Participation of the enzymes involved in the biosynthesis of biogenic amines in biochemical interactions between wheat (Triticum aestivum; Poaceae) and bird cherry-oat aphid (Rhopalosiphum padi; Aphididae) Cezary Sempruch * , Bogumil Leszczy  nski, Martyna Wilczewska, Hubert Sytykiewicz, Pawel Czerniewicz, Sylwia Golawska, Grzegorz Chrzanowski, Henryk Matok Siedlce University of Natural Sciences and Humanities, Department of Biochemistry and Molecular Biology, Prusa 12, 08-110, Siedlce, Poland article info Article history: Received 3 September 2015 Received in revised form 12 January 2016 Accepted 31 January 2016 Available online xxx Keywords: Triticum aestivum Rhopalosiphum padi Amino acid decarboxylation Polyamines Tyramine abstract The studies concerned changes in the activities of ornithine decarboxylase (ODC), lysine decarboxylase (LDC) and tyrosine decarboxylase (TyDC) in tissues of wheat (Triticum aestivum L.) infested with bird cherry-oat aphid (Rhopalosiphum padi L.). Obtained results showed that the activities of the enzymes were stimulated in the less susceptible wheat Kontesa cv. infested by the aphids. In the case of the more susceptible Tonacja cv., on most occasions a decrease in the enzyme activities occurred. Such re- sponses were especially clear for TyDC in both analysed cvs., and for LDC and ODC in the case of Kontesa cv. Thus it may be concluded that amino acid decarboxylation plays an important part in the biochemical defence developed in wheat tissues in response to R. padi infestation. The changes in the activities of the decarboxylases were dependent on the wheat genotype as well as the duration of the infestation. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Biogenic amines are known biomolecules involved in plant responses to abiotic and biotic stresses (Feriduddin et al., 2013; Jim enez-Bremont et al., 2014). However, the participation of plant amines and their amide derivatives obtained by conju- gation with hydroxycinnamic acids (HCAAs) in insecteplant interactions has so far been poorly described. Strong partici- pation of polyamines (PAs) in molecular plant defence mechanisms may result from scavenging and/or generating free radicals, regulation of gene expression and formation of toxic products (Del Duca et al., 2014). In addition, these compounds may form ionic and/or covalent bonds with nucleic acids, proteins and phospholipids. As a result, PAs influence enzyme activities, the integrity of chromatin and biomembranes, and the functioning of receptors and transcriptional factors in signalling pathways. HCAA derivatives were involved in responses of different plant species against Liriomyza trifolii (Burgess), Manduca sexta (L.) and Spodoptera littoralis (Boisduval) (Tebayashi et al., 2007; Bassard et al., 2010). These * Corresponding author. E-mail address: cezar@uph.edu.pl (C. Sempruch). Contents lists available at ScienceDirect Biochemical Systematics and Ecology journal homepage: www.elsevier.com/locate/biochemsyseco http://dx.doi.org/10.1016/j.bse.2016.01.005 0305-1978/© 2016 Elsevier Ltd. All rights reserved. Biochemical Systematics and Ecology 65 (2016) 33e39