Polypeptide composition of fraction 1 protein subunits in the genus Petunia

Heterogeneity of alkaline small subunits of ribulose 1,5 bisphosphate carboxylase-oxygenase from Medicago sativa and M. falcata

The isolated leaf proteins of lucerne (Medicago sativa L. and M. falcata L.) were fractionated by Sepharose 6B column chromatography. Analysis of fractionated proteins indicated that the 2nd peak component was almost entirely ribulose 1,5 bisphosphate carboxylase-oxygenase (Rubisco) which represented 57% of the total recovered protein.Rubisco yielded one large subunit (LSU) and one small subunit (SSU) polypeptide after SDS gel electrophoresis.Isoelectric focusing of the SSU of Rubisco from genotypes of M. sativa cv. Hunter River (HR), Hairy Peruvian (HP) and of M. falcata (MF) showed two SSU components for HR and HP, and three components for MF. Most components of genotypes were located in the alkaline region of the gel. While the pIs of the SSU components of HR and HP were identical they differed from those of the SSU of MF thus demonstrating heterogeneity for SSU in Medicago.It is suggested that the alkaline nature of SSU may have some adaptive physiological significance.

Two dimensional analysis of chloroplast proteins from normal and cytoplasmic male sterile Brassica napus

Stromal and thylakoid proteins isolated from normal (N) and cytoplasmic male sterile (cms) lines of Brassica napus have been compared using a two dimensional gel separation. It has been shown that: 1) stromal compartments of the two lines were very similar; 2) although there was extensive homology between protein maps of thylakoids isolated from the two lines, these could be distinguished by the spots corresponding to the β subunits of the coupling factor CF1 from the ATPase complex.

Restriction endonuclease analysis of chloroplast DNA in interspecies somatic Hybrids of Petunia

Restriction endonuclease cleavage pattern analysis of chloroplast DNA (cpDNA) of three different interspecific somatic hybrid plants revealed that the cytoplasms of the hybrids contained only cpDNA of P. parodii. The somatic hybrid plants analysed were those between P. parodii (wild type) + P. hybrida (wild type); P. parodii (wild type)+P. inflata (cytoplasmic albino mutant); P. parodii (wild type) + P. parviflora (nuclear albino mutant). The presence of only P. parodii chloroplasts in the somatic hybrid of P. parodii + P. inflata is possibly due to the stringent selection used for somatic hybrid production. However, in the case of the two other somatic hybrids P. parodii + P. hybrida and P. parodii + P. parviflora it was not possible to determine whether the presence of only P. parodii chloroplasts in these somatic hybrid plants was due to the nature of the selection schemes used or simply occurred by chance. The relevance of such somatic hybrid material for the study of genomic-cytoplasmic interaction is discussed, as well as the use of restriction endonuclease fragment patterns for the analysis of taxonomic and evolutionary inter-relationships in the genus Petunia.

Polypeptide composition of fraction 1 protein of the somatic hybrid between Petunia parodii and Petunia parviflora

The analysis of the subunit polypeptide composition of Fraction 1 protein provides information on the expression of both chloroplast and nuclear genomes. Fraction 1 protein, isolated from leaves of the somatic hybrid plants derived form the fusion of protoplasts of Petunia parodii and P. parviflora, was analyzed for its subunit polypeptide composition by isoelectric focusing in 8 M urea. The fraction 1 protein enzyme oligomer in the somatic hybrid plants contained small subunits resulting from the expression of both parental nuclear genomes, but probably only one of the parental large subunits, namely that of P. parodii. The relevance of such somatic hybrid material for the study of nucleocytoplasmic interrelationship is discussed, as well as the use of these fraction 1 protein isoelectric focusing patterns for the analysis of taxonomic relationships in Petunia.

A comparison of the polypeptide isoelectric points and antigenic determinant sites of the large subunit of fraction 1 protein from Lycopersicon esculentum, Nicotiana tabacum and Petunia hybrida

The large subunit of Fraction 1 protein from Lycopersicon esculentum, Nicotiana tabacum and Petunia hybrida has been examined by isoelectric focusing of the S-carboxymethylated polypeptides, and by double immunodiffusion with antiserum raised against Fraction 1 protein. The immunological results reveal heterogeneity in the large subunit primary structure not identified by isoelectric focusing. A variable phylogeny can be generated depending on whether serological or electrofocusing criteria are used.