A DIGE proteomic analysis of wheat flag leave treated with Terra-Sorb foliar, a free amino acid-based biostimulator

The flag leaf is the most important source of carbohydrate during wheat kernel filling. Around a 75% of all sugars stored in the kernel come from carbon fixed by this leaf. Previous studies have shown that application of Terra-Sorb ® foliar, an L-α-amino acid-based product from enzymatic hydrolysis with a high ratio of free-to-total amino acids, increases plant photosynthetic activity and chlorophyll content, promotes rapid recovery from stress and improves fruit set. In this work, we have undertaken a proteomic approach using DIGE in order to explore molecular mechanisms potentially involved in the biostimulating effect of Terra-Sorb® foliar on wheat. Thirty seven protein spots were found to change in abundance, out of which 8 were down regulated and 29 up regulated in treated leaves. Proteins identified up- and down-regulated suggest an improvement of wheat productivity by Terra-Sorb ® foliar application by a combination of an enhanced CO2 fixation, a more active protein synthesis and a decrease of oxidative stress.