Phosphorus Compounds of Cotton Embryos and Their Changes during Germination.

The phosphorus compounds of cotton embryos, particularly ribonucleic (RNA) and deoxyribonucleic (DNA) acid, and their metabolism during germination have not been intensively investigated with modern methods of analysis. In the period 1913 to 1918 Anderson (1) and Rather (9) elucidated the true nature of phytic acid, the principal form of seed phosphorus. Although Anderson obtained the hexaphosphate of inositol, Rather found only the pentaphosphoric acid derivative clue to the activity of the enzyme phytase. In 1946 Fontaine and co-workers (5) presented results showing an increase in the percentage of phosphorus in the inorganic form during germination. Pons et al (8) developed an analytical system for analysis of the phosplhorus fractions of plant materials and in 1953 reported data on the phytin-, inorganic-, lipid-, ester-, ancl nucleic acid-P contents of cotton embryos. More recently Ergle and Eaton (3) reported on the amounts of similar fractions, plus protein-P, in various cotton tissues including 10-clay-old ovules andl mature embryos. In the present paper information on the phosphorus compoundls of cotton embryos has been extended to include RNA and DNA and the changes which they and the above mentioned phosphorus fractions undergo duriing germination and early seedling development. Results on Paymaster 54B, Deltapine TPSA, and Mesilla Valley Acala, representative of early, intermediate, and late maturing cottons, respectively, are compared.