BIOTECHNOLOGICAL APPROACHES FOR IMPROVING SWEETPOTATO CROP WITH MULTIPLE VIRUS RESISTANCE

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: OTHER GRANTS
• Reporting Frequency: Annual
• Accession No.: 1015117
• Grant No.: 2018-38821-27741
• Cumulative Award Amt.: $298,915.00
• Proposal No.: 2017-07526
• Project Start Date: Mar 15, 2018
• Project End Date: Mar 14, 2023
• Grant Year: 2018
• Program Code: [EQ]- Research Project

Recipient Organization
ALCORN STATE UNIVERSITY
(N/A)
ALCORN STATE,MS 39096

Performing Department
Agriculture

Non Technical Summary
Sweetpotato (Ipomoea batatas (L.) Lam.; Convolvulaceae), a plant widely grown in all tropical and subtropical areas, is among the 10 most important food crops worldwide. As a crop produced by vegetative propagation, "cultivar decline" due to viral infections significantly reduces sweetpotato yield and storage root quality. In the United States, Sweet potato feathery mottle virus (SPFMV) and Sweet potato leaf curl virus (SPLCV) are two of the most prevalent sweetpotato viruses that cause devastating diseases and yield reductions. Even though resistance to viral infections remains the most cost effective way of disease management, to date, immune resistance to these viruses has not been identified in I. batatas. In this study, we will explore a novel biotechnological method to develop transgenic sweetpotato plants with resistance to these two viruses. The overall goal of this project is to develop and manage sweetpotato viral disease resistance through biotechnology approaches in US, aiming at increasing the sweetpotato yield, quality and investment return for farmers. Specifically, we propose the following objectives: 1) To develop a plant transformation and regeneration protocol for the production of value-added sweetpotato lines using popular production lines; 2) To create transgenic virus resistance lines in sweetpotato to multiple important epidemic viruses; 3) To conduct biological evaluation of the transgenic lines for their resistance to multiple viruses under diverse growth conditions and agricultural practices. Successful execution of this project will significantly boost quality of life and environment in the underserved communities and enhance research and education capacities of Alcorn State University.

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
202	1450	1081	100%

Knowledge Area
202 - Plant Genetic Resources;

Subject Of Investigation
1450 - Sweet potato;

Field Of Science
1081 - Breeding;

Keywords

sweetpotato

viral disease resistance

genetic engineering

value added

Goals / Objectives
The overall goal of this project is to develop and manage sweetpotato viral disease resistance through biotechnology approaches in US, aiming at increasing the sweetpotato yield, quality and investment return for farmers. Specifically, we propose the following objectives: 1) To develop a plant transformation and regeneration protocol for the production of value-added sweetpotato lines using popular production lines; 2) To create transgenic virus resistance lines in sweetpotato to multiple important epidemic viruses; 3) To conduct biological evaluation of the transgenic lines for their resistance to multiple viruses under diverse growth conditions and agricultural practices.

