Changes of defense proteins in the extracellular proteome of grapevine (Vitis vinifera cv. Gamay) cell cultures in response to elicitors ☆ M.J. Martinez-Esteso a , S. Sellés-Marchart a , J.C. Vera-Urbina a , M.A. Pedreño b , R. Bru-Martinez a, ⁎ a Plant Proteomics and Functional Genomics Group, Department of Agrochemistry and Biochemistry, Faculty of Science, University of Alicante, Alicante, Spain b Plant Peroxidases Group, Department of Plant Physiology, Faculty of Biology, University of Murcia, Murcia, Spain ARTICLE INFO ABSTRACT Article history: Received 15 July 2009 Accepted 1 October 2009 In plant cells, elicitors induce defense responses that resemble those triggered by pathogen attack, such as the synthesis of phytoalexins and pathogen-related proteins which accumulate in the extracellular space. In the search for the particular proteins involved in defense responses, we investigated the changes in the extracellular proteome of a grapevine (Vitis vinifera cv. Gamay) cell suspension in response to elicitation with methylated cyclodextrins (MBCD) and methyl jasmonate (MeJA). Twenty-five of the 39 spots differentially expressed in 2-D gels were identified and found to be encoded by 10 different genes: three secretory peroxidases, chitinase-III, β-1,3-glucanase, thaumatin-like, SGNH plant lipase-like, NtPR27-like, xyloglucan endotransglycosylase and subtilisin-like protease. Most of them belong to the pathogenesis-related type proteins. A new class III secretory basic peroxidase and chitinase III were strongly induced in cultures treated with MBCD alone or combined with MeJA, while cultures treated with MeJA alone displayed a general repression of most of the extracellular proteins. Some of the proteins induced in grapevine cell cultures by MBCD are induced in other species by activators of systemic acquired resistance (SAR), a form of plant immunity. Collectively, the results suggest that treatment with MBCD resembles the effect of SAR induction agents in cell cultures. © 2009 Elsevier B.V. All rights reserved. Keywords: Grapevine Cell culture Extracellular proteome 2-DE Chitinase-III Class III secretory basic peroxidase 1. Introduction The analysis of plant responses to biotic stress in terms of biochemical and molecular changes provides unique infor- mation to interpret the mechanisms that plants have developed to resist diseases and pests. Because of the high input of phytochemicals, environmental concerns are push- ing modern agriculture to face the fight against pathogens by exploiting biological resources, such as the natural resistance of the species. Therefore, the identification of molecular resistance mechanisms becomes a central issue [1]. Proteo- mics has emerged as a new and powerful tool to investigate the important biological phenomenon of disease resistance to disclose the involvement of sets of gene products which have not previously been explored by hypothesis-driven studies. JOURNAL OF PROTEOMICS 73 (2009) 331 – 341 ☆ This article is part of M.J. Martinez-Esteso's PhD Thesis. ⁎ Corresponding author. Department of Agrochemistry and Biochemistry, Faculty of Sciences, University of Alicante, Ctra. San Vicente del Raspeig s/n, E-03080 Alicante, Spain. E-mail address: Roque.Bru@ua.es (R. Bru-Martinez). 1874-3919/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.jprot.2009.10.001 available at www.sciencedirect.com www.elsevier.com/locate/jprot