Proteomics Uncovers a Role for Redox in Drought Tolerance in Wheat

Abstract

Proteomic analysis offers a new approach to identify a broad spectrum of genes that are expressed in living systems. We applied a proteomic approach to study changes in wheat grain in response to drought, a major environmental parameter adversely affecting development and crop yield. Three wheat genotypes differing in genetic background were cultivated in field under well-watered and drought conditions by following a randomized complete block design with four replications. The overall effect of drought was highly significant as determined by grain yield and total dry matter. About 650 spots were reproducibly detected and analyzed on 2-DE gels. Of these, 121 proteins showed significant change under drought condition in at least one of the genotypes. Mass spectrometry analysis using MALDI-TOF/TOF led to the identification of 57 proteins. Two-thirds of identified proteins were thioredoxin (Trx) targets, in accordance with the link between drought and oxidative stress. Further, because of contrasting changes in the tolerant and susceptible genotypes studied, several proteins emerge as key participants in the drought response. In addition to providing new information on the response to water deprivation, the present study offers opportunities to pursue the breeding of wheat with enhanced drought tolerance using identified candidate genetic markers. The 2-DE database of wheat seed proteins is available for public access at http://www.proteome.ir.

Heat-shock dependent oligomeric status alters the function of a plant-specific thioredoxin-like protein, AtTDX

“…Cytosolic extracts prepared from an Arabidopsis suspension cell culture (Arabidopsis thaliana L. Heynh, Ecotype Columbia) were heat-treated at 70°C for 30 min and ultracentrifuged at 134,600 ϫ g for 15 min. The supernatants were subjected to SEC by using a Superdex 200 HR column, and HMW complexes eluted from the void volume of SEC were collected and identified by 2D PAGE and MALDI-TOF analyses, as described (30). Among the proteins identified, AtTDX was chosen to be a target in this study.…”

Assessing wheat (Triticum aestivum L.) genetic diversity using quality traits, amplified fragment length polymorphisms, simple sequence repeats and proteome analysis

“…Twelve quality traits including protein percentage, bread volume, percentage of moisture in flour, hardness index, water absorption, falling number, wet and dry gluten contents, gluten index, contents of gliadin and glutenin and SDS sedimentation volume were recorded in triplicate as previously described (Hajheidari et al, 2007) and the data means were used for the analyses.…”

“…Protein extraction was applied according to Finnie et al (2002) and Hajheidari et al (2007). The total protein concentration was quantified by the Bradford assay (Bio-Rad Laboratories Inc.) with bovine serum albumin as the standard.…”

“…The total protein concentration was quantified by the Bradford assay (Bio-Rad Laboratories Inc.) with bovine serum albumin as the standard. Two-dimensional electrophoresis analysis was performed as previously described (Salekdeh et al, 2002;Hajheidari et al, 2007). For isoelectric focusing (IEF), 18-cm 5. immobilized pH gradient (IPG) strips with a linear gradient (pH 4-7) were used and the second dimension was performed on a 12% SDS-polyacrylamide gel.…”

“…Melanie 3 software (GeneBio, Geneva, Switzerland) was used to analyse gel images, as described in the user's manual. After scanning, spot detection, protein quantification, spot pairing and analyses were carried out as previously described (Hajheidari et al, 2007 (Hajheidari et al, 2007). …”