Progress in the research on the innovative evolutionary history of Bolete species from brown rot to symbiosis

In forest soil, wood-decomposing fungi, litter-decomposing fungi and ectomycorrhizal fungi form an intricate hypha network
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As a decomposer of organic matter, saprophytic fungi play an irreplaceable role in the material circulation and energy flow of forest ecosystems
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As a symbiotic partner of plants, ectomycorrhizal fungi can transfer carbohydrates synthesized by plant photosynthesis to the soil microbial community for use by microorganisms
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Studying the similarities and differences between saprophytic fungi and symbiotic fungi in terms of carbon source, nitrogen source acquisition and organic matter degradation will help to understand the ecological processes and functions of different nutrient types of fungi in the ecosystem
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The Bolete is one of the most abundant species in the Agaricomycetes, including 5 suborders, 16 families, and about 1,000 species.
It is widespread all over the world and often appears in the later stages of forest succession
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The vast majority of this order are symbiotic ectomycorrhizal fungi with diverse host plants, but the base group is saprophytic brown rot fungi, which is an ideal object for studying the evolution of fungal nutrient types
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On the basis of sequencing the genomes of representative species of this order, through comparative genomics analysis, the study found that in the evolution process of Bolete species from brown rot habit to ectomycorrhizal symbiosis habit, three innovations occurred at the genome level : (1) The key genes of plant cell wall degrading enzymes are significantly lost, but they still retain a certain ability to degrade, although the branches of symbiotic habits are different; (2) the expansion of transposable elements has occurred, Promote the formation of genes encoding proteases, lipases, and small secretory proteins; (3) In the late Miocene, the symbiotic Bolete and Suillus suborders have undergone significant gene expansion, which may be related to host plants or Boletus edulis habitat preference is related
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 The research was completed by Yang Zhuliang's research team from the Kunming Institute of Botany, Chinese Academy of Sciences and Francis Martin's team from the Nancy Center of the French National Agri-Food and Environmental Research Institute.
The relevant research results are titled Evolutionary innovations through gain and loss of genes in the ectomycorrhizal Boletales, online Published on New Phytologist
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The research work is supported by the Chinese Academy of Sciences Strategic Leading Science and Technology Special Project (Class B), the key foreign cooperation projects of the International Cooperation Bureau of the Chinese Academy of Sciences, the General Project of the National Natural Science Foundation of China, the Project of the Youth Innovation Promotion Association of the Chinese Academy of Sciences, and the Management Committee of the China Scholarship Council
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 Figure 1.
Genome assembly and annotation results of representative species of Bolete.
Figure 2.
Characteristics of secreted proteome of representative species of Bolete.
Figure 3.
Multivariate analysis of the substitution of related genes among different nutritional types of fungi of Bolete.
Figure 4 .
Difference analysis of transposable elements based on Kimura distance (red: ectomycorrhizal fungi, blue: brown rot fungi) Figure 5.
Collinearity analysis of Boletus species (a, b) and transposable elements and secreted proteins Analysis of the average distance of genes in the genome (c) Figure 6.
Reconstruction of gene replication history of Bolete species (a) and changes in gene replication rate during evolution (b) Source: Kunming Institute of Botany, Chinese Academy of Sciences