Levels of aminoacyl-tRNA synthetases, tRNA nucleotidyltransferase and ATP in germinating lupin seeds.

Transfer RNAs in dry lupin seeds are aminoacylated to a low extent (Kedzierski, W. and Pawełkiewicz, J. (1977) Phytochemistry 16, 503-504) and are partly degraded at the acceptor terminus (Dziegielewski, T. and Pawełkiewicz, J. (1977) Bull. Acad. Polon. Sci. Ser. Biol. 7, 4oo-435). Increase in the levels of tRNA aminoacylation and disappearance of defective tRNA molecules during seed germination are not accompanied by significant changes in the levels of phenylalanyl-, arginyl-, valyl-tRNA synthetases and tRNA nucleotidyltransferase. Additionally, no inhibitor of aminoacylation of valine tRNA has been detected in dry seeds. However, dry seeds contain very low ATP amounts, which increase dramatically during germination. The above results suggest that a very low ATP level is a factor limiting the aminoacylation and reparation of tRNA molecules at early stages of seed germination.