Germination of Rye Embryos Following Hydration-Dehydration Treatments: Enhancement of Protein and RNA Synthesis and Earlier Induction of DNA Replication

Abstract

On germination of low viability embryos of rye, var. Lovasz Patonai, the rate of protein syn thesis increases during the early hours of imbibition and high rates of DNA replication commence around the 9th hour. If embryos are imbibed for 3 or 6 h then dehydrated back to their original weight, their rate of protein synthesis when next imbibed closely corresponds to that of embryos germinated for a period equal to that of the hydration pre-treatment plus the duration of the second imbibition. Pre-treatment also enhances subsequent RNA synthesis and embryos hydrated for 9 h then dehydrated start major DNA synthesis at once as water is again supplied. Many changes occurring during these periods of hydration pre treatment must therefore be stable to subsequent dehydration. Damage occurs to areas that are first active in protein and RNA synthesis if pre-treatments extend beyond 9 h and sub sequent germination of the embryo is then impaired. The implications of these results are discussed in relation to the effects of hydration pre-treatments upon enhanced germination and the stability to dehydration of the products of early RNA and protein synthesis.