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CRU Scientists
- Hans Alborn
- John Beck
- Anna Block
- Charles Hunter
- Caitlin Rering
- Charles Stuhl

**Ph.D.** in Plant Molecular and Cellular Biology University of Florida (2004)**Masters** in Biochemistry University of Bath, England (2000)Phone 352-374-5761Email anna.block@ars.usda.govDr. Block joined the Chemistry Research Unit at USDA-ARS-CMAVE in 2015 and the focus of her research is on **the chemical defenses of maize (corn) against insect pests**, particularly fall armyworm and corn silk flies. Maize uses a variety of chemicals to defend itself against herbivorous insects both directly by inhibiting insect growth, feeding or attraction and indirectly by attracting predators or parasites. These chemicals include volatile organic compounds, flavonoids, benzoxazinoids and phytoalexins. The Block lab uses co-expression analysis and knowledge-guided approaches to identify genes involved in the production of these chemical defenses. CRISPR/Cas9 and transposon based strategies are then used to isolate maize mutants in these genes to confirm their function and unravel the function of the chemicals they produce. Ultimately this research allows the development of molecular-breeding approaches for the production of maize lines with increased pest resistance. This in turn reduces the production and environmental costs of growing maize. The Block group also studies the impact of abiotic stresses (elevated carbon dioxide, flooding, drought and extreme temperature) on the chemical defenses of maize and the impact these combinatorial stresses have on insect resistance. These studies provide vital knowledge required for the development of breeding and management strategies that are effective in real world "multi-stress" environments.**External Funding:**Co-PD on USDA-NIFA-SCRI grant #2018-51181-28419 "Sweet CAP: Integrated technologies to improve sweet corn production and marketability" (2018-2022)PI on USDA-AMS Florida Department of Agriculture and Consumer services, Specialty Crop Block Grant AM180100XXXXG046 "Silkfly resistance in sweetcorn" (2019-2020)- Projects Regulation, Biosynthesis, and Function of Plant Chemical Defenses and their Role in Climate-Resilient AgricultureIn-House Appropriated (D) Accession Number:444364The Extraordinary Connections Between the Catabolism of Flavonols and Benzoate MetabolismNon-Funded Cooperative Agreement (N) Accession Number:441480CAREER: Unraveling the Metabolic Networks Underlying Plant Stress AdaptationNon-Funded Cooperative Agreement (N) Accession Number:443334Sweet CAP: Integrated Technologies to Improve Sweet Corn Production and MarketabilityReimbursable Cooperative Agreement (R) Accession Number:443456- Publications - (Clicking on the reprint icon  will take you to the publication reprint.)  
- Genome analysis and hyphal movement characterization of the hitchhiker endohyphal Enterobacter sp. from Rhizoctonia solani  -(Peer Reviewed Journal)   Zhang, P., Huguet-Tapia, J., Peng, Z., Obasa, K., Block, A.K., White, F.F. 2024. Genome analysis and hyphal movement characterization of the hitchhiker endohyphal Enterobacter sp. from Rhizoctonia solani. Applied and Environmental Microbiology. https://doi.org/10.1128/aem.02245-23.   
- Maize Terpene Synthase 1 impacts insect bahavoir via the production of monoterpene volatiles beta-myrcene and linalool  -(Peer Reviewed Journal)   Yactayo Chang, J.P., Broadhead, G.T., Housler, R.J., Resende, M., Verma, K., Louis, J., Basset, G.J., Beck, J.J., Block, A.K. 2023. Maize Terpene Synthase 1 impacts insect bahavoir via the production of monoterpene volatiles beta-myrcene and linalool. Phytochemistry. 2024,218,113957. https://doi.org/10.1016/j.phytochem.2023.113957.   
- The evolution of strictly monofunctional naphthoquinol C3methyltransferases is vital in cyanobacteria and plastids  -(Peer Reviewed Journal)   Stutts, L., Latimer, S., Batyrshina, Z., Dickinson, G., Alborn, H.T., Block, A.K., Basset, G.J. 2023. Cyanobacteria and plastids harbor strictly monofunctional naphthoquinol C-methyltransferases. The Plant Cell.  https://doi.org/10.1093/plcell/koad202.   
