Department of Crop Sciences
Dean Riechers
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Dean Riechers

N-331 Turner Hall
1102 S. Goodwin
Urbana, IL 61801
(217) 333-9655

Research Areas

Preventing Crop Injury from Herbicides with Herbicide Safeners.

A major component of my research program involves investigating the potential to alleviate crop injury from herbicides through the use of safeners. A major goal of my research is to elucidate the biochemical and molecular basis of safener mechanism of action for increasing herbicide detoxification in cereal crops. These investigations into safener mechanism of action in maize, sorghum, and wheat have resulted in a basic and more thorough understanding of how herbicide safeners function in cereal crops, as well as gain insights into inducible detoxification systems in plants. Our most recent findings have contributed significantly to understanding the genes, proteins and enzymes involved in herbicide detoxification in cereal crops, as well as towards comprehending the basic mechanism(s) of herbicide safeners for improving herbicide selectivity. For example, our recent proteomic and RNAseq results provide the framework for targeting which genes/proteins are critical for the safener responses in cereal crop coleoptiles. Recent discoveries in my lab also indicate that safeners trigger the expression of proteins in a plant defense pathway that is normally regulated by oxylipins, which are synthesized in plants from the breakdown products of lipids and oxidized fatty acids in response to stress. Tissue microdissection combined with RNAseq to analyze safener-responsive, tissue-specific transcriptomes in the outer cell layers of grain sorghum coleoptiles has led to successfully attracting funding from the USDA-NIFA to further pursue this research area.

Safener-treated sorghum shoot cross section, depicting GST subcellular localization (green) and cell nuclei (blue). Cells are outlined in red due to anti-PIN2 labeling.

Mechanisms of Evolved Weed Resistance to Herbicides.

The discovery of an HPPD-resistant waterhemp population in McLean County, IL in 2009 in a seed corn production field was of great interest to our research group. Our initial work on this population indicated that it is cross resistant to all HPPD inhibitors currently marketed in the U.S., as well as multiple resistant to atrazine and ALS inhibitors. My research group has investigated enhanced herbicide metabolism via P450s and GSTs as the mechanisms conferring resistance to mesotrione and atrazine, respectively, within this waterhemp population. This work sets the framework for control of the recently discovered HPPD-resistant waterhemp population from McLean County, IL (as well as several new HPPD-resistant waterhemp and Palmer amaranth populations throughout the Midwest) and for guiding further biochemical and molecular studies aimed at unraveling HPPD and atrazine non-target site-resistance mechanism(s) within these populations.

Soybean Injury from Plant Growth Regulator (PGR) Herbicides

Several auxin-like herbicides (dicamba, clopyralid, 2,4-D) commonly used in corn for postemergence weed control can injure soybeans at extremely low rates. These plant growth regulator (PGR) herbicides can drift onto nearby soybean fields, or can be directly applied at very low rates if spray tanks are not thoroughly cleaned before spraying soybeans. These herbicides can cause severe injury to newly emerging soybean leaves, and also delayed maturity and decreased yield. Injury symptoms include leaf cupping, strapping, parallel veination, and puckering.

We are working on developing a laboratory assay to detect the presence of these PGR herbicides in soybean leaves, based on their effects on gene expression levels and expression patterns. Using molecular techniques such as RT-PCR and differential display of mRNA, we can fingerprint the expression of one or many genes in soybean leaves that have been treated with very low levels of the PGR herbicides. We hope to find a gene (or genes) that is only expressed in PGR-treated soybean leaves, and will then use the expression of this gene as a molecular marker to diagnose the presence of the herbicide. We have already found an auxin-regulated gene that is only expressed in soybean leaves treated with each of the three PGR herbicides listed above. We also hope to find specific genes that can be used to distinguish among dicamba, clopyralid, and 2,4-D.


