Phaseolin Types Research Articles

F1 hybrid weakness in the common bean

The geographic origin of cultivars involved in F1 hybrid weakness was established using phaseolin type, as determined by one-dimensional SDS/PAGE. In all cases investigated, F1 weakness arose in crosses between an ‘S’ phaseolin, small-seeded parent of Middle American origin and a ‘T’ or a ‘C’ phaseolin, large-seeded parent of Andean origin. The appearance of F1 hybrid weakness reflects the geographical isolation of common bean cultivars of the two regions and points to the existence of two separate gene pools in cultivated common bean germplasm.

Complete nucleotide sequence of a French bean storage protein gene: Phaseolin

The complete nucleotide sequences of the gene and the mRNA coding for a specific phaseolin type French bean major storage protein have been determined. Comparison of these sequences reveals a phaseolin gene structure consisting of 80 base pairs (bp) of 5' untranslated DNA, 1,263 bp of protein-encoding DNA which is interrupted by five intervening sequences (IVS1, 72 bp; IVS2, 88 bp; IVS3, 124 bp; IVS4, 128 bp; and IVS5, 103 bp), and 135 bp of 3' untranslated DNA. Sequences characteristic of eukaryotic promoters "CCAAT" and "TATA" are present in the 5' flanking DNA, and the eukaryotic poly(A) addition signal A-A-T-A-A-A occurs 16 bp before the first nucleotide of poly(A). The derived amino acid sequence yields an amino acid composition and a molecular weight compatible with those found for the beta-type phaseolin protein. Two regions that probably serve as carbohydrate-peptide linkage recognition sites have been identified. A region of highly hydrophobic amino acids at the NH(2) terminus of the protein suggests the presence of a signal peptide in the newly synthesized phaseolin protein.

Genetic Divergence among Commercial Classes of Phaseolus vulgaris in Relation to Phaseolin Pattern1

Abstract Screening of 107 bean cultivars and plant introductions (PI) by 2-dimensional electrophoresis revealed only 3 different phaseolin patterns: Tendergreen (T), Sanilac (S), and Contender (C). The majority of the lines had either the ‘T’ (25%) or ‘S’ (69%) phaseolin patterns, with only 6% having the ‘C’ pattern. Phaseolin pattern was not strictly associated with commercial class but most cultivars with the ‘T’ pattern were snap beans, while the majority of lines with the ‘S’ pattern were dry beans. Furthermore, the phaseolin types of 15 cultivars were associated with previous cultivar groupings that were based on calculations of genetic relationships. A genetic distinction was noted between the groups of cultivars containing the ‘T’ and ‘S’ phaseolin patterns.