Orchid Center jointly decodes Melan genes to reveal the Molecular Regulation Mechanism of National Orchid Art

Carry forward the national orchid culture and spread the knowledge of orchids

At the 28th China (Wengyuan) Orchid Expo, Professor Liu Zhongjian, director of Orchid Center, released the major scientific research achievements of the project "the Evolution of Cymbidium Genome and National Orchid Morphology", which is the first in the world to successfully draw the physical map of the orchid genome.

Orchidaceae plants (commonly known as orchids) account for 10% of the world's plant species, with high scientific research, ecological, ornamental, cultural and medicinal value, is one of the most precious wild plant resources in China. Cymbidium sinense, also known as "annulus orchid", is known as one of the top ten traditional flowers in China, is the most ornamental value of the species, but also one of the most Guangdong characteristics of flower species, its cultivation of horticultural varieties are numerous, this kind of phenomenon is very rare in the flower industry. In terms of the diversity of leaf color patterns and the complexity of changes, its leaf art can be called the top of all foliage plants.

In order to seize the opportunity of scientific research, obtain a large amount of genetic resources and genetic information, build a high-throughput molecular biology and bioinformatics research platform, and build a large-scale information analysis system and database adapted to the biological data era, in January 2017, Guangdong Academy of Agricultural Sciences, Orchid Center and South China normal University jointly formed a key research team. Launched the Guangdong Natural Science Foundation research team project "study on the Molecular Regulation Mechanism of differentiation and Development of Cymbidium", and carried out the study of "Magnolia genome". This major research project is the first in the world to carry out genome-wide sequencing and bioinformatics analysis of Cymbidium, as well as sequencing and analysis of related transcriptome.

After joint efforts and in-depth research, the scientific research team successfully drew a physical map of the genome of Cymbidium (Hi-C), chromosome level assembly, Scaffold N501159MreContig N50200K. The analysis results show that the chromosome number of Cymbidium is 2N=2X=40, the genome size is 4.25G, the heterozygosity is about 1.5%, and the repeat sequence is 80%, which belongs to the high heterozygous complex genome. The predicted number of protein coding genes is 29895.

Through the analysis of the genomic data of Cymbidium, combined with the cutting-edge molecular biology methods such as RNA sequencing technology, proteome sequencing technology, miRNA detection, gene function verification, protein interaction analysis and so on, the researchers found out the key events in the evolution of the orchid, so as to analyze the evolution process of the orchid morphology and decode the mystery of the changeable morphology of the orchid. The research team made full use of the resource advantages of Guangdong characteristic Cymbidium to study the functional genes of important characters of orchids based on whole genome sequencing. all the elements of "national orchid art" (including line art, leaf art, flower color, flower fragrance, flower pattern, etc.) were decoded from genome to morphology, and the molecular regulation network model of important characters was established. the molecular regulation mechanism of ornamental traits of Chinese orchid was revealed. It provides practical theoretical guidance for horticultural character improvement, molecular breeding and gene editing of national orchid.