research communities. • Students, postdocs, and early career scientists. • Agricultural community, including the citrus industry, growers, and consumers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?• The project has provided research training and mentoring opportunities to several undergraduate students, graduate students, research technicians, as well as early career postdocs and research scientists. • The students and staff were routinely mentored by the PIs in laboratory techniques and scientific inquiry. • The students and staff were also given opportunities to attend and present their research at professional conferences. • Additionally, senior staff was provided opportunities to junior mentor staff, thus enhancing their teaching and mentoring skills. How have the results been disseminated to communities of interest?• As detailed in Obj. 6, project updates and results were periodically disseminated by the team members to various groups of stakeholders in TX, FL, and CA through a variety of avenues, including in-person meetings, workshops, and various social media channels, as detailed in the extension/outreach accomplishments above. • The results were also periodically disseminated to the broader scientific community through research publications and presentations at regional and international conferences. What do you plan to do during the next reporting period to accomplish the goals?• We will continue the proposed research activities in the laboratory, greenhouse, and field trials. Any additional candidate small molecules and AMPs that demonstrated promising activity in the hairy root assays will be moved to the greenhouse and field testing pipeline. • Results from the efficacy/field trials will be utilized to initiate economic feasibility studies in order to evaluate the profitability of adopting new HLB therapies on new and existing groves. • We will continue our outreach and extension activities to stakeholders in TX, FL, and CA and to the broader scientific community through a variety of avenues such as meetings, conferences, publications, and online media.

Impacts
What was accomplished under these goals? The proposed objectives/activities are underway and on track. Briefaccomplishments are below: Obj. 1. High throughput hairy root pre-screening and selection of effective HLB therapies. For this reporting period, we completed screening new chemistries (agrochemicals and natural products) for anti-CLas activity. Together with the previously selected candidates, we have, in total, identified ~6-8 promising candidates. Three of them were also advanced to field trials (Obj. 2-3). Additionally, we developed an improved citron-based hairy root transformation for efficacy testing. The new sources/methods enabled faster testing ofthe efficacy of AMPs or small molecules in as little as 2 months. The results are being compiled for publication in a peer-reviewed journal. Obj. 2. Evaluation of antimicrobial peptides using CTV vector in citrus trees. For this reporting period, we continued our research on evaluating CTV-AMP efficacy in HLB-affected citrus trees in the experimental field sites of Southern Gardens Citrus in FL. Briefly, all the field trials are being conducted under approved EPA EUP/BRS and USDA permits. The experimental design comprises a randomized complete block design with 50-60 tree replicates under natural HLB/ACP pressure. As per the workflow, the respective CTV-AMP expressing mother citrus plants were first generated in the greenhouse. Subsequently, the CTV-AMP expressing inoculum was grafted onto citrus nursery treesready to be planted in the field. The stability and CTV expression of the CTV-AMP inserts are monitored and periodically verified by RT-PCR in both the mother and the field plants. The HLB incidence in the field is also monitored by qPCR. Fruit yield and other plant health traits (canopy volume, trunk diameter, etc.) will be analyzed annually. The preliminary data show promising yield improvement compared to controls. These results are presented at multiple meetings and conferencesand compiled for publication in a peer-reviewed journal. Obj. 3. Evaluation of small molecule therapies in citrus trees. For this reporting period, we completed a second round of injections andevaluation of anti-CLas small molecules (~3 candidates) along with Oxytetracycline (OTC) in HLB-affected citrus trees by trunk injections. As before, the molecules were delivered into trees using trunk injections with Chemjet injectors above the graft union, two per tree on opposite sides. Multiple tree health traits will be assessed periodically by ground truthing and unmanned aerial vehicles (UAVs). Examples include measurement of disease index, flushing rate, canopy volume/density, CLas titers biannually, pre-harvest fruit drop, and ultimately fruit yield (boxes/tree), as well as quality traits annually during harvest season. Data shows promising yield (quantity and quality) improvement in the trees injected with few new molecules compared to controls. These results are presented at multiple meetings and conferencesand compiled for publication in a peer-reviewed journal. Obj. 4. Pursue data collection for regulatory approvals of the new therapies. This objective is NOT funded by NIFA. It isindependently pursued by our industry partners, Southern Gardens Citrus, and a sub-licensee company, Silvec Biologics LLC. A suite of good laboratory practice (GLP) data collection was pursued using agency guidelines