Drought stress effects on germination and reserve degradation of Aspidosperma polyneuron seeds

Abstract

Seeds are exposed to diverse environmental factors when dispersed, including abiotic stresses, which will affect germination. Drought is the most important factor affecting germination, since water is essential for seed development. Aspidosperma polyneuron is a native endangered species which has been extensively exploited, mainly for timber extraction purposes. This study analyzed germination and degradation of soluble sugars and proteins of A. polyneuron seeds during germination under water stress. Seeds were placed on Germitest papers moistened with different water potential solutions, varying from 0.0 to -1.4 MPa. Degradation of soluble sugars and soluble proteins was assessed in five stages of germination at the different water potentials. A. polyneuron seeds lost germination capacity as the water potential decreased, being unable to germinate below -0.6 MPa. Glutelin was the most abundant storage protein in the seed, while prolamin was the least. Reserve degradation was altered in negative water potentials. Soluble proteins are degraded faster and soluble sugars are degraded slower as the water potential drops.