What are the genomic consequences for plastids in a mixotrophic orchid (Epipactis helleborine)?

Botany ◽  
2020 ◽  
Author(s):  
Janice Valencia-D. ◽  
William Mark Whitten ◽  
Kurt M Neubig
Keyword(s):  
Plastid Genome ◽  
Selective Pressure ◽  
Stable Condition ◽  
Controlled Processes ◽  
Albino Plant ◽  
Photosynthetic Genes ◽  
Mycoheterotrophic Plants ◽  
Epipactis Helleborine ◽  
And Function ◽  
Green Coloration

The chloroplast (plastid) controls carbon uptake, so its DNA sequence and function are highly conserved throughout the land plants. But for those that have alternative carbon supplies, the plastid genome is susceptible to suffer mutations in the photosynthetic genes and overall size reduction. Fully mycoheterotrophic plants receive organic carbon from their fungi partner, do not photosynthesize and also do not exhibit green coloration (or produce substantial quantities of chlorophyll). Epipactis helleborine (L.) Crantz exhibits all trophic modes from autotrophy to full mycoheterotrophy. Albinism is a stable condition in individuals of this species and does not prevent them from producing flowers and fruits. Here we assemble and compare the plastid genome of green and albino individuals. Our results show that there is still strong selective pressure in the plastid genome. Therefore, the few punctual differences among them, to our knowledge, do not affect any normal photosynthetic capability in the albino plant. These findings suggest that mutations or other genetically controlled processes in other genomes, or environmental conditions, are responsible for the phenotype.

scholarly journals Mycorrhizal Communities and Isotope Signatures in Two Partially Mycoheterotrophic Orchids

2021 ◽  
Vol 12 ◽  
Author(s):  
Hans Jacquemyn ◽  
Rein Brys ◽  
Michael Waud ◽  
Alexandra Evans ◽  
Tomáš Figura ◽  
...  
Keyword(s):  
Isotopic Signatures ◽  
Carbon And Nitrogen ◽  
Wide Range ◽  
Terrestrial Orchids ◽  
Significant Enrichment ◽  
Mycoheterotrophic Plants ◽  
C And N ◽  
Species Specific ◽  
Epipactis Helleborine ◽  
Isotope Analyses

Partial mycoheterotrophy, the ability of plants to obtain carbon from fungi throughout their life cycle in combination with photosynthesis, appears to be more common within the Plant Kingdom than previously anticipated. Recent studies using stable isotope analyses have indicated that isotope signatures in partially mycoheterotrophic plants vary widely among species, but the relative contributions of family- or species-specific characteristics and the identity of the fungal symbionts to the observed differences remain unclear. Here, we investigated in detail mycorrhizal communities and isotopic signatures in four co-occurring terrestrial orchids (Platanthera chlorantha, Epipactis helleborine, E. neglecta and the mycoheterotrophic Neottia nidus-avis). All investigated species were mycorrhizal generalists (i.e., associated with a large number of fungi simultaneously), but mycorrhizal communities differed significantly between species. Mycorrhizal communities associating with the two Epipactis species consisted of a wide range of fungi belonging to different families, whereas P. chlorantha and N. nidus-avis associated mainly with Ceratobasidiaceae and Sebacinaceae species, respectively. Isotopic signatures differed significantly between both Epipactis species, with E. helleborine showing near autotrophic behavior and E. neglecta showing significant enrichment in both carbon and nitrogen. No significant differences in photosynthesis and stomatal conductance were observed between the two partially mycoheterotrophic orchids, despite significant differences in isotopic signatures. Our results demonstrate that partially mycoheterotrophic orchids of the genus Epipactis formed mycorrhizas with a wide diversity of fungi from different fungal families, but variation in mycorrhizal community composition was not related to isotope signatures and thus transfer of C and N to the plant. We conclude that the observed differences in isotope signatures between E. helleborine and E. neglecta cannot solely be explained by differences in mycorrhizal communities, but most likely reflect a combination of inherent physiological differences and differences in mycorrhizal communities.

Multiple and different genomic rearrangements of the rbcL gene are present in the parasitic orchid Neottia nidus-avis

Genome ◽  
2012 ◽  
Vol 55 (09) ◽  
pp. 629-637 ◽  
Author(s):  
Donata Cafasso ◽  
Gianni Chinali
Keyword(s):  
Plastid Genome ◽  
Photosynthetic Capacity ◽  
Parasitic Plants ◽  
Flowering Plants ◽  
Genomic Rearrangements ◽  
Rbcl Gene ◽  
Individual Plant ◽  
Fixed Carbon ◽  
Photosynthetic Genes ◽  
Rbcl Sequences

