Fredrick A. Bliss

Insecticidal Activity and Lectin Homology of Arcelin Seed Protein

Arcelin, a major seed protein discovered in wild beans (Phaseolus vulgaris), has toxic effects on an important bean bruchid pest, Zabrotes subfasciatus. Transfer of the arcelin-1allele to bean cultivars and addition of purified arcelin to artificial seeds results in high levels of insect resistance. The nucleotide and derived amino acid sequences of the arcelin-1 complementary DNA are very similar to those of genes encoding the bean seed lectin, phytohemagglutinin. The gene or genes encoding arcelin may have evolved from a phytohemagglutinin gene or genes resulting in an effective mechanism for resistance to bean bruchids.

Genetic variation in the subunits of globulin-1 storage protein of French bean

SummaryCharge and molecular weight heterogeneity of globulin-1 (G1) polypeptides of the bean, Phaseolus vulgaris L., were revealed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Different bean cultivars were classified into three groups: ‘Tendergreen’, ‘Sanilac’, and ‘Contender’ on the basis of their protein subunit composition. Nine distinct major bands: α51,α49, α48.5,β48T, β48S, β47, γ45.5, γ45S, and γ45C, and two minor bands: γ46T and γ46S were found to account for the three profiles seen on one-dimensional SDS-PAGE. Two-dimensional analysis revealed these eleven protein bands to be composed of a minimum of fourteen distinct protein subunits. The ‘Tendergreen’ and ‘Sanilac’ types differ in their G1 polypeptide composition. The protein patterns of the ‘Contender’ types are intermediate, containing many protein subunits found in the patterns of the ‘Tendergreen’ and ‘Sanilac’ types suggesting a genetic and evolutionary relationship.

Linkage relationships between genes controlling seed proteins in French bean

SummaryThe inheritance of phaseolin and globulin-2 (G2)/albumin polypeptides was investigated in crosses involving varieties which exhibited the three electrophoretic banding patterns of phaseolin found in French bean. ‘Total’ seed protein extracts of single seeds of the F1 and F2 generations from the crosses: ‘Sanilac’ × ‘Contender’, ‘BBL 240’ × ‘Contender’, and ‘Sanilac’ × ‘BBL 240’ were analyzed by two-dimensional electrophoresis. Segregation of the genes controlling phaseolin and G2/albumin polypeptides, and those controlling a further five groups of seed proteins (A, B, D, E, and F) were observed. No recombinant electrophoretic phenotypes were seen for phaseolin or G2/albumin polypeptides suggesting that the genes controlling each of these groups of polypeptides are closely linked and segregate like single Mendelian genes. The phaseolin genes and G2/albumin genes were not linked to each other. The group of genes controlling phaseolin polypeptides were linked to those controlling group B proteins, and those controlling G2/albumin polypeptides were linked to those controlling group F proteins.

Comparison of globulin proteins from Phaseolus vulgaris with those from Vicia faba

Abstract Extraction of maturing Phaseolus vulgaris seeds with an ascorbic acid—NaCI medium facilitated the preparation of two globulin fractions which wer

Bean lectins : Part 1: Relationships between agglutinating activity and electrophoretic variation in the lectin-containing G2/albumin seed proteins of french bean (Phaseolus vulgaris L.).

SummarySingle seeds of over 100 bean cultivars were analyzed by two-dimensional electrophoresis. The cultivars could be classified into eight groups by virtue of their G2/albumin electrophoretic patterns: TG2, SG2, VG2, PrG2, BG2, MG2, PG2, and PiG2, The polypeptide compositions of these types were largely inter-related having particular polypeptides in common. It was possible to correlate the G2/albumin patterns with agglutinating activity of cow and rabbit blood cells as measured by the agglutination ratio (minimum concentration of extract required to agglutinate cow blood cells: minimum concentration of extract required to agglutinate rabbit blood cells). The active lectin polypeptides were identified by extracting lectins from agglutinated erythrocytes and by comparing the qualitative similarities and differences of the G2/albumin patterns and their agglutination activities. A reference catalogue of over 100 bean cultivars giving their phaseolin and G2/albumin electrophoretic patterns, and agglutination ratios is presented.

