scholarly journals The marine-associated lifestyle of ameronothroid mites (Acari, Oribatida) and its evolutionary origin: a review

Acarologia ◽  
2017 ◽  
Vol 57 (3) ◽  
pp. 693-721
Author(s):  
Tobias Pfingstl
Keyword(s):  
Salt Marshes ◽  
Activity Patterns ◽  
Molecular Genetic ◽  
Sandy Beaches ◽  
Mangrove Forests ◽  
Long Distance ◽  
Long Distance Transport ◽  
Littoral Habitat ◽  
Wide Range ◽  
Marine Littoral

Existing literature on marine associated Ameronothroidea is reviewed and recapitulated. Although these littoral oribatid mites strongly resemble typical terrestrial mites, they have evolved different adaptions of various kinds to the marine littoral environment. In order to cope with intertidal wave action, most species show reduced and compact sensilla as well as sickle-shaped and elongated claws. Complex cerotegument based plastron mechanisms have evolved to allow breathing under flooded conditions and enabling these organisms to survive an average of more than a month completely submerged in saltwater. Behavioural adaptations include aggregations, diurnal and circatidal activity patterns, daily and seasonal migrations and thigmotaxis. Most taxa show no reproductive adaptions to the littoral habitat but some have developed ovoviviparity to protect the offspring and a few also have evolved distinct sexual dimorphism supposed to allow direct mating and secure sperm transfer in this constantly changing environment. Ameronothroid taxa are basically generalized feeders grazing on intertidal algae, lichens and fungi which also serve as microhabitat. Coastal areas all over the globe have been colonized and these mites can be found in a wide range of habitats: e.g. polar shores, rocky coasts, sandy beaches, tropical mangrove forests, brackish river estuaries and salt marshes. The families show a distinct climate related distribution pattern, with the Ameronothridae (Podacaridae included) in polar and cold temperate regions and the Fortuyniidae and Selenoribatidae in subtropical and tropical areas. Long distance transport to remote islands is supposed to be mainly achieved by bird phoresy in Ameronothridae and by dispersal via strong ocean currents in Fortuyniidae and Selenoribatidae. In literature there are basically two contrasting theories explaining the evolutionary invasion of marine associated habitats by ameronothroid mites, one favoring a monophyletic origin and a single land-to-sea transition event and another preferring an independent terrestrial ancestry and accordingly multiple invasions of the marine littoral environment. Recent molecular genetic studies support the latter theory and render the present superfamily of Ameronothroidea a polyphyletic taxon.

scholarly journals De novo indol-3-ylmethyl glucosinolate biosynthesis, and not long-distance transport, contributes to defence of Arabidopsis against powdery mildew

2019 ◽  
Author(s):  
Pascal Hunziker ◽  
Hassan Ghareeb ◽  
Lena Wagenknecht ◽  
Christoph Crocoll ◽  
Barbara Ann Halkier ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Broad Spectrum ◽  
De Novo ◽  
Epidermal Cells ◽  
Host Cells ◽  
Long Distance ◽  
Glucosinolate Biosynthesis ◽  
Golovinomyces Orontii ◽  
Long Distance Transport ◽  
Wide Range

AbstractPowdery mildew is a fungal disease that affects a wide range of plants and reduces crop yield worldwide. As obligate biotrophs, powdery mildew fungi manipulate living host cells to suppress defence responses and to obtain nutrients. Members of the plant order Brassicales produce indole glucosinolates that effectively protect them from attack by non-adapted fungi. Indol-3-ylmethyl glucosinolates are constitutively produced in the phloem and transported to epidermal cells for storage. Upon attack, indol-3-ylmethyl glucosinolates are activated by CYP81F2 to provide broad-spectrum defence against fungi. How de novo biosynthesis and transport contribute to defence of powdery mildew-attacked epidermal cells is unknown. Bioassays and glucosinolate analysis indicate that GTR glucosinolate transporters are not involved in antifungal defence. Using quantitative live-cell imaging of fluorophore-tagged markers, we show that accumulation of the glucosinolate biosynthetic enzymes CYP83B1 and SUR1 is induced in epidermal cells attacked by the non-adapted barley powdery mildew Blumeria graminis f.sp. hordei. By contrast, glucosinolate biosynthesis is attenuated during interaction with the virulent powdery mildew Golovinomyces orontii. Interestingly, SUR1 induction is delayed during the Golovinomyces orontii interaction. We conclude that epidermal de novo synthesis of indol-3-ylmethyl glucosinolate contributes to CYP81F2-mediated broad-spectrum antifungal resistance and that adapted powdery mildews may target this process.

The Fine Structure of Phloem Cells

1985 ◽  
Vol 43 ◽  
pp. 632-635
Author(s):  
James Cronshaw
Keyword(s):  
Structural Studies ◽  
High Concentration ◽  
Long Distance ◽  
Phloem Tissue ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
P Protein ◽  
Companion Cells ◽  
Electron Microscopical ◽  
Distance Transport

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.

A FUNDAMENTAL STUDY ON CARBON STORAGE BY ZOSTERA MARINA IN ISE BAY, JAPAN

2017 ◽  
Author(s):  
Hideki Kokubu ◽  
Hideki Kokubu
Keyword(s):  
Carbon Storage ◽  
Salt Marshes ◽  
Zostera Marina ◽  
Standing Stock ◽  
Coastal Ecosystems ◽  
Blue Carbon ◽  
Mangrove Forests ◽  
Fundamental Study ◽  
Strong Argument ◽  
Ise Bay

Blue Carbon, which is carbon captured by marine organisms, has recently come into focus as an important factor for climate change initiatives. This carbon is stored in vegetated coastal ecosystems, specifically mangrove forests, seagrass beds and salt marshes. The recognition of the C sequestration value of vegetated coastal ecosystems provides a strong argument for their protection and restoration. Therefore, it is necessary to improve scientific understanding of the mechanisms that stock control C in these ecosystems. However, the contribution of Blue Carbon sequestration to atmospheric CO2 in shallow waters is as yet unclear, since investigations and analysis technology are ongoing. In this study, Blue Carbon sinks by Zostera marina were evaluated in artificial (Gotenba) and natural (Matsunase) Zostera beds in Ise Bay, Japan. 12-hour continuous in situ photosynthesis and oxygen consumption measurements were performed in both areas by using chambers in light and dark conditions. The production and dead amount of Zostera marina shoots were estimated by standing stock measurements every month. It is estimated that the amount of carbon storage as Blue Carbon was 237g-C/m2/year and 197g-C/m2/year in the artificial and natural Zostera marina beds, respectively. These results indicated that Zostera marina plays a role towards sinking Blue Carbon.

scholarly journals From tree to architecture: how functional morphology of arborescence connects plant biology, evolution and physics

2021 ◽  
Author(s):  
Anita Roth-Nebelsick ◽  
Tatiana Miranda ◽  
Martin Ebner ◽  
Wilfried Konrad ◽  
Christopher Traiser
Keyword(s):  
Land Plant ◽  
Plant Evolution ◽  
Ecological Niches ◽  
Long Distance ◽  
Ongoing Research ◽  
Long Distance Transport ◽  
Theoretical Approaches ◽  
Trade Offs ◽  
Interfacial Physics ◽  
Plant Water Transport

AbstractTrees are the fundamental element of forest ecosystems, made possible by their mechanical qualities and their highly sophisticated conductive tissues. The evolution of trees, and thereby the evolution of forests, were ecologically transformative and affected climate and biogeochemical cycles fundamentally. Trees also offer a substantial amount of ecological niches for other organisms, such as epiphytes, creating a vast amount of habitