Evolutionary and functional potential of ploidy increase within individual plants: somatic ploidy mapping of the complex labellum of sexually deceptive bee orchids

Abstract

Comparison of the two genera failed to demonstrate the hypothesized pattern of frequent polyploid speciation in genera showing extensive endoreplication. Endoreplication in Ophrys appears more strongly positively correlated with cell size/complexity than with cell location or secretory role. Epigenetic control of gene overexpression by localized induction of endoreplication within individual plant organs may represent a significant component of a plant's developmental programme, contributing substantially to organ plasticity.

Anatomy, Flow Cytometry, and X-Ray Tomography Reveal Tissue Organization and Ploidy Distribution in Long-Term In Vitro Cultures of Melocactus Species

“…Similar to M. glaucescens , long-term cultures of Mammillaria san-angelis did not show any change in ploidy with age of the culture and a maximum ploidy of ~32C was observed ( Palomino et al, 1999 ). Consistency of the endopolyploidy pattern in cacti tissues regardless of the age of culture, further confirms that endoreduplication cycles in plants are genetically regulated to drive cell differentiation and offer a fine-tooled response during plant development ( Cebolla et al, 1999 ; Nagymihály et al, 2017 ; Bateman et al, 2018 ; Bhosale et al, 2019 ). The endoreduplication program can differ among species of the same genus ( Palomino et al, 2016 ).…”

“…Variations in ploidy between species are related to loss or addition of repeats in the genome, which may reflect micro- and macroscopic alterations during genome evolution ( Das et al, 1998b ). As a consequence, studies on ploidy have focused mostly on the systematics and evolution of this phenomenon ( Bateman et al, 2018 ).…”

“…Only recently has the potential consequences of duplication events affecting specific cells or tissues been recognized, based on the use of homogenized tissues employed in flow cytometry analyses ( Bateman et al, 2018 ). In this study, flow cytometry allowed the temporal, topological and cytological characterization of M. glaucescens and M. paucispinus stems and revealed mixed ploidy (mixoploidy) corresponding to 2C, 4C, 8C, 16C, and ~32C DNA content.…”

“…The onset of endoreduplication is a cytogenetic imprint of the transition from the embryogenic to the storage product accumulation phases during seed filling and within embryo development in species with small and large genome sizes ( Ochatt and Abirached-Darmency, 2020 ). Smaller genomes favor also several rounds of endocycles (endoreduplication), which produce cells with higher DNA content and a different specialization ( Bateman et al, 2018 ). In addition, endocycles occur predominantly in cells with large volumes ( Breuer et al, 2014 ).…”

Integrating restriction site-associated DNA sequencing (RAD-seq) with morphological cladistic analysis clarifies evolutionary relationships among major species groups of bee orchids

“…The single-digest RAD-seq laboratory protocol was adapted from that detailed by Paun et al (2016) , with the following modifications. Given that the mean genome size of Ophrys approximates 1C = 10 pg ( Leitch et al , 2009 ; Bateman et al , 2018 ), the RAD-seq library was prepared using the restriction enzyme Sbf I (New England Biolabs, Germany). For each individual we used 210 ng of starting plant material, shearing the restricted and P1-ligated DNA with a Bioruptor Pico (Diagenode) for two cycles of 30 s ‘on’, 60 s ‘off ‘.…”