Journal Articles

Ma, R., Evans, A.F., and Riechers, D.E. 2016. Differential responses to preemergence and postemergence atrazine in two atrazine-resistant waterhemp populations. Agron. J. 108:1196–1202.
Peterson, M.A., McMaster, S.A., Riechers, D.E., Skelton, J.J., and Stahlmann, P.W. 2016. 2,4-D past, present, and future: A review. Weed Technol. 30:303–345.
Skelton, J.J., Ma, R., and Riechers, D.E. 2016. Waterhemp (Amaranthus tuberculatus) control under drought stress with 2,4-D and glyphosate. Weed Biol. Manag. 16:34–41.
Hausman, N.E., P.J. Tranel, D.E. Riechers, and A.G. Hager. 2016. Responses of a waterhemp (Amaranthus tuberculatus) population resistant to HPPD-inhibiting herbicides to foliar-applied herbicides. Weed Technol. 30:106–115.
Ma, R., Skelton, J.J., and Riechers, D.E. 2015. Measuring rates of herbicide metabolism in dicot weeds with an excised leaf assay. J. Visual. Expt. (103) e53236: DOI:10.3791/53236.
Huffman J.L., Hausman, N.E., Hager, A.G., Riechers, D.E., and Tranel, P.J. 2015. Genetics and inheritance of non-target-site resistances to atrazine and mesotrione in an Illinois waterhemp (Amaranthus tuberculatus) population. Weed Sci. 63:799–809.
Guo, J., C.W. Riggins, N.E. Hausman, A.G. Hager, D.E. Riechers, and P.J. Tranel. 2015. Non-target-site based resistance to ALS inhibitors in waterhemp. Weed Sci. 63:399–407.
Ma R., S.S. Kaundun, P.J. Tranel, C.W. Riggins, D.L. McGinness, A.G. Hager, T. Hawkes T, E. McIndoe, and D.E. Riechers. 2013. Distinct detoxification mechanisms confer resistance to mesotrione and atrazine in a population of waterhemp. Plant Physiol. 163:363–377.
Hausman, N.E., P.J. Tranel, D.E. Riechers, D.J. Maxwell, L.C. Gonzini, and A.G. Hager. 2013. Responses of an HPPD inhibitor-resistant waterhemp (Amaranthus tuberculatus) population to soil-residual herbicides. Weed Technol. 2013 27:704–711.
Hausman, N.E., S. Singh, P.J. Tranel, D.E. Riechers, S.S. Kaundun, N.D. Polge, D.A. Thomas, and A.G. Hager. 2011. Resistance to HPPD-inhibiting herbicides in a population of waterhemp (Amaranthus tuberculatus) from Illinois, United States. Pest Manag. Sci. 67:258-261.
Mithila, J., J.C. Hall, W.G. Johnson, K.B. Kelley, and D.E. Riechers. 2011. Evolution of resistance to auxinic herbicides: historical perspectives, mechanisms of resistance, and implications for broadleaf weed management in agronomic crops. Weed Sci. 59:445-457.
Riechers, D.E., K. Kreuz, and Q. Zhang. 2010. Detoxification without intoxication: herbicide safeners activate plant defense gene expression. Plant Physiol. 153:3-13.
A.J. Woodyard, J.A. Hugie, and D.E. Riechers. 2009. Interactions of mesotrione and atrazine in two weed species with different mechanisms for atrazine resistance. Weed Sci. 57:369-378.
A.J. Woodyard, G.A. Bollero, and D.E. Riechers. 2009. Broadleaf weed management in corn utilizing synergistic postemergence herbicide combinations. Weed Technol. 23:513-518.
A. S. Davis, J. C. Hall, M. Jasieniuk, M. A. Locke, E. C. Luschei, D. A. Mortensen, D. E. Riechers, R. G. Smith, T. M. Sterling, and J. H. Westwood. 2009. Weed science research and funding: a call to action. Weed Sci. 57:442-448.
Pataky, J.K., M.M. Williams II, D.E. Riechers and M.D. Meyer. 2009. A common genetic basis for cross-sensitivity to mesotrione and nicosulfuron in sweet corn hybrid cultivars and inbreds grown throughout North America. J. Amer. Soc. Hort. Sci. 134:252-260.
