Effect of fluazifop-p-butyl treatment on pigments and polyamines level within tissues of non-target maize plants Marcin Horbowicz a , Cezary Sempruch b,⇑ , Ryszard Kosson c , Danuta Koczkodaj a , Dajana Walas a a Department of Plant Physiology and Genetics, University of Natural Sciences and Humanities, Prusa 12, 08-110 Siedlce, Poland b Department of Biochemistry and Molecular Biology, University of Natural Sciences and Humanities, Prusa 12, 08-110 Siedlce, Poland c Research Institute of Horticulture, Konstytucji 3 Maja 1/3, 96-100 Skierniewice, Poland article info Article history: Received 20 November 2012 Accepted 12 May 2013 Available online 20 May 2013 Keywords: Maize Fluazifop-p-butyl Anthocyanins Polyamines Amino acid decarboxylases abstract Fluazifop-p-butyl (FL) is one of the most popular graminicides from arylophenoxypropionate group. These herbicides act as inhibitors of acetyl-CoA carboxylase (ACCase) that catalyzes the formation of mal- onyl-CoA during metabolism of lipids and/or of some secondary compounds. On the other hand arylopro- pionates and cyclohexanediones cause phytotoxic effects by stimulating free-radicals generation and causing oxidative stress in susceptible plants. However, the importance of disturbances in plant pigments and polyamines accumulation for this effect is not clear. The aim of this work is to quantify the phyto- toxicity of FL to non target maize plant and to explain how photosynthetic pigments, anthocyanins (ANC) and polyamines participate in this interaction. Obtained results showed reduction of chlorophyll a and b, but only in case of the highest herbicide dose. Lower FL concentrations caused increase of the photosynthetic pigments, or were not effective. A similar effect was stated for putrescine, while spermidine was reduced within epicotyl of leaf tissues. In case of 2-phenylethylamine (PEA), there was observed a lack of significant changes within leaves and an increase in epicotyl under the middle and the highest dose of the herbicide. Moreover, FL induced ANC accumulation in epicotyls of maize seedlings. The activity of such key enzymes of polyamine biosynthesis as: ornithine decarboxylase (ODC) and lysine decarboxylase (LDC), increased in leaves treated with herbicide at the lowest concentration and decreased under the highest. However, in case of epicotyls the decreasing tendency was observed with the exception of ODC under the highest FL dose. The activity of tyrosine decarboxylase (TyDC) was importantly elevated only within epi- cotyls under the lower FL concentrations. It was concluded that FL inhibits maize growth, and the inten- sity of the effect is positively correlated with the herbicide concentration. The phenomenon was related to changes in content of pigments, polyamines and activity of studied enzymes. Ó 2013 Elsevier Inc. All rights reserved. 1. Introduction Aryloxyphenoxypropionates and cyclohexanediones act as inhibitors of acetyl CoA carboxylase (EC 6.4.1.2) that catalyzes ATP-dependent formation of malonyl-CoA from acetyl-CoA and bicarbonate [1]. This product is needed for a number of reactions, including de novo fatty acids biosynthesis in chloroplasts, elonga- tion of the acids on endoplasmic reticulum and synthesis of some secondary metabolites, such as flavonoids and anthocyanins. The enzyme present in most grasses is sensitive to these herbicides, while the one in dicots is not [2]. Dicot plants, which are insensi- tive to graminicides, have a multi-enzyme complex type of carbox- ylase, while grasses have a multifunctional protein. Detailed study of multifunctional forms of ACCase carboxylases suggests that her- bicide resistance is correlated with cooperativity of herbicide bind- ing to the native dimeric form of the carboxylase [2]. Thus, both groups of herbicides are called graminicides due to their selectivity in control of weeds belongs to grasses (Poaceae). Together they ac- count for approx. 10% of the current global herbicide market. The inhibition of ACCase activity by graminicides results in severe growth defects leading to plant death [3]. The other hypothesis assumes that graminicides cause phyto- toxic effects through stimulation in susceptible plants of free-rad- ical production, causing an oxidative stress [4–6]. For example, 0048-3575/$ - see front matter Ó 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.pestbp.2013.05.008 Abbreviations: ACCase, acetyl-CoA carboxylase; ADC, arginine decarboxylase; ANC, anthocyanins; dcSAM, decarboxylated S-adenosylmethionine; DMSO, dimeth- ylsulfoxide; EDTA, ethylenediaminetetracetic acid; FL, fluazifop-p-butyl; LDC, lysine decarboxylase; ODC, ornithine decarboxylase; PAs, polyamines; PEA, 2-phenyleth- ylamine; PLP, pirydoxal 5 0 -phosphate; PS II, photosystem II; Put, putrescine; ROS, reactive oxygen species; SAMDC, S-adenosylmethionine decarboxylase; Spd, sper- midine; Spm, spermine; TNBS, trinitrobenzosulfonic acid; TyDC, tyrosine decarboxylase. ⇑ Corresponding author. Fax: +48 25 6445959. E-mail address: cezar@ap.siedlce.pl (C. Sempruch). Pesticide Biochemistry and Physiology 107 (2013) 78–85 Contents lists available at SciVerse ScienceDirect Pesticide Biochemistry and Physiology journal homepage: www.elsevier.com/locate/pest