Department of Plant Molecular Biology, University of Delhi, South Campus, Dhaula Kuan, New Delhi 110 021, India
1Present address: Department of Biological Sciences, University of Maryland, Baltimore County, Catonsville, MD, USA.
2International Centre for Genetic Engineering and Biotechnology, Aruna Asaf AN Marg, New Delhi 110067, India.
* Corresponding author.
A large number of polypeptides were phosphorylated when in vitro protein phosphorylation was carried out in nuclei isolated from dark-grown seedlings. For studying the effect of light, dark-grown seedlings were exposed to light and the isolated nuclear proteins phosphorylated in vitro. Although 4 h of white light was sufficient to alter the phosphorylation status of at least two polypeptides of 19 and 17 kD but the effect of light was more pronounced after irradiation for 8 h or more, leading to virtual disappearance of a 19 kD and emergence of a 17 kD phosphopolypeptide. Studies using norflurazon, a bleaching herbicide, indicate that, in addition to 19 and 17 kD phosphopolypeptides, another 21 kD phosphopolypeptide may be involved in the de-etiolation process. However, the nature of the photoreceptor involved in these light-induced changes in nuclear protein phosphorylation remains to be established.
wheat, Triticum aestivum L, light, nuclei, protein phosphorylation
