Effects of high temperature on protein synthesis during germination of maize (Zea mays L.).

The poor germination of maize seeds at high temperatures (>37°C) is related to the low rate of protein synthesis by the embryo. The apparatus of translation was not heat-labile when embryos were incubated for 2 h at 41°C, and cell free extracts from seeds imbibed for 16 h at this temperature were able to translate exogenous mRNA, indicating that ribosomes and other subcellular components were present and functional. Analysis of polysome profiles from embryos imbibing at high temperature indicated that the low rate of protein synthesis was due to the non-availability of active mRNA.