What is the effect of PnbHLH23 gene on the regulation of metabolites synthesis in Panax notoginseng?
Panax notoginseng is a perennial herb of the family Panaxaceae, which has high medicinal value, which is due to the fact that Panax notoginseng flowers not only contain a higher content of saponins, but also contain flavonoids, polysaccharides, amino acids and other beneficial metabolites.
The bHLH gene plays an important role in the synthesis of metabolites in a variety of plants, but it is not known whether it can regulate the synthesis of metabolites during the development of Panax notoginseng.
In order to study the function of bHLH gene in Panax notoginseng flower, the bHLH gene was cloned in this study and named it PnbHLH23, which has a full length of 762 bp and encodes 253 amino acids, but this gene encodes egg
White has only a helix-loop-helix (HLH) region and lacks a DNA-binding domain, which is an atypical bHLH protein.
The results showed that the molecular formula of PnbHLH23 protein was C1259H2033N341O407S6, the molecular weight was about 28.65 kD, the total number of atoms was 4046, and the theoretical isoelectric point was 5.14, indicating that PnbHLH23 protein was an acidic protein.
The number of negatively charged amino acid residues was 41, the number of positively charged amino acid residues was 33, and the instability index was 64.09, indicating that PnbHLH23 protein was unstable protein, the fat coefficient was 92.96, and the average hydrophilicity coefficient was -0.45.
The bioinformatics analysis of PnbHLH23 protein showed that PnbHLH23 protein, like bHLH protein in most plants, was an unstable hydrophilic protein.
PnbHLH23 protein does not contain signal peptides and has no transmembrane region, does not belong to secreted proteins and membrane structural proteins, and is mainly present in the nucleus by subcellular localization.
The secondary structure of PnbHLH23 protein was analyzed, and it was found that the α-helix and random coil accounted for 44.66%, the extended chain accounted for 9.49%, and the β-fold protein accounted for only 1.19%.
NCBICDSearch was used to analyze the conserved domain of the sequence, and it was found that bHLH23 protein had a conserved domain of bHLH, and the starting and ending amino acid sites of the domain were 57~121, which was in line with the typical structure of the bHLH protein family
Features.
Multiple sequence alignment and phylogenetic analysis showed that PnbHLH23 protein and American ginseng bHLH23 protein had the highest homology, with a similarity of 99.6%, and the bHLH23 protein had the highest homology because both Panax notoginseng and American ginseng belonged to the most recent kinship of Panaxaceae ginseng.
At the same time, the bHLH sequence homology of PnbHLH23 protein and other plants was also higher than 65%, which means bHLH
The amino acid sequence of the protein is conserved in different plants.
The results of this study showed that the PnbHLH23 gene of Panax notoginseng was the most closely related to the PqbHLH23 gene of American ginseng, so it was speculated that the PnbHLH23 gene may be involved in the regulation of terpenoid synthesis in Panax notoginseng flowers.
The expression of bHLH gene was expressed in the rhizomes, leaves, flowers of different plants, and the expression levels were different at different developmental stages of the same plant, indicating that the gene played different functions in different tissues and organs and at different developmental stages of the same tissues and organs.
This is similar to the results of this study, that is, the relative expression levels of PnbHLH23 gene in different developmental stages of Panax notoginseng were different, and the initial blooming stage was significantly lower than that in the half-blooming stage and the full-blooming stage, while the full-blooming stage was the highest compared with other periods.
This may be due to the fact that different plants have different flowering periods, and different metabolites unique to the flowers of different plants.
Conclusion:
In conclusion, this study speculated that PnbHLH23 played an important role in the flowering of Panax notoginseng and may have an important effect on the synthesis of secondary metabolites during the full flowering period.
