Changes in Soluble RNA and Ribonuclease Activity During Germination of Wheat

Gross changes in protein and nucleic acid were studied in germinating wheat seeds. The nucleic acid fraction was separated on columns of methylated albumin-keiselguhr. It was found that more than 50% of the transfer RNA was lost from the embryo in the first 10 to 15 hours of germination. This was followed by a period of rapid resynthesis of transfer RNA, to the normal level at about 20 hours. The decline and increase in transfer RNA was accompanied by a change in the ratios of certain amino acid acceptor species. Evidence is also presented that an embryo ribonuclease is lost during the first 10 to 15 hours, followed by the appearance of a second seedling ribonuclease between 15 and 30 hours of germination.