The Effect of Growth in D2O on the Metabolism of Winter Rye

The metabolism of winter rye seedlings (Secale cereale, L. ev.Winter) cultured in 99.8 per cent D₂O was investigated. Comparedwith water-grown seedlings, the protein content was much lowerin the D₂O-cultured seedlings and the pattern of incorporationof ³H]leucine and ³H]phenylalanine into protein was substantiallydifferent. Seedlings cultured in D₂O incorporated ³H]thymidineinto DNA, but did not take up ³H]uridine. The results suggestthat some of the toxic effects of D₂O culture on higher plantscan be attributed to a partial block of protein synthesis.