| Abstract: | Hilton, J. R. and Thomas, B. 1987. Photoregulation of phytochromesynthesis in germinating embryos of Avena sativa L.—J.exp. Bot. 38: 1704–1712. The effect of light on the accumulation of phytochrome in germinatingAvena embryos was determined. A quantitative ELISA using monoclonalantibody AFRC MAC 56 was used to measure specifically type 1(or dark) phytochrome. A pulse of red light given after 14 himbibition but prior to the onset of type 1 phytochrome synthesis,strongly inhibited subsequent type 1 phytochrome accumulation.This effect of red light at 14 h was reversible by far-red lightindicating the involvement of phytochrome. Red light also inhibitedphytochrome synthesis after 18 h and 24 h imbibition but after24 h, far-red light did not reverse the effect. The effect ofred light treatment at 18 h was reversed by giving a pulse offar-red light at any time up to 30 h. Seed germination was notinfluenced by light under the conditions of these experiments.It is proposed that type 2 (or light) phytochrome may be responsiblefor photoregulation of type 1 phytochrome synthesis in germinatingAvena embryos. Key words: Photoregulation, phytochrome, seed. |
