Abscisic acid is not necessary for gravitropism in primary roots of Zea mays.
Primary roots of Zea mays L. cv. Tx 5855 treated with fluridone are strongly graviresponsive, but have undetectable levels of abscisic acid (ABA).  Primary roots of the carotenoid-deficient w-3, vp-5, and vp-7 mutants of Z. mays are also graviresponsive despite having undetectable amounts of ABA.  Graviresponsive roots of untreated and wild-type seedlings contain 286 to 317 ng ABA g-1 f. wt, respectively.  These results indicate that ABA is not necessary for root gravicurvature.
Moore
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Department of Biological Sciences, Wright State University, Dayton, Ohio 45435.
D000040:Abscisic Acid / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000502:physiology; D017343:Genes, Plant; D018522:Gravitropism / Q000502:physiology*; D006540:Herbicides / Q000494:pharmacology; D009154:Mutation; D018517:Plant Roots / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D011728:Pyridones / Q000494:pharmacology; D003313:Zea mays / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000254:growth & development
D006540:Herbicides; D011728:Pyridones; C013351:fluridone; D000040:Abscisic Acid