Water-deficit-induced changes in cytoskeleton-bound and other polysomal populations in embryonic tissue during triticale caryopsis germination

Abstract

We studied the influence of water-deficit stress on the process of formation of different polysomal populations, their abundance and stability in embryonic tissue during triticale caryopsis germination. Osmotic stress retarded the ability of seeds to germinate and decreased the content of the total ribosomal fraction in embryos. In control samples, the fraction of free polysomes was the most abundant and this population of polysomes decreased sharply in osmotic stress conditions. Water-deficit stress applied during germination profoundly changed the proportions between different polysome populations in the total ribosomal fraction of embryonic tissue. The predominant population in these conditions was the cytoskeleton-bound fraction. This may indicate an important role for cytoskeleton-bound polysomes in the synthesis of stress-induced proteins. We hypothesize that there must be an active mechanism of translational control that permits specific proteins to be synthesized despite a reduction in total protein synthesis.