Dr. Choaa El-Mohtar

Dr. Choaa El-Mohtar

Program Emphasis

My program works mainly with the development and the deployment of CTV infectious clones for basic science research and practical purposes (HLB/Asian citrus psyllid control). For basic science research, CTV field isolates are mainly populations of different strains that have different phenotypes in different citrus host species. Using different strains of CTV infectious clones and citrus hosts, we are trying to elucidate the long distance movement and complex interactions that occur within a single citrus host among the different strains of CTV.

For practical purposes, the citrus industry in Florida is crippled by citrus greening/HLB and its efficient accumulation and spread by the asian citrus psyllid (ACP), Diaphorina citri. Both HLB and CTV are associated with the phloem tissue. We are attempting to mitigate the HLB effect on citrus production by using the CTV-T36 infectious clone as a delivery machine of potential therapeutic sequences to induce plant resistance and target HLB and ACP.


PhD in Plant Pathology, University of Florida 2011

MS in Plant Protection, American University of Beirut 2003

BS in Agriculture, American University of Beirut, 2001

BS in Chemistry, American University of Beirut, 1997

Previous Positions

Postdoctoral Associate, 2012-2017. CREC, University of Florida, Lake Alfred FL

Research Assistant 2009-2011, CREC, University of Florida, Lake Alfred FL

Alumni Fellow 2005-2009, CREC, University of Florida, Lake Alfred FL

Research Assistant 2003-2005, Plant Science department, American University of Beirut

BS in Chemistry, American University of Beirut, 1997

Refereed Papers

Killiny, N., Harper, S.J., El Mohtar, C., and Dawson W.O. 2016. Minor coat and heat-shock proteins are involved in binding of citrus tristeza virus to the foregut of its aphid vector, Toxoptera citricida. Appl. Environ. Microbiol. AEM.01914-16; Accepted manuscript postedonline 12 August 2016, doi:10.1128/AEM.01914-16

Atallah O.O,  Kang S.H.,  El-Mohtar C. A.,  Shilts T., Bergua M., Folimonova, S.Y. 2016. A 5’-proximal region of the Citrus tristeza virus genome encoding two leader proteases is involved in virus superinfection exclusion Virology 489 108–115

Bergua, M., Zwart, M.P., El-Mohtar, C., Shilts, T., Elena, S.F., and Folimonova, S.Y. 2014. A viral protein mediates superinfection exclusion at the whole-organism level but is not required for exclusion at the cellular level. Journal of Virology 88, 11327–11338.

Hajeri, S., Killiny, N., El-Mohtar, C., Dawson, W.O., Gowda, S. 2014. Citrus tristeza virus-based RNAi in citrus plants induces gene silencing in Diaphorina citri, a phloem-sap sucking insect vector of citrus greening disease (Huanglongbing). Journal of Biotechnology 176, 42-49.

El-Mohtar, C. and Dawson, W.O. 2014.Exploring the limits of vector construction based on Citrus tristeza virus. Virology, 448, 274-283.

Ambrós, S., El-Mohtar, C., Ruiz-Ruiz, S., Peña, L., Guerri, J., Dawson, W.O., and Moreno, P., 2011. Agroinoculation of Citrus tristeza virus causes systemic infection and symptoms in the presumed nonhost Nicotiana benthamiana. MPMI 24, 1119-1131.

Dakhil, H.A., Abou-Fakhr, H.E., El-Mohtar C., and Abou-Jawdah, Y., 2011. Survey of leafhopper species in almond orchards infected with almond witches’-broom phytoplasma in Lebanon. Journal of Insect Science 11:60 available online: insectscience.org/11.60

Atamian, H., Dagher, R., Gerges, E., Sobh, H., Talhouk, R., El Mohtar, C., and Abou-Jawdah, Y., 2009. Breeding for a Lebanese type of tomato with combined resistance to Tomato yellow leaf curl virus, fusarium and verticillium wilts using marker assisted selection tools. In Proceedings of the Second International Symposium on Tomato Diseases: Acta Horticulturae 808, 151-156.

El-Mohtar, C., Atamian, H., Dagher, R., Abou-Jawdah, Y., Salus, M., and Maxwell, D., 2007. Marker assisted selection of tomato genotypes with I2 gene of resistance to Fusarium oxysporum f. sp. lycopersici. Plant Disease 91, 758-762.

Abou-Jawdah, Y., El Mohtar, C., Atamian, H., and. Sobh, H. 2006. First report of Tomato chlorosis virus in Lebanon. Plant Disease 90, 378.

Abou-Jawdah, Y., El Mohtar, C., and. Sobh, H. 2006. First Report of Tomato
spotted wilt virus on tomatoes in Lebanon. Plant Disease 90, 376.

Eid, S., Abou-Jawdah, Y., El-Mohtar, S., Sobh, H. and Havey, M. 2006. Tolerance in Cucumber to Cucurbit yellow stunting disorder virus. Plant disease 90, 645-649.

Abou-Jawdah Y., A. Karakashian , H. Dakhil, S. El-Mehtar, and Lee I.M. 2003. Almond witches’ broom phytoplasma, an epidemic disease in Lebanon. Phytopathology 93: S2.

Abou -Jawdah, Y., Dakhil, H., El-Mehtar, S. and Lee, I.M. 2003. Almond witches’- broom phytoplasma, a potential threat to almond, peach and nectarine. Canadian Journal of Plant Pathology 25, 28-32.

Proceedings and Abstracts (in International Conferences

Eid S., Hourani H., El-Mohtar C., Sobh H., Havey M. and Abou-Jawdah Y. 2008. Screening cucumber accessions for resistance to CYSDV and preliminary studies on the mechanisms of virus tolerance. Abstract book of the 14 symposium: Frontiers in Agriculture – Abiotic and Biotic Stress in Plants, November 3-7, 2008, Amman, Jordan.

Eid, S., Abou-Jawdah, Y., El-Mohtar, C., Sobh, H., and Havey, M. 2006. Screening cucumber accessions for resistance to Cucurbit yellow stunting disorder virus. Proceedings of the 12th Mediterranean Phytopathological Congress, Rhodes Island, Greece 10-15 June 2006. Page 115.

El-Mohtar C. A., Abou-Jawdah Y. A., Atamian, H. S., Salus M. S. and Maxwell D. P. 2006. A PCR method to detect tomato genotypes with the I-2 gene for resistance to Fusarium oxysporum f. sp. lycopersici race 2. Phytopathology 96:S32

El-Mohtar S., Atamian H., Dagher R., and Abou-Jawdah Y. 2005. A PCR based method for screening tomato lines for resistance to race2 of Fusarium oxysporum f. sp. lycopersici. Proceeding of the XV meeting of the Eucarpia Tomato Working Group, Bari, Italy, September 20-23, 2005.

Professional Membership

International Organization of Citrus Virology (IOCV)