The sequencing and assembly data of this study have been stored in the National Gene Bank Life Big Data Platform (CNGBdb), and the project number is CNP000 1056? .
Begonia plants are mainly distributed in tropical and subtropical regions, most of which live in humid environment and belong to typical shade plants. In addition, Begonia is one of the most valuable ornamental flowers in gardening, with various leaf types and spots, rich colors and high ornamental value.
The research team completed the whole genome assembly of four kinds of begonia, including Begonia crassipes, Begonia Baise, Begonia grandiflora and Begonia peltata, and completed the shallow genome sequencing of 74 global representative species. The assembly results showed that the genome size of the four species ranged from 33 1 MB to 799 MB, the number of genes ranged from 22,059 to 23,444, and the BUSCO evaluation reached more than 9 1%. High-quality genome assembly provides an important reference for functional genomics research and molecular breeding of begonia.
It was also found that the ancestors of Begonia experienced a unique genome-wide doubling event (WGD) about 35 million years ago, which made an important contribution to the diversity evolution and shade tolerance of Begonia. After the occurrence of WGD, many genes related to photosynthesis and energy metabolism were preserved and enriched, and it was found that the receptor genes related to red light, blue light and ultraviolet light reception (PHOT, CYR 1/2, PHY and UVR8) all kept multiple copies, and some of them had functional differentiation, which was of great significance for Begonia plants to adapt to shading environment and improve photosynthetic utilization rate.
It was found that transposon (TE) occupies a large proportion in the genome of Begonia, and its interspecific specificity is high. There are obvious differences in the types and quantities of active tellurium among different species. The insertion mode and quantity of TE in different positions of functional gene promoter and intron are obviously different among different species, and some genes related to stress response are biased, which reveals that TE is closely related to the formation and adaptability of Begonia species.
In addition, hybridization and gene infiltration have made great contributions to the diversity of begonia, especially in species distributed in America, where ancestors may have had many hybridization events.
The results provide a new insight into the diversity formation and adaptive evolution of Begonia, and an important reference for the study of Begonia in post-genomics.
Dr. Li Lingfei, Dr. Dong Shanshan and Dr. Li Na from the Plant Research Center of Huxian Botanical Garden, Dr. Chen Xiaoli, associate researcher Fang Dongming and Dr. Guo Xing from Huada Institute of Life Sciences are the first authors. In addition, a number of domestic and foreign research institute partners participated in the research, including Edinburgh Royal Botanical Garden, Xishuangbanna Botanical Garden, Nanning Botanical Garden, Shanghai Chen Shan Botanical Garden, Singapore Botanical Garden, Institute of Botany of Chinese Academy of Sciences, Kunming Botanical Garden, Fujian Agriculture and Forestry University, Nanjing Agricultural University, South China Agricultural University, Guangdong Academy of Agricultural Sciences, University of Florida, and Ghent University in Belgium. Liu Huan, a researcher at Huada Institute of Life Sciences, and Zhang Shouzhou, a researcher at Huxian Botanical Garden, are communication authors. The related work has been supported by the national R&D key project and the scientific research project of Shenzhen Urban Management Bureau.
References: https://doi.org/10.11/NPH.17949.