Analysis of storage proteins in a worldwide collection of pea seeds

Abstract

Peas (Pisum sativum L.) are an important source of vegetable protein for both humans and animals. However, pea seed proteins are limited in sulfur-containing amino acids (SCAA) and thus considered to be an insufficient source. The main seed proteins in pea are 7S (vicilins, convicilins) and 11S (legumins) globulins. Because 11S globulins contain more SCAA than 7S globulins, variations in the 7S/11S ratio affects the nutritional quality of pea seeds. Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) was used to separate seed proteins from 260 pea genotypes from around the world (the EUCLEG collection). Based on the electropherogram, 18 protein bands were densitometrically measured. Protein compositional data are intrinsically multivariate. The protein concentration of each genotype is presented in closed form i.e., sum up to 100%. Therefore, for multivariate data analysis specific statistical methodology was used. All methods used in the study were carried out in classical and robust manner that was resistant to outlier observations. The storage protein composition of the genotypes studied varied greatly; in some cases, only traces of the main components were found. The results suggest that some of the genotypes tested could be useful in various breeding programs aimed at producing agronomically viable plants, yielding high-protein seed with specific composition of storage proteins for specific food applications.