MLO gene is an unique negative regulatory factor for disease resistance in plants, and the mutation in the gene can lead to broad-spectrum disease resistance in plants. In this study, a DNA and cDNA sequence of cassava MLO12 gene were cloned from the entire cassava genome and named MeMLO12. This gene has a total length of 3743 nt and a coding region (ORF) of 1728 nt, with a complete open reading frame containing 15 exons and 14 introns, encoding 586 amino acids. The protein has a molecular weight of 67.2 kDa and an isoelectric point of 8.85. MeMLO12 protein is located on the endoplasmic reticulum membrane, without signal peptides, and forms seven transmembrane domains at 23-45, 74-96, 161-183, 285-307, 312-334, 371-393, 413-435 aa. Quantitative analysis by qRT PCR revealed significant differences in the expression of MeMLO12 gene in resistant and susceptible cassava germplasms after infection with Xanthomonas axonopodis, indicating a negative regulatory effect in the interaction between cassava and Xam. Selecting the 11th exon of the gene for Snap Gene Viewer analysis, 10 455 seed sequences of sgRNA were obtained. Three target sequences of approximately23nt were selected, with a G terminus at the 3′ end of the base composition, and they were constructed onto the CRISPR-Cas9 vector. After verification, it was confirmed that the three target sequences of MeMLO12 have been successfully constructed onto the gene editing vector, named pSGR-Cas9-AT-MeMLO12 vector.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |