Water Uptake and Protein Synthesis in Germinating Wheat Embryos under the Osmotic Stress of Polyethylene Glycol

The effect of osmotic stress on wheat-seed germination was testedby imbibition in aqueous polyethylene glycol solutions at differentconcentrations. The experiments were designed to allow blockingand the subsequent recovery of germination by 12 h or 24 h pre-imbibitionof seeds in osmoticum, followed by transfer to water. Seedswere alternatively presoaked in water for 12 or 24 h, then transferredto polyethylene-glycol solutions to study the induced blockingof germination. Water content and [³H]leucine incorporationinto embryo tissues (as a measure of in vivo protein synthesis)were determined over a 48-h imbibition period. A close relationshipwas established overall between hydration status and proteinsynthesis rate. Osmotic stress seems to have a strong influenceupon the quantitative synthesis of proteins, suggesting thatthis biochemical activity is associated with the regulationof the germination process. Triticum durum, embryo, osmotic stress, water uptake, protein synthesis