- Maize terpene synthase 8 (ZmTPS8) contributes to a complex blend of  fungal-elicited antibiotics  -(Peer Reviewed Journal)   Saldivar, E.V., Ding, Y., Poretsky, E., Bird, S., Block, A.K., Huffaker, A., Schmelz, E.A. 2023. Maize terpene synthase 8 (ZmTPS8) contributes to a complex blend of  fungal-elicited antibiotics. Plants. 12(5):1111. https://doi.org/10.3390/plants12051111.   
- Metabolic link between auxin production and specialized metabolites in Sorghum bicolor  -(Peer Reviewed Journal)   Perez, V.C., Dai, R., Tomiczek, B., Mendoza, J.S., Greening, A., Reed, E.S., Vermerris, W., Block, A.K., Kim, J. 2023. Metabolic link between auxin production and specialized metabolites in Sorghum bicolor. Journal of Experimental Botany. 74:364-376. https://doi.org/10.1093/jxb/erac421.   
- The impact of post-harvest storage on sweetcorn aroma  -(Peer Reviewed Journal)   Yactayo Chang, J.P., Boehlein, S., Libertini, G., Beiriger, R., Resende, M., Bruton, R.G., Alborn, H.T., Tracy, W.F., Block, A.K. 2022. The impact of post-harvest storage on sweetcorn aroma. Phytochemistry Letters. 52:33-39. https://doi.org/10.1016/j.phytol.2022.09.001.   
- Production of the green leaf volatile (Z)-3-hexenal by a zea mays hydroperoxide lyase  -(Peer Reviewed Journal)   Yactayo Chang, J.P., Hunter III, C.T., Alborn, H.T., Christensen, S.A., Block, A.K. 2022. Production of the green leaf volatile (Z)-3-hexenal by a zea mays hydroperoxide lyase. Plants. 11(17):2201. https://doi.org/10.3390/plants11172201.   
- Dedicated farnesyl diphosphate synthases circumvent isoprenoid-derived growth-defense tradeoffs in Zea mays  -(Peer Reviewed Journal)   Tang, H.V., Berryman, D.L., Mendoza, J.S., Yactayo Chang, J.P., Li, Q., Christensen, S.A., Hunter III, C.T., Best, N.B., Soubeyrand, E., Akhtar, T., Basset, G.J., Block, A.K. 2022. Dedicated farnesyl diphosphate synthases circumvent isoprenoid-derived growth-defense tradeoffs in Zea mays. Plant Journal. https://doi.org/10.1111/tpj.15941.   
- SbCYP79A61 Produces Phenylacetaldoxime Which is a Precursor of Benzyl Cyanide and Phenylacetic Acid in Sorghum bicolor  -(Pre-print Publication)   Perez, V.C., Dai, R., Tomiczek, B., Mendoza, J.S., Greening, A., Reed, E.S., Vermerris, W., Block, A.K., Kim, J. 2022. SbCYP79A61 Produces Phenylacetaldoxime Which is a Precursor of Benzyl Cyanide and Phenylacetic Acid in Sorghum bicolor. bioRxiv. https://doi.org/10.1101/2022.05.11.491506.   
- Xanthomonas hortorum pv. gardneri TAL effector AvrHah1 is necessary and sufficient for increased persistence of Salmonella enterica on tomato leaves  -(Peer Reviewed Journal)   Cowles, K.N., Block, A.K., Barak, J.D. 2022. Xanthomonas hortorum pv. gardneri TAL effector AvrHah1 is necessary and sufficient for increased persistence of Salmonella enterica on tomato leave. Scientific Reports. 12, 7313. https://doi.org/10.1038/s41598-022-11456-6   
- Kaempferol as a precursor for ubiquinone (coenzyme Q) biosynthesis: An atypical node between specialized metabolism and primary metabolism  -(Review Article)   Berger, A., Latimer, S., Stutts, L.R., Soubeyrand, E., Block, A.K., Basset, G.J. 2022. Kaempferol as a precursor for ubiquinone (coenzyme Q) biosynthesis: An atypical node between specialized metabolism and primary metabolism. Current Opinion in Plant Biology. 66, 102165. https://doi.org/10.1016/j.pbi.2021.102165.   
