Publication Date:
2024-02-09
Description:
Fruits play a crucial role in seed dispersal. They open along dehiscence zones. Fruit dehiscence zone formation has been intensively studied in Arabidopsis thaliana. However, little is
\nknown about the mechanisms and genes involved in the formation of fruit dehiscence zones
\nin species outside the Brassicaceae. The dehiscence zone of A. thaliana contains a lignified
\nlayer, while dehiscence zone tissues of the emerging orchid model Erycina pusilla include a
\nlipid layer. Here we present an analysis of evolution and development of fruit dehiscence
\nzones in orchids. We performed ancestral state reconstructions across the five orchid subfamilies to study the evolution of selected fruit traits and explored dehiscence zone developmental genes using RNA-seq and qPCR. We found that erect dehiscent fruits with nonlignified dehiscence zones and a short ripening period are ancestral characters in orchids.
\nLignified dehiscence zones in orchid fruits evolved multiple times from non-lignified zones.
\nFurthermore, we carried out gene expression analysis of tissues from different developmental stages of E. pusilla fruits. We found that fruit dehiscence genes from the MADS-box gene
\nfamily and other important regulators in E. pusilla differed in their expression pattern from
\ntheir homologs in A. thaliana. This suggests that the current A. thaliana fruit dehiscence
\nmodel requires adjustment for orchids. Additionally, we discovered that homologs of A. thaliana genes involved in the development of carpel, gynoecium and ovules, and genes
\ninvolved in lipid biosynthesis were expressed in the fruit valves of E. pusilla, implying that
\nthese genes may play a novel role in formation of dehiscence zone tissues in orchids. Future
\nfunctional analysis of developmental regulators, lipid identification and quantification can
\nshed more light on lipid-layer based dehiscence of orchid fruits.
Repository Name:
National Museum of Natural History, Netherlands
Type:
info:eu-repo/semantics/article
Format:
application/pdf
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