Institute of Botany, Chinese Academy of Sciences, Xiangshan, Haidian, Beijing, 100093, China.
Novogene Bioinformatics Institute, Beijing, 100083, China.
BMC Plant Biol. 2022 Apr 7;22(1):179. doi: 10.1186/s12870-022-03573-1.
To illustrate the molecular mechanism of mycoheterotrophic interactions between orchids and fungi, we assembled chromosome-level reference genome of Gastrodia menghaiensis (Orchidaceae) and analyzed the genomes of two species of Gastrodia.
Our analyses indicated that the genomes of Gastrodia are globally diminished in comparison to autotrophic orchids, even compared to Cuscuta (a plant parasite). Genes involved in arbuscular mycorrhizae colonization were found in genomes of Gastrodia, and many of the genes involved biological interaction between Gatrodia and symbiotic microbionts are more numerous than in photosynthetic orchids. The highly expressed genes for fatty acid and ammonium root transporters suggest that fungi receive material from orchids, although most raw materials flow from the fungi. Many nuclear genes (e.g. biosynthesis of aromatic amino acid L-tryptophan) supporting plastid functions are expanded compared to photosynthetic orchids, an indication of the importance of plastids even in totally mycoheterotrophic species.
Gastrodia menghaiensis has the smallest proteome thus far among angiosperms. Many of the genes involved biological interaction between Gatrodia and symbiotic microbionts are more numerous than in photosynthetic orchids.
为了阐明兰科植物天麻与其共生真菌之间的菌根互惠共生的分子机制，我们组装了天麻的染色体水平参考基因组，并对两种天麻的基因组进行了分析。
与自养兰花相比，甚至与菟丝子（一种寄生植物）相比，天麻的基因组在全球范围内都明显减少。我们在天麻基因组中发现了与菌根定植相关的基因，并且涉及天麻与共生微生物之间生物相互作用的许多基因比光合兰花中的更多。脂肪酸和铵根转运蛋白的高表达基因表明真菌从兰花中获取物质，尽管大多数原料是从真菌流向兰花。与光合兰花相比，支持质体功能的许多核基因（例如芳香族氨基酸 L-色氨酸的生物合成）都有所扩展，这表明即使在完全菌根异养的物种中，质体也很重要。
天麻拥有迄今为止在被子植物中最小的蛋白质组。与光合兰花相比，涉及天麻与共生微生物之间生物相互作用的许多基因比光合兰花中的更多。
