Proteomics Reveals the Effects of Salicylic Acid on Growth and Tolerance to Subsequent Drought Stress in Wheat

Pretreatment with 0.5 mM salicylic acid (SA) for 3 days significantly enhanced the growth and tolerance to subsequent drought stress (PEG-6000, 15%) in wheat seedlings, manifesting as increased shoot and root dry weights, and decreased lipid peroxidation. Total proteins from wheat leaves exposed to (i) 0.5 mM SA pretreatment, (ii) drought stress, and (iii) 0.5 mM SA treatment plus drought-stress treatments were analyzed using a proteomics method. Eighty-two stress-responsive protein spots showed significant changes, of which 76 were successfully identified by MALDI-TOF-TOF. Analysis of protein expression patterns revealed that proteins associated with signal transduction, stress defense, photosynthesis, carbohydrate metabolism, protein metabolism, and energy production could by involved in SA-induced growth and drought tolerance in wheat seedlings. Furthermore, the SA-responsive protein interaction network revealed 35 key proteins, suggesting that these proteins are critical for SA-induced tolerance.