Differential gene expression reveals mechanisms related to habitat divergence between hybridizing orchids from the Neotropical coastal plains

Autor(es)

Santos Leal, Barbara Simoes ^[1] ; Brandao, Marcelo Mendes ^[2] ; Palma-Silva, Clarisse ^[1] ; Pinheiro, Fabio ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Dept Biol Vegetal, BR-13083862 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Ctr Biol Mol & Engn Genet, BR-13083862 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BMC PLANT BIOLOGY; v. 20, n. 1 DEC 10 2020.
• Citações Web of Science: 0

Resumo

BackgroundClosely related hybridizing species are ideal systems for identifying genomic regions underlying adaptive divergence. Although gene expression plays a central role in determining ecologically-based phenotypic differences, few studies have inferred the role of gene expression for adaptive divergence in Neotropical systems. In this study, we conduct genome-wide expression analysis alongside soil elemental analysis in sympatric and allopatric populations of Epidendrum fulgens and E. puniceoluteum (Orchidaceae), which occur in contrasting adjacent habitats in the Neotropical coastal plains.ResultsThese species were highly differentiated by their gene expression profiles, as determined by 18-21% of transcripts. Gene ontology (GO) terms associated with reproductive processes were enriched according to comparisons between species in both allopatric and sympatric populations. Species showed differential expression in genes linked to salt and waterlogging tolerance according to comparisons between species in sympatry, and biological processes related to environmental stimulus appeared as representative among those transcripts associated with edaphic characteristics in each sympatric zone. Hybrids, in their turn, were well differentiated from E. fulgens, but exhibited a similar gene expression profile to flooding-tolerant E. puniceolutem. When compared with parental species, hybrids showed no transcripts with additive pattern of expression and increased expression for almost all transgressive transcripts.ConclusionsThis study sheds light on general mechanisms promoting ecological differentiation and assortative mating, and suggests candidate genes, such as those encoding catalase and calcium-dependent protein kinase, underling adaptation to harsh edaphic conditions in the Neotropical coastal plains. Moreover, it demonstrates that differential gene expression plays a central role in determining ecologically-based phenotypic differences among co-occurring species and their hybrids. (AU)

• Processo FAPESP: 18/18967-9 - Especiação ecológica em zonas híbridas neotropicais: seleção divergente, expressão diferencial e história demográfica de Epidendrum fulgens e E. puniceoluteum (Orchidaceae)
• Beneficiário: Bárbara Simões Santos Leal
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 16/22785-8 - O papel da seleção por habitats distintos na manutenção da integridade de espécies em zonas de hibridação natural
• Beneficiário: Fábio Pinheiro
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Regular