and included in a registration application package to support pesticide registration regulatory requirements for EPA approval. These included, but were not limited to, a market basket study, health/dietary risk assessment, non-target effects on beneficial, pollinator/honeybee toxicity, and product characterization. Recently, the CTV-AMP EPA registration process has progressed to the Full Science Review Phase of the EPA Pesticide Regulation Improvement Act (PRIA) registration process following thesuccessful completion of Milestone #4 -Technical Screen in July 2024. We hope to continue these industry engagements and pursue the remainder of the regulatory approval process to bring the AMPs to market soon. Obj. 5. Evaluate the economic feasibility of deploying new HLB therapies. Ongoing. The results from the efficacy/field trials of OTC and new chemistries were provided to the economists so they couldinitiate economic feasibility studies. The goal is to evaluate the profitability of adopting new HLB therapies on new and existing groves. The work is ongoing, and future reports will report outcomes to the stakeholders. Obj. 6. Extension and outreach to inform stakeholders Team members presented multiple talks at the VII International Research Conference on Huanglongbing (IRCHLB VII). March 26-29. Riverside, CA. Attendees: ~400 Team members presented at the 2024 Annual Meeting (2024) of the American Phytopathological Society-Caribbean Division (APS-CD), April 15-17, Merida, Mexico. Attendees: ~60. Team members presented the project findings at the Plant Health 2024 annual meeting of the American Phytopathological Society (APS), July 27-30, Memphis, TN. Attendees: ~500 Team members presented progress in aUSDA APHIS PPQ-S&T-Domestic & Emergency Scientific Support (DESS) webinar on May 10, Washington, DC. Team members presented the project findings at the Society for Experimental Biology annual meeting, July 2-5, Prague, CZ. Attendees: ~500 Team members were invited as speakers to the 2024 Florida Citrus Mutual and the 2024 Texas Citrus Mutual annual conferences. We also leveraged several means to engage stakeholders by publishing news releases on the project findings and individual meetings with citrus stakeholders in TX, FL, CA, and the wider public. These were prepared and disseminated through regional and national news outlets and social media channels. Our extension team, affiliated with regional citrus research and extension centers in TX, FL, and CA, continuously interacted with citrus growers, industry, and other stakeholders. Team members also participated in citrus growers' and organizations' meetings (e.g., CRDF, TCM, TCPDMC, TAMUK-Citrus Center), where the project activities/updates were provided to the stakeholders. Lastly, our project advisory board included multiple growers and industry and commodity group members, who were periodically informed of the project activities at the annual advisory board meeting and by engaging with them individually.

Publications

  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Bedre, R., Kavuri, N. R., Ramasamy, M., Irigoyen, S., Nelson, A., Rajkumar, M. S., & Mandadi, K. (2024). Long intergenic non-coding RNAs modulate proximal protein-coding gene expression and tolerance to Candidatus Liberibacter spp. in potatoes. Communications Biology, 7, 1095.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: A. Aksenov, A., Blacutt, A., Ginnan, N., Rolshausen, P.E., V. Melnik, A., Lotfi, A., C. Gentry, E., Ramasamy, M., Zuniga, C., Zengler, K. and Mandadi, K.K., (2024). Spatial chemistry of citrus reveals molecules bactericidal to Candidatus Liberibacter asiaticus. Scientific Reports, 14, p.20306.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Ramasamy, M., Rajkumar, M.S., Irigoyen, S., Bedre, R., Berg, K., Kolomiets, M., Ibanez-Carrasco, F., and Mandadi, K. K. (2024) CRISPR-CAS9 editing of NPR3 confers resistance to potato zebra chip disease. Plant Biotechnol. J. 22, 2635-2637.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Wang, H., Irigoyen, S., Liu, J., Ramasamy, M., Padilla, C., Bedre, R., Yang, C., Thapa, S.P., Mulgaonkar, N., Ancona, V., He, P., Coaker, G., Fernando, S., and Mandadi, K.K. (2024) Inhibition of a conserved bacterial dual-specificity phosphatase confers plant tolerance to Candidatus Liberibacter spp. iScience, 27, 109232.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Rajkumar, M.S, Ibanez-Carrasco, F., Avila, C. A., & Mandadi, K. K. (2024). Insights into Bactericera cockerelli and Candidatus Liberibacter solanacearum interaction: a tissue-specific transcriptomic approach. Frontiers in Plant Science, 15, 1393994.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Mallawarachchi, S., Haoqi W., Nirmitee M., Irigoyen, S., Padilla, C., Mandadi, K., Borneman, J., and Fernando, S. (2024) Specifically targeting antimicrobial peptides for inhibition of Candidatus Liberibacter asiaticus. J. App. Microbiol. 135, no. 4, lxae061.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Hajeri, S., Olkowski, S., Kumagai, L., McRoberts, N., and Yokomi, R.K. (2023). Alternative tissue sampling for improved detection of Candidatus Liberibacter asiaticus. Plants 12, 3364.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Yokomi, R. K., and Hajeri, S. (2023). Survey estimates of the incidence and diversity of Citrus tristeza virus in California. Journal of Citrus Pathology, 10(1).