TABLE 2.
Application of CRISPR/Cas system in sweet potato (Ipomoea batatas), cassava (Manihot esculenta Crantz), yam (Dioscorea spp.), and carrot (Daucus carota subsp. sativus).
| Plant | Method of delivery | Technology | Target gene (s) | Trait associated with the genes | Type of mutation | Results | References |
| Sweet potato (Ipomoea batatas) | |||||||
| Cvs. Xushu22 and Taizhong6, Sweet potato (Ipomoea batatas) | Agrobacterium-mediated transformation; IbSBEII-sgRNA2 and IbSBEII-sgRNA12 vectors | CRISPR/Cas9 system | Granule-bound starch synthase and starch branching enzyme (IbGBSSI and IbSBEII) | Tuber starch quality | Deletions, substitutions, and insertions | Knockout of IbGBSSI reduced amylopectin, while the knockout of IbSBEII increased the amylose percentage | Wang et al., 2019 |
| Yam (Dioscorea spp.) | |||||||
| Cv. D. alata, Yam (Dioscorea spp.) | Agrobacterium-mediated transformation | CRISPR/Cas9 system | Phytoene desaturase gene (DrPDS) | Albino | Deletion and insertion | Promoter DaU6.5 performed best, while DaU6.2 and DaU6.3 yielded similar efficiency for expressing gRNAs | Syombua et al., 2021 |
| Cassava (Manihot esculenta) | |||||||
| Model cv.60444, Cassava (Manihot esculenta) | Agrobacterium-mediated transformation; pCAMBIA2300 vector | CRISPR/Cas9 system | Novel cap-binding protein (nCBP-1 and nCBP-2) genes | Cassava brown streak disease (CBSD) | Deletions and insertions | Reduced CBSD severity in root and stem | Gomez et al., 2018 |
| Cassava (Manihot esculenta) | Agrobacterium-mediated transformation; pJET1.2 vector | CRISPR/Cas9 system | African cassava mosaic virus genes (AC2 and AC3) | African cassava mosaic virus | Single-nucleotide insertion, and substitution | Resulted in the lack of resistance | Mehta et al., 2019 |
| Cvs. model cv.60444, M. esculenta T200 and M. esculenta TME3, Cassava (Manihot esculenta) | PEG-mediated transfection method of protoplasts | CRISPR/Cas9 system | Ubiquitin E3 ligase gene (MeE3L) | South African cassava mosaic virus (SACMV) | Single-nucleotide insertion | Accumulation of SACMV DNA was increased in the mutant lines | Chatukuta and Rey, 2020 |
| Carrot (Daucus carota subsp. Carota) | |||||||
| Carrot (Daucus carota subsp. Carota) | Agrobacterium-mediated transformation; pYPQ154, pYPQ166, and pYPQ167 | CRISPR/Cas9 system | F3H | Anthocyanin compound | Small Indels, and long chromosome fragment deletions | Individual transgenic calli, which differing in degree of discoloration from white, mosaic to purple. No transgenic plant was regenerated | Klimek-Chodacka et al., 2018 |
| Cvs. Kurodagosun and Deep purple, Carrot (Daucus carota subsp. Carota) | Agrobacterium-mediated transformation; VK005 vector | CRISPR/Cas9 system | DcPDS and DcMYB113-like genes | Albino and purple depigmentation | Insertion, deletion, and substitution | Generated Albino-type and purple depigmented plants | Xu et al., 2019 |