Work

Proanthocyanidins: Key for Resistance to Globisporangium (Formerly Pythium) Seed Rot of Pea

Year: 2024

Type: article

Abstract: Pea ( Pisum sativum ) dominant for the fundamental color gene A showed a high level of resistance to Globisporangium ultimum (formerly Pythium ultimum ) seed rot. Reciprocal crosses demonstrated that, with our materials, such resistance was associated with the testa (seedcoat) phenotype but not the embryo phenotype. Dominance of A over a was complete for this trait. Neither wrinkled seed form ( r ) nor green cotyledons ( i ) diminished resistance when A was dominant, although both recessive alleles diminished resistance when seeds were borne on white-flowering ( a ) plants. The product of the A gene functions in the pathway leading to flavonoids, including proanthocyanidins (PAs) and anthocyanidins. We found that resistance to G. ultimum seed rot was closely associated with not only dominant A but also testa PAs and testa sclerenchyma. Even A testas that lacked anthocyanins but contained PAs and sclerenchyma showed a high level of seed rot resistance. Moreover, a mutation removing PAs and sclerenchyma in a narrow zone from the hilum to the radicle markedly increased susceptibility. The PAs in pea testas were predominantly prodelphinidins in seeds from purple-flowered plants ( A B ) and procyanidins from pink-flowered plants ( A b ). Compared with procyanidins, prodelphinidins have higher antioxidant activity but are more likely to sequester iron, a particular concern with dry pea. Although A B testas were more resistant than A b to seed rot, the difference seemed too slight to militate against growing pink-flowered pea. We stressed the need for more histological comparisons of A B and A b testas, and we indicated that genes and their phenotypic effects examined during the current study could be useful for modeling biosynthesis of PAs and related cell walls.

Source: Journal of the American Society for Horticultural Science

DOI: 10.21273/jashs05340-23

Authors: Elmer E. Ewing, Norman F. Weeden, Ivan Simko

Institutions: Cornell University, New York State College of Agriculture & Life Sciences, Montana State University, Agricultural Research Service, United States Department of Agriculture

Language: English

Topic: Genetic and Environmental Crop Studies

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $3,500