Mango (Mangifera indica L.) is one of the major cash crops in the tropics and a typical respiratory leap fruit, whose ripening senescence is associated with ethylenee. AP2/ERF transcription factors are widely present in plants, and it is found that the transcription factors are involved in the signal transduction of endogenous ethylene synthesis in fruits, and are key genes in the ethylene signaling pathway, playing an important role in plant growth and development, response to adversity stress and storage and transportation. To investigate the effect of AP2/ERF transcription factor on post-harvest mango ripening and senescence, a MiERF2 gene of 915 bp in length, encoding 305 amino acids, was cloned by PCR using Guifei mango as the target of this study. The molecular formula of MiERF2 protein was C1449H2259N433O470S11. The molecular weight was 33 618.16 Da, the total atomic number was 4622. The theoretical isoelectric point was 7.66, with 30 positively charged residues and 29 negatively charged residues. The protein was hydrophilic and structurally unstable. MiERF2 didn’t contain a signal peptide, didn’t contain a transmembrane region, and phosphorylation modification was mainly threonine. MiERF2 contained a conserved structural domain of AP2, the secondary structure was dominated by 66.12% of random curl, also contained 24.67% of α-helix, 1.32% of β-fold, 7.89% of the extended chain. Its three-dimensional structure model contained three β-fold and one α-helix, consistent with the characteristics of the AP2 structural domain. The results of motif analysis and multiple sequence matching indicated that MiERF2 protein belonged to the ERF subfamily. Phylogenetic analysis showed that the closest relative to MiERF2 was the pistachio PvERF109-like, which is also a member of the Lacertidae family. Onion subcellular localization results showed that MiERF2 was localized in the nucleus. Quantitative real-time fluorescence analysis showed that the expression of MiERF2 differed after 400 μg/mL ethephon treatment at different harvest maturity. In 60% maturity mango, the expression of MiERF2 in the treatment group peaked at 9 d and then was significantly lower than that in the control group. In 80% maturity mango, the expression of MiERF2 in the control group was significantly higher than that in the treatment group during storage, except for 18 d. It is suspected that this gene would play a negative regulatory role in ethylene regulation of fruit ripening. This study would provide a theoretical basis for revealing the regulatory role of ERF transcription factors in postharvest ripening and senescence of mango.
| 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 |