Proteomic study of β-aminobutyric acid-mediated cadmium stress alleviation in soybean.

The present study highlights the protective role of β-aminobutyric acid (BABA) in alleviating cadmium (Cd) stress in soybean. Proteomic analyses revealed that out of 66 differentially abundant protein spots in response to Cd challenge, 17 were common in the leaves of BABA-primed and non-primed plants. Oxygen-evolving enhancer protein 1 and ribulose bisphosphate carboxylase small chain 1 were detected in increase abundance in both groups of leaves. Among the 15 commonly decreased protein spots, the relative intensity levels of heat shock cognate 70-kDa protein, carbonic anhydrase, methionine synthase, and glycine dehydrogenase were partially restored after BABA treatment. Moreover, BABA priming significantly enhanced the abundance of the defense-related protein peroxiredoxin and glycolytic enzymes in response to Cd exposure. Additionally, the impact of Cd on the physiological state of BABA-primed and non-primed plants was analyzed using a biophoton technique. The finding of comparatively low biophoton emission in BABA-primed leaves under Cd stress indicates that these plants experienced less oxidative damage than that of non-primed plants. Proteomic study coupled with biophoton analysis reveals that BABA pretreatment helps the plants to combat Cd stress by modulating plants' defence mechanism as well as activating cellular detoxification system to protect the cells from Cd induced oxidative stress damages.