Induction of water deficit tolerance by cold shock and salicylic acid during germination in the common bean

The application of short-term stresses or elicitors in seedlings or embryos with high metabolic activity might increase multi-adversity tolerance. Beans seeds cv. IAC-Carioca were exposed to cold shock temperatures (S 7°C 24h) and salicylic acid (SA 0.01 mM 48h) during imbibition to study physiological responses to osmotic stress physiological responses. The seeds were soaked in paper towel imbibed in water or salicylic acid at 25°C for 24h. The seed were subsequently submitted to temperatures of 7oC and 25oC for another 24h in water or salicylic acid. Following each treatment, the seeds were transferred to mannitol solutions (0, -0.3, -0.6, and -1.2 MPa) and evaluated after seven days for germination, vigour, shoot and root length, dry mass, proline accumulation and protein electrophoretic profile. Treatments with salicylic acid and cold shock did not affect germination, but germination was reduced through the mannitol-induced progression of water deficit. However, both salicylic acid and cold shock treatments affected seed vigour. The application of salicylic acid increased root and total seedling length and dry weight, especially at intermediate water stress levels. Both salicylic acid and cold shock treatments changed the protein pattern of the treated seeds, but only SA showed promise as a technology for seed treatment.