ORIGINAL PAPER Changes in fatty acids composition, hydrogen peroxide generation and lipid peroxidation of salt-stressed corn (Zea mays L.) roots Hichem Hajlaoui Æ Mounir Denden Æ Naceur El Ayeb Received: 24 June 2008 / Revised: 30 January 2009 / Accepted: 13 February 2009 / Published online: 10 March 2009 Ó Franciszek Go ´rski Institute of Plant Physiology, Polish Academy of Sciences, Krako ´w 2009 Abstract Comparative study about the salt-induced oxidative stress and lipid composition has been realised in primary root tissues for two varieties of maize (Zea mays L.) in order to evaluate their responses to salt stress. The root growth, root water content (WC), hydrogen peroxide (H 2 O 2 ) generation, lipid peroxidation, membrane stability index and the changes in the profile of fatty acids com- position were investigated. Salinity impacts in term of root growth, water content, H 2 O 2 generation, lipid peroxidation and membrane destabilisation were more pronounced in primary roots of Aristo than in those of Arper indicating more sensitivity of the first variety. It was confirmed by gas chromatography that the composition of fatty acids in roots of both varieties was constituted mainly by 16:0 and 18:0 as major saturated fatty acids and 18:1x9, 18:2x6 and 18:3x3 as major unsaturated fatty acids. Total lipid extracts from the roots of both varieties showed that the lipid saturation level increased under salt stress, notwith- standing the increased proportion of polyunsaturated fatty acids. The changes in lipid saturation being predominantly due to decreases in oleic acid (18:1x9) and increases in palmitic acid (16:0). However, Arper root extracts con- tained a lower proportion of saturated lipids than Aristo. The enhanced proportion of highly polyunsaturated fatty acids especially linolenic and eicosapentaenoic acids was considered to be the characteristic of the relatively salt tolerance in Arper roots. Keywords Salinity  Roots  Oxidative damages  Fatty acids composition  Zea mays L. Abbreviations FM Fresh mass DM Dry mass WC Root water content ROS Reactive oxygen species H 2 O 2 Hydrogen peroxide TiCl 4 Titanium chloride MDA Malondialdehyde TCA Trichloroacetic acid TBA Thiobarbituric acid TBARS Total 2-thiobarbituric acid reactive substances FA Fatty acids U/S Ratio of unsaturated to saturated fatty acids MSI Membrane stability index Introduction Salinity is a widespread problem, and it is considered to be one of the most serious constraints facing agriculture today, especially in the arid and semi-arid areas of the world (Eraslan et al. 2007). Also, these areas are often under intense radiation and high temperatures throughout the year, thus constraining their primary productivity (Hajlaoui Communicated by S. Weidner. H. Hajlaoui (&) Institut National de Recherche en Ge ´nie Rural, Eaux et Fore ˆts (INRGREF), Unite ´ d’Expe ´rimentation Agricole, Oued Souhail, BP 20, 8000 Nabeul, Tunisia email: hajlaoui2001@yahoo.fr M. Denden Institut Supe ´rieur Agronomique de Chott-Mariem, 4042 Sousse, Tunisia N. E. Ayeb Institut Supe ´rieur de Biotechnologie de Monastir, BP 10, 5000 Monastir, Tunisia 123 Acta Physiol Plant (2009) 31:787–796 DOI 10.1007/s11738-009-0293-4