Further Studies on RNA in Relation to Auxin-Induced Cell Elongation in Yeast (Saccharomyces ellipsoideus).

Auxin stimulates cell elongation in the respiration-deficient mutant strain P602 of yeast. In the normal strain KV2, auxin has no such effect when given alone, but a stimulation can be demonstrated if gibberellic acid (GA) is supplied with the auxin, or prior to the auxin treatment. Ribonucleic acid (RNA) was prepared from the phenol fraction of extracts of P602 and of etiolated Avena coIcoptiles in which the auxin response is also independent of exogenous GA). In the presence of these RNA preparations auxin caused a positive response (cell elongation) in KV2 without GA. RNA preparations from KV2 itself had no such effect, whereas those from GA-treated Jerusalem artichoke demonstrated the effect. The action of the preparations from P602 and front GA-treated Jerusalem artichoke is ascribed to RNA because the activity was destroyed by treatment with ribonuclease and with alkali. [ABSTRACT FROM AUTHOR]