| Title: | Unidirectional transitions in nectar gain and loss suggest food deception is a stable evolutionary strategy in Epidendrum (Orchidaceae): insights from anatomical and molecular evidence |
| Author(s): | Cardoso-Gustavson P; Saka MN; Pessoa EM; Palma-Silva C; Pinheiro F; |
| Address: | "Instituto de Botanica, Nucleo de Pesquisa do Orquidario do Estado, Sao Paulo, SP, 04301-902, Brazil. Departamento de Botanica, Instituto de Biociencias, Universidade Estadual Paulista, Rio Claro, SP, 13506-900, Brazil. Centro de Ciencias Biologicas, Departamento de Botanica, Universidade Federal de Pernambuco, Recife, PE, 50670-420, Brazil. Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, 13083-862, Brazil. Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, 13083-862, Brazil. biopinheiro@yahoo.com.br" |
| DOI: | 10.1186/s12870-018-1398-y |
| ISSN/ISBN: | 1471-2229 (Electronic) 1471-2229 (Linking) |
| Abstract: | "BACKGROUND: Nectar gain and loss are important flower transitions observed in angiosperms, and are particularly common in orchids. To understand such transitions, the availability of detailed anatomical data and species-level phylogenies are crucial. We investigated the evolution of food deception in Epidendrum, one of the largest orchid genera, using genus phylogeny to map transitions between nectar gain and loss among different clades. Associations between anatomical and histochemical changes and nectar gain and loss were examined using fresh material available from 27 species. The evolution of nectar presence/absence in Epidendrum species was investigated in a phylogenetic framework of 47 species, using one nuclear and five plastid DNA regions available from GenBank and sequenced in this study. RESULTS: The presence or absence of nectar was strongly associated with changes in the inner epidermal tissues of nectaries. Nectar-secreting species have unornamented epidermal tissue, in contrast to the unicellular trichomes found on the epidermis of food deceptive species. Bayesian tests confirmed that transitions occurred preferentially from nectar presence to nectar absence across the Epidendrum phylogeny. In addition, independent nectar loss events were found across the phylogeny, suggesting a lack of constraint for these transitions. CONCLUSIONS: Ornamented nectaries may play an important role in the deceptive pollination strategy by secreting volatile organic compounds and providing tactile stimuli to pollinators. The recurrent and apparently irreversible pattern of nectar loss in Epidendrum suggests that food deception may constitute an alternative evolutionarily stable strategy, as observed in other orchid groups" |
| Keywords: | "*Biological Evolution DNA, Chloroplast/genetics DNA, Plant/genetics Food Chain Orchidaceae/*anatomy & histology/genetics/*physiology Phylogeny Plant Nectar/*analysis *Pollination Character reconstruction Cuniculus Evolution Nectar Nectary anatomy Orchidac;" |
| Notes: | "MedlineCardoso-Gustavson, Poliana Saka, Mariana Naomi Pessoa, Edlley Max Palma-Silva, Clarisse Pinheiro, Fabio eng 440367/2014-0/Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/ 0588/12-1/Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/ 300927/2016-9/Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/ 300819/2016-1/Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/ 300927/2016-9/Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior/ 0469-13-0/Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior/ England 2018/09/06 BMC Plant Biol. 2018 Sep 4; 18(1):179. doi: 10.1186/s12870-018-1398-y" |
