scholarly journals Terrestrial-type nitrogen-fixing symbiosis between seagrass and a marine bacterium

Nature ◽  
2021 ◽  
Author(s):  
Wiebke Mohr ◽  
Nadine Lehnen ◽  
Soeren Ahmerkamp ◽  
Hannah K. Marchant ◽  
Jon S. Graf ◽  
...  
Keyword(s):  
Amino Acids ◽  
Marine Bacterium ◽  
Posidonia Oceanica ◽  
Flowering Plants ◽  
Land Plants ◽  
Seagrass Meadows ◽  
Marine Habitats ◽  
Intimate Association ◽  
Related Plant ◽  
Early Land

AbstractSymbiotic N2-fixing microorganisms have a crucial role in the assimilation of nitrogen by eukaryotes in nitrogen-limited environments1–3. Particularly among land plants, N2-fixing symbionts occur in a variety of distantly related plant lineages and often involve an intimate association between host and symbiont2,4. Descriptions of such intimate symbioses are lacking for seagrasses, which evolved around 100 million years ago from terrestrial flowering plants that migrated back to the sea5. Here we describe an N2-fixing symbiont, ‘Candidatus Celerinatantimonas neptuna’, that lives inside seagrass root tissue, where it provides ammonia and amino acids to its host in exchange for sugars. As such, this symbiosis is reminiscent of terrestrial N2-fixing plant symbioses. The symbiosis between Ca. C. neptuna and its host Posidonia oceanica enables highly productive seagrass meadows to thrive in the nitrogen-limited Mediterranean Sea. Relatives of Ca. C. neptuna occur worldwide in coastal ecosystems, in which they may form similar symbioses with other seagrasses and saltmarsh plants. Just like N2-fixing microorganisms might have aided the colonization of nitrogen-poor soils by early land plants6, the ancestors of Ca. C. neptuna and its relatives probably enabled flowering plants to invade nitrogen-poor marine habitats, where they formed extremely efficient blue carbon ecosystems7.

scholarly journals Chromatin organization in early land plants reveals an ancestral association between H3K27me3, transposons, and constitutive heterochromatin

2019 ◽  
Author(s):  
Sean A. Montgomery ◽  
Yasuhiro Tanizawa ◽  
Bence Galik ◽  
Nan Wang ◽  
Tasuku Ito ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Significant Proportion ◽  
Three Dimensional ◽  
Flowering Plants ◽  
Land Plants ◽  
Marchantia Polymorpha ◽  
Genome Packaging ◽  
Protein Coding ◽  
Distinctive Features ◽  
Early Land

SummaryGenome packaging by nucleosomes is a hallmark of eukaryotes. Histones and the pathways that deposit, remove, and read histone modifications are deeply conserved. Yet, we lack information regarding chromatin landscapes in extant representatives of ancestors of the main groups of eukaryotes and our knowledge of the evolution of chromatin related processes is limited. We used the bryophyte Marchantia polymorpha, which diverged from vascular plants 400 Mya, to obtain a whole chromosome genome assembly and explore the chromatin landscape and three-dimensional organization of the genome of early land plants. Based on genomic profiles of ten chromatin marks, we conclude that the relationship between active marks and gene expression is conserved across land plants. In contrast, we observed distinctive features of transposons and repeats in Marchantia compared with flowering plants. Silenced transposons and repeats did not accumulate around centromeres, and a significant proportion of transposons were marked by H3K27me3, which is otherwise dedicated to the transcriptional repression of protein coding genes in flowering plants. Chromatin compartmentalization analyses of Hi-C data revealed that chromatin regions belonging to repressed heterochromatin were densely decorated with H3K27me3 but not H3K9 or DNA methylation as reported in flowering plants. We conclude that in early plants, H3K27me3 played an essential role in heterochromatin function, suggesting an ancestral role of this mark in transposon silencing.

DID EARLY LAND PLANTS PRODUCE A STEPWISE-CHANGE IN ATMOSPHERIC OXYGEN DURING THE LATE ORDOVICIAN (SANDBIAN ~ 458 MA)?

2019 ◽  
Author(s):  
Y. Datu Adiatma ◽  
◽  
Matthew R. Saltzman ◽  
Seth A. Young ◽  
Elizabeth M. Griffith ◽  
...  
Keyword(s):  
Atmospheric Oxygen ◽  
Late Ordovician ◽  
Land Plants ◽  
Stepwise Change ◽  
Early Land

Fungal symbiosis with early land plants

Science ◽  
2021 ◽  
Vol 372 (6544) ◽  
pp. 803.18-805
Author(s):  
Pamela J. Hines
Keyword(s):  
Land Plants ◽  
Fungal Symbiosis ◽  
Early Land

An enumeration of natural products from microbial, marine and terrestrial sources

2020 ◽  
Vol 5 (8) ◽  
Author(s):  
Fidele Ntie-Kang ◽  
Daniel Svozil
Keyword(s):  
Amino Acids ◽  
Natural Products ◽  
Biologically Active ◽  
Lead Compound ◽  
Chemical Databases ◽  
Natural Sources ◽  
Chemical Structures ◽  
Chemically Modified ◽  
Marine Habitats ◽  
Metabolic Properties

