Mild-NaCl stress increases protein and nitrogen contents of common bean (Phaselous vulgaris) grains

Legumes are highly valued as a food and feed source because of its high nutritional value, with the common bean being the most consumed pulse within this family. However, this species is highly sensitive to saline stress, which is becoming an increasing problem in the agricultural context due to rising levels of soil salinization because of anthropogenic activities (secondary salinization). Therefore, the current contribution reports the response of common bean seeds (Phaselous vulgaris, Cultivar ‘ICA Pijao’) to saline stress applied as 0 to 60 g of sodium chloride (NaCl) per pot (i.e. 0.48 ± 0.03 to 4.82 ± 0.47 dS m⁻¹) at the start of the trial. By 14 d, only plants exposed to the lowest NaCl concentration survived (15 g NaCl per pot). The imposition of saline stress resulted in a significant reduction of root biomass and yield and an increase in leaf senescence. However, there was evidence to indicate a small (significant) increase in the protein content of grain from plants exposed to salt stress (27.28 ± 0.98%) compared with control plants (25.47 ± 0.35%) as well as the nitrogen (N) content of grain (4.36 ± 0.16 and 4.07 ± 0.05% in salt stressed and control plants, respectively).