- Metabolomics by UHPLC-HRMS reveals the impact of heat stress on pathogen-elicited immunity in Maize  -(Peer Reviewed Journal)   Christensen, S.A.; Santana, E.; Alborn, H.T.; Block, A.K.; Chamberlain, C.A. 2021. Metabolomics by UHPLC-HRMS reveals the impact of heat stress on pathogen-elicited immunity in Maize. Metabolomics. 17:6. https://doi.org/10.1007/s11306-020-01739-2.   
- A dedicated flavin-dependent monooxygenase catalyzes the hydroxylation of demethoxyubiquinone into ubiquinone (Coenzyme Q) in Arabidopsis  -(Peer Reviewed Journal)   Latimer, S., Keene, S.A., Berger, A., Bernet, A., Soubeyrand, E., Wright, J., Clarke, C.F., Block, A.K., Colquhoun, T.A., Elowsky, C., Christensen, A., Basset, G.J. 2021. A dedicated flavin-dependent monooxygenase catalyzes the hydroxylation of demethoxyubiquinone into ubiquinone (Coenzyme Q) in Arabidopsis. Journal of Biological Chemistry. 297,101283. https://doi.org/10.1016/j.jbc.2021.101283.   
- A maize leucine-rich repeat receptor-like protein kinase mediates responses to fungal attack  -(Peer Reviewed Journal)   Block, A.K., Tang, H.V., Hopkins, D., Mendoza, J.S., Solemslie, R.K., Christensen, S.A., Du Toit, L.J. 2021. A maize leucine-rich repeat receptor-like protein kinase mediates responses to fungal attack. Planta. 254, 73. https://doi.org/10.1007/s00425-021-03730-0.   
- Metabolite analysis of Arabidopsis CYP79A2 overexpression lines reveals turnover of benzyl glucosinolate and an additive effect of different aldoximes on phenylpropanoid repression  -(Peer Reviewed Journal)   Perez, V.C., Dai, R., Block, A.K., Jeongim, K. 2021. Metabolite analysis of Arabidopsis CYP79A2 overexpression lines reveals turnover of benzyl glucosinolate and an additive effect of different aldoximes on phenylpropanoid repression. Plant Signaling and Behavior. 16, 1966586. https://doi.org/10.1080/15592324.2021.1966586.   
- Zea mays volatiles that influence oviposition and feeding behaviors of Spodoptera frugiperda  -(Peer Reviewed Journal)   Yactayo Chang, J.P., Mendoza, J.S., Willms, S.D., Beck, J.J., Rering, C.C., Block, A.K. 2021. Zea mays volatiles that influence oviposition and feeding behaviors of Spodoptera frugiperda. Journal of Chemical Ecology. 47, 799-809. https://doi.org/10.1007/s10886-021-01302-w.   
- Aldoximes are precursors of auxins in Arabidopsis and maize  -(Peer Reviewed Journal)   Perez, V.E.; Dai, R.; Bing Bai, B.; Tomiczek, B.; Askey, B.; Zhang, Y.; Ding, Y.; Grenning, A.; Block, A.K.; and Kim, J. 2021 Aldoxime-derived auxin biosynthesis occurs in both Arabidopsis and maize. New Phytologist. https://doi: 10.1111/nph.17447   
- 3-oglycosylation of kaempferol restricts the supply of the benzenoid precursor of ubiquinone (Coenzyme Q) in Arabidopsis thaliana  -(Peer Reviewed Journal)   Soubeyrand, E.; Latimer, S.; Bermert, A.C.; Keene, S.A.; Johnson, T.S.; Shin, D.; Block, A.K.; Colquhoun, T.A.; Shaefnner, A.R.; Kim, J.; Basset, G.J. 2021. 3-oglycosylation of kaempferol restricts the supply of the benzenoid precursor of ubiquinone (Coenzyme Q) in Arabidopsis thaliana. Phytochemistry. 186,112738. https://doi.org/10.1016/j.phytochem.2021.112738.   