Breeding Common Bean for Improved Quantity and Quality of Seed Protein

The common bean (Phaseolis vulgaris L.), which is native to the Western Hemisphere, is an important dietary component for many people worldwide. It is a major source of protein in the Americas and in parts of Asia and Africa where animal products are either scarce or too expensive for widespread consumption. Despite its present extensive cultivation, it could contribute more to the world’s food reserves. Grain yields remain low, nitrogen fixation is low and variable, and seed protein nutritional qualities are less than optimum for man and other animals. If the potential of the common bean is to be fully realized, improvements in these characteristics must be made.

Electrophoretic analysis of protein changes during the development of the French bean fruit

Abstract The protein complement of bean ( Phaseolus vulgaris ) seeds and pods was shown to change greatly during fruit development. Synthesis of storage protein was initiated when the seed attained 10 mm length, the subsequent accumulation rapidly diluting out other proteins readily detectable after electrophoresis on acrylamide gels of extracts from younger seeds. In contrast, the number of bands obtained on electrophoresis of proteins from the pod decreased as a result of degradative changes as the fruit matured.

Selection for increased percentage phaseolin in common bean : 1. Comparison of selection for seed protein alleles and S1 family recurrent selection.

SummaryTwo selection methods were compared to determine which was more efficient for increasing percentage phaseolin in the common bean (Phaseolus vulgaris L.). A base population consisting of families segregating for six seed protein alleles (PhasS, PhasC, PhasT, phas-, lec-, and Arcl+), all of which have measurable effects on percentage phaseolin, was subjected to either three cycles of S1 family recurrent selection for increased percentage phaseolin (PPS), or one cycle of selection for combinations of the protein alleles (PAS) known to have positive effects on phaseolin accumulation. One cycle of PAS resulted in an increase in percentage phaseolin that was equivalent to three cycles of PPS. Selection under both methods produced increases in several correlated traits including percentage total protein, phaseolin as a percent of total protein, mg protein/seed, and mg phaseolin/seed. The amount of nonphaseolin protein per seed decreased, while seed yield was unaffected by either selection procedure. By selecting for favorable seed protein alleles identified by electrophoresis, it was possible to rapidly increase percentage phaseolin without the need for field evaluation.

Bean lectins : 5. Quantitative genetic variation in seed lectins of Phaseolus vulgaris L. and its relationship to qualitative lectin variation.

SummarySeeds of forty bean cultivars having different lectin types based on two-dimensional isoelectric focusing-sodium dodecyl sulfate polyacrylamide gel electrophoresis (IEF-SDS/PAGE) were analyzed for quantities of lectin, phaseolin and total protein. Significant differences were found among groups of cultivars with different lectin types for the quantity of lectin and phaseolin. Cultivars with more complex lectin types based on IEF-SDS/PAGE tended to have higher quantities of lectin and lower quantities of phaseolin than cultivars with simple lectin types. An association between lectin type and the quantity of lectin and phaseolin was found also in the seeds of F2 plants that segregated in a Mendelian fashion for two lectin types. Seeds from plants with the complex lectin type had more lectin and less phaseolin than seeds from plants with the simple lectin type. Therefore, the genes controlling qualitative lectin variation also may influence the quantitative variation of lectin and phaseolin. The results of this study are related to other studies on the quantitative variation for seed proteins and to the possible molecular basis for variation in the quantity of lectins in beans.

Bean lectins : Part 2: Relationship between qualitative lectin variation in Phaseolus vulgaris L. and previous observations on purified bean lectins.

SummaryThe relationship between the polypeptide composition and the agglutination behaviour of the lectin-containing G2/albumin protein groups has allowed the identification of the active lectin polypeptides in different cultivars of Phaseolus vulgaris (Brown et al. accompanying paper). These results were used to ascertain the particular G2/albumin group contained in the various lectin sources used previously for the purification of lectin proteins. Many studies were found to have included lectin sources which contained the same G2/albumin pattern (TG2) and this common denominator has permitted the direct comparison of the properties reported for these purified lectins. Thus, much of the extensive literature on bean lectins is concurred.