Leaf Senescence in a Nonyellowing Mutant of Festuca pratensis: Metabolism of Cytochrome f

• Published in: Plant physiology (Bethesda) Vol. 93; no. 2; pp. 588 - 595
• Main Authors: T. G. Emyr Davies, Thomas, Howard, Thomas, Barry J., Lyndon J. Rogers
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.06.1990
• Subjects: Antibodies; Antiserum; Biological and medical sciences; Cellular senescence; Chloroplasts; Cytochromes; Fundamental and applied biological sciences. Psychology; Genotypes; Leaves; Plant physiology and development; Plants; Plastids; Senescence and abscission; Thylakoids; Vegetative apparatus, growth and morphogenesis. Senescence; Monocotyledones; Membrane protein; Senescence; Stability; Plant leaf; Thylakoid; Cytochrome f; Festuca pratensis; Investigation method; Gramineae; Angiospermae; Pigment protein complex; Turnover; Spermatophyta; Mutation; Fodder crop
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.93.2.588

In a mutant genotype of Festuca pratensis Huds., net degradation of a number of thylakoid membrane proteins during senescence is impaired. Previous studies have suggested that the highly hydrophobic intrinsic chlorophyll-binding proteins were the definitive subjects of the metabolic lesion. In the present study we find that cytochrome f, as determined by haem-staining, Western blotting, enzyme-linked immunosorbent assay, and immunogold electron microscopy, is also abnormally stable in the mutant. The structural feature common to all the proteins in the mutant so far recognized to be abnormally stable is possession of a tetrapyrrole prosthetic group. It is suggested that degradation of chlorophyll and haem may regulate degradation of the associated apoproteins, and hence has an important role to play in membrane protein turnover and in mobilisation of amino acids during chloroplast disassembly.