- The 13-lipoxygenase MSD2 and the w-3 fatty acid desaturase MSD3 impact Spodoptera frugiperda resistance in Sorghum  -(Peer Reviewed Journal)   Block, A.K.; Xin, Z; and Christensen, S.A. 2020 The 13-lipoxygenase MSD2 and the w-3 fatty acid desaturase MSD3 impact Spodoptera frugiperda resistance in Sorghum. Planta 252:62 https://doi:10.1007/s00425-020-03475-2   
- Approaches for assessing the impact of Zea mays (Poaceae) on the behavior of Spodoptera frugiperda (Lepidoptera: Noctuidae) and its parasitoid Cotesia marginiventris (Hymenoptera: Braconidae)  -(Peer Reviewed Journal)   Block, A.K.; Mendoza, J.S.; Rowley, A.L.; Stuhl, C.J.; Meagher Jr, R.L. 2021. Approaches for assessing the Impact of Zea mays on the behavior of Spodoptera frugiperda and its parasitoid Cotesia marginiventris. Florida Entomologist. 103:505-513. https://doi.org/10.1653/024.103.00414   
- Plant defense chemicals against insect pests  -(Peer Reviewed Journal)   Yactayo Chang, J.P.; Tang, H.V.; Mendoza, J.S.; Christensen, S.A.; Block, A.K. 2020. Plant defense chemicals against insect pests. Agronomy. 10:1156. 2020 https://doi.org/10.3390/agronomy10081156.   
- Arabidopsis 4-COUMAROYL-COA LIGASE 8 contributes to the biosynthesis of the benzenoid ring of coenzyme Q in peroxisomes  -(Peer Reviewed Journal)   Soubeyrand, E., Kelly, M., Bernert, A.C., Keene, S.A., Latimer, S., Johnson, T.S., Elowsky, C., Colquhoun, T.A., Block, A.K., Basset, G.J. 2019. Arabidopsis 4-COUMAROYL-COA LIGASE 8 contributes to the biosynthesis of the benzenoid ring of coenzyme Q in peroxisomes. Biochemical Journal. 476(22):3521-3532. https://doi.org/10.1042/BCJ20190688.   
- Setaria viridis as a model for translational genetic studies of jasmonic acid-responsive insect defenses in Zea mays  -(Peer Reviewed Journal)   Hunter III, C.T., Block, A.K., Christensen, S.A., Li, Q., Rering, C.C., Alborn, H.T. 2020. Setaria viridis as a model for translational genetic studies of jasmonic acid-responsive insect defenses in Zea mays. Plant Science. 291, February 2020, 110329. https://doi.org/10.1016/j.plantsci.2019.110329.   
- Xanthomonas translucens commandeers the host rate-limiting step in ABA  biosynthesis for disease susceptibility  -(Peer Reviewed Journal)   Peng, Z., Hu, Y., Zhang, J., Huguet-Tapia, J.C., Block, A.K., Park, S., Sapkota, S., Liu, Z., Liu, S., White, F.F. 2019. Xanthomonas translucens commandeers the host rate-limiting step in ABA  biosynthesis for disease susceptibility. Proceedings of the National Academy of Sciences. 42,vol 16, 20938-20948.  https://doi.org/10.1073/pnas.1911660116.   
- Fighting on two fronts: Elevated insect resistance in flooded maize  -(Peer Reviewed Journal)   Block, A.K., Hunter III, C.T., Sattler, S.E., Rering, C.C., Mcdonald, S., Basset, G.J., Christensen, S.A. 2019. Fighting on two fronts: Elevated insect resistance in flooded maize. Plant Cell and Environment. https://doi.org/10.1111/pce.13642.   
