1. Significance Caffeine and ibuprofen may negatively affect plant growth.  Caffeine and ibuprofen generally exist at concentrations below 1 ppm in surface waters but their concentrations are possibly higher in the biosolids that are applied to agricultural land. Crop plants with significantly lower Cr levels may negatively impact human and animal health.  Chromium is believed to enhance glucose metabolism in humans by enhancing insulin receptor sensitivity and increasing translocation of glucose transporter to the cell membrane. Root Growth Results ICP-OES Results Mineral Accumulation of a Model Plant, Arabidopsis thaliana, After Exposure to Caffeine and Ibuprofen Kyle Butzine and Dr. Catherine Chan butzinekj29@uww.edu and chanc@uww.edu University of Wisconsin – Whitewater Introduction High volume pharmaceuticals are excreted by humans and sometimes disposed through the sewer system. Terrestrial plants can be exposed to these pharmaceuticals through flooding and biosolid application. Preliminary results suggest two frequently used drugs, caffeine and ibuprofen, have negative effects on plant growth at 100 ppm and 10 ppm, respectively. We tested the synergistic effects of applying both caffeine and ibuprofen at the same time to a model land plant, Arabidopsis thaliana. We monitored the growth of Arabidopsis during drug exposure, and quantified mineral accumulation by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Our goal is to correlate phenotypic effects of drug exposure to differences in mineral accumulation. Methods Germinate seeds in standard plant agar media. Transplant seedlings into media with varying concentrations of caffeine and ibuprofen and monitor growth. Microwave digest dried plant tissue with a mixture of 50% nitric acid, 30% hydrogen peroxide, and 20% water. Microwave Digestion Parameters Analyze samples for macro nutrients (Ca, Mg, Na, K, S, P) and micro nutrients (Al, B, Co, Cr, Cu, Fe, Mn, Mo, Ni, V, Zn) by ICP-OES. Wavelength Parameters for ICP-OES (nm) Conclusion Aluminum and Chromium levels significantly decrease when Arabidopsis are exposed to as low as 1 ppm caffeine + 1 ppm ibuprofen. Arabidopsis exposed to select pharmaceuticals may have altered physiology and mineral nutrient content, even when there is no observable phenotypic effects. Applying caffeine and ibuprofen simultaneously does not result in enhanced toxicity in Arabidopsis. Acknowledgements Merck/ AAAS Undergraduate Science Research Program University of Wisconsin Whitewater Undergraduate Research Program College of Letters and Sciences, Dean Mary Pinkerton Dr. John Ejnik Figure 1 & Figure 2: Root growth after 24 hours of drug exposure. T 0 indicates initial root length, and T 24 indicates root length after 24 hours exposure to 10 ppm caffeine + 10 ppm ibuprofen. Plants exposed to caffeine and ibuprofen grew significantly less than control plants. Significant difference was calculated based on 95% confidence. Stage Power (W) Ramp Time (Min)PSITemp. Hold Time (Min) 116005:00400705:00 216005:004001005:00 3160020:0040018010:00 Mo202.031 Zn213.857 Co228.616 Ni231.604 Fe238.204 Mn257.61 Cr267.716 Cu324.752 Al396.153 Sr407.771 Ba455.403 Mg285.213 Ca317.933 V292.402 Na589.592 K766.49 Sr180.669 P213.617 B249.772 ElementAverage Ratio +/- Standard Error Al0.7740.048 B0.6360.265 Ba1.7611.279 Co3.4462.121 Cr0.5580.011 Cu0.8590.084 Fe1.1220.207 Mn0.9280.281 Mo1.2430.413 Ni1.3650.566 Sr1.2090.242 V0.7930.426 Zn1.3440.272 ElementAverage Ratio +/- Standard Error Ca1.2910.159 K1.3020.381 Mg1.3680.302 Na1.4700.392 P1.6980.489 S1.3330.450 Control10 ppm Caffeine + 10 ppm Ibuprofen Figure 2 Figure 3 Figure 3: Elements that were significantly different between plants treated with various combinations of caffeine and ibuprofen and control plants. A ratio of 1 indicates no change in the accumulation of a particular mineral between treated and untreated plants. Aluminium and chromium were present at significantly lower concentrations in caffeine- and ibuprofen-treated plants. Significant difference was determined by Student’s t-test. (N=3,p<.05) Table 1: The average ratio and standard error between untreated plants and plants treated with 10 ppm caffeine + 10 ppm ibuprofen for macro elements. No macro element concentrations were significantly different between untreated plants and treated plants. (N=3,p<.05) Table 2: The average ratio and standard error between untreated plants and plants treated with 10 ppm caffeine + 10 ppm ibuprofen for microelements. Aluminum and chromium had significantly different concentrations between untreated plants and treated plants. (N=3,p<.05) Table 1 Table 2 T0T0 T 24 T0T0 Adapted from http://lpi.oregonstate.edu/infocenter/minerals/chromium Figure 1 1cm