Proteomic analysis of canola root inoculated with bacteria under salt stress Farzad Banaei-Asl a, b , Ali Bandehagh b , Ebrahim Dorani Uliaei b , Davoud Farajzadeh c , Katsumi Sakata d , Ghazala Mustafa a , Setsuko Komatsu a, ⁎ a National Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba 305-8518, Japan b Department of Plant Breeding and Biotechnology, University of Tabriz, Tabriz 51666-16471, Iran c Department of Cellular and Molecular Biology, Azarbaijan Shahid Madani University, Tabriz 53751-71379, Iran d Maebashi Institute of Technology, Maebashi 371-0816, Japan ARTICLE INFO ABSTRACT Article history: Received 30 January 2015 Accepted 4 April 2015 Available online 17 April 2015 Plant-growth promoting bacteria can ameliorate the negative effects of salt stress on canola. To better understand the role of bacteria in canola under salt stress, salt-sensitive (Sarigol) and salt-tolerant (Hyola308) cultivars were inoculated with Pseudomonas fluorescens and protein profiles of roots were compared. Bacterial inoculation increased the dry weight and length of canola roots under salt stress. Using a gel-free proteomic technique, 55 commonly changed proteins were identified in Sarigol and Hyola308 roots inoculated with bacteria under salt stress. In both canola cultivars, proteins related to amino acid metabolism and tricarboxylic acid cycle were affected. Hierarchical cluster analysis divided the identified proteins into three clusters. Proteins related to Clusters II and III, which were secretion-associated RAS super family 1, dynamin-like protein, and histone, were increased in roots of both Sarigol and Hyola308 inoculated with bacteria under salt stress. Based on pathway mapping, proteins related to amino acid metabolism and the tricarboxylic acid cycle significantly changed in canola cultivars inoculated with or without bacteria under salt stress. These results suggest that bacterial inoculation of canola roots increases tolerance to salt stress by proteins related to energy metabolism and cell division. Biological significance Plant-growth promoting bacteria as an emerging aid can ameliorate the negative effect of salt stress on canola. To understand the role of bacteria in canola under salt stress, salt sensitive Sarigol and tolerant Hyola308 cultivars were used. Dry weight and length of canola root were improved by inoculation of bacteria under salt stress. Using gel-free proteomic technique, 55 commonly changed proteins identified in Sarigol and Hyola308 inoculated with bacteria under salt stress. In both canola cultivars, the number of proteins related to amino acid metabolism and tricarboxylic acid cycle was more than other categories with higher change in protein abundance. Hierarchical cluster analysis divided into 3 clusters. Cluster II including secretion-associated RAS super family 1 and dynamin-like protein and Cluster III including histones H2A were increased by bacterial inoculation in both cultivars. Keywords: Proteomics Canola Root Plant-growth promoting bacteria Salt JOURNAL OF PROTEOMICS 124 (2015) 88 – 111 Abbreviations: LC, liquid chromatography; MS, mass spectrometry; P5CS, delta 1-pyrroline-5-carboxylate synthase. ⁎ Corresponding author at: National Institute of Crop Science, National Agriculture and Food Research Organization, Kannondai 2-1-18, Tsukuba 305-8518, Japan. Tel.: +81 29 838 8693; fax: +81 29 838 8694. E-mail address: skomatsu@affrc.go.jp (S. Komatsu). http://dx.doi.org/10.1016/j.jprot.2015.04.009 1874-3919/© 2015 Elsevier B.V. All rights reserved. Available online at www.sciencedirect.com ScienceDirect www.elsevier.com/locate/jprot