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Mandadi, K.K. (2024). Novel strategies to screen and evaluate genetic- and chemical-based solutions for crop improvement. Annual Conference of the Society for Experimental Biology (SEB), July 2-5. Prague, CZ.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Mandadi, K.K. (2024). Citrus CAP: A NIFA Center of Excellence for Discovery and Development of Citrus Greening Therapies. Invited Webinar for USDA APHIS PPQ-S&T-Domestic & Emergency Scientific Support (DESS), May 10, Washington DC.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Mandadi, K.K. (2024). Identification and evaluation of new chemicals and antimicrobial peptides for HLB management. International Research Conference on Huanglongbing (IRCHLB VII). March 26-29. Riverside, CA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Ancona V., Yang, C., Mandadi, K. Field Evaluation of Small Molecules for Citrus Huanglongbing Management in Texas. International Research Conference on Huanglongbing (IRCHLB VII). March 26-29. Riverside, CA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Yang, C., Pasupuleti, L., Mandadi, K., Ancona, V. Assessing the Effect of Propidium Monoazide on Sequencing the Viable Endophytic Microbiome in Huanglongbing-affected Citrus. International Research Conference on Huanglongbing (IRCHLB VII). March 26-29. Riverside, CA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Ancona V., Yang, C., Mandadi, K. Field Evaluation of Small Molecules for Management of Citrus Huanglongbing in Texas. APS Caribbean Division 2024  April 15-17  Merida, MX
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Ancona V., Yang, C., Mandadi, K (2024). Field Evaluation of Novel Small Molecules for Mitigation of Citrus Huanglongbing in Texas. International Congress of Plant Pathogenic Bacteria & Biocontrol. July 7-12. Blacksburg, VA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Yang, C., Pasupuleti, L., Mandadi, K., Ancona, V. Deciphering Microbiome of Huanglongbing-affected Citrus Trees Applied by Oxytetracycline in South Texas. International Congress of Plant Pathogenic Bacteria & Biocontrol. July 7-12. Blacksburg, VA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Albrecht U. (2024) Antibiotic Injection for Managing HLB. International Citrus Congress Challenges and Perspectives, Universidad Aut�noma de Tamaulipas, Tamaulipas, Mexico, 6 Nov 2024.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Albrecht U. (2024) An Industry in Crisis. Florida Ag Policy Outlook Conference. Gulf Coast Research and Education Center, Wimauma, FL, 17 April.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Albrecht U. (2024) State of Emergency. International Research Conference on Huanglongbing (IRCHLB VII). March 26-29. Riverside, CA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Xicay A. E., S.D. Zapata, K.K. Mandadi, V. Contreras, F.A. Ibanez-Carrasco. Economic Feasibility of Novel HLB Control Strategies Selected Paper. 2023 Food Distribution Research Society Annual Meeting. Washington, DC, November 13, 2023.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Xicay, A., S. Zapata, K.K. Mandadi, V. Contreras, F.A. Ibanez-Carrasco. Evaluating the Economic Implications of Novel Citrus Greening Control Strategies Selected Paper. 2024 Southern Agricultural Economics Association Annual Meeting. Atlanta, GA, February 06, 2024.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Zapata, S. D., A. E. Xicay, K.K. Mandadi, V. Contreras. Are New Chemical Treatments for Huanglongbing Cost-Effective? Evidence from Texas Selected Poster. 2024 International Research Conference on Huanglongbing. Riverside, CA, March 26-29, 2024.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Olaniyi, I.A., Jung, J., Enciso, J., Mandadi, K.K. (2024). Estimating Tree-Level Yield of Citrus Fruit Using Multi-temporal UAS Data. 2024 North American Plant Phenotyping Network (NAPPN) Conference. Feb 13-15. West Lafayette, IN.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Olaniyi, I.A., Jung, J., Enciso, J., Mandadi, K.K. (2024). Estimating Tree-Level Yield of Citrus Fruit Using Multi-temporal UAS Data. 2024 IEEE Geoscience and Remote Sensing Society (GRSS) Image Analysis and Data Fusion (IADF) School. Sep 10-13. University of Sannio, Benevento, Italy.
  • Type: Other Journal Articles Status: Published Year Published: 2024 Citation: Yokomi, R. and Hajeri, S. (2023). Surveys of Citrus tristeza virus in California orchards. Citrograph 14(2):62-67.
  • Type: Other Journal Articles Status: Published Year Published: 2024 Citation: Hajeri, S., Kumagai, L., Olkowski, S., Yokomi, R., and McRoberts, N. (2023) Improving tissue sampling for consistent detection of CLas. Citrograph 14(2):52-58.
  • Type: Other Journal Articles Status: Published Year Published: 2024 Citation: Mitra, A., Bodaghi, S., Gadhave, K., Helm-Rodriguez, S., Yokomi, R., Frolli, A., El-Kereamy, A., Vidalakis, G. (2024). Biology and transmissibility of CYVaV-like RNA. Citrograph 15(2):64-70.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Xicay A. E., S.D. Zapata, K.K. Mandadi, V. Contreras. Evaluating the Cost-Effectiveness of Novel Chemical Control Strategies for Huanglongbing (HLB) in Texas Selected Paper. 2024 Agricultural and Applied Economics Association Annual Meeting. New Orleans, LA, July 29, 2024.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: I Olaniyi, J Enciso, KK Mandadi, J Jung. Estimating Tree-LEVEL YIELD of Citrus Fruit Using MULTI-Temporal UAS Datasets. 2023 ASA, CSSA, SSSA International Annual Meeting.