Hugie, J.A., G. Bollero, P.J. Tranel, and D.E. Riechers. 2008. Defining the rate requirements for synergism between mesotrione and atrazine in redroot pigweed (Amaranthus retroflexus). Weed Sci. 56:265-270.
Zhang, Q., and D.E. Riechers. 2008. Proteomics: an emerging technology for weed science research. Weed Sci. 56:306-313.
Nordby, J.N., M.M. Williams II, J.K. Pataky, D.E. Riechers, and J.D. Lutz. 2008. A common genetic basis in sweet corn inbred Cr1 for cross sensitivity to multiple cytochrome P450-metabolized herbicides. Weed Sci. 56:376-382.
Kelley, K.B., and D.E. Riechers. 2007. Recent developments in auxin biology and new opportunities for auxinic herbicide research. Pestic. Biochem. Physiol. 89:1-11.
Volenberg, D.S., P.J. Tranel, J.F. Holt, F.W. Simmons, S.C. Weller, A. Sharkhuu, and D.E. Riechers. 2007. Assessment of two biotypes of Solanum ptycanthum that differ in resistance levels to imazamox. Weed Res. 47:353-363.
Zhang, Q, F.-X. Xu, K.N. Lambert, and D.E. Riechers. 2007. Safeners coordinately induce the expression of multiple proteins and MRP transcripts involved in herbicide metabolism and detoxification in Triticum tauschii seedling tissues. Proteomics 7:1261-1278.
Kelley, K.B., Q. Zhang, K.N. Lambert, and D.E. Riechers. 2006. Evaluation of auxin-responsive genes in soybean for detection of off-target plant growth regulator herbicides. Weed Sci. 54:220-229.
Pataky, J.K., J.N. Nordby, M.M. Williams, and D.E. Riechers. 2006. Inheritance of cross-sensitivity in sweet corn to herbicides applied postemergence. J. Amer. Soc. Hort. Sci. 131:744-751.
Bierman, R.E., D.E. Riechers, C.L. Sprague, G. Bollero, and W.L. Pedersen. 2006. Fungicide-herbicide interaction in soybean (Glycine max). Crop Prot. 25:134-139.
Reiling, K.L., F.W. Simmons, D.E. Riechers, and L.E. Steckel. 2006. Application timing and soil factors affect sulfentrazone phytotoxicity to two soybean (Glycine max (L.) Merr.) cultivars. Crop Prot. 25:230-234.
Zhou, W., F.L. Kolb, and D.E. Riechers. 2005. Identification of proteins induced or up-regulated by Fusarium head blight infection in the spikes of hexaploid wheat (Triticum aestivum). Genome 48:770-780.
Williams, M.M., J.K. Pataky, J.N. Nordby, D.E. Riechers, C.L. Sprague, and J.B. Masiunas. 2005. Cross-sensitivity in sweet corn to nicosulfuron and mesotrione applied postemergence. Hort. Sci. 40:1801-1805.
Kelley, K.B., L.M. Wax, A.G. Hager, and D.E. Riechers. 2005. Soybean response to plant growth regulator herbicides is affected by other postemergence herbicides. Weed Sci. 53:101-112.
Bunting, J.A., C.L. Sprague, and D.E. Riechers. 2005. Incorporating foramsulfuron into annual weed control systems for corn. Weed Technol. 19:160-167.
Holappa, L.D., M.K. Walker-Simmons, T.H.D. Ho, D.E. Riechers, D.M. Beckles, and R.L. Jones. 2005. A Triticum tauschii protein kinase related to wheat PKABA1 is associated with ABA signaling and is distributed between the nucleus and cytosol. J. Cereal Sci. 41:333-346.
Bunting, J.A., C.L. Sprague, and D.E. Riechers. 2004. Proper adjuvant selection for foramsulfuron activity. Crop Prot. 23:361-366.
Kelley, K.B., K.N. Lambert, A.G. Hager, and D.E. Riechers. 2004. Quantitative expression analysis of GH3, a gene induced by plant growth regulator herbicides in soybean. J. Agric. Food Chem. 52:474-478.
Zhang, Q., and D.E. Riechers. 2004. Proteomic characterization of herbicide safener-induced proteins in the coleoptile of Triticum tauschii seedlings. Proteomics 4:2058-2071.
Bunting, J.A., C.L. Sprague, and D.E. Riechers. 2004. Absorption and activity of foramsulfuron in giant foxtail (Setaria faberi) and woolly cupgrass (Eriochloa villosa) with various adjuvants. Weed Sci. 52:513-517.
Bunting, J.A., C.L. Sprague, and D. E. Riechers. 2004. Physiological basis for tolerance of corn hybrids to foramsulfuron. Weed Sci. 52:711-717.
Bunting, J.A., C.L. Sprague, and D.E. Riechers. 2004. Corn tolerance as affected by the timing of foramsulfuron applications. Weed Technol. 18:757-762.
Milliman, L.D., D.E. Riechers, L.M. Wax, and F.W. Simmons. 2003. Characterization of two biotypes of imidazolinone-resistant eastern black nightshade. Weed Sci. 51:139-144.
Riechers, D.E., Q. Zhang, F.-X. Xu, and K.C. Vaughn. 2003. Tissue-specific expression and localization of safener-induced glutathione S-transferase proteins in Triticum tauschii. Planta 217:831-840.
Xu, F.-X., E.S. Lagudah, S. P. Moose, and D.E. Riechers. 2002. Tandemly duplicated safener-induced glutathione S-transferase genes from Triticum tauschii contribute to genome- and organ-specific expression in hexaploid wheat. Plant Physiol. 130:362-373.
Riechers, D.E. and M.P. Timko. 1999. Structure and expression of the gene family encoding putrescine N-methyltransferase in Nicotiana tabacum: new clues to the evolutionary origin of cultivated tobacco. Plant Mol. Biol. 41:387-401.
Riechers, D.E., A. Kleinhofs, G.P. Irzyk, and S.S. Jones. 1998. Chromosomal location and expression of a herbicide safener-regulated glutathione S-transferase gene in Triticum aestivum and linkage relations in Hordeum vulgare. Genome 41:368-372.
Riechers, D.E., G. P. Irzyk, E.P. Fuerst, and S.S. Jones. 1997. Nucleotide sequence of a cDNA encoding a safener-induced glutathione S-transferase (accession no. AF004358) from Triticum tauschii (PGR97-110). Plant Physiol. 114:1568.
Riechers, D.E., G.P. Irzyk, S.S. Jones, and E.P. Fuerst. 1997. Partial characterization of glutathione S-transferases from wheat (Triticum spp.) and purification of a safener-induced glutathione S-transferase from Triticum tauschii. Plant Physiol. 114:1461-1470.
Riechers, D.E., K. Yang, G.P. Irzyk, S.S. Jones, and E.P. Fuerst. 1996. Variability of glutathione S-transferase levels and dimethenamid tolerance in safener-treated wheat and wheat relatives. Pestic. Biochem. Physiol. 56:88-101.
Riechers, D.E., E.P. Fuerst, and K.D. Miller. 1996. Initial metabolism of dimethenamid in safened and unsafened wheat shoots. J. Agric. Food Chem. 44:1558-1564.
Riechers, D.E., L.M. Wax, R.A. Liebl, and D.G. Bullock. 1995. Surfactant effects on glyphosate efficacy. Weed Technol. 9:281-285.
Riechers, D.E., L.M. Wax, R.A. Liebl, and D.R. Bush. 1994. Surfactant-increased glyphosate uptake into plasma membrane vesicles isolated from common lambsquarters leaves. Plant Physiol. 105:1419-1425.
Wade, B.R., D.E. Riechers, R.A. Liebl, and L.M. Wax. 1993. The plasma membrane as a barrier to herbicide penetration and site for adjuvant action. Pestic. Sci. 37:195-202.
Riechers, D.E. 1991. Herbicide resistance in weeds. J. Agron. Educ. 20:63-65.

