Analysis of β-amylase gene (Amyβ) variation reveals allele association with low enzyme activity and increased firmness in cooked sweetpotato (Ipomoea batatas) from East Africa
| Autor: | Roger Pelle, Nasser Yao, Martina Kyallo, Linly Banda, Jolien Swanckaert, Esther Magiri, Dorcus C. Gemenet, Mukani Moyo, Tawanda Muzhingi, Robert O. M. Mwanga, Jean-Baka Domelevo Entfellner, Arnold N. Onyango |
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| Rok vydání: | 2021 |
| Předmět: |
Orange-fleshed
Genetics biology Nutrition. Foods and food supply Agriculture (General) Locus (genetics) Single-nucleotide polymorphism Agricultural and Biological Sciences (miscellaneous) Enzyme assay S1-972 Exon Sweetpotato Genetic variation biology.protein Nucleotide variation Optimal cooking time TX341-641 Texture Amylase Allele Beta-amylase Agronomy and Crop Science Gene Food Science |
| Zdroj: | Journal of Agriculture and Food Research, Vol 4, Iss, Pp 100121-(2021) |
| ISSN: | 2666-1543 |
| Popis: | β-amylase is a thermostable enzyme that hydrolyses starch during cooking of sweetpotato (Ipomoea batatas) storage roots, thereby influencing eating quality. Its activity is known to vary amongst genotypes but the genetic diversity of the beta-amylase gene (Amyβ) is not well studied. Amyβ has a highly conserved region between exon V and VI, forming part of the enzyme's active site. To determine the gene diversity, a 2.3 kb fragment, including the conserved region of the Amyβ gene was sequenced from 25 sweetpotato genotypes. The effect of sequence variation on gene expression, enzyme activity, and firmness in cooked roots was determined. Six genotypes carrying several SNPs within exon V, linked with an AT or ATGATA insertion in intron V were unique and clustered together. The genotypes also shared an A336E substitution in the amino acid sequence, eight residues upstream of a substrate-binding Thr344. The genotypes carrying this allele exhibited low gene expression and low enzyme activity. Enzyme activity was negatively correlated with firmness (R = −0.42) in cooked roots. This is the first report of such an allele, associated with low enzyme activity. These results suggest that genetic variation within the AmyB locus can be utilized to develop markers for firmness in sweetpotato breeding. |
| Databáze: | OpenAIRE |
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