Citrus Research and Education Center

Publications - Dr. Ahmad Omar

Publications

Peer-reviewed Research

Grosser, J.W., F.G. Gmitter, \, J. Chater, M. Dutt, A. Omar, and L.M. Cano. 2024. Citrus rootstock breeding in an HLB-endemic environment with an industry in crisis. Italus Hortus 31:73-78. https://doi.org/10.26353/j.itahort/2024.1.7378.

Ikram, M., N.I. Raja, A.H. Mohamed, Z.-U.-R. Mashwani, A.A. Omar, H. Gharibi, and R.A. Zubarev. 2024. Differential impact of plant-based selenium nanoparticles on physio-biochemical properties, antioxidant defense system and protein regulation in fruits of huanglongbing-infected ‘Kinnow’ mandarin plants. Frontiers in Plant Science 15. https://doi.org/10.3389/fpls.2024.1476497

Rizk, R., E. Zayed, A. Amin, A. Omar, and H. Oraby. 2024. Effectiveness of DNA barcoding, SCOT markers and phytochemical characterization in biodiversity assessment of some Zea mays hybrids. SOUTH AFRICAN JOURNAL OF BOTANY 165:59-69. https://doi.org/10.1016/j.sajb.2023.12.020.

Su H, Wang Y, Xu J, Omar AA, Grosser JW, Calovic M, Zhang L, Feng Y, Vakulskas CA, Wang N (2023) Generation of the transgene-free canker-resistant Citrus sinensis using Cas12a/crRNA ribonucleoprotein in the T0 generation. Nature Communications 14 (1):3957. https://doi.org/10.1038/s41467-023-39714-9

Gaikwad PN, Sharma V, Singh J, Sidhu GS, Singh H, Omar AA (2023) Biotechnological advancements in Phytophthora disease diagnosis, interaction and management in citrus. Scientia Horticulturae 310:111739. https://doi.org/10.1016/j.scienta.2022.111739

Ennab HA, Mohamed AH, El-Hoseiny HM, Omar AA, Hassan IF, Gaballah MS, Khalil SE, Mira AM, Abd El-Khalek AF, Alam-Eldein SM (2023) Humic Acid Improves the Resilience to Salinity Stress of Drip-Irrigated Mexican Lime Trees in Saline Clay Soils. Agronomy 13 (7):1680. https://doi.org/10.3390/agronomy13071680

ElSayed AI, Mohamed AH, Rafudeen MS, Omar AA, Awad MF, Mansour E (2022) Polyamines mitigate the destructive impacts of salinity stress by enhancing photosynthetic capacity, antioxidant defense system and upregulation of calvin cycle-related genes in rapeseed (Brassica napus). Saudi J Biol Sci 29 (5):3675–3686. https://doi.org/10.1016/j.sjbs.2022.02.053

Jia H, Omar AA, Orbovic V, Wang N (2021) Generating biallelic canker-resistant ‘Duncan’ grapefruit plant via CRISPR-Cas9. Phytopathology. https://doi.org/10.1094/PHYTO-04-21-0144-R

ElSayed AI, Boulila M, Rafudeen MS, Mohamed AH, Sengupta S, Rady M, Omar AA (2020) Melatonin regulatory mechanisms and phylogenetic analyses of melatonin biosynthesis related genes extracted from peanut under salinity stress. Plants 9 (7):854. https://doi.org/10.3390/plants9070854

Killiny N, Jones SE, Hijaz F, Kishk A, Santos-Ortega Y, Nehela Y, Omar AA, Yu Q, Gmitter FG, Grosser JW, Dutt M (2020) Metabolic Profiling of Hybrids Generated from Pummelo and Citrus latipes in Relation to Their Attraction to Diaphorina citri, the Vector of Huanglongbing. Metabolites 10 (12). https://doi.org/10.3390/metabo10120477

Murata, M.M., Omar, A.A., Mou, Z., Chase, C.D., Grosser, J.W., Graham, J.H., 2018. Novel plastid-nuclear genome combinations enhance resistance to citrus canker in cybrid grapefruit. Frontiers in Plant Science, 9:1858. https://dx.doi.org/10.3389%2Ffpls.2018.01858

