| Title: | Labellar Structure of the Maxillaria splendens Alliance (Orchidaceae: Maxillariinae) Indicates Floral Polyphenols as a Reward for Stingless Bees |
| Author(s): | Davies KL; Pansarin ER; Stpiczynska M; |
| Address: | "School of Earth and Environmental Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK. Department of Biology, FFCLRP, University of Sao Paulo, Av. Bandeirantes 3900, Ribeirao Preto 14040-901, Sao Paulo, Brazil. Faculty of Biology, University of Warsaw, Botanic Garden, Al. Ujazdowskie 4, 00-478 Warszawa, Poland" |
| ISSN/ISBN: | 2223-7747 (Print) 2223-7747 (Electronic) 2223-7747 (Linking) |
| Abstract: | "Several studies have reported stingless Meliponini bees gathering hairs from the labella of Maxillaria spp., including M. ochroleuca, a member of the M. splendens alliance. Such hairs usually contain food materials and are thought to have nutritional value. The papillose labella of representatives of the Maxillaria splendens alliance, however, bear scattered, simple 1-5-celled uniseriate trichomes (hairs) that lack food materials. By contrast, here, as well as polyphenolic compounds, typical labellar papillae usually contain small quantities of starch, protein, and minute droplets of lipid, the last probably involved in the production of fragrance. Towards the labellum apex occur elevated groups of papillae that lack food materials, but contain volatile compounds, probably fragrance precursors. In the past, the terms 'trichomes' or 'hairs' and 'papillae' have been used interchangeably, causing some confusion. Since the trichomes, however, unlike the papillae, are easily detachable and can fragment, it is most likely they, not the papillae, that have previously been observed being collected by bees, but their poor food content indicates that they do not function as food-hairs. Even so, our field observations of M. ochroleuca reveal that stingless bees scrape polyphenol-rich labellar tissue and possibly use this material to produce a resinous, complex, heterogeneous substance commonly referred to as 'bee glue', used for nest construction and repair" |
| Keywords: | Maxillaria Meliponini bees Sem fluorescence microscopy food-hair food-reward histochemistry labellum light microscopy lipid papillae pollination polyphenols protein pseudopollen resin starch trichomes; |
| Notes: | "PubMed-not-MEDLINEDavies, Kevin L Pansarin, Emerson R Stpiczynska, Malgorzata eng grant to MS/Botanic Garden, University of Warsaw/ Switzerland 2023/02/26 Plants (Basel). 2023 Feb 17; 12(4):921. doi: 10.3390/plants12040921" |