In parasitic plants that have lost most, if not all, of their photosynthetic genes, the genome of their plastids has also undergone a dramatic reduction. For example, photosynthetic genes, such as rbcL, frequently become pseudogenes, in which large portions of the gene have been found to be deleted. Orchids are flowering plants with several parasitic lineages. This is consistent with the observation that parasitic orchids can invade pre-existing mutualistic associations between ectomycorrhizal trees and fungi to obtain fixed carbon and nutrients. In addition, some parasitic species are devoid of chlorophyll, and consequently, have lost their photosynthetic capacity. Here, the organization of the plastid genome of the parasitic orchid Neottia nidus-avis (L.) Rich. was investigated using sequencing and hybridization experiments. In particular, genomic rearrangements in the rbcL region of this parasitic orchid were analyzed. At least three distinct rbcL sequences were found to be present as pseudogenes and were likely located in the plastid genome. Based on these results, it is hypothesized that N. nidus-avis contains different plastomes, each with a different pseudogene, and these can exist within the same individual plant.

scholarly journals Kajian Tipologi Bangunan pada Pusat Rehabilitasi Mental Disorder

2020 ◽  
Vol 3 (2) ◽  
pp. 53-67
Author(s):  
Karlina Rahadatul Aisy ◽  
Anisa Anisa
Keyword(s):  
Mental Disorder ◽  
Stable Condition ◽  
Physical Aspect ◽  
Rehabilitation Center ◽  
Unstable Condition ◽  
The Public ◽  
Form And Function ◽  
Rehabilitation Centers ◽  
Building Typology ◽  
And Function

This study is aimed to describe typologies in building mental rehabilitation rehabilitation centers. Building typology is obtained through analysis based on form and function. Typological analysis is useful as input in the design of buildings, and rehabilitation center. The research method used is descriptive interpretative qualitative, to get the typology after identifying the activities, functions, and shapes of buildings. As a first step of the patient's activity and space are identified first. The conclusions obtained from the typology study of mental disorder rehabilitation center are the physical arrangement of the rehabilitation center mass: (1) multi-mass and scattered; (2) the zone is divided into several, namely the public in the outermost, semi-public for patient activities, and private for therapy and patient rest. From the physical aspect, it refers to the forms of simple facades, openings that are given a trellis or passive, as well as simple rooms and furniture that do not endangering the patient. In the unstable condition of the patient, an isolation room is controlled by the nurse. In a stable condition, patients can learn a variety of plans which are carried out inside or outside the room.

Diversity and function of the microbial community under strong selective pressure of rotifers

2019 ◽  
Vol 59 (8) ◽  
pp. 775-783 ◽  
Author(s):  
Edyta Fiałkowska ◽  
Beata Klimek ◽  
Ariel Marchlewicz ◽  
Wioleta Kocerba-Soroka ◽  
Joanna Starzycka ◽  
...  
Keyword(s):  
Microbial Community ◽  
Selective Pressure ◽  
Strong Selective Pressure ◽  
And Function

scholarly journals Accurate prediction of orthologs in the presence of divergence after duplication

2018 ◽  
Author(s):  
Manuel Lafond ◽  
Mona Meghdari Miardan ◽  
David Sankoff
Keyword(s):  
Theoretical Basis ◽  
Selective Pressure ◽  
Source Code ◽  
Phylogenetic Reconstruction ◽  
Mutation Rates ◽  
Prediction Methods ◽  
Orthologous Genes ◽  
Evolutionary Path ◽  
And Function ◽  
Modular Framework

AbstractMotivationWhen gene duplication occurs, one of the copies may become free of selective pressure and evolve at an accelerated pace. This has important consequences on the prediction of orthology relationships, since two orthologous genes separated by divergence after duplication may differ in both sequence and function. In this work, we make the distinction between the primary orthologs, which have not been affected by accelerated mutation rates on their evolutionary path, and the secondary orthologs, which have. Similarity-based prediction methods will tend to miss secondary orthologs, whereas phylogeny-based methods cannot separate primary and secondary orthologs. However, both types of orthology have applications in important areas such as gene function prediction and phylogenetic reconstruction, motivating the need for methods that can distinguish the two types.ResultsWe formalize the notion of divergence after duplication, and provide a theoretical basis for the inference of primary and secondary orthologs. We then put these ideas to practice with the HyPPO (Hybrid Prediction of Paralogs and Orthologs) framework, which combines ideas from both similarity and phylogeny approaches. We apply our method to simulated and empirical datasets, and show that we achieve superior accuracy in predicting primary orthologs, secondary orthologs and paralogs.AvailabilityHyPPO is a modular framework with a core developed in Python, and is provided with a variety of C++ modules. The source code is available at https://github.com/manuellafond/[email protected], [email protected], [email protected]

scholarly journals Social drive and the evolution of primate hearing

2012 ◽  
Vol 367 (1597) ◽  
pp. 1860-1868 ◽  
Author(s):  
Marissa A. Ramsier ◽  
Andrew J. Cunningham ◽  
James J. Finneran ◽  
Nathaniel J. Dominy
Keyword(s):  
High Frequency ◽  
Social Complexity ◽  
Selective Pressure ◽  
General Rule ◽  
Auditory Brainstem ◽  
Published Data ◽  
Vocal Signals ◽  
Brainstem Response ◽  
Response Method ◽  
And Function

