On the evening of April 21, 2022, Beijing time, Nature Plants published the latest research findings of a team of orchid researchers led by Professor Lan Siren and Professor Liu Zhongjian from Fujian Agriculture and Forestry University. The study, titled "Genomes of leafy and leafless Platanthera orchids illuminate the evolution of mycoheterotrophy," sheds new light on the molecular mechanisms underlying the development of mycoheterotrophy in orchids. By comparing and analyzing the genomes of species representing three evolutionary life forms of mycoheterotrophic orchids (initial, partial, and fully mycoheterotrophic), the research revealed insights into how these orchids form their morphology and acquire nutrients.

Gastrodia elata and Corallorhiza striata, two orchids from the subfamily Orchidoideae, have the largest genomes among all sequenced orchids to date. These are also the first orchids from this subfamily to have their genomes sequenced, filling a significant gap in the study of orchid evolution and holding great scientific significance. As Professor Lan Siren, one of the authors of the paper, stated: "We have always been curious about why all orchid seeds are dust-like and lack endosperm, and how fully mycoheterotrophic orchids, like Gastrodia elata (a leafless and rootless orchid), develop their morphology and acquire the necessary nutrients. The mechanisms behind these complex traits have remained unclear and have been referred to as the 'ghost orchid' mystery. Our research found that fully mycoheterotrophic orchids hijack fungal nutrients by expressing trehalase genes and activating phosphorus and nitrogen response mechanisms, thus unraveling the evolutionary mystery of the 'ghost orchid.'"

DOI：https://doi.org/10.1038/s41477-022-01127-9