The six primary carotenoids found in most plant species include zeaxanthin, antheraxanthin, violaxanthin, lutein, β-carotene, and neoxanthin (Sandmann, 2001). Carotenoids are pigments integrated into light-harvesting complexes of chloroplasts that function as photoprotectants; carotenoids quench free radicals, perform non-photochemical quenching, and dissipate excess heat and light energy (Croce et al., 1999; Demmig-Adams et al., 1996; Frank and Cogdell, 1996). Carotenoids can also function as light-harvesting pigments by channeling photons unabsorbed by the chlorophyll molecule to the reaction center for photosynthesis (Niyogi, 1999; Polle et al., 2001)
Carotenoid synthesis begins with dimerization of the C20 compound geranyl-geranyl pyrophosphate to produce phytoene, the first C40 carotenoid (Buchanan et al., 2000). Phytoene is metabolized to lycopene through a series of desaturation reactions (Buchanan et al., 2000). Branching of the pathway occurs when lycopene is cyclized into α-carotene or β-carotene, and α-carotene forms lutein and lutein-5,6-epoxide (epoxylutein), whereas β-carotene forms neoxanthin and the xanthophyll cycle pigments (zeaxanthin, antheraxanthin, and violaxanthin) (Buchanan et al., 2000; Demmig-Adams et al., 1996).
Mesotrione, topramezone, and tembotrione are herbicides that affect carotenoid biosynthesis by inhibiting HPPD (EC 220.127.116.11), a precursor to plastoquinone and tocopherols (Bollman et al., 2008; Grossman and Ehrhardt, 2007; Mitchell et al., 2001; Pallett et al., 1998; Secor, 1994). Inhibition of HPPD prevents the formation of plastoquinone, a cofactor required for phytoene desaturase to convert phytoene to phytofluene to ζ-carotene and successive carotenoids (Buchanan et al., 2000). Tissue bleaching (i.e., whitening) that occurs after mesotrione, tembotrione, and topramezone application is attributed to a decrease in carotenoid production from reduced phytoene desaturase activity. The lack of tocopherols also contributes to plant death through a decrease in buffering capacity to reactive oxygen species (Matringe et al., 2005).
Topramezone and tembotrione are currently registered for use in corn (Zea mays L.) (Anonymous, 2006, 2009a; Bollman et al., 2008) and are being evaluated for weed control efficacy in turfgrass and ornamentals (Armel et al., 2009; Brosnan et al., 2010). Mesotrione is currently registered for weed control in turf (Anonymous, 2009b) and has been shown to injure common bermudagrass [Cynodon dactylon (L.) Pers.]. McCurdy et al. (2008) and Willis et al. (2007) reported bermudagrass injury with mesotrione ranging from 9% to 44%; however, this injury did not result in plant mortality in either study. Bermudagrass injury after treatment with topramezone and tembotrione has not been described in detail.
Data describing the physiological effects of treating common bermudagrass with several rates of mesotrione, topramezone, and tembotrione are limited. Understanding carotenoid fluctuations after applications of mesotrione, topramezone, and tembotrione may provide valuable insight into improving bermudagrass control strategies with these herbicides. Thus, the objective of this study was to evaluate changes in common bermudagrass carotenoid pigments after treatment with mesotrione, topramezone, and tembotrione.
