Messenger ribonucleoprotein particles in dry wheat and rye embryos : In vitro translation and size distribution.

Extracts prepared from dry wheat (Triticum aestivum L.; var. Cama) and rye (Secale cereale L.

The rye embryo system as an alternative to the wheat system for protein synthesis in vitro.

Isolated rye embryos are a readily available source for the preparation of very active, cell-free, protein-synthesizing systems. Incorporation levels up to 2000 pmol leucine per 50 mul assay are routinely obtained at saturating TMV (Tobacco mosaic virus) RNA concentrations; at limiting messenger RNA concentrations the incorporation exceeds 1000 leucine molecules per TMV RNA molecule. The characteristics of this cell-free system for the translation of TMV RNA are identical with those of a similarly prepared wheat germ system.

Effect of 5-fluorouracil and cycloheximide on the early development of Phycomyces blakesleeanus spores and the activity of N-acetylglucosamine synthesizing enzymes.

The development of germinating Phycomyces spores was not inhibited by 5-fluorouracil (1mM) until the emergence of the germination tube. Fluorouracil was incorporated into RNA as efficiently as uracil; it did not inhibit the synthesis of proteins and the increase in respiratory activity during early development. Cycloheximide inhibited development as well as the increase in respiration and protein synthesis.

Some properties of trehalase from Phycomyces blakesleeanus.

Trehalase (alpha, alpha-trehalase glucohydrolase EC 3.2.1.

Glucose metabolism of dormant and heat-activated spores of Phycomyces blakesleeanus burgeff.

The metabolism of [(14)C]glucose has been studied in Phycomyces spores during dormancy, activation, and the initial stages of germination. Dormant spores are able to take up and metabolize exogenous glucose into different products; the major part of it goes to trehalose synthesis (up to 60% when the external glucose concentration exceeds 10(-3) M). During activation itself (i.

Trehalase activity in dormant and activated spores of Phycomyces blakesleeanus.

Heat treatment of Phycomyces sporangiospores, which breaks dormancy, causes a very rapid 10- to 15fold increase in trehalase activity; soon after the heat shock the enzyme activity decays. This phenomenon can be repeated several times by repeating the heat shocks. Prolonging the heat treatment over the minimum required time delays the decay of enzyme activity.