- Specialized naphthoquinones present in Impatiens glandulifera extra-floral nectaries inhibit the growth of fungal nectar microbes  -(Peer Reviewed Journal)   Block, A.K., Yakubova, E., Widhalm, J.R. 2019. Specialized naphthoquinones present in Impatiens glandulifera extra-floral nectaries inhibit the growth of fungal nectar microbes. Plant Direct. 3(5):1-7. https://doi.org/10.1002/pld3.132.   
- TAT1 and TAT2 tyrosine aminotransferases have both distinct and shared functions in tyrosine metabolism and degradation in Arabidopsis thaliana  -(Peer Reviewed Journal)   Wang, M., Toda, K., Block, A.K., Maeda, H.A. 2019. TAT1 and TAT2 tyrosine aminotransferases have both distinct and shared functions in tyrosine metabolism and degradation in Arabidopsis thaliana. Journal of Biological Chemistry. 294(10):3563-3576. https://doi.org/10.1074/jbc.RA118.006539.   
- The peroxidative cleavage of kaempferol contributes to the biosynthesis of the benzenoid moiety of ubiquinone in plants  -(Peer Reviewed Journal)   Soubeyrand, E., Johnson, T.S., Latimer, S., Block, A.K., Kim, J., Colquhoun, T.A., Butelli, E., Martin, C., Chapple, C., Basset, G.J. 2018. The peroxidative cleavage of kaempferol contributes to the biosynthesis of the benzenoid moiety of ubiquinone in plants. The Plant Cell. 30:2910-2921. https://doi.org/10.1105/tpc.18.00688.   
- Production and function of terpenoid defense compounds in maize (Zea mays)  -(Review Article)   Block, A.K., Vaughan, M.M., Schmelz, E.A., Christensen, S.A. 2018. Production and function of terpenoid defense compounds in maize (Zea mays). Planta. https://doi.org/10.1007/s00425-018-2999-2.   
- Interactions among plants, insects, and microbes: elucidation of inter-organismal chemical communications in agricultural ecology  -(Peer Reviewed Journal)   Beck, J.J., Alborn, H.T., Block, A.K., Christensen, S.A., Hunter III, C.T., Rering, C.C., Seidl-Adams, I., Stuhl, C.J., Torto, B., Tumlinson, J.H. 2018. Interactions among plants, insects, and microbes: elucidation of inter-organismal chemical communications in agricultural ecology. Journal of Agricultural and Food Chemistry. 66(26):6663-6674. doi:10.1021/acs.jafc.8b01763.   
- Pesticides on the inside: Exploiting the natural chemical defenses of maize against insect and microbial pests  -(Peer Reviewed Journal)   Christensen, S.A., Hunter III, C.T., Block, A.K. 2018. Pesticides on the inside: Exploiting the natural chemical defenses of maize against insect and microbial pests. ACS Symposium Series. https://doi.org/10.1021/bk-2018-1294.ch006.   
- Metabolic reconstructions identify plant 3-methylglutaconyl-CoA hydratase that is crucial for branched-chain amino acid catabolism in mitochondria  -(Peer Reviewed Journal)   Latimer, S., Li, Y., Nguyen, T.T., Soubeyrand, E., Fatihi, A., Elowsky, C., Block, A.K., Pichersky, E., Basset, G.J. 2018. Metabolic reconstructions identify plant 3-methylglutaconyl-CoA hydratase that is crucial for branched-chain amino acid catabolism in mitochondria. Plant Journal. doi:10.1111/tpj.13955.   
- Contrasting insect attraction and herbivore-induced plant volatile production in maize  -(Peer Reviewed Journal)   Block, A.K., Hunter III, C.T., Rering, C.C., Christensen, S.A., Meagher Jr, R.L. 2018. Contrasting insect attraction and herbivore-induced plant volatile production in maize. Planta. doi:10.1007/s00425-018-2886-x.   
