Comprehensive proteomic analysis of canola leaf inoculated with a plant growth-promoting bacterium, Pseudomonas fluorescens, under salt stress

Abstract

Plant growth-promoting bacteria can improve the tolerance of canola to salt stress. To better understand the effects of plant growth-promoting bacterium on the protein profiles of canola under salt stress condition, proteomics was performed. Salt-sensitive (Sarigol) and -tolerant (Hyola308) canola cultivars were inoculated with Pseudomonas fluorescens FY32, and the protein profiles of canola leaves were compared using a PEG-fractionation method. Cluster analysis of canola cultivars based on a stress tolerance index of several morphological parameters was used to confirm that Sarigol and Hyola308 were salt-sensitive and -tolerant cultivars, respectively. Using a gel-free proteomic technique, 154 and 94 proteins in Hyola308 and 100 and 144 proteins in Sarigol were uniquely identified in non-inoculated and bacterial-inoculated cultivars, respectively. By PEG fractionation, a total of 132 and 207 proteins were identified in non-inoculated and inoculated Hyola308, respectively. Notably, the abundance of copper/zinc superoxide dismutase 1 was significantly increased in inoculated Hyola308 under severe salt stress and decreased under moderate salt stress. In addition, the enzyme activity of delta-1-pyrroline-5-carboxylate synthase was significantly increased non-inoculated Hyola308 and the activity of succinate dehydrogenase was increased in inoculated Hyola308 leaves exposed to salt stress. Taken together, these results suggest that the bacterial inoculation of canola increases salt tolerance by inducing an increase in the abundance of proteins related to glycolysis, tricarboxylic acid cycle, and amino acid metabolism.

Molecular response of canola to salt stress: insights on tolerance mechanisms

“…Similarly, another study reported high activity of SOD, GPX, and CAT as well as upregulation of Cu/Zn SOD in the leaves under 150 mM NaCl. Upregulation of Cu/Zn SOD has similarly been demonstrated for Hyola308 under 150 and 300 mM NaCl stress (Banaei-Asl et al 2016). All these studies provide evidence to confirm that tolerant cultivars show remarkably more ROS scavenging activity than sensitive cultivars (Banaei-Asl et al 2016;Heidari 2010;Yıldız et al 2015).…”

“…Upregulation of Cu/Zn SOD has similarly been demonstrated for Hyola308 under 150 and 300 mM NaCl stress (Banaei-Asl et al 2016). All these studies provide evidence to confirm that tolerant cultivars show remarkably more ROS scavenging activity than sensitive cultivars (Banaei-Asl et al 2016;Heidari 2010;Yıldız et al 2015). Furthermore, the role of glutathione synthesis in canola is defined as oxidative protective mechanism (Ruiz & Blumwald 2002).…”

“…This protein has been identified by proteomic analysis of canola cultivars under salt stress (Banaei-Asl et al 2015). The Ras-related small GTP-binding protein has also been identified in canola leaves under salt stress (Banaei-Asl et al 2016;Bandehagh et al 2011). …”

“…Proteomic analysis of canola-tolerant cultivars indicated that the abundance of P5CS in the root and leaves are increased (Banaei-Asl et al 2015;Banaei-Asl et al 2016;Yıldız et al 2015). It has been shown that high accumulation of proline in canola attributes to activating its biosynthesis and preventing its degradation (Xue et al 2009).…”

Molecular response of canola to salt stress: insights on tolerance mechanisms

“…Studies on canola have indicated significantly increased proline contents in the root and leaves of both salt-tolerant and sensitive cultivars under salt stress, and comparatively more in tolerant cultivars than sensitive ones (Dolatabadian et al 2008;Xue et al 2009). Proteomic analysis of canola-tolerant cultivars indicated that the abundance of P5CS in the root and leaves are increased (Banaei-Asl et al 2015;Banaei-Asl et al 2016;Yıldız et al 2015). It has been shown that high accumulation of proline in canola attributes to activating its biosynthesis and preventing its degradation (Xue et al 2009).…”