Comparative Analysis of Sorghum bicolor Proteome in Response to Drought Stress and following Recovery

Abstract

The adaptive response of Sorghum bicolor landraces from Egypt to drought stress and following recovery was analyzed using two-dimensional difference gel electrophoresis, 2D-DIGE. Physiological measurements and proteome alterations of accession number 11434, drought tolerant, and accession number 11431, drought sensitive, were compared to their relative control values after drought stress and following recovery. Differentially expressed proteins were analysed by Matrix assisted laser desorption ionisation time-of-flight mass spectrometry, MALDI-TOF-MS. Alterations in protein contents related to the energy balance, metabolism (sensu Mewes et al. 1997), and chaperons were the most apparent features to elucidate the differences between the drought tolerant and sensitive accessions. Further alterations in the levels of proteins related to transcription and protein synthesis are discussed.

Figure 1

Fv/Fm values (a), PI_abs (b), and RWC (c) of # 11434, drought tolerant, and # 11431, drought sensitive, genotypes. Standard deviation was calculated using 5 independent measurements. One-way ANOVA test was used to assess the significance of differences at P < 0.001 (∗∗∗), P < 0.01 (∗∗), or P < 0.05 (∗) between treatments and their respective controls.

Figure 2

Differentially expressed proteins on 10% SDS-PAGE following separation on 24 cm nonlinear strips pH 3–10, scanning, and staining with Colloidal Coomassie Brilliant Blue. Black arrows represent proteins expressed in both genotypes. Black arrows with round bottom represent expressed proteins in # 11434, drought tolerant genotype, and white arrows with round bottom represent expressed proteins in # 11431, drought sensitive, genotype.