Progress 09/15/22 to 09/14/23

Outputs
Target Audience:The following target audience was reached by the efforts and activities of this reporting period. • Plant pathology, microbiology, and biotechnology scientific research communities. • Students, postdocs, and early career scientists. • Agricultural community, including the citrus industry, growers, and consumers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?• The project has provided research training and mentoring opportunities to several undergraduate students, graduate students, research technicians, as well as early career postdocs and research scientists. • The students and staff were routinely mentored by the PIs in laboratory techniques and scientific inquiry. • The students and staff were also given opportunities to attend and present their research at professional conferences. • Additionally, senior staff was provided opportunities to junior mentor staff, thus enhancing their teaching and mentoring skills. How have the results been disseminated to communities of interest?• Project updates and results were periodically disseminated by the team members to various groups of stakeholders in TX, FL, and CA through a variety of avenues, including in-person meetings, workshops, and various social media channels, as detailed in the extension/outreach accomplishments above. • The results were also periodically disseminated to the broader scientific community through research publications and presentations at regional and international conferences. What do you plan to do during the next reporting period to accomplish the goals?• We will continue the proposed research activities in the laboratory, greenhouse, and field trials. Any additional candidate small molecules and AMPs that demonstrated promising activity in the hairy root assays will be moved to the greenhouse and field testing pipeline. • Results from the efficacy/field trials will be utilized to initiate economic feasibility studies in order to evaluate the profitability of adopting new HLB therapies on new and existing groves. • We will continue our outreach and extension activities to stakeholders in TX, FL, and CA and to the broader scientific community through a variety of avenues such as meetings, conferences, publications, and online media.

Impacts
What was accomplished under these goals? The proposed objectives/activities are underway and on track. Briefaccomplishments are below: Obj. 1. High throughput hairy root pre-screening and selection of effective HLB therapies. For this reporting period, after screening multiple classes of therapies (defensins/antimicrobial peptides and small molecules/chemistries) in hairy root assays, we identified ~6-8 promising candidates that were advanced to field trials (Obj. 2-3). Additionally, we have started screening new libraries of chemistries (agrochemicals and natural products) to gain more hits. We have also optimized the efficiency of the hairy root transformation and efficacy testing by evaluating new explant sources based on citron. The new sources/methods enabled testing the efficacy of AMPs in as little as 2 months. Additionally, we have developed new methods to regenerate stable citrus transgenic plants from hairy roots, and the results are published in the Plant Biotechnology Journal. Together, these continuous developments have been helpful in further speeding up the AMP and therapeutic testing pipeline. Obj. 2. Evaluation of antimicrobial peptides using CTV vector in citrus trees. For this reporting period, CTV-AMP vector optimization and cloning were completed with the selected AMPs. The performance of the citrus trees expressing the first batch of CTV-AMPs was also evaluated in the experimental field sites of Southern Gardens Citrus in FL. The preliminary data show promising yield improvement compared to controls. These updates were presented at the 2023 Annual Project Directors meeting in D.C. The evaluation of the new batches of AMPs will be pursued similarly for the remainder of the project's timeframe and will be reported accordingly. Briefly, all the field trials are being conducted under approved EPA EUP/BRS and USDA permits. The experimental design comprises a randomized complete block design with 50-60 tree replicates under natural HLB/ACP pressure. As per the workflow, the respective CTV-AMP expressing mother citrus plants were first generated in the greenhouse. Subsequently, the CTV-AMP expressing inoculum was graft inoculated onto citrus nursery trees ready to be planted in the field. The stability and CTV expression of the CTV-AMP inserts is monitored and periodically verified by RT-PCR in both the mother and the field plants. The HLB incidence in the field is also monitored by qPCR. Fruit yield and other plant health traits (canopy volume, trunk diameter, etc.) will be analyzed annually. Obj. 3. Evaluation of small molecule therapies in citrus trees. For this reporting period, we completed testing of the first batch of small molecule (~3 candidates) treatments along with Oxytetracycline (OTC) in HLB-affected citrus trees in TX by trunk injections. Preliminary data shows promising yield (quantity and quality) improvement in the trees injected with the new molecules compared to controls. The effects were on par or better than OTC. These updates were presented at the 2023 Annual Project Directors meeting in D.C. We have also initiated a second year of injections of the same trees to determine the cumulative effects. As before, the molecules were delivered into trees using trunk injections with Chemjet injectors above the graft union, two per tree on opposite sides. Multiple tree health traits will be assessed periodically by ground truthing and unmanned aerial vehicles (UAVs). Examples include measurement of disease index, flushing rate, canopy volume/density, CLas titers biannually, pre-harvest fruit drop, and ultimately fruit yield (boxes/tree), and quality traits annually during harvest season. Obj. 4. Pursue data collection for regulatory approvals of the new therapies. This objective is NOT funded by NIFA. It