Perspectives on the genetic improvement of health- and nutrition-related traits in pea

Abstract

Pea (Pisum sativum L.) is a widely grown pulse crop that is a source of protein, starch and micronutrients in both human diets and livestock feeds. There is currently a strong global focus on making agriculture and food production systems more sustainable, and pea has one of the smallest carbon footprints of all crops. Multiple genetic loci have been identified that influence pea seed protein content, but protein composition is also important nutritionally. Studies have previously identified gene families encoding individual seed protein classes, now documented in a reference pea genome assembly. Much is also known about loci affecting starch metabolism in pea, with research especially focusing on improving concentrations of resistant starch, which has a positive effect on maintaining blood glucose homeostasis. Diversity in natural germplasm for micronutrient concentrations and mineral hyperaccumulation mutants have been discovered, with quantitative trait loci on multiple linkage groups identified for seed micronutrient concentrations. Antinutrients, which affect nutrient bioavailability, must also be considered; mutants in which the concentrations of important antinutrients including phytate and trypsin inhibitors are reduced have already been discovered. Current knowledge on the genetics of nutritional traits in pea will greatly assist with crop improvement for specific end uses, and further identification of genes involved will help advance our knowledge of the control of the synthesis of seed compounds.

Keywords: Genetics; Nutrition; Pea; Quality traits.

Fig. 1

Changes in starch morphology in r mutant pea seeds compared with round-seeded (R) pea seeds, unstained or stained (top panel). Comparison of glucose and insulin response curves in humans following consumption of wrinkled (solid lines), compared with control near-isogenic round (dotted lines), pea seeds (lower panel). The glucose and insulin response data are re-plotted from Petropoulou et al. (2020).

Fig. 2

Introgression of the trypsin inhibitor null allele from Pisum elatius (JI 262) into a cultivar of Pisum sativum (JI 3253), showing the selection for seed size and seed coat phenotypes in lines carrying the null allele through successive backcross (Bc) generations (F₂, F₃).