Omar, A.A., Mohamed, A.H., Nasr, M.I., El-Halafawy, K.A., Alabsawy, E.A., Hamdi, A.I., Zayed, E.M., 2018. Molecular characterization of Soybean (Glycine max L. Merr) genotypes tolerant and susceptible to cotton leaf worm (Spodoptera littoralis). American Journal of Biochemistry and Molecular Biology 8, 34-47. https://doi.org/10.3923/ajbmb.2018.34.47

Omar, A.A., Murata, M.M., El-Shamy, H.A., Graham, J.H., and Grosser, J.W. 2018. Enhanced resistance to citrus canker in transgenic mandarin expressing Xa21 from rice. Transgenic Research. 27:179-191. http://dx.doi.org/10.3923/ajbmb.2018.34.47

Killiny, N., M.F. Valim, S.E. Jones, A.A. Omar, F. Hijaz, F.G. Gmitter Jr, and J.W. Grosser. 2017. Metabolically speaking: Possible reasons behind the tolerance of ‘Sugar Belle’ mandarin hybrid to huanglongbing. Plant Physiol. Biochem. 116:36-47. https://doi.org/10.1016/j.plaphy.2017.05.001

Omar, A.A., M.M. Murata, Q. Yu, F.G. Gmitter, Jr., C.D. Chase, J.H. Graham, and J.W. Grosser. 2017. Production of three new grapefruit cybrids with potential for improved citrus canker resistance. In Vitro Cell. Dev. Biol. Plant. 53:256-269. https://doi.org/10.1007/s11627-017-9816-7

Khalifa, S.A., A.A. Omar, and A.H. Mohamed. 2017. The effect of substituting milk fat by peanut oil on the quality of white soft cheese. International Journal of Dairy Science. 12:28-40. http://doi.org/10.3923/ijds.2017.28.40

ElSayed, A.I., M. Boulila, D.C. Odero, A.A. Omar, A.M. Gomaa, and R. Viswanathan. 2017. Characterization of ORF0 and ORF1 and their Roles in Recombination and Replication of Sugarcane yellow leaf virus. American Journal of Biochemistry and Molecular Biology. 7:41-52. http://dx.doi.org/10.3923/ajbmb.2017.41.52

Ibrahim, M.M., A.O. Mohamed, A.H. Mohamed, and A.A. Omar. 2016. Effect of some girdling treatments on fruiting behavior and physio-chemical properties of Washington navel orange trees. Journal of Agriculture and Veterinary Science. 9:58-65. https://doi.org/10.9790/2380-0906015865

Zayed, E., M. Sayed, and A.A. Omar. 2015. Genetic variations between two ecotypes of Egyptian clover by inter-simple sequence repeat (ISSR) techniques. African Journal of Biotechnology. 14:1947-1953. https://doi.org/10.5897/AJB2015.14609

Grosser, J.W., A.A. Omar, J.A. Gmitter, and J.P. Syvertsen. 2012. Salinity Tolerance of ‘Valencia’ Orange Trees on Allotetraploid Rootstocks. Proc. Fla. State Hort. Soc. 125:50-55.

Grosser, J.W., M. Dutt, A.A. Omar, V. Orbovic, and G. Barthe. 2011. Progress towards the development of transgenic disease resistance in citrus. Acta Hort. (ISHS). 892:101-107. https://doi.org/10.17660/ActaHortic.2011.892.12

Dutt, M., A.A. Omar, V. Orbovic, G. Barthe, and J.W. Grosser. 2010. Progress towards incorporation of antimicrobial peptides for disease resistance in citrus. ICC:258-264.

Omar, A.A., A.H. Mohamed, and J.W. Grosser. 2009. Study of transgene expression by phloem-specific promoter in transgenic citrus plant. Journal of Biological Chemistry and Environmental Sciences. 4: 647-661.

