Physiological and biochemical responses of seed vigor during common bean germination under water deficit

ABSTRACT:

Water deficit causes oxidative stress in plants through the overproduction of reactive oxygen species, whose mitigation depends on antioxidant activity. Considering that seed vigor influences tolerance to adverse conditions, this study evaluate the physiological response of seeds with contrasting vigor under water deficit to identify metabolic differences that influencing the performance of the seed lot. Seeds of the BAF07 genotype were subjected to five and ten days of artificial aging to obtain lots with contrasting vigor. Subsequently, germination and seedling performance tests were carried out, measuring root, hypocotyl, and total seedling length. The antioxidant components catalase, ascorbate peroxidase, guaiacol peroxidase, and proline, as well as the oxidative stress marker malondialdehyde, were quantified. The contrast between artificial aging and water deficit revealed physiological and metabolic differences among seed lots. Low-vigor seeds exhibited reduced germination performance and seedlings with greater lipid peroxidation and increased antioxidant enzyme activity. These results indicate that initial seed vigor is a key determinant tolerance to water deficit, highlighting its role in preserving metabolic balance essential for seedling establishment.

Index terms:
catalase; malondialdehyde; peroxidase; Phaseolus vulgaris L.; proline