Project Methods
Objective 1: To develop a plant transformation and regeneration protocol for the production of value-added sweetpotato lines using popular production lines.Sweet potato varieties 'Beauregard' and 'Jewel', and ASU breeding line "Excel 2", will be used for transformation. All the plants material will be subcultured every 4 weeks onto a fresh MS medium (Murashige and Skoog, 1962) supplemented with 3% sucrose. Cultures are maintained in a temperature controlled chamber at 26°C with a 16-h photoperiod, with light intensity ranging from 400 to 1,000 μmol m-2 s-1. Dissected leaf disks, petiole and stem segments from the in vitro manipulated stock will be used as explants to gene transformation.In the United States, SPFMV and SPLCV are two of the most prevalent sweetpotato viruses that cause devastating diseases and yield reductions. In this study, we will explore novel biotechnological approaches to develop the PDR in transgenic sweetpotato plants with resistance to these two viruses. The SPFMV and SPLCV genomes were cloned from the MS field isolates by Dr. Chunquan Zhang (Co-PI) (Zhang et. al., 2015, Akrong et. al., 2016). Dr. Zhang further engineered part of coat protein (CP) gene of SPFMV and the replication origin region of SPLCV into a binary vector pCAMBIA1303 for Agrobacterium-mediated or direct biolistic delivery-based genetic transformation for transgene expression. SPFMV CP partial gene sequence and SPLCV replication origin sequence were designed in antisense for the optimal induction of RNA silencing in sweetpotato. Likewise, the SPFMV CP partial gene sequence and SPLCV replication origin sequence were blasted with the available isolates in US, and the conserved regions were selected, thus the transgenic sweetpotato is expected to have SPFMV and SPLCV resistance in and beyond Mississippi. With a two-year of pre-experiment, a high efficient transformation and plant regeneration system has been optimized for sweetpotato cultivars 'Jewel' in our lab (Meng et. al, 2016).Objective 2: To create transgenic viral resistance lines in sweetpotato to multiple important epidemic viruses.To evaluate the transgenic events generated in objective 1, we will conduct molecular characterization by doing PCR and Southern blot analysis. Total genomic DNA will be isolated from leaf tissue of putative transgenic and untransformed (control) plants using the ZR Plant/Seed DNA MiniprepTM kit (Zymo Research, SA). PCR analysis will be used for initial detection of putative transgenic plants. Primers complementary to the individual transgene segments of SPFMV and SPLCV will be used to detect the integrity of the transgene construct in plants. Amplification will be performed in an automated thermal cycler. For Southern blot analysis, total plant DNA (20 μg) from putative transgenic plants will be digested overnight at 37 °C with restriction endonuclease HindIII. DNA fragments will be separated by electrophoresis at 40 V for 3 h in a 1.2 % agarose gel and blotted onto positively charged nylon membranes (Roche, Germany) using the VacuGene XL Vacuum blotting System (GE Healthcare Bio-Sciences, Sweden). DNA fragments will be fixed to the membrane by UV crosslinking for 2-3 min (Stratalinker, Stratagene, CA, USA). The hybridization probe corresponding to the SPFMV segment will be used for the detection of the transgene and generated and labeled with alkali-labile digoxigenin (DIG-dUTP) in PCR using the PCR DIG Probe Synthesis kit (Roche, Germany). Hybridization of the probe to membrane and subsequent chemiluminescence detection by enzyme immunoassay will be performed using the DIG High Prime DNA Labeling and Detection Starter Kit II (Roche, Germany) according to manufacturer's instructions.Objective 3: To conduct biological evaluation on the transgenic lines for their resistance to multiple viruses under diverse growth conditions and agricultural practices.Transgenic plants will be assayed for virus resistance according to the method described by Okada et al. (2002). Vine samples that were NCM-ELISA positive for infection with isolates of SPFMV and SPLCV will be graft-inoculated onto 3 week-old indicator plants, Ipomoea setosa Ker Gawl. Two to three weeks post inoculation, typical virus induced symptoms will be observed on growing leaves of indicator plants. The vine cuttings from these virus-infected I. setosa plants served as scions (inoculum) in grafting experiments.

Progress 03/15/18 to 03/07/23

Outputs
Target Audience:The graduate and undergraduate students, lab technician, extension agents, farmers are the terget audience for this project. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During the execution of this project, the graduate and undergraduate students, lab technician, extension agents were trained with better skills and knowledge related with plant tissue culture techniques, crop genetic engineering and gene transformation, disease diagnosis techniques and field practices. Three courses related with tissue culture and genetic engineering techniques were well developed at undergraduate and graduate class levels. All the personnel mentioned above are benefit for the training and professional development. How have the results been disseminated to communities of interest?The research data were presented to several scientific meetings, including the annual Mississippi Academy of Sciences Meeting at Biloxi, MS and the 8th annual Center of Research Symposium at Alcorn State University. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Food security and nutrition security exist as the major concerns in many countries of the world. The sweetpotato (Ipomoea batatasL.), a member of the Convolvulaceae family, is the world's seventh most important food crop. However, as a crop produced by vegetative propagation, cultivar decline due to viral infections significantly reduces sweetpotato yield and storage root quality.Sweetpotato leaf curl virus(SPLCV) andSweetpotato virus C(SPVC) are two of the main viruses that cause devastating diseases and yield reductions in Mississippi.In this study, we developed an efficientAgrobacterium-mediated transformation approach to create transgenic sweetpotato plants with improved performance. The SPLCV and SPVC dual resistance genetic segment was introduced into a binary vector for expression. 10 lines of transgenic plants were generated from sweetpotato line PI318846. A grafting technique was used to test the viral resistance of the transgenic plants. 8 lines have detected the SPLCV infection, 2 were free of SPLCV infection.Successful execution of this projectsignificantly boost quality of life and environment in the underserved communities and enhance research and education capacities of Alcorn State University.

