Anacardium occidentalie Linn is a typical tropical fruit tree, which is mainly planted in Yunnan and Hainan provinces of China. Cashew cultivation has important economic, social and ecological values. It is of great value to realize realize the strategy of rural revitalization in China, increase farmers' production and income, and achieve common prosperity. Cashews are very sensitive to low temperatures, and they will be severely damaged at 8 ℃and the growth will stop. Therefore, lowtemperature stress is an important abiotic stress that restricts cashew growth. CBF transcription factors play important roles in plant response to abiotic stresses such as low temperature, drought and salt. However, the role of CBF gene family in cashews has not been elucidated, and the expression pattern of this family in response to low temperature stress is unknown. In this study, in order to explore the basic characteristics of the CBF gene family in cashew nuts, six AoCBF gene family transcription factors were identified and obtained from the cashew transcriptome by bioinformatics methods, and the physical and chemical properties, protein structure, phylogeny, promoter action elements and expression patterns under low temperature induction were analyzed. The length of the six AoCBF proteins ranged from 189 to 334 aa, and the molecular weight of the proteins ranged from 21.31 to 37.89 kDa. The isoelectric points of the six AoCBF proteins were less than 7, indicating that the proteins were acidic. The proteins all contained an AP2/ERF domain. Motif analysis showed that there were five motifs in AoCBF genes, and the absence of different AoCBF gene motifs implied the absence of related functions. Phylogenetic tree analysis showed that the six AoCBF genes could be divided into two subgroups, A and B, in which group A contained one gene and group B only contained five genes. The analysis of homeotropic elements of promoter showed that AoCBF gene might be involved in the response to hormone and abiotic stress. Fluorescence quantitative expression analysis showed that all the six AoCBF genes responded to low temperature and cold stress to different degrees, indicating that AoCBF played a role in the biological process of cashew nut in response to low temperature stress. The results summarized the basic characteristics of the AoCBF gene family and accumulated basic data for further molecular resistance research and application of cashews AoCBF genes.
| 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 |