Lesions in post-ribosomal supernatant fractions associated with loss of viability in pea (Pisum arvense) seed.

RNA synthesis and protein synthesis in viable pea embryonic axis tissue commences during the first hour of water imbibition whilst DNA synthesis commences after 8 h of imbibition. Neither DNA synthesis nor protein synthesis could be detected in non-viable axis tissue during the first 24 h of imbibition but some RNA synthesis is detectable during this period. Both post-ribosomal supernatant and ribosomal fractions from imbibed non-viable embryonic axis tissue were impaired in their ability to support polyphenylalanine synthesis in a cell-free protein-synthesising system, yet the same fractions isolated from unimbibed non-viable axis tissue were as efficient as equivalent fractions from unimbibed viable axis tissue in the support of polyphenylalanine synthesis in the cell-free system. A major lesion in elongation factor 1 activity and additional lesions in elongation factor 2 and phenylalanyl-tRNA synthetase activities were detected in the post-ribosomal supernatants isolated from non-viable embryonic axis tissue.