Mining and identification of members of MYB transcription factor family in Lonicera macranthoides / 中国中药杂志

As a large family of transcription factors, the MYB family plays a vital role in regulating flower development. We studied the MYB family members in Lonicera macranthoides for the first time and identified three sequences of 1R-MYB, 47 sequences of R2R3-MYB, two sequences of 3R-MYB, and one sequence of 4R-MYB from the transcriptome data. Further, their physicochemical properties, conserved domains, phylogenetic relationship, protein structure, functional information, and expression were analyzed. The results show that the 53 MYB transcription factors had different conserved motifs, physicochemical properties, structures, and functions in wild type and 'Xianglei' cultivar of L. macranthoides, indicating their conservation and diversity in evolution. The transcript level of LmMYB was significantly different between the wild type and 'Xianglei' cultivar as well as between flowers and leaves, and some genes were specifically expressed. Forty-three out of 53 LmMYB sequences were expressed in both flowers and leaves, and 9 of the LmMYB members showed significantly different transcript levels between the wild type and 'Xianglei' cultivar, which were up-regulated in the wild type. The results provide a theoretical basis for further studying the specific functional mechanism of the MYB family.

Cloning and function analysis of chalcone isomerase gene and chalcone synthase gene in Lonicera macranthoides / 中国中药杂志

In order to explore the functions of genes of key rate-limiting enzymes chalcone isomerase(CHI) and chalcone synthase(CHS) in the biosynthesis of flavonoids in Lonicera macranthoides, this study screened and cloned the cDNA sequences of CHI and CHS genes from the transcriptome data of conventional variety and 'Xianglei' of L. macranthoides. Online bioinformatics analysis software was used to analyze the characteristics of the encoded proteins, and quantitative reverse-transcription polymerase chain reaction(qRT-PCR) to detect the expression of CHI and CHS in different parts of the varieties at different flowering stages. The content of luteo-loside was determined by high performance liquid chromatography(HPLC) and the correlation with the expression of the two genes was analyzed. The results showed that the CHI and CHS of the two varieties contained a 627 bp and 1170 bp open reading frame(ORF), respectively, and the CHI protein and CHS protein were stable, hydrophilic, and non-secretory. qRT-PCR results demonstrated that CHI and CHS of the two varieties were differentially expressed in stems and leaves at different flowering stages, particularly the key stages. Based on HPLC data, luteoloside content was in negative correlation with the relative expression of the genes. Thus, CHI and CHS might regulate the accumulation of flavonoids in L. macranthoides, and the specific functions should be further studied. This study cloned CHI and CHS in L. macranthoides and analyzed their expression for the first time, which laid a basis for investigating the molecular mechanism of the differences in flavonoids such as luteoloside in L. macranthoides and variety breeding.

Cloning and Expression Patterns of LmC3H1 Gene in Lonicera macranthoides and Its Correlation with Chlorogenic Acid Content / 中国实验方剂学杂志

Objective::To clone p-coumaroyl quinate/shikimate 3' -hydroxylase gene from Lonicera macranthoides, and analyze its bioinformatics and expression patterns with chlorogenic acid content, in order to speculate the functions of LmC3H1 gene from L. macranthoides. Method::The full-length cDNA sequence of LmC3H1 gene was cloned by reverse trascription polymerase chain reaction(RT-PCR) and RACE techniques. The bioinformatics analysis of the gene sequence was carried out by using relevant software.Real-time fluorescence quantification PCR(Real-time PCR) and HPLC were used to determine relative expression of LmC3H1 and content of chlorogenic acid in stems, leaves and flowers of different flowering stages. Result::The LmC3H1 (GenBank: MN177695) gene was cloned, and the open reading frame (ORF) of it was 1 533 bp in length and encoded 510 amino acids. The molecular formula was C2618H4134N718O727S22, the relative molecular mass was 58 005.32, and the isoelectric point was 8.92.It was a hydrophilic protein located in the chloroplast with a transmembrane region LLLIPAVLFLISLVYPLI, and contained a conserved domain CYTOCHROME_P450(433-422 aa) in cytochrome P450.The results of Real-time PCR showed that LmC3H1 was expressed in different degrees in stems, leaves and different flowering stages of L. macranthoides. In the flower development stage, the relative expression of white bud stage was the highest, followed by flower buds and white flowering stage. The ratio of flower to stem and leaf was the highest, and the relative expression of flower was the highest. The HPLC results showed that the content of chlorogenic acid increased from greenish white to golden yellow in flowering stage and golden yellow flowering stage. Among the different organs, the flower had the highest chlorogenic acid, and the stem showed the lowest. Conclusion::The LmC3H1 gene of L. macranthoides is cloned, suggesting that LmC3H1 might be involved in the biosynthesis of L. macranthoides chlorogenic acid. This study provides a basis for further studying the functions of the gene and exploring the biosynthesis and regulation mechanism of L. macranthoides chlorogenic acid, while laying the foundation for the genetic improvement of L. macranthoides.