Table 2.
Key genes underlying the vitamin contents that may subjected to wheat grain nutritional improvement.
| Vitamin | Related metabolites | Key candidate genes | Orthologs |
|---|---|---|---|
| VA | β-carotene, provitamin A, β-cryptoxanthin, retinol derivatives | RALDH, retinal dehydrogenase; REH, retinyl ester hydrolase; PSY∗, phytoene synthase | 7A1357000; 7B1296800; 7D1285000 |
| VB1 | thiamine, thiamin pyrophosphate | TMP-PPase, thiamin-phosphate pyrophosphorylase; THI∗, thiamine thiazole synthase | 7A0916800; 7B0760700; 7D0879600 |
| VB2 | riboflavin, flavin adenine dinucleotide, flavin mononucleotide | RibA, GTP cyclohydrolase II; RibB, 3,4-dihydroxy-2-butanone 4-phosphate synthase; PyrR∗, pyrimidine reductase | 6A0988100; 6B1211700; 6D0873600 |
| VB3 | niacin, niacinamide, nicotinamide adenine dinucleotide (phosphate) | NadA, quinolinate synthase; nitrate reductase∗ | 6A0038200; 6B0056200; 6D0042700 |
| VB5 | pantothenic acid, pantetheine, pantethine | PanB, 3-methyl-2-oxobutanoate hydroxymethyltransferase; PanK∗, pantothenate kinase | 5A0779300; 5B0811000; 5D0737600 |
| VB6 | pyridoxine/pyridoxal/pyridoxamine 5′-phosphate | PDX∗, pyridoxal 5′-phosphate synthase | 2A0661600; 2B0746500; 2D0617200 |
| VB7 | biotin, biocytin | DTBS, desthiobiotin synthetase; BIO∗, biotin synthase | 6A0389100; 6B0491900; 6D0338900 |
| VB9 | folic acid, tetrahydrofolic acid derivatives | FPGS, folylpolyglutamate synthetase; DHFR∗, dihydrofolate reductase; DHFS, dihydrofolate synthase; DHPS, dihydropteroate synthase | 2A1204700; 2B1374200; 2D1159900 |
| VC | ascorbic acid | PMI, phosphomannose isomerase; Alase, aldonolactonase; GGP∗, GDP-L-galactose phosphorylase | 4A0537700; 4B0239000; 4D0202300 |
| VE | tocopherols and tocotrienols | VTE1∗, tocopherol cyclase; VTE2, homogentisate phytyl transferase; VTE3, dimethyl-phytylquinol methyl transferase; VTE4, γ-tocopherol C-methyl transferase | 1A0584500; 1B0677200; 1D0555800 |
The wheat candidate genes are generated by sequence alignment against reported genes marked by asterisks. Wheat gene IDs are abbreviations based on the IWGSC Chinese Spring genome v.2.1 annotation. For instance, 7A1357000 denotes TraesCS03G7A1357000.