- Commercial hybrids and mutant genotypes reveal complex protective roles for inducible terpenoid defenses -(Peer Reviewed Journal)   Christensen, S.A., Sims, J., Vaughan, M.M., Hunter III, C.T., Block, A.K., Willett, D.S., Alborn, H.T., Huffaker, A., Schmelz, E.A. 2018. Commercial hybrids and mutant genotypes reveal complex protective roles for inducible terpenoid defenses. Journal of Experimental Botany. doi:10.1093/jxb/erx495.   
- Herbivore derived fatty acid-amides elicit reactive oxygen species burst in plants -(Peer Reviewed Journal)   Block, A.K., Christensen, S.A., Hunter III, C.T., Alborn, H.T. 2017. Herbivore derived fatty acid-amides elicit reactive oxygen species burst in plants. Journal of Experimental Botany. doi:10.1093/jxb/erx449.   
- Fungal and herbivore elicitation of a newly identified maize sesquiterpenoid, zealexin A4, is constrained by abiotic stress  -(Peer Reviewed Journal)   Christensen, S.A., Huffaker, A., Sims, J., Hunter III, C.T., Block, A.K., Vaughan, M.M., Willett, D.S., Mylroie, E., Williams, P.C., Schmelz, E.A. 2017. Fungal and herbivore elicitation of a newly identified maize sesquiterpenoid, zealexin A4, is constrained by abiotic stress. Planta. 247(4):863-873. https://doi.org/10.1007/s00425-017-2830-5.   
- The effects of climate change associated abiotic stresses on maize phytochemical defenses -(Review Article)   Vaughan, M.M., Block, A., Christensen, S., Allen, L.H., Schmelz, E.A. 2017. The effects of climate change associated abiotic stresses on maize phytochemical defenses. Phytochemistry Reviews. doi: 10.1007/s11101-017-9508-2.   
- Elevated carbon dioxide reduces emission of herbivore induced volatiles in Zea mays -(Peer Reviewed Journal)   Block, A.K., Vaughan, M.M., Christensen, S.A., Alborn, H.T., Tumlinson, J.H. 2017. Elevated carbon dioxide reduces emission of herbivore induced volatiles in Zea mays. Plant Cell and Environment. doi:10.1111/pce.12976.   
- Seteria viridis as a model for pathogen resistance in the Poaceae -(Abstract Only)     
- Reduced stomatal conductance in plants grown under elevated carbon dioxide leads to lower emission of herbivore induced volatiles. -(Abstract Only)     
- Phylloquinone (vitamin K1): occurrence, biosynthesis and functions -(Review Article)   Basset, G.J., Latimer, S., Fatihi, A., Soubeyrand, E., Block, A.K. 2017. Phylloquinone (vitamin K1): occurrence, biosynthesis and functions. Mini-Reviews in Medicinal Chemistry. 17(12):1028-1038.   
- Plant defense against insect herbivory -(Abstract Only)     
- Maize pathogens suppress inducible phytoalexin production to thwart innate plant immunity -(Abstract Only)     
- MSH1 is a plant organellar DNA binding and thylakoid protein under precise spatial regulation to alter development -(Peer Reviewed Journal)   Virdi, K.S., Wamboldt, Y., Kundariya, H., Laurie, J.D., Keren, I., Kumar, S., Block, A.K., Basset, G., Luebker, S., Elowsky, C., Day, P.M., Roose, J.L., Bricker, T.M., Elthon, T., Mackenzie, S.A. 2016. MSH1 is a plant organellar DNA binding and thylakoid protein under precise spatial regulation to alter development. Molecular Plant. 9(2):245-260.   

**Plant Molecular Biology Lab Members****Dr. Anna Block**(Research Molecular Biologist)	 	  **Jorrel Mendoza**(Biological Science Technician)	         **Dr. Ariel Sorg**(Post-Doctoral Researcher)	        **Dr. Hui Liu**(Post-Doctoral Researcher)	        **Kristin Roy**(Student Researcher)	      **Anvitha Dhulipala**(Student Researcher)	      **Madison Cross**(Student Researcher)	      **Kaylee Tran**(Student Researcher)	      Return to top                Last Modified:5/10/2024            Connect with ARSSign up-  ARS Home 
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