TABLE 1.
Nutritional and functional quality-improved crops by gene-editing technologies.
| Crop class | Scientific name(Common name) | Target gene | Target function | Improved trait | Trait group | Editing method | Repair mechanism | Delivery technique | Reference | USDA’s answer to ‘Am I regulated?’/ Subject of commecialization |
| Staple crop | Oryza sativa (Rice) | BADH2 | Betaine aldehyde dehydrogenase | Increased fragrance content | Functional metabolite | TALEN | NHEJ | Agrobacterium-mediated transformation | Shan et al., 2015 | |
| SBEIIb | Starch branching enzyme | Increased amylose content | Starch | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Sun et al., 2017 | |||
| Waxy | Waxy protein/Granule-bound starch synthase | Improved glutinosity by lower amylose/amylopectin ratio | Starch | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Zhang J. et al., 2018 | |||
| rc | Rc/Basic helix–loop–helix transcription factor | Production of proanthocyanidins and anthocyanidins | Functional metabolite | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Zhu et al., 2019 | |||
| Triticum aestivum (Wheat) | α-Gliadin | α-Gliadin | Low-gluten wheat with strong reduction in α-gliadins | Protein | CRISPR/Cas9 | HDR | Particle bombardment | Sánchez-León et al., 2018 | ||
| GW2 | Grain weight 2/RING-type E3 ubiquitin ligase | Increased grain weight and protein content | Protein | CRISPR/Cas9 | NHEJ | Particle bombardment | Zhang Y. et al., 2018 | |||
| Zea mays (Maize/Corn) | IPK1 | Inositol-1,3,4,5,6-pentakisphosphate 2-kinase | Reduced phytic acid content | Anti-nutrient | ZFNs | HR | Whisker-mediated transformation | Shukla et al., 2009 | Not considered to be regulated/Dow AgroScience 2012 | |
| IPK1A, IPK, MRP4 | Inositol phosphate kinase, Multidrug resistance-associated protein4 | Reduced phytic acid content | Anti-nutrient | CRISPR/Cas9, TALEN | NHEJ | Agrobacterium-mediated transformation | Liang et al., 2014 | |||
| MADS47 | MADS-box protein zmmads47 | Reduced zein protein | Protein | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Qi et al., 2016 | |||
| Wx1 | Waxy protein/Granule-bound starch synthase | High-amylopectin starch | Starch | CRISPR/Cas9 | NHEJ | Biolistic transformation | Waltz, 2016a | Not considered to be regulated/Dupont Pioneer 2016 | ||
| Solanum tuberosum (Potato) | GBSS | Granule-bound starch synthase | High-amylopectin starch | Starch | CRISPR/Cas9 | NHEJ | PEG-mediated transfection | Andersson et al., 2017 | ||
| GBSS | Granule bound starch synthase | Absence of amylose | Starch | CRISPR/Cas9 | NHEJ | Ribonucleoprotein delivery | Andersson et al., 2018 | |||
| GBSS1 | Granule bound starch synthase I | Low amlyose starch in tubers | Starch | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Kusano et al., 2018 | |||
| PPO | Polyphenol oxidase | Reduced browning | Market value | TALEN | NHEJ | PEG-mediated transfection | – | Not considered to be regulated/Calyxt Inc.*, 2016 | ||
| PPO5 | Polyphenol oxidase | Reduced black spot, enzymatic darkening and discoloration in potato tubers | Market value | TALEN | NHEJ | Agrobacterium-mediated transformation | – | Not considered to be regulated/Simplot Plant Sciences, 2016 | ||
| PPO2 | Polyphenol oxidase | Reduced browning | Market value | CRISPR/Cas9 | NHEJ | Ribonucleoprotein delivery | Gonzalez et al., 2020 | |||
| 16DOX | Steroid 16α-hydroxylase | Absence of steroidal glycoalkaloids | Anti-nutrient | CRISPR/Cas9 | NHEJ | Agrobacterium rhizogenes | Nakayasu et al., 2018 | |||
| SSR2 | Sterol side chain reductase 2 | Reduced steroidal glycoalkaloids | Anti-nutrient | TALEN | NHEJ | Agrobacterium-mediated transformation | Yasumoto et al., 2019 | |||
| VInv | Vacuolar invertase | Reduced sugars in tubers causing reduced acrylamide in chips with improved cold storage and processing quality | Toxic substance | TALEN | NHEJ | PEG-mediated transfection | Clasen et al., 2016 | Not considered to be regulated/Calyxt Inc.*, 2014 | ||
| Oilseed crop | Brassica napus (Rapeseed) | FAD2_Aa | Fatty acid desaturase 2 | Increased oleic acid content | Lipid | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Okuzaki et al., 2018 | |
| Camelina sativa (Camelina) | DGAT1, PDAT1 | Diacylglycerol acyltransferase, Phospholipid: diacylglycerol acyltransferase | Altered fatty acid composition with reduced oil content | Lipid | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Aznar-Moreno and Durrett, 2017 | ||
| FAD2 | Delta-12 desaturase | Reduced levels of polyunsaturated fatty acids | Lipid | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Morineau et al., 2017 | |||
