The growth and gravitropic responses of wild‐type and auxinresistant mutants of Arabidopsis thaliana

摘要: Growth and gravitropism have been studied in three mutant strains of Arabidopsis thaliana L, that are resistant to auxin-herbicide. Two the mutations allelic recessive (aux-1 aux-2) unlinked a dominant mutation, Dwf, which confers very high level auxin-resistance is apparently lethal when homozygous. The aux-1 Dwf altered response gravity whereas aux-2 appears be gravitropically normal. After 96 h normal, vertical position only minor differences elongation were observed between roots wild-type, aux-2, but hypocotyls significantly retarded compared with normal wild-type. In progeny selfed plants, where both (dwf) agravitropic (Dwf) seedlings present, had much longer shorter than dwf+. During 22 continuous stimulation optimum angle for wild-type was 135° (i.e. organ points obliquely upwards), decreasing responses order 90° 45°. nature confirmed as no significant obtained at any angles. marked contrast, negative gravitropic greater terms final attained h, 6 rate lower aux-1. After varying periods horizontal position, curvature developed, decreased rapidly almost disappeared during ensuing rotation on clinostats (2 4 rpm). Rotation effect behaviour