Key Laboratory of Orchid Conservation and Utilization of National Forestry and Grassland Administration at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China; State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China; Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Shanghai 201602, China.
Key Laboratory of Orchid Conservation and Utilization of National Forestry and Grassland Administration at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, School of Future Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Shenzhen Key Laboratory for Orchid Conservation and Utilization and The National Orchid Conservation Center of China, The Orchid Conservation and Research Center of Shenzhen, Shenzhen 518114, China.
School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
Key Laboratory of Orchid Conservation and Utilization of National Forestry and Grassland Administration at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Key Laboratory of Orchid Conservation and Utilization of National Forestry and Grassland Administration at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: lkzx@fafu.edu.cn.
State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China. Electronic address: luoyb@ibcas.ac.cn.
Key Laboratory of Orchid Conservation and Utilization of National Forestry and Grassland Administration at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: zjliu@fafu.edu.cn.
Genes that introgress between species can influence the evolutionary and ecological fate of recipients exposed to novel environments. However, key questions on the patterns and molecular mechanisms of introgression in perennial herbaceous plants, which enable distantly related invasive species to thrive in extreme habitats, remain largely unanswered. Here, we report unidirectional introgression from the local species Dendrobium huoshanense to the distantly related invasive species Dendrobium catenatum (Dendrobium officinale) in lithophytic habitats of eastern China. The introgressed regions, which comprise approximately 1% of the genome, contain genes that regulate responses to drought, cold, and metal-ion stresses. Notably, introgressed loci such as CDPK, HHP, PIF, BRI1, and FY show distinct selection signatures and differential expression compared with their paralogs, each playing a distinct role in drought and cold-stress responses. In addition, CIPK23, PDR9, and HAM demonstrate differential expression relative to their paralogous genes and alleles within introgressed loci, indicating their potential involvement in responses to metal-ion stress. Introgression thus facilitates the colonization of arid, metal-enriched sedimentary habitats by D. catenatum. These findings enhance our understanding of Orchidaceae evolution and reveal the evolutionary role of unidirectional introgression in the adaptation of perennial herbaceous plants to extreme environments.
Keywords: Dendrobium; distantly related species; introgression; invasive species; metal-ion stress