Abouziena, H.F., A.A. Omar, S.D. Sharma, and M. Singh. 2009. Efficacy comparison of some new natural product herbicides for weed control at two growth stages. Weed Technol. 23:431-437. https://doi.org/10.1614/WT-08-185.1

Abouziena, H.F., R.A. Elmergawi, S. Sharma, A.A. Omar, and M. Singh. 2009. Zinc antagonizes glyphosate efficacy on yellow nutsedge (Cyperus esculentus). Weed Sci. 57:16-20. https://doi.org/10.1614/WS-08-084.1

Omar, A.A., and J.W. Grosser. 2008. Comparison of endoplasmic reticulum targeted and non-targeted cytoplasmic GFP as a selectable marker in citrus protoplast transformation. Plant Sci. 174:131-139. https://doi.org/10.1016/j.plantsci.2007.10.003

Omar, A.A., M.G.H. Dekkers, J.H. Graham, and J.W. Grosser. 2008. Estimation of Transgene Copy Number in Transformed Citrus Plants by Quantitative Multiplex Real-Time PCR. Biotechnol. Prog. 24:1241-1248. https://doi.org/10.1002/btpr.62

Omar, A.A., W.Y. Song, and J.W. Grosser. 2007. Introduction of Xa21, a Xanthomonas-resistance gene from rice, into 'Hamlin' sweet orange [Citrus sinensis (L.) Osbeck] using protoplast-GFP co-transformation or single plasmid transformation. J. Horticult. Sci. Biotechnol. 82:914-923. https://doi.org/10.1080/14620316.2007.11512326

Omar, A.A., and J.W. Grosser. 2007. Protoplast co-transformation and regeneration of transgenic `Hamlin` sweet orange plants containing a cDNA Xa21 Xanthomonas resistance gene and GFP. Acta Horticulture. 738:235-244. https://doi.org/10.17660/ActaHortic.2007.738.23

Abouziena, H.F., E.R. El-Desoki, S. Sharma, A.A. Omar, and M. Singh. 2007. Evaluation of sowing in hills on ridges as a new technique for enhancement of Wheat (Triticum aestivum, L) Productivity. Egyptian Journal of Agronomy. 29:85-100.

Past Positions

Professor (Sabbatical), 2021 – Present, Biochemistry Department, College of Agriculture, Zagazig University, Egypt
Associate Professor (Sabbatical), 2016 – 2021, Biochemistry Department, College of Agriculture, Zagazig University, Egypt
Postdoctoral Associate, 2011 – 2018, CREC, University of Florida, Lake Alfred FL
Assistant Professor, 2009 – 2016, Biochemistry Department, College of Agriculture, Zagazig University, Egypt
Postdoctoral Associate, 2006 – 2009, CREC, University of Florida, Lake Alfred FL
Research Assistant, 2000 – 2006, CREC, University of Florida, Lake Alfred FL
Research Assistant, 1994 – 1999, Biochemistry Department, College of Agriculture, Zagazig University, Egypt
Chemist and Researcher, 1993 – 1994, Micro-Analysis Unit, Center Lab, College of Agriculture, Zagazig University, Egypt

Book Chapters

Soriano L, Omar A.A., Martinelli AP (2022) Citrus Protoplast Isolation and Plant Regeneration Through Somatic Embryogenesis. In: Ramírez-Mosqueda MA (ed) Somatic Embryogenesis: Methods and Protocols. Springer US, New York, NY, pp 111-126. https://doi.org/10.1007/978-1-0716-2485-2_9

Omar A.A., ElSayed AI, Mohamed AH (2022) Tangerine (Citrus reticulata) Wastes: Chemistry, Properties and Applications. In: Ramadan MF, Farag MA (eds) Mediterranean Fruits Bio-wastes. Springer Nature, Switzerland. https://doi.org/10.1007/978-3-030-84436-3_11

Omar, A.A., M. Dutt, F.G. Gmitter, Jr., and J.W. Grosser. 2016. Somatic Embryogenesis: Still a Relevant Technique in Citrus Improvement. In In Vitro Embryogenesis in Higher Plants. Vol. 1359. M.A. Germanà and M. Lambardi, editors. Springer, New York. 289-327.

Grosser, J.W., and A.A. Omar. 2011. Protoplasts – an increasingly valuable tool in plant research. In Plant Cell Culture, Development and Biotechnology. R.N. Trigiano and D.J. Gray, editors. Taylor and Francis (CRC Press, LLC), Boca Raton, Florida.