Publications

• Type: Journal Articles Status: Under Review Year Published: 2023 Citation: Lei Wang, Andrew J. Tonsager, Wenguang Zheng, Yingjun Wang, Dan Stessman, Wei Fang, Kenna E. Stenback, Alexis Campbell, Rezwan Tanvir, Jinjiang Zhang, Samuel, Cothron, Dongli Wan, Yan Meng, Martin H. Spalding, Basil J. Nikolau, Ling Li (2023). Single-cell genetic models to evaluate orphan gene function: the case of QQS regulating carbon and nitrogen Allocation. Frontiers. (Under Review).
• Type: Journal Articles Status: Submitted Year Published: 2023 Citation: Lei Wang, Carol M. Foster, Wieslawa I. Mentzen, Rezwan Tanvir, Yan Meng, Basil J. Nikolau, Dan Nettleton, Alan M. Myers, and Eve Syrkin Wurtele, Ling Li (2023). Unraveling the connection between starch granule metabolism and acetyl-CoA utilization. Frontiers. (Under Review)
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Favour Afolabi, Yan Meng and Ling Li (2022). Utilizing novel biotechnology to develop new sweetpotato varieties with improved protein levels and broad-spectrum disease resistance. 8th Annual Center for Research Excellence Symposium, Lorman, Mississippi. Alcorn State University, Lorman, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Myshawn Smith, Yan Meng, Victor Njiti, Chunquan Zhang (2022). Adaptation of Johnson Grass Mosaic Virus infection cDNA clone for agroinfiltration inoculation. 8th Annual Center for Research Excellence Symposium, Lorman, Mississippi. 8th Annual Center for Research Excellence Symposium, Alcorn State University, Lorman, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Tymesha Nabors, Chunquan Zhang and Yan Meng (2022). Developing Agrobacterium-mediated transformation approach to improve the viral resistance in sweetpotato ((Ipomoea batatas L.). 8th Annual Center for Research Excellence Symposium, Alcorn State University, Lorman, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Yan Meng, Tymesha Nabors, Favour Afolabi and Chunquan Zhang (2022). Developing Agrobacterium-mediated transformation approach to improve the viral resistance and protein levels in sweetpotato (Ipomoea batatas L.). 86th Annual Mississippi Academy of Sciences Meeting, Biloxi, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Favour Afolabi, Yan Meng and Ling Li (2022). Utilizing novel biotechnology to develop new sweetpotato varieties with improved protein levels and broad-spectrum disease resistance. Association of 1890 Research Directors, Atlanta, Georgia
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Tatyana Hollingbird, Chunquan Zhang and Yan Meng (2023). Developing sweetpotato germplasms with increased protein levels and improved viral disease resistance. 87th Annual Mississippi Academy of Sciences Meeting, Biloxi, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Jacob Piazza and Yan Meng (2023). Optimization of plant regeneration protocol for selective elite lines in sweetpotato (ipomoea batatas (l.) Lam). 87th Annual Mississippi Academy of Sciences Meeting, Biloxi, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Alpha Jones, Chunquan Zhang and Yan Meng (2023). Using meristem-tip tissue culture technique to remove viruses from sweetpotato. 87th Annual Mississippi Academy of Sciences Meeting, Biloxi, Mississippi