isindependently pursued by Southern Gardens Citrus (SGC) and partners. SGC has developed a plan and initiated various required data collections and waivers to seek EPA approvals for promising defensin/AMP therapies. A suite of good laboratory practice (GLP) data collection will be pursued using agency guidelines and included in a registration application package to support pesticide registration regulatory requirements for approval. These included, but were not limited to, a market basket study, health/dietary risk assessment, non-target effects on beneficial, pollinator/honeybee toxicity, and product characterization. Obj. 5. Evaluate the economic feasibility of deploying new HLB therapies. Initiated. Recent results from the efficacy/field trials of OTC and new chemistries were provided to the economists to initiate economic feasibility studies. The goal is to evaluate the profitability of adopting new HLB therapies on new and existing groves. The work is ongoing, and future reports will report outcomes to the stakeholders. Obj. 6. Extension and outreach to inform stakeholders Team members organized citrus greening workshops/symposiums at the 2023 Annual Meeting (2023) of the American Phytopathological Society-Caribbean Division (APS-CD) at South Padre Island, TX. Attendees: ~60. Team members organized and presented multiple talks at the 2nd Congress of the International Society for Citrus Huanglongbing and Phloem-Colonizing Bacterial Pathosystems (IS-CHPP), October 25-28, Clearwater Beach, FL. Attendees: ~100 Team members presented a poster entitled "Advanced Testing of Promising HLB Therapies and Extending Outcomes to the Citrus Industry" to showcase the project highlights at the Plant Health 2023 annual meeting of the American Phytopathological Society (APS), August 12-16, Denver, CO. Team members organized and presented at the 76th Annual Meeting of Subtropical Agriculture and Environments Society, Weslaco, TX. Attendees: ~50. A NIFA ECDRE research project snapshot was published on the Science for Citrus Health website. Attendees: World Wide Web. Team members were invited as speakers at the 2023 Florida Citrus Mutual and the 2023 Texas Citrus Mutual annual conferences. We also leveraged several means to engage stakeholders by publishing news releases on the project findings and/or individual meetings with citrus stakeholders in TX, FL, CA, and the wider public. These were prepared and disseminated through regional and national news outlets and on social media channels. Our extension team, affiliated with regional citrus research and extension centers in TX, FL, and CA, continuously interacted with citrus growers, industry, and other stakeholders. Team members also participated in citrus growers' and organizations' meetings (e.g., CRDF, TCM, TCPDMC, TAMUK-Citrus Center), where the project activities/updates were provided to the stakeholders. Lastly, our project advisory board included multiple growers and industry and commodity group members, who were periodically informed of the project activities both at the annual advisory board meeting and by engaging with them individually.

Publications

  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Ramasamy, M., Dominguez, M.M., Irigoyen, S., Padilla, C.S., and Mandadi, K.K. Rhizobium rhizogenes-mediated hairy root induction and plant regeneration for bioengineering citrus. (2023) Plant Biotechnol. J. 21, 1728-1730
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Kennedy, J.P., Wood, K., Pitino, M., Mandadi, K., Igwe, D.O., Shatters, R., Widmer, T.L., Niedz, R., and Heck, M. (2023). A perspective on current therapeutic molecule screening methods against Candidatus Liberibacter asiaticus, the presumed causative agent of citrus Huanglongbing. Phytopathology. 113, 1171-1179
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Tuncel, A., Pan, C., Sprink, T., Wilhelm, R., Barrangou, R., Li, L., Shih, P.M., Varshney, R.K., Tripathi, L., Van Eck, J. Mandadi, K., and Qi, Y. (2023). Genome-edited foods. Nature Reviews Bioengineering, pp.1-18 https://www.nature.com/articles/s44222-023-00115-8
  • Type: Journal Articles Status: Under Review Year Published: 2023 Citation: Wang, H., Irigoyen, S., Liu, J., Ramasamy, M., Padilla, C., Bedre, R., Yang, C., Thapa, S.P., Mulgaonkar, N., Ancona, V., He, P., Coaker, G., Fernando, S., and Mandadi, K.K. Molecular modeling and ligand screening identify two novel small molecules that confer plant tolerance to Candidatus Liberibacter spp.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Wang, H., Mulgaonkar, N., Mallawarachchi, S., Ramasamy, M., Padilla, C.S., Irigoyen, S., Coaker, G., Mandadi, K.K. and *Fernando, S. (2022). Evaluation of Candidatus Liberibacter asiaticus efflux pump inhibition by antimicrobial peptides. Molecules, 27, 8729.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Mandadi, K. K. (2023). New technologies to control HLB and promote tree health., Texas Citrus Mutual Annual Meeting. Sep 12, Weslaco, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Mandadi, K. K. (2023). Evaluation of novel antimicrobials for HLB management. Florida Citrus Industry Annual Conference, Florida Citrus Mutual. June 14-16, Bonita Springs, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Mandadi, K.K. (2023) Discovery and evaluation of new antimicrobials for citrus greening disease management. Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD). Feb 9-10, South Padre Island, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Mandadi, K.K. (2022). Evaluation of defensin antimicrobial peptides and small molecules as therapies for citrus greening disease management. 2nd Congress of the International Society for Citrus Huanglongbing and Phloem-Colonizing Bacterial Pathosystems (IS-CHPP), October 25-28, Clearwater Beach, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Mandadi, K.K. (2022). Novel approaches to screening antimicrobials against fastidious pathogens. UC-Riverside, Plant Pathology Seminar series. October 13, Riverside, CA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Liu, J., Padilla, C., Irigoyen, S., He, P., and Mandadi, K.K. (2023) A dual-specificity phosphatase of C. Liberibacter sp. interacts with citrus ATPases and interferes with immune responses. Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD). Feb 9-10, South Padre Island, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Kavuri, N. R., Bedre, R., Ramasamy, M., Irigoyen, S., Nelson, A., Mandadi, K. K. (2023) Identification of long intergenic non-coding RNA modulated by Candidatus Liberibacter spp. in potato. Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD). Feb 9-10, South Padre Island, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Ramasamy, M., Rajkumar, M.S., Irigoyen, S., Bedre, R., Berg, K., Kolomiets, M., Ibanez-Carrasco, F., Mandadi, K. K. (2023) CRISPR-CAS9 editing of NPR3 confers resistance to potato zebra chip disease. Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD). Feb 9-10, South Padre Island, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Mora, V., Ramasamy, M., Damaj, M.B., Irigoyen, S., Ancona, V., Avila, C.A., Vales, M.I., Ibanez, F. and Mandadi, K.K. (2023) Identification of potato zebra chip disease resistance among wild Solanum species. Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD). Feb 9-10, South Padre Island, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Padilla, C.S., Dominguez, M.M., and Mandadi, K.K. (2023) An Agrobacterium-based stable plant transformation method applicable to a variety of Citrus cultivars. Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD). Feb 9-10, South Padre Island, TX
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Kulshreshtha, A., Ramasamy, M., Padilla, C., Irigoyen, S., and Mandadi, K.K. (2023) Efficient and rapid citrus hairy root transformation for gene expression and functional studies. Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD). Feb 9-10, South Padre Island, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Ancona, V. (2023). Tree demonstration on Oxytetracycline trunk injections for use in combating HLB. Texas Citrus Mutual Annual Meeting. Sep 12, Weslaco, TX
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Yang, C., Ancona, V. (2023). Implementation of Propidium Monoazide-qPCR for Assessing Antibiotic Effectiveness against Candidatus Liberibacter asiaticus in Citrus. Subtropical Agriculture and Environments Society. Annual meeting. February 9-10, 2023. South Padre Island, TX
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Alabi, O.J. (2023). An overview of current and emerging disease threats to citrus production in Texas. Subtropical Agriculture and Environments Society. Annual meeting. February 9-10, 2023. South Padre Island, TX
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Pasupuleti, L., Yang, C., Ibanez, F., Ancona, V. (2023). The effect of citrus flush stage in the distribution of trunk-injected oxytetracycline for HLB Management. American Phytopathological Society Caribbean Division Meeting. February 9-10,2023. South Padre Island, TX
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Pasupuleti, L.A., Yang, C., Ibanez-Carrasco, F., Ancona, V. (2022). Assessing the effect of trunk-injected oxytetracycline on Candidatus Liberibacter asiaticus titers in flushing and non-flushing citrus branches. 2nd Congress of the International Society for Citrus Huanglongbing and Phloem-colonizing Bacterial Pathosystems. October 25-28, 2022. Clearwater Beach, FL
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Yang, C., Ancona, V. (2022). Developing a Rapid Viability Propidium Monoazide-PCR Method for Assessing Treatment Effectiveness against Candidatus Liberibacter asiaticus in Citrus. 2nd Congress of the International Society for Citrus Huanglongbing and Phloem-colonizing Bacterial Pathosystems. October 25-28, 2022. Clearwater Beach, FL
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Albrecht, U., Archer, L., de Freitas, J., Moreno, G., Tardivo, C. (2023) Trunk Injection of oxytetracycline consistently improves yield and fruit quality of huanglongbing-affected citrus trees. Annual Meeting of the American Society for Horticultural Sciences, FL. July 31-Aug 4, Orlando, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Khalid, M.F., Ramasamy, M., Yang, C., Pasupleti, L.A., Irigoyen, S., Ibanez, F., Ancona, V.A., Mandadi, K.K., Albrecht, U. (2023). Evaluation of novel anti-CLas compounds administered by trunk injection against Huanglongbing in Texas and Florida. Annual Meeting of the American Society for Horticultural Sciences, FL. July 31-Aug 4, Orlando, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Albrecht, U. (2023). Making it work  adopting trunk injection for HLB management. Florida Citrus Industry Annual Conference, June 14-18, Bonita Springs, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Albrecht, U. (2023). The latest on trunk injection. Citrus Expo, Aug 16-17, Tampa, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Olaniyi, I.A., Jung, J., Enciso, J., Mandadi, K.K. (2023) Estimating Tree-level Yield of Citrus fruit using multi-temporal UAS datasets. 2023 Digital Forestry Retreat. Aug 1, Purdue University, West Lafayette, IN.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Juan Enciso, Catherine R. Simpson, Veronica Ancona, David Laughlin, and Kranthi Mandadi (2022). The use of UAS in Irrigation in South Texas. International Citrus Congress, 06-11 November, Mersin, Turkey.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: El Mohtar C.A., Shilts T., Robertson C., Bierman C.T., Graffam, C. Robinson M., Dawson W.O. Using Citrus tristeza virus (CTV)-based vector as a platform for the management of Huanglongbing (HLB). 2nd Congress ISCHPP Confronting the Phloem Colonizing Bacterial Pathosystems Together. October 25-28, 2022. Clearwater Beach, Florida, U.S.A.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Alabi, O.J., Mandadi, K.K. (2023). An advanced testing of promising HLB therapies and extending outcomes to the citrus industry. Plant Health 2023 Annual Meeting of the American Phytopathological Society (APS), August 12-16, Denver, CO, U.S.A.