Ahrens, W.H., Cox, D.J. & Budhwar, G. 1990 Use of the arcsine and square root transformations for subjectively determined percentage data Weed Sci. 38 452 458
Armel, G.R., Klingeman, W.E. & Flanagan, P.C. 2009 Evaluation of various mixtures of HPPD and PSII inhibitors for weed control in several ornamental plants. Proc Northeast. Weed Sci. Soc. 63 68
Baroli, I., Do, A.D., Yamane, T. & Niyogi, K.K. 2003 Zeaxanthin accumulation in the absence of a functional xanthophyll cycle protects Chlamydomonas reinhardtii from photooxidative stress Plant Cell 15 992 1008
Bollman, J.D., Boerboom, C.M., Becker, R.L. & Fritz, V.A. 2008 Efficacy and tolerance to HPPD-inhibiting herbicides in sweet corn Weed Technol. 22 666 674
Brosnan, J.T., Armel, G.R., Klingeman, W.E. III,, Breeden, G.K., Vargas, J.J. & Flanagan, P.C. 2010 Selective Star-of-Bethlehem control with sulfentrazone and mixtures of mesotrione and topramezone with bromoxynil and bentazon in cool-season turfgrass HortTechnology 20 315 318
Buchanan, B.B., Gruissem, W. & Jones, R.L. 2000 Biochemistry and molecular biology of plants 1159 1160 John Wiley and Sons, Inc Somerset, NJ
Corbett, J.L., Askew, S.D., Thomas, W.E. & Wilcut, J.W. 2004 Weed efficacy evaluations for bromoxynil, glufosinate, glyphosate, pyrithiobac, and sulfosate Weed Technol. 18 443 453
Croce, R., Weiss, S. & Bassi, R. 1999 Carotenoid-binding sites of the major light-harvesting complex II of higher plants J. Biol. Chem. 274 29613 29623
Davies, B.H. & Köst, H.P. 1988 Chromatograhpic methods for the separation of carotenoids 1 185 Köst H.P., Zweig G. & Sherma J. CRC handbook of chromatography, plant pigments: Fat soluble pigments Vol. 1 CRC Press Boca Raton, FL
Demmig-Adams, B. 1990 Carotenoids and photoprotection in plants. A role for the xanthophyll zeaxanthin Biochim. Biophys. Acta 1020 1 24
Depka, B., Jahns, P. & Trebst, A. 1998 β-carotene to zeaxanthin conversion in the rapid turnover of the D1 protein of photosystem II FEBS. Let. 424 267 270
Emenhiser, C., Simunovic, N., Sander, L.C. & Schwartz, S.J. 1996 Separation of geometric carotenoid isomers in biological extracts using a polymeric C30 column in reverse-phase liquid chromatography J. Agr. Food Chem. 44 3887 3893
Grossman, K. & Ehrhardt, T. 2007 On the mechanism of action and selectivity of the corn herbicide topramezone; a new inhibitor of 4-hydroxyphenylpyruvate dioxygenase Pest Manag. Sci. 63 429 439
Kimura, M. & Rodriguez-Amaya, D.B. 1999 Sources of errors in the quantitative analysis of food carotenoids by HPLC Archivos latinoamericanos de nutricioìn 49 58S 66S
Kopsell, D.A., Barickman, T.C., Sams, C.E. & McElroy, J.S. 2007 Influence of nitrogen and sulfur on biomass production and carotenoid and glucosinolate concentrations in watercress (Nasturtium officinale R. Br.) J. Agr. Food Chem. 55 10628 10634
Matringe, M., Sailland, A., Pelissier, B., Roland, A. & Zink, O. 2005 p-hydroxyphenylpyruvate dioxygenase inhibitor-resistant plants Pest Manag. Sci. 61 269 276
McCurdy, J.D., McElroy, J.S., Breeden, G.K. & Kopsell, D.A. 2008 Mesotrione plus prodiamine for smooth crabgrass (Digitaria ischaemum) control in established bermudagrass turf Weed Technol. 22 275 279
Mitchell, G., Bartlett, D.W., Fraser, T.E.M., Hawkes, T.R., Holt, D.C., Townson, J.K. & Wichert, R.A. 2001 Mesotrione: A new selective herbicide for use in maize Pest Manag. Sci. 57 120 128
Niyogi, K.K. 1999 Photoprotection revisited: Genetics and molecular approaches Annu. Rev. Plant Physiol. Plant Mol. Biol. 50 333 359
Niyogi, K.K., Bjorkman, O. & Grossman, A.R. 1997 The roles of specific xanthophylls in photoprotection Proc. Natl. Acad. Sci. USA 94 14162 14167
Pallett, K.E., Little, J.P., Sheekey, M. & Veerasekaran, P. 1998 The mode of action of isoxaflutole, I. Physiological effects, metabolism, and selectivity Pestic. Biochem. Physiol. 62 113 124
Polle, J.E.W., Niyogi, K.K. & Melis, A. 2001 Absence of the pigments lutein, violaxanthin, and neoxanthin affects the functional chlorophyll antenna size of photosystem II but not photosystem I in the green alga Chlamydomonas Reinhardtii Plant Cell Physiol. 5 482 491
Willis, J.B., Askew, S.D. & McElroy, J.S. 2007 Improved white clover control with mesotrione by tank-mixing bromoxynil, carfentrazone, and simazine Weed Technol. 21 739 743
Yelverton, F.H., Hoyle, J.A., Gannon, T.W. & Warren, L.S. 2009 Plant counts, digital image analysis, and visual ratings for estimating weed control in turf: Are they correlated? Proc. South Weed Sci. Soc. 62 399
Young, B.G., Zollinger, R.K. & Bernards, M.L. 2007 Variability of tembotrione efficacy as influenced by commercial adjuvant products. Proc North Central Weed Sci. Soc. 62 141