Progress 03/15/21 to 03/14/22

Outputs
Target Audience:The target audience during this reporting peroid includes farmers, seed companies, researchers, graduate students and undergraduate students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During the execution of this project, the graduate and undergraduate students, lab technician, extension agents were trained with better skills and knowledge related with plant tissue culture techniques, crop genetic engineering and gene transformation, disease diagnosis techniques and field practices. Three courses related with tissue culture and genetic engineering techniques were well developed at undergraduate and graduate class levels. All the personnel mentioned above are benefit for the training and professional development. How have the results been disseminated to communities of interest?The research data were presented to several scientific meetings, including the annual Mississippi Academy of Sciences Meeting at Biloxi, MS and the 8th annual Center of Research Symposium at Alcorn State University. What do you plan to do during the next reporting period to accomplish the goals?Our next goals to be accomplished will be objectives 2 and 3. Especially, to create more transgenic viral resistance lines in sweetpotato to multiple important epidemic viruses and to conduct viral resistance evaluation of the transgenic lines to multiple viruses under diverse growth conditions and agricultural practices. PI, Co-PIs and collaborators will continue to arrange meetings to discuss plans for execution of the goals.

Impacts
What was accomplished under these goals? We have been focusing on objective 3 in year four. An Agrobacterium-mediated transformation protocol was well-developed in the lab, and 10 PCR confirmed transgenic plants were obtained from sweetpotato line PI318846; We are generating transgenic sweetpotato plants from another commercial sweetpotato line PI566648. The viral resistance of transgenic plants is under investigation under controlled environment, by using grafting method, the protocol has been optimized during this period. The resistance of the transgenic plants to SPLCV and SPVC is under detecting by PCR or RT-PCR.

Publications

• Type: Books Status: Published Year Published: 2021 Citation: Meng Y, Zhang C and Njiti V (2021). Using Biotechnological approaches for virus elimination in sweet potato: a review. (book/chapter) in: Cutting-edge Research in Agricultural Sciences Vol. 11
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Tymesha Nabors and Yan Meng (2021). Agrobacterium-mediated transformation of sweet potato for improved resistance to viruses. 85th Annual Mississippi Academy of Sciences Meeting, Biloxi, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Myshawn Smith, Yan Meng, Victor Njiti, Chunquan Zhang (2021). Adaptation of johnson grass mosaic virus infection cDNA clone for agroinfiltration inoculation. 85th Annual Mississippi Academy of Sciences Meeting, Biloxi, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Florence Obialor, Chunquan Zhang, Yan Meng (2021). Using grafting technique to detect the viral resistance of transgenic sweet potato plants. 85th Annual Mississippi Academy of Sciences Meeting, Biloxi, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: E. Nnuji-John, C. Zhang, Y. Meng, V. Njiti (2021). Adaptation of Johnsongrass Mosaic Virus Genomic cDNA Clones for Agroinfiltration-based Inoculation. 7th Annual Center for Research Excellence, Alcorn State University, Lorman, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: M. Bajaj, F. Afolabi and Y. Meng (2021). Developing New Varieties of Sweetpotato with Improved Performance by Using a Novel Biotechnological Approach. 7th Annual Center for Research Excellence, Alcorn State University, Lorman, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: F. Afolabi and Y. Meng (2021). Novel Biotechnology to develop new sweetpotato varieties with improved protein levels and viral resistance. 7th Annual Center for Research Excellence, Alcorn State University, Lorman, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: T. Nabors and Y. Meng (2021). Using a Novel Biotechnological Approach to Improve Sweet Potato Crop with Multiple Virus Resistance. 7th Annual Center for Research Excellence, Alcorn State University, Lorman, Mississippi
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: D. Gbenga, Y. Meng and C. Zhang (2021). Developing a plant virus based foreign gene expression and silencing functional genomics platform on sweet potato. 7th Annual Center for Research Excellence, Alcorn State University, Lorman, Mississippi
• Type: Theses/Dissertations Status: Published Year Published: 2021 Citation: Aundrea Coleman (2021). Genetically engineered sweetpotato: a novel approach to improve sweetpotato viral resistance, Alcorn State University, Lorman, Mississippi

Progress 03/15/20 to 03/14/21

Outputs
Target Audience:The graduate and undergraduate students, lab technician, extension agents, farmers are the terget audience for this project. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During the execution of this project, the graduate and undergraduate students, lab technician, extension agents were trained with better skills and knowledge related with plant tissue culture techniques, crop genetic engineering and gene transformation, disease diagnosis techniques and field practices. Three courses related with tissue culture and genetic engineering techniques were developed at undergraduate and graduate class levels. All the personnel mentioned above are benefit for the training and professional development. How have the results been disseminated to communities of interest?The research data were presented to several scientific meetings regionally or nationally. What do you plan to do during the next reporting period to accomplish the goals?Our next goals to be accomplished will be objectives 2 and 3. Especially, to create more transgenic viral resistance lines in sweetpotato to multiple important epidemic viruses and to conduct biological evaluation the transgenic lines for their resistance to multiple viruses under diverse growth conditions and agricultural practices. PI, Co-PIs and collaborators will continue to arrange meetings to discuss plans for execution of the goals.