Progress 09/15/21 to 09/14/22

Outputs
Target Audience:The following target audience was reached by the efforts and activities of this reporting period. Plant pathology,microbiology, and biotechnologyscientific research communities. Students, postdocs, and early career scientists. Agricultural community, including the citrus industry,growers, and consumers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The project has provided research training and mentoring opportunities to severalundergraduate students, graduate students, research technicians, as well as early career postdocs and research scientists. The students and staff were routinely mentored by the PIs in laboratory techniques and scientific inquiry. The students and staff were also given opportunities to attend and present their research at professional conferences. Additionally, senior staff was provided opportunities to junior mentor staff, thus enhancing their teaching and mentoring skills. How have the results been disseminated to communities of interest? Project updates and results were periodically disseminated by the team members to various groups of stakeholders in TX, FL, and CAthrough a variety of avenues, including in-person meetings, workshops, and various social media channels, as detailed in the extension/outreach accomplishments above. The results were also periodically disseminated to the broader scientific community throughresearch publications andpresentations at regional and international conferences. What do you plan to do during the next reporting period to accomplish the goals? We will continue the proposed research activities in the laboratory, greenhouse, and field trials. Any additional candidatesmall molecules and AMPs that demonstrated promising activity in the hairy root assays will be moved to thegreenhouse and field testing pipeline. Results from the efficacy/field trials will be utilized to initiate economic feasibility studies in order to evaluate the profitability of adopting new HLB therapies on new and existing groves. We will continue our outreach and extension activities to stakeholdersin TX, FL, and CA and to the broader scientific community through a variety of avenues such as meetings,conferences, publications, and online media.

Impacts
What was accomplished under these goals? The proposed objectives/activitiesare underway and on track. Briefaccomplishments forthis reporting period are below: Obj. 1. High throughput hairy root pre-screening and selection of effective HLB therapies. Two classes of therapies were evaluated: a) defensins/antimicrobial peptides (AMPs) and b) small molecules/chemistries. For evaluating AMPs, each of the coding regions was cloned into binary expression vectors and transformed into CLas-citrus hairy roots using the optimized hairy root transformation methods. Hairy root tissue samples were collected for molecular diagnostics at ~90-120 days to confirm the expression of the candidate AMP using RT-qPCR, followed by CLas molecular diagnostics/data analysis to determine efficacy. For small-molecule therapeutic screening, CLas-citrus hairy root cultures were initiated as per established protocols, and QC was conducted periodically to determine CLas titers in the hairy roots. Subsequently, the CLas-citrus hairy roots were used for the HR assays with several candidate molecules, followed by molecular diagnostics/data analysis to determine efficacy. Statistical analysis was performed using ANOVA/Post hoc and/or Student's t-test as appropriate to determine significant differences. Together, these experiments identified multiple AMPs and small molecules that were advanced to in planta trials. Obj. 2. Evaluation of antimicrobial peptides using CTV vector in citrus trees. For AMP evaluation, CTV vector optimization and cloning were initiated with the selected AMPs. A batch of CTV-defensin testing is also underway under greenhouse conditions. After confirmation of the systemic spread of the CTV-AMP in the trees, the material will be used as a source of inoculum to graft citrus trees for field planting. The field trials will be conducted in FL under EPA EUP, and USDA APHIS/BRS permits. These trials will be performed in a randomized complete block design under natural HLB/ACP pressure. Obj. 3. Evaluation of small molecule therapies in citrus trees. Phytotoxicity assays with the small molecules were initiated and completed in the greenhouse citrus plants. Based on the results of the phytotoxicity, appropriate dosages for field treatments were formulated. Field tree scouting and diagnostics in TX and FL locations were completed, and the first round of trials was initiated in the two locations. Delivery of the molecules into trees was achieved using trunk injections with Chemjet injectors above the graft union, two per tree on opposite sides. Multiple tree health traits will be assessed periodically by ground truthing and by using unmanned aerial vehicles. Examples include measurement of disease index, flushing rate, canopy volume/density, CLas titers biannually, pre-harvest fruit drop, and ultimately fruit yield (boxes/tree), and quality traits annually during harvest season. Obj. 4. Pursue data collection for regulatory approvals of the new therapies. This objective is NOT funded by NIFA. It isindependently pursued by Southern Gardens Citrus (SGC). SGC has initiated various required data collections and waivers to seek EPA approvals for promising defensin/AMP therapies. A suite of good laboratory practice (GLP) data collection was being pursued using agency guidelines and included in a registration application package to support pesticide registration regulatory requirements for approval. These included but were not limited to, a market