Vigor and reserve mobilization of common bean seed during germination under salt stress conditions

The mobilization of reserves determines the formation of seedlings during germination, being influenced by seed vigor and adverse stress conditions. Seeds with higher vigor have greater potential for mobilization of reserves, and it can favor performance under conditions of salt stress. The objective of this study was to identify how the mobilization of reserves stored in common bean seeds contributes to the overcoming of salt stress, seeking to identify the difference in hydrolysis and mobilization of reserves among seeds with superior vigor. Seeds from two genotypes contrasting in vigor (BAF44 and BAF55) were used. Salt stress was simulated using sodium chloride, and evaluations were performed at one, three, five and seven days of germination. The variables analyzed in seedling was length, dry mass, and metabolic expenditure, while biochemical analyses of total starch, total protein, total soluble sugars, total soluble proteins, and alpha-amylase activity were evaluated in the embryonic axis and/or cotyledons. The salt stress condition negatively affected the performance of the seedlings, resulting in a decrease in length, mass accumulation, and reduced use of seed reserves, associated with a lower hydrolysis of starch and proteins. Seeds with higher vigor showed higher dry mass and seedling length even when subjected to salt stress conditions, because of greater hydrolysis capacity and use of soluble proteins and soluble sugars, which result in seedlings with better performance under control and salt stress conditions.