Relation of special RNA to sensitivity of yeast strains to auxin

RNA functional in auxin action was studied in the followingfour strains of yeasts differing in their sensitivity to auxin:KV2, diploid strain of Saccharomyces ellipsoideus irresponsiveto auxin but made responsive by gibberellic acid treatment;N55, auxinresponsive mutant derived from KV2; A2-0, diploidstrain of 5. cerevisiae irresponsive even when gibberellic acidis given; and A2–N102, responsive mutant derived fromA2–0. The RNA fraction extracted from N55 and partitionedin a phenol layer sensitized KV2 to auxin. This kind of RNAwas not detected in KV2 cells. The functional RNA from N55 wasof low molecular weight, as was functional RNA isolated fromgibberellic acid-treated Jerusalem artichoke tuber. Gibberellicacid-treated KV2 cells have been known to contain RNA whichfunctions similarly to the RNA mentioned above. Both A2–0and A2–N102 contained RNA which made KV2 cells responsiveto auxin. Some factors other than functional RNA may determinethe difference in the sensitivity to auxin between A2–0and A2–N102. (Received August 20, 1968; )