The structure and function of primate communication have attracted much attention, and vocal signals, in particular, have been studied in detail. As a general rule, larger social groups emit more types of vocal signals, including those conveying the presence of specific types of predators. The adaptive advantages of receiving and responding to alarm calls are expected to exert a selective pressure on the auditory system. Yet, the comparative biology of primate hearing is limited to select species, and little attention has been paid to the effects of social and vocal complexity on hearing. Here, we use the auditory brainstem response method to generate the largest number of standardized audiograms available for any primate radiation. We compared the auditory sensitivities of 11 strepsirrhine species with and without independent contrasts and show that social complexity explains a significant amount of variation in two audiometric parameters—overall sensitivity and high-frequency limit. We verified the generality of this latter result by augmenting our analysis with published data from nine species spanning the primate order. To account for these findings, we develop and test a model of social drive. We hypothesize that social complexity has favoured enhanced hearing sensitivities, especially at higher frequencies.

scholarly journals Morphofunctional Traits and Pollination Mechanisms ofCoronilla emerusL. Flowers (Fabaceae)

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Giovanna Aronne ◽  
Manuela Giovanetti ◽  
Veronica De Micco
Keyword(s):  
Selective Pressure ◽  
Pollen Viability ◽  
Pollination Efficiency ◽  
Pollen Transfer ◽  
Stigma Receptivity ◽  
Pollination Mechanisms ◽  
Hand Pollination ◽  
And Function ◽  
Different Parts ◽  
Floral Larceny

It is accepted that the papilionaceous corolla of the Fabaceae evolved under the selective pressure of bee pollinators. Morphology and function of different parts ofCoronilla emerusL. flowers were related to their role in the pollination mechanism. The corolla has a vexillum with red nectar lines, a keel hiding stamens and pistil, and two wing petals fasten to the keel with two notched folds. Pollinators land on the complex of keel and wings, trigger the protrusion of pollen and finally of the stigma from the keel tip. Data on pollen viability and stigma receptivity prove that flowers are proterandrous. The results of hand-pollination experiments confirmed that insects are fundamental to set seed. Interaction with pollinators allows not only the transport of pollen but also the rupture of the stigmatic cuticle, necessary to achieve both allogamy and autogamy. Field observations showed that Hymenoptera, Lepidoptera, and Diptera visited the flowers. Only some of the Hymenoptera landed on the flowers from the front and elicited pollination mechanisms. Most of the insects sucked the nectar from the back without any pollen transfer. Finally, morphological and functional characteristics ofC. emerusflowers are discussed in terms of floral larceny and reduction in pollination efficiency.

scholarly journals The First Plastid Genome of the Holoparasitic Genus Prosopanche (Hydnoraceae)

Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 306 ◽  
Author(s):  
Matthias Jost ◽  
Julia Naumann ◽  
Nicolás Rocamundi ◽  
Andrea A. Cocucci ◽  
Stefan Wanke
Keyword(s):  
Plastid Genome ◽  
Essential Gene ◽  
Genome Structure ◽  
Gene Content ◽  
Recent Common Ancestor ◽  
Ribosomal Protein Genes ◽  
Most Recent Common Ancestor ◽  
Gene Sets ◽  
Evolutionary Trajectories ◽  
Mycoheterotrophic Plants

Plastomes of parasitic and mycoheterotrophic plants show different degrees of reduction depending on the plants’ level of heterotrophy and host dependence in comparison to photoautotrophic sister species, and the amount of time since heterotrophic dependence was established. In all but the most recent heterotrophic lineages, this reduction involves substantial decrease in genome size and gene content and sometimes alterations of genome structure. Here, we present the first plastid genome of the holoparasitic genus Prosopanche, which shows clear signs of functionality. The plastome of Prosopanche americana has a length of 28,191 bp and contains only 24 unique genes, i.e., 14 ribosomal protein genes, four ribosomal RNA genes, five genes coding for tRNAs and three genes with other or unknown function (accD, ycf1, ycf2). The inverted repeat has been lost. Despite the split of Prosopanche and Hydnora about 54 MYA ago, the level of genome reduction is strikingly congruent between the two holoparasites although highly dissimilar nucleotide sequences are observed. Our results lead to two possible evolutionary scenarios that will be tested in the future with a larger sampling: 1) a Hydnoraceae plastome, similar to those of Hydnora and Prosopanche today, existed already in the most recent common ancestor and has not changed much with respect to gene content and structure, or 2) the genome similarities we observe today are the result of two independent evolutionary trajectories leading to almost the same endpoint. The first hypothesis would be most parsimonious whereas the second would point to taxon dependent essential gene sets for plants released from photosynthetic constraints.

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