Abstract
The amounts of two growth inhibitors in diffusates from illuminatedhalves of phototropically stimulated oat (Avena sativa L.)coleoptile tips were larger than those from shaded halves. The less polarinhibitor was isolated from diffusates from oat coleoptile tips illuminatedwithblue light, and identified as uridine from 1H NMR spectrum. Thedistribution of endogenous uridine in diffusates from the illuminated andshadedsides of coleoptile tips unilaterally exposed to blue light for 3, causing a first positive phototropic curvature, and fromdark-control tips, was determined using a physicochemical assay. The uridineconcentration was significantly higher in the diffusates from the illuminatedside than in those from the shaded side and the dark-control. Uridine inhibitedthe growth of etiolated oat coleoptile tips at concentrations of 30 and above. These results suggest that uridine plays a role inthe phototropism of oat coleoptiles.
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Anai T., Aizawa H., Ohtake N., Kosemura S., Yamamura S. and Hasegawa K. 1996. A new auxin-inhibiting substance, 4-Cl-6,7-dimethoxy-2-benzoxazolinone, from light-grown maize shoots. Phytochemistry. 42: 273–275.
Bruinsma J. and Hasegawa K. 1989. Phototropism involves a lateral gradient of growth inhibitors, not of auxin. A review Environ. Exp. Bot. 29: 25–36.
Bruinsma J. and Hasegawa K. 1990. A new theory of phototropism-its regulation by a light-induced gradient of auxin-inhibiting substances. Physiol. Plant. 79: 700–704.
Hasegawa K., Sakoda M. and Bruinsma J. 1989. Revision of the theory of phototropism in plants: a new interpretation of a classical experiment. Planta. 178: 540–544.
Hasegawa K., Togo S., Urashima M., Mizutani J., Kosemura S. and Yamamura S. 1992. An auxin-inhibiting substance from lightgrown maize shoots. Phytochemistry. 31: 3673–3676.
Hasegawa T., Yamada K., Kosemura S., Yamamura S. and Hasegawa K. 2000. Phototropic stimulation induces the conversion of glucosinolate to phototropism-regulating substance of radish hypocotyls. Phytochemistry. 54: 274–279.
Went F.W. 1928. Wuchsstoff und Wachstum. Rec. Trav. Bot. Neerl. 25: 1–116.
Went F.W. and Thimann K.V. 1937. Phytohormones. MacMillan, New York.
Yamada K., Nakano H., Yokotani-Tomita K., Bruinsma J., Yamamura S. and Hasegawa K. 2000. Repetition of the classical Boysen-Jensen and Nielsen's experiment on phototropism of oat coleoptiles. J. Plant Physiol. 156: 323–329.
Yokotani-Tomita K., Kato J., Kosemura S., Yamamura S., Kushima M., Kakuta H. et al. 1997. Light-induced auxin-inhibiting substance from sunflower (Helianthus annuus L.) seedlings. Phytochemistry. 46: 503–506.
Yokotani-Tomita K., Kato J., Yamada K., Kosemura S., Yamamura S., Bruinsma J. et al. 1999. 8-Epixanthatin, a light-induced growth inhibitor, mediates the phototropic curvature in sun-flower (Helianthus annuus L.) hypocotyls. Physiol. Plant. 106: 326–330.
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Hasegawa, T., Yamada, K., Kosemura, S. et al. Isolation and identification of a light-induced growth inhibitor in diffusates from blue light-illuminated oat (Avena sativa L.) coleoptile tips. Plant Growth Regulation 33, 175–179 (2001). https://doi.org/10.1023/A:1017571628931
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DOI: https://doi.org/10.1023/A:1017571628931