ABSTRACT
BACKGROUND: In soybean, at least 16 seed proteins have been identified as causing allergenic reactions in sensitive individuals. As a soybean genebank accession low in the immunodominant protein P34 (Gly m Bd 30K) has recently been found, introgression of the low-P34 trait into adapted soybean germplasm has been attempted in order to improve the safety of food products containing soybean protein. Therefore, marker-assisted selection and proteomics were applied to identify and characterize low-P34 soybeans. RESULTS: In low-P34 lines selected from a cross-population, concentrations of the P34 protein as identified with a polyclonal antibody were reduced by 50-70% as compared to P34-containing controls. Using 2D electrophoresis and immunoblotting, the reduction of P34 protein was verified in low-P34 lines. This result was confirmed by liquid chromatographic-tandem mass spectrometric analysis, which revealed either a reduction or complete absence of the authentic P34 protein as suggested from presence or absence of a unique peptide useful for discriminating between conventional and low-P34 lines. CONCLUSION: Marker-assisted selection proved useful for identifying low-P34 soybean lines for the development of hypoallergenic soy foods. The status of the P34 protein in low-P34 lines needs further characterization. In addition, the food safety relevance of low-P34 soybeans should be tested in clinical studies. © 2016 Society of Chemical Industry.
Subject(s)
Antigens, Plant/adverse effects , Crosses, Genetic , Down-Regulation , Glycine max/chemistry , Plant Breeding , Seeds/chemistry , Soy Foods/analysis , Soybean Proteins/adverse effects , Antigens, Plant/genetics , Antigens, Plant/metabolism , Enzyme-Linked Immunosorbent Assay , Expert Systems , Food Hypersensitivity/diet therapy , Food Hypersensitivity/prevention & control , Food Safety , Functional Food/adverse effects , Functional Food/analysis , Gene Expression Regulation, Plant , Genetic Linkage , Genetic Markers , Humans , Microsatellite Repeats , Proteomics/methods , Seeds/adverse effects , Seeds/growth & development , Seeds/metabolism , Selection, Genetic , Soy Foods/adverse effects , Soybean Proteins/genetics , Soybean Proteins/metabolism , Glycine max/adverse effects , Glycine max/growth & development , Glycine max/metabolismABSTRACT
Genetic relationships among 104 accessions of Cucurbita pepo were assessed from polymorphisms in 134 SSR (microsatellite) and four SCAR loci, yielding a total of 418 alleles, distributed among all 20 linkage groups. Genetic distance values were calculated, a dendrogram constructed, and principal coordinate analyses conducted. The results showed 100 of the accessions as distributed among three clusters representing each of the recognized subspecies, pepo, texana, and fraterna. The remaining four accessions, all having very small, round, striped fruits, assumed central positions between the two cultivated subspecies, pepo and texana, suggesting that they are relicts of undescribed wild ancestors of the two domesticated subspecies. In both, subsp. texana and subsp. pepo, accessions belonging to the same cultivar-group (fruit shape) associated with one another. Within subsp. pepo, accessions grown for their seeds or that are generalists, used for both seed and fruit consumption, assumed central positions. Specialized accessions, grown exclusively for consumption of their young fruits, or their mature fruit flesh, or seed oil extraction, tended to assume outlying positions, and the different specializations radiated outward from the center in different directions. Accessions of the longest-fruited cultivar-group, Cocozelle, radiated bidirectionally, indicating independent selection events for long fruits in subsp. pepo probably driven by a common desire to consume the young fruits. Among the accessions tested, there was no evidence for crossing between subspecies after domestication.
Subject(s)
Cucurbita/genetics , Evolution, Molecular , Microsatellite Repeats/genetics , Phenotype , Phylogeny , Polymorphism, Genetic/genetics , Fruit/anatomy & histology , Principal Component Analysis , Species SpecificityABSTRACT
Four cultigens of Cucurbita moschata resistant to zucchini yellow mosaic virus were crossed with the susceptible 'Waltham Butternut' and with each other in order to clarify the mode of inheritance of resistance and relationships among the genes involved. Five loci were segregating, with genes for resistance Zym-0 and Zym-4 carried by 'Nigerian Local' and one of them also carried by 'Nicklow's Delight,' Zym-1 carried by 'Menina,' and zym-6 carried by 'Soler.' A recessive gene carried by 'Waltham Butternut,' zym-5, is complementary with the dominant Zym-4 of 'Nigerian Local,' that is, the resistance conferred by Zym-4 is only expressed in zym-5/zym-5 individuals. Gene zym-6 appears to be linked to either Zym-0 or Zym-4, and it is also possible that Zym-1 is linked to one of them as well.