Impacts
What was accomplished under these goals? We having been focusing objectives 2 and 3 in year three. Plant regeneration protocols for four sweetpotato lines have been optimized. An Agrobacterium-mediated transformation protocol was well-developed in the lab, and 12 transgenic plants were obtained from one sweetpotato line; the transgenic events were confirmed by PCR. We are continuing to generate transgenic sweetpotato lines on another sweetpotato line. The viral resistance of transgenic plants is in investigation under controlled environment, by using biological approach and indicating plant setosa grafting method. The results needs to be further clarified.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Meng Y, Zhang C and Njiti V (2020). Virus elimination in sweetpotato: from meristem-tip culture to storage roots production: a review. Adv Agri Tech Plant Sciences 3(1): 180048

Progress 03/15/19 to 03/14/20

Outputs
Target Audience:The target audiences reached by efforts were the graduate and undergraduate students, lab technician, extension agents during this reporting period. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During the execution of this project, the graduate and undergraduate students, lab technician, extension agents were trained with better skills and knowledge related with plant tissue culture techniques, crop genetic engineering and gene transformation, disease diagnosis techniques and field practices. Three courses related with tissue culture and genetic engineering techniques were developed at undergraduate and graduate class levels. Flyers on plant disease management by applying modern biotechniques together with on-site demonstration and presentation have educated small farmers with raising awareness of viral disease knowledge based IPM for better environment protection. All the personnel mentioned above are benefit for the training and professional development. How have the results been disseminated to communities of interest?The research data were presented to several scientific meetings regionally or nationally. Posters, printed flyers and oral presentations during field days and workshops have direct impacted farmers knowledge base and raise discussion on how to integrated agricultural biotechnology into sweetpotato production practices. What do you plan to do during the next reporting period to accomplish the goals?Our next goals to be accomplished will be objectives 2 and 3. Especially, to create more transgenic viral resistance lines in sweetpotato to multiple important epidemic viruses and to conduct biological evaluation the transgenic lines for their resistance to multiple viruses under diverse growth conditions and agricultural practices. PI, Co-PIs and collaborators will continue to arrange meetings to discuss plans for execution of the goals.

Impacts
What was accomplished under these goals? We having been focusing objectives 2 and 3 in year two; sweetpotato elite lines collected from Plant Genetic Resources Conservative Unit: USDA:ARS (Griffin, Georgia) and Mississippi State University were used for plant regeneration. Plant regeneration protocols for four sweetpotato lines have been optimized. An Agrobacterium-mediated transformation protocol was well developed and optimized in the lab, and 12 transgenic plants were obtained, and transgenic events were confirmed by PCR. The viral resistance of transgenic plants is in investigation under controlled environment, and the result needs to be further clarified.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Aundrea Coleman, Toni-Ann Nelson, Chunquan Zhang, Victor Njiti and Yan Meng. Genetically engineered sweetpotato: a novel approach to improve sweetpotato viral resistance, 2020, 84th Mississippi Academy of Sciences Annual Meeting, Biloxi, MS
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Tony-Ann Nelson, Aundrea Coleman and Yan Meng. Development of efficient plant regeneration protocols from diverse genotypes of sweetpotato (Ipomoea batatas (L.) Lam), 2020, 84th Mississippi Academy of Sciences Annual Meeting, Biloxi, MS
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Chiamaka Udedibor, Yan Meng, Chunquan Zhang and Victor Njiti. Virus elimination in sweetpotato through meristem tip culture and thermotherapy, 2020, 84th Mississippi Academy of Sciences Annual Meeting, Biloxi, MS
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Emmanuella Nnuji-John, Chiamaka Udedibor, Yan Meng, Chunquan Zhang and Victor Njiti. Virus-free sweetpotato: from meristem-tip culture to storage roots production, 2020, 84th Mississippi Academy of Sciences Annual Meeting, Biloxi, MS
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Myshawn Smith, Daniela F. Adjaye, Yan Meng, Victor Njiti, Chunquan Zhang. Sweetpotato polyphenol oxidase molecular study and its potential as crispr/cas9 target for genome editing application, 2020, 84th Mississippi Academy of Sciences Annual Meeting, Biloxi, MS
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Chunquan Zhang, Victor Njiti and Yan Meng. An update of using biotechnological approaches to improve sweetpotato viral disease resistance, National Sweetpotato Collaborators Group Meeting, 2020, Nashville, TN