AbstractThe discovery of a new drug is a multidisciplinary and very costly task. One of the major steps is the identification of a lead compound, i.e. a compound with a certain degree of potency and that can be chemically modified to improve its activity, metabolic properties, and pharmacokinetics profiles. Terrestrial sources (plants and fungi), microbes and marine organisms are abundant resources for the discovery of new structurally diverse and biologically active compounds. In this chapter, an attempt has been made to quantify the numbers of known published chemical structures (available in chemical databases) from natural sources. Emphasis has been laid on the number of unique compounds, the most abundant compound classes and the distribution of compounds in terrestrial and marine habitats. It was observed, from the recent investigations, that ~500,000 known natural products (NPs) exist in the literature. About 70 % of all NPs come from plants, terpenoids being the most represented compound class (except in bacteria, where amino acids, peptides, and polyketides are the most abundant compound classes). About 2,000 NPs have been co-crystallized in PDB structures.

scholarly journals Posidonia oceanica as a Source of Chromophoric Dissolved Organic Matter for the Oligotrophic NW Mediterranean Coast

2020 ◽  
Vol 8 (11) ◽  
pp. 911
Author(s):  
Francesca Iuculano ◽  
Carlos M. Duarte ◽  
Jaime Otero ◽  
Xosé Antón Álvarez-Salgado ◽  
Susana Agustí
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Rocky Shore ◽  
Posidonia Oceanica ◽  
Mediterranean Coast ◽  
Balearic Islands ◽  
Chromophoric Dissolved Organic Matter ◽  
Absorption Increase ◽  
Seagrass Meadows ◽  
Nw Mediterranean

Posidonia oceanica is a well-recognized source of dissolved organic matter (DOM) derived from exudation and leaching of seagrass leaves, but little is known about its impact on the chromophoric fraction of DOM (CDOM). In this study, we monitored for two years the optical properties of CDOM in two contrasting sites in the Mallorca Coast (Balearic Islands). One site was a rocky shore free of seagrass meadows, and the second site was characterized by the accumulation of non-living seagrass material in the form of banquettes. On average, the integrated color over the 250–600 nm range was almost 6-fold higher in the beach compared with the rocky shore. Furthermore, the shapes of the CDOM spectra in the two sites were also different. A short incubation experiment suggested that the spectral differences were due to leaching from P. oceanica leaf decomposition. Furthermore, occasionally the spectra of P. oceanica was distorted by a marked absorption increase at wavelength < 265 nm, presumably related to the release of hydrogen sulfide (HS−) associated with the anaerobic decomposition of seagrass leaves within the banquettes. Our results provide the first evidence that P. oceanica is a source of CDOM to the surrounding waters.

scholarly journals Notes on Early Land Plants Today. 71. New synonyms, new names and new combinations in Lejeuneaceae (Marchantiophyta)

Phytotaxa ◽  
2015 ◽  
Vol 208 (1) ◽  
pp. 97 ◽  
Author(s):  
Tamas Pócs ◽  
Rui-Liang Zhu ◽  
Elena Reiner-Drehwald ◽  
Lars Söderström ◽  
Anders Hagborg ◽  
...  
Keyword(s):  
Land Plants ◽  
New Combinations ◽  
New Synonyms ◽  
The Family ◽  
Early Land

For the coming checklist of hornworts and liverworts (Söderström et al., in press) a few validations, transfers and synonymizations in the family Lejeuneaceae are still required. 

Notes on Early Land Plants Today. 69. Circumscription of Plagiochilaceae (Marchantiophyta) with a preliminary infrageneric subdivision of Plagiochila

Phytotaxa ◽  
2015 ◽  
Vol 208 (1) ◽  
pp. 75 ◽  
Author(s):  
Lars Söderström ◽  
Anders Hagborg ◽  
Matt Von Konrat
Keyword(s):  
Current Knowledge ◽  
Land Plants ◽  
New Combinations ◽  
Molecular Studies ◽  
Nomen Novum ◽  
Early Land

Plagiochilaceae is here circumscribed to include 10 genera, Acrochila, Chiastocaulon, Dinckleria, Pedinophyllopsis, Pedinophyllum, Plagiochila, Plagiochilidium, Plagiochilion, Pseudolophocolea and Xenochila. For the forthcoming world checklist of hornworts and liverworts we here summarize the current knowledge and identify the sections of Plagiochila that are currently recognized by morphological and molecular studies. Plagiochila is provisionally divided into 28 sections based on recent morphological and molecular studies. Plagiochila ecuadorica and Plagiochila sciophila subsp. ciliigera are new combinations, Plagiochila umbrosioides is a nomen novum.

scholarly journals Conserved Organisation of 45S rDNA Sites and rDNA Gene Copy Number among Major Clades of Early Land Plants

PLoS ONE ◽  
2016 ◽  
Vol 11 (9) ◽  
pp. e0162544 ◽  
Author(s):  
Marcela Rosato ◽  
Aleš Kovařík ◽  
Ricardo Garilleti ◽  
Josep A. Rosselló
Keyword(s):  
Copy Number ◽  
Gene Copy Number ◽  
Land Plants ◽  
Gene Copy ◽  
45S Rdna ◽  
Rdna Gene ◽  
Rdna Sites ◽  
Early Land
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