Characterization of Three Photosystem II Mutants in Zea mays L. Lacking a 32,000 Dalton Lamellar Polypeptide 1

AUTOR(ES)

Leto, Kenneth J.

RESUMO

Two fully blocked and one partially blocked photosystem II nuclear mutants have been selected in Zea mays. The fully blocked mutants lack photosystem II activity, variable fluorescence, the light-inducible C-550 signal, the high potential form of cytochrome b-559, and most or all of the low potential form of the cytochrome. The block in these mutants may primarily affect the reducing side of photosystem II, inasmuch as chloroplasts isolated from both mutants exhibit an elevated F695 fluorescence emission peak. The partially blocked mutant exhibits partial photosystem II activity and a reduction, but not the total loss of the variable fluorescence yield, the C-550 signal, and the high potential form of cytochrome b-559. Lamellae isolated from the fully blocked mutants are greatly deficient for a major lamellar polypeptide with an apparent molecular weight of 32,000 daltons, whereas lamellae from the partially blocked mutant show the partial loss of this same polypeptide, suggesting that the 32,000 dalton polypeptide is necessary for the proper function of photosystem II.

Documentos Relacionados

• Nuclear Involvement in the Appearance of a Chloroplast-Encoded 32,000 Dalton Thylakoid Membrane Polypeptide Integral to the Photosystem II Complex 1
• Characterization of the 32,000 Dalton Chloroplast Membrane Protein: III. Probing Its Biological Function in Spirodela1
• Structure of the chloroplast gene for the precursor of the Mr 32,000 photosystem II protein from mustard (Sinapis alba L.).
• The rapidly metabolized 32,000-dalton polypeptide of the chloroplast is the "proteinaceous shield" regulating photosystem II electron transport and mediating diuron herbicide sensitivity.
• Isolation and partial characterization of a Mr 32,000 protein with inhibin activity from porcine follicular fluid.