| FAD2 | Fatty acid desaturase 2 | Reduced levels of polyunsaturated fatty acids | Lipid | CRISPR/Cas9 | NHEJ | Floral dip method | Jiang et al., 2017 | |||
| FAE1 | Fatty acid elongase 1 | Reduced very long-chain fatty acids and increased C18 unsaturated fatty acids | Lipid | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Ozseyhan et al., 2018 | |||
| Glycine max (Soybean) | FAD2-1A, FAD2-1B | Fatty acid desaturase 2 | Reduced levels of polyunsaturated fatty acids | Lipid | TALEN | NHEJ | Agrobacterium-mediated transformation | Haun et al., 2014 | Approved/Calyxt Inc.*, 2019 | |
| FAD2-1A, FAD2-1B, FAD3A | Fatty acid desaturase 2-1A and -1B,Fatty acid desaturase 3 | Reduced levels of polyunsaturated fatty acids | Lipid | TALEN | NHEJ | Agrobacterium mediated transformation, Biolistic mediated transformation | Demorest et al., 2016 | Not considered to be regulated/Calyxt Inc.*, 2015 | ||
| Horticulturural crop | Agaricus bisporus (Mushroom) | PPO | Polyphenol oxidase | Reduced browning | Market value | CRISPR/Cas9 | NHEJ | PEG-mediated transformation | Waltz, 2016b | Not considered to be regulated/Pennsylvania State University, 2016 |
| Nicotiana tabacum (Tobacco) | BBL | Berberine bridge enzyme-like | Reduced levels of nicotine | Toxic substance | Meganuclease | NHEJ | Agrobacterium-mediated transformation | – | Not considered to be regulated/North Carolina State University, 2017 | |
| Solanum lycopersicum (Tomato) | ALC | Alcobaca (ALC)/NAC domain protein (NAC-NOR) | Delayed fruit ripening causing long-shelf life | Market value | CRISPR/Cas9 | HDR | Agrobacterium-mediated transformation | Yu et al., 2017 | ||
| ANT1 | Anthocyanin mutant 1/Myb transcription factor | Increased contents of anthocyanin | Functional metabolite | TALEN, CRISPR/Cas9 | HR | Agrobacterium-mediated transformation | Čermák et al., 2015 | |||
| GAD2, GAD3 | Glutamate decarboxylase 2 and 3 | Higher γ-aminobutyric acid content | Functional metabolite | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Nonaka et al., 2017 | |||
| GABA-TP1, GABA-TP3, CAT9, SSADH | Pyruvate-dependent GABA transaminases 1 and 3, Cationic amino acid transporter, Succinate semialdehyde dehydrogenase | Higher γ-aminobutyric acid content | Functional metabolite | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Li et al., 2018b | |||
| lncRNA1459 | Ripening-related long non-coding RNA1459 | Repressed fruit ripening, ethylene production and lycopene accumulation | Market value | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Li et al., 2018a | |||
| L1L4/NF-YB6 | LEAFY-COTYLEDON1-LIKE4/Nuclear transcription factor Y (NF-Y) gene | Reduced contents of the anti-nutrient oxalic acid | Anti-nutrient | ZFN | NHEJ | Electroporation | Gago et al., 2017 | |||
| MYB12 | R2R3-MYB transcription factor | Pink colortrait by absence of yellow-colored flavonoid naringenin chalcone in tomato peels | Market value | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Deng et al., 2018 | |||
| RIN | MADS-box transcription factor/Ripening inhibitor | Delayed fruit ripening | Market value | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Ito et al., 2015 | |||
| RIN/LeMADS | MADS-box transcription factor/Ripening inhibitor | Delayed fruit ripening and reduced ethylene production | Market value | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Jung et al., 2018 | |||
| SGR1, LCY-E, Blc, LCY-B2 | Stay-green 1, Lycopene ε-cyclase, Beta-lycopene cyclase, Lycopene β-cyclase 2 | Increased contents of lycopene and beta-carotenoids | Functional metabolite | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Li et al., 2018d | |||
| Solanum pimpinellifolium (Current tomato) | CycB, SP, O, MULT, FAS, FW2.2 | Lycopene b-cyclase, Self-pruning, Ovate, Multiflora, Fasciated, Fruit weight 2.2 | Increased contents of lycopene (5x) as nutritional value with alteration in the size (3x) and number (10x) of the fruits | Functional metabolite | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Zsögön et al., 2018 | ||
| GGP1, SP, SP5, CLV3, WUS | GGP1 encoding a vitamin C–biosynthetic enzyme, Self-pruning, Self-pruning 5g, CLV3, Homeobox-encoding gene WUS | Increased contents of vitamin C | Functional metabolite | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Li et al., 2018c | |||
| Vitis vinifera (Grape) | IdnDH | L-idonate dehydrogenase | Reduced levels of tartaric acid | Anti-nutrient | CRISPR/Cas9 | NHEJ | Agrobacterium-mediated transformation | Ren et al., 2016 |
* Calyxt Inc. was renamed from Cellectis Plant Sciences.