Salt-induced root protein profile changes in seedlings of maize inbred lines with differing salt tolerances

Salt stress is one of the severest growth limited-factors to agriculture production. To gain in-depth knowledge of salt-stress response mechanisms, the proteomics analysis from two maize (Zea mays L.) inbred lines was carried out using two-dimensional gel electrophoresis (2-DGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). There were 57 salt-regulated proteins identified, 21 and 36 proteins were differentially regulated in inbred lines 'Nongda 1145' (salt-resistant) and 'D340' (salt-sensitive), respectively. The identified proteins were distributed in 11 biological processes and seven molecular functions. Under salt stress, proteins related to antioxidation and lignin synthesis were increased in both inbred lines. The relative abundance of proteins involved in translation initiation, elongation, and protein proteolysis increased in 'Nongda 1145' and decreased in 'D340'. In addition, the abundance of proteins involved in carbohydrate metabolism, protein refolding, ATP synthase and transcription differed between the two inbred lines. Our results suggest that the enhanced ability of salt-tolerant inbred line 'Nongda 1145' to combat salt stress occurs via regulation of transcription factors promoting increased antioxidation and lignin biosynthesis, enhanced energy production, and acceleration of protein translation and protein proteolysis.