basket study, health/dietary risk assessment, non-target effects on beneficial, pollinator/honeybee toxicity, and product characterization. Obj. 5. Evaluate the economic feasibility of deploying new HLB therapies. Results from the ongoing efficacy/field trials will be utilized in the future to initiate economic feasibility studies. The goal is to evaluate the profitability of adopting new HLB therapies on new and existing groves. Obj. 6. Extension and outreach to inform stakeholders Team members have been active in organizing and presenting at several symposia, workshops, and meetings. Specifically, team members organized and presented a citrus greening workshop/symposium at the Joint Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD) and Entomological Society of America South-Eastern Branch (SEB), San Juan, Puerto Rico. Its titled "Citrus greening or Huanglongbing (HLB): Strategies for mitigation and control." The goal was to provide an update on the HLB status and ongoing R&D efforts on new strategies and therapies to control the vector and the pathogen. We covered HLB epidemiology, insect vector management, RNAi, and new therapeutic screening and delivery systems to control HLB. Attendees: ~30. Team members also organized and presented at the symposium of the 76th Annual Meeting of Subtropical Agriculture and Environments Society, Weslaco, TX. Relevant topics covered included ongoing R&D efforts on new strategies and therapies to control HLB, as well as perspectives on the state of affairs of the citrus industry after the freezes. Attendees: ~50. Team members published a Research Snapshot article that is available for download on the Science for Citrus Health website. Attendees: World wide web. Mandadi, K., Irigoyen, S., Ramasamy, M. (2021). Novel tools for antimicrobial testing and discovery of new HLB therapies. Science for Citrus Health. We also leveraged several means to engage stakeholders by publishing news releases on the project overview aimed to inform citrus stakeholders in TX, FL, and CA and the wider public. These were prepared and disseminated through regional and national news outlets, as well as on social media channels. Our extension team, affiliated with regional citrus research and extension centers in TX, FL, and CA, had continuous interactions with citrus growers, industry, and other stakeholders. Team members also participated in citrus commodity and growers' board meetings where the project activities/updates were provided to the stakeholders. Lastly, our project advisory board included multiple growers, industry, and commodity group members, who were periodically informed of the project activities both at the annual advisory board meeting, as well as engaging with them individually.

Publications

  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Wang, X., Mandadi, K., Peña, L., Cao, M. and Zhou, C. (2022). Evolutionary genomics of Candidatus Liberibacter spp. and their interactions with plant and insect-vector hosts. Front. Microbiol., 13.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Mandadi, Kranthi (2022). Genetic and biotechnology strategies to control insect-vectored diseases. 76th Annual Meeting of Subtropical Agriculture and Environments Society, March 11, Weslaco, TX
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Ibanez-Carrasco, Freddy (2022). Importance of Vector Control management under HLB stress. Insect Interactions with Microbes and Plant Hosts (Applied), March 25, College Station, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Mandadi, Kranthi (2022). High throughput therapeutic screening using hairy root system. Joint Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD) and Entomological Society of America South-Eastern Branch (SEB). March 26-30, San Juan, PR.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Albrecht, Ute (2022). Vascular delivery of HLB therapies. Joint Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD) and Entomological Society of America South-Eastern Branch (SEB). March 26-30, San Juan, PR.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Irey, Mike (2022). Mitigation of the now endemic, once exotic disease of HLB in Florida - 17 years after introduction. Joint Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD) and Entomological Society of America South-Eastern Branch (SEB). March 26-30, San Juan, PR.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Alabi, Olufemi (2022). Huanglongbing (citrus greening disease): Current situation and epidemiological insights. Joint Annual Meeting of the American Phytopathological Society Caribbean Division (APS-CD) and Entomological Society of America South-Eastern Branch (SEB). March 26-30, San Juan, PR.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Jung, Jinha (2022). Democratization of Geospatial Data for Artificial Intelligence in Agriculture. Envisioning 2050 in the Southeast: AI-driven innovations in agriculture, March 9-11, Auburn, AL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Enciso, Juan, U Cholula, A Masih, JL Chavez, J Solorzano, A Laredo. (2021) Evaluating the Use of True Color Unmanned Aerial System images for Irrigation Scheduling in Citrus. 6th Decennial National Irrigation Symposium, December 6-8, 2021, San Diego, CA
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Dominguez, M.M., Padilla, C.S. & Mandadi, K.K. (2022). A versatile Agrobacterium-based plant transformation system for genetic engineering of diverse citrus cultivars. Front. Plant Sci. 13.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: El-Mohtar, C. A., Shilts, T., Robertson, C., Levy, A., & Dawson, W. O. (2021). Gene therapy using Citrus tristeza virus to manage HLB disease. In PHYTOPATHOLOGY, 111, pp. 179-179.