Amylase Activity and Soluble Sugars Content of Durum Wheat Seeds During Germination Under Water Stress

Abstract

Water deficit is a critical abiotic stress that significantly affects the productivity of durum wheat (Triticum turgidum ssp. durum) worldwide. It impacts various growth stages, including seed germination, vegetative growth, reproductive development and crop maturity. Among these stages, seed germination is particularly sensitive. In this study, we aimed to assess the effect of water deficit by manipulating the water potential of the germination medium [0, − 1, − 1.5 and − 2 MPa (Megapascal)]. Our results revealed that a decrease in the osmotic potential influenced all seedling parameters. Specifically, we observed variations in the activity of amylase, an enzyme involved in starch breakdown during germination. The timing of amylase activity depended on both the germination duration and the severity of water deficit. After 24 h, amylase activity increased due to reduced water potential, but it reached its peak after 48 h and subsequently decreased significantly under water stress. This enzymatic activity led to the accumulation of simple sugars in germinating seeds. Interestingly, our study also revealed intraspecific variability in the response to water stress. Specifically, seeds from the Chen’s and Simeto genotypes exhibited higher accumulation of soluble sugars compared to other genotypes, indicating their greater tolerance to water deficit. Considering this, integrating these tolerant genotypes into genetic improvement programs could enhance durum wheat resilience to water scarcity. Understanding the impact of water deficit on seed germination and seedling development is crucial for developing strategies to mitigate its effects and improve crop productivity in water-limited environments.