Progress 03/15/18 to 03/14/19

Outputs
Target Audience:During this reporting period, the target audiences were ASU research scientists, undergraduate and graduate students, small farmers and extension specialists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During the execution of this project, the graduate and undergraduate students, lab technician, extension agents were trained with better skills and knowledge related with plant tissue culture techniques, crop genetic engineering and gene transformation, disease diagnosis techniques and field practices. Two courses related with tissue culture and genetic engineering techniques were developed at undergraduate and graduate class levels. Flyers on plant disease management by applying modern biotechniques together with on-site demonstration and presentation have educated small farmers with raising awareness of viral disease knowledge based IPM for better environment protection. All the personnel mentioned above are benefit for the training and professional development. How have the results been disseminated to communities of interest?The research data were presented to several scientific meetings regionally or notionally. Posters, printed flyers and oral presentations during field days and workshops have direct impacted farmers knowledge base and raise discussion on how to integrated agricultural biotechnology into sweetpotato production practices. What do you plan to do during the next reporting period to accomplish the goals?Our next goals to be accomplished will be objectives 2 and 3. Especially, to create transgenic viral resistance lines in sweetpotato to multiple important epidemic viruses and to conduct biological evaluation the transgenic lines for their resistance to multiple viruses under diverse growth conditions and agricultural practices. PI, Co-PIs and collaborators will continue to arrange meetings to discuss plans for execution of the goals.

Impacts
What was accomplished under these goals? We having been focusing objectives 1 and 2 in year one; sweetpotato elite lines have been collected from Plant Genetic Resources Conservative Unit: USDA:ARS (Griffin, Georgia) and Mississippi State University. Plant regeneration protocols for three sweetpotato lines have been optimized. An Agrobacterium-mediated transformation protocol was well developed in the lab, and transgenic plants were obtained and transgenic events were confirmed by PCR. Sweetpotato plants infected with Sweet Potato Leaf Curl Virus and Sweet Potato Feathery Mottle Virus was investigated and will be used for transgenic plants anti-virus tests.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: 1. Kyler Holmes, Chunquan Zhang, Yan Meng (2018). Analysis of full-length infectious genomic cDNA clones of SPFMV and SPLCV and exploiting the approaches of biotechnology in sweetpotato for virus diseases resistance, 5th Mcbios, Starkville, MS
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: 2. Faith Iseguede, Victor Njiti, Chunquan Zhang, Yan Meng (2018). Establishment and application of a virus?free sweetpotato program for limited?resource farmers in Mississippi, USDA/NIFA PD meeting, Washington DC.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: 3. Faith Iseguede, Yan Meng, Chunquan Zhang, Victor Njiti (2019). Biotechnological approaches for improving sweetpotato viral disease resistance in Mississippi. National sweetpotato collaborator group meeting, Birmingham, AL
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: 4. Faith Iseguede, Yan Meng, Chunquan Zhang, Victor Njiti (2019). Elimination and detection of viruses in meristem-derived plantlets of sweetpotato in Mississippi. 5th Annual Centers for Research Excellence Symposium, Alcorn State University
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: 5. Faith Iseguede, Yan Meng, Chunquan Zhang, Victor Njiti (2019). Using biotechnological approaches for improving sweetpotato viral disease resistance, Mississippi Academy Society meeting, Hattiesburg, MS.