Proteomic Analysis of PEG-Induced Drought Stress Responsive Protein in TERF1 Overexpressed Sugarcane (Saccharum officinarum) Leaves

Drought is the major abiotic stress limiting sugarcane growth and productivity. ERF proteins regulate a variety of stress responses in plant. Overexpression of TERF1 can enhance the tolerance of transgenic sugarcane to drought stress. To improve the efficiency of sugarcane breeding, better understanding of the tolerance mechanism at molecular level is required. Two-dimensional gel electrophoresis (2-DE) coupled tandem mass spectrometry (MS/MS) analyses were conducted to compare the leaf proteome of the TERF1 OE and WT sugarcane plants to PEG stress. Using statistical program, 50 significantly differential protein spots were detected, of which 36 spots were identified by PMF and MS/MS fragmentation. Most of the identified proteins corresponded to metabolism, energy, protein synthesis, and disease/defense. Results implicated that the involvement of different metabolic pathways that may be activated in the TERF1 overexpressed transgenic sugarcane to cope with drought environment. Of the identified proteins, abundance of pentatricopeptide repeat (PPR) containing protein and peptidyl prolyl cis-trans isomerase (PPIase) were decreased, but the abundance of vital proteins, such as metabolism protein (14-3-3 like protein), photosynthetic protein (RuBisCO large subunit, PEP carboxylase), ferredoxin, glyceraldehyde 3-phosphate dehydrogenase, elongation factor Tu, several small heat shock proteins, and peroxidases were increased. Analysis of protein properties showed that majority of the differentially abundant proteins associated with drought were stable, hydrophilic, and transmembrane proteins. Thus, the results of our study unravel the regulatory mechanism of TERF1 for drought stress tolerance of transgenic sugarcane and provide new insight into adaptation to osmotic stress through altering the expression of particular proteins.