Contributed Chapters

Riechers, D.E., and Green, J.M. 2016. Herbicide Selectivity and the Role of Safeners. M. Jugulam, Ed., "Biology, Physiology and Molecular Biology of Weeds," CRC Press: Taylor & Francis Group (in press).
Matsumoto H., Riechers D.E., Lygin A.V., Baluška F., Sivaguru M. 2015. Aluminum signaling and potential links with safener-induced detoxification in plants. In Aluminum Stress Adaptation in Plants, Panda S., Baluška F., Eds., Book series "Signaling and Communication in Plants – Vol. 24." Springer International Publishing, Switzerland. DOI 10.1007/978-3-319-19968-9_1
Riechers, D.E., K.C. Vaughn, and W.T. Molin. 2005. The role of plant glutathione S-transferases in herbicide metabolism. In Environmental Fate and Safety Management of Agrochemicals, J.M. Clark, H. Ohkawa, eds., ACS Symposium Series 899, American Chemical Society, Washington DC, pp. 216-23

Other Publications

Extension Publications
Kelley, K., D. Riechers, D. Nordby, and A. Hager. 2004. Plant Growth Regulator Injury to Soybeans. Extension fact sheet, posted on the internet at:
Riechers, D.E., E.P. Fuerst, and C.M. Boerboom. 1994. Advancements in the development of seed-applied herbicide safeners for wheat. Wash. State Univ. Coop. Ext. Tech. Rep. 94-6, p. 102.
Boerboom, C.M., E.P. Fuerst, and D.E. Riechers. 1993. Wheat safener research targeted for jointed goatgrass control. Wash. State Univ. Coop. Ext. Tech. Rep. 93-4, pp. 77-78.

Invited Lectures

"Herbicide Safeners: New Insights into Inducible Signaling Mechanisms in Crops," Weed Science Society of America annual meeting, Symposium entitled "Recent Research Investigating Herbicide Metabolism in Weed Science," Tucson, AZ. 2017.
"Investigating Herbicide Safeners For Enhancing Herbicide Selectivity: Inducible Detoxification Mechanisms In Cereal Crop Tissues." Dow AgroSciences, Indianapolis, IN. 2014.
"Mechanisms of Herbicide Safeners in Enhancing Crop Protection", BASF - Global Research Crop Protection, BioScience Research Symposium, Limburgerhof, Germany. 2011.
"Development of Resistance to the Auxinic Herbicides: Historical Perspectives, Genetics, and Mechanisms of Weed Resistance", Southern Weed Science Society Annual Meeting, San Juan, Puerto Rico. Symposium entitled "2,4-D - Past, Present, and Future." 2011.
"Development of Resistance to the Auxinic Herbicides: Historical Perspectives, Genetics, and Mechanisms of Weed Resistance", North Central Weed Science Society Annual Meeting, Lexington, KY. Symposium entitled "2,4-D - Past, Present, and Future. Status of One of the World's Most Widely Used Herbicides." 2010.
"Application of Proteomics Techniques to Weed Science Research", Weed Science Society of America annual meeting, Symposium entitled "Using Emerging Technologies to Study Weed Biology: an Educational Forum", San Antonio, TX. 2007.
"Role of Herbicide Metabolism in Weed Resistance to Herbicides", American Chemical Society Symposium, Agrochemicals Division, San Francisco, CA. 2006.
"Proteomics Approaches for Studying Herbicide Safener Mechanism of Action in Triticum tauschii Seedlings", BASF BioScience Research Symposium, St. Johann, Germany. 2005.
"Regulation and Function of Herbicide Safener-Inducible Glutathione S-Transferases in the Model Grass Species Triticum tauschii", 4th Int'l. Weed Science Congress, Durban, South Africa. 2004.
"Role of Plant Glutathione S-Transferases in Herbicide Metabolism", 3rd Pan Pacific Conference on Pesticide Science, Honolulu, HI, June 2003.
"Analyzing Gene Expression at the Protein Level: Using Proteomics Techniques to Investigate Herbicide Safener Mechanism of Action", North Central Weed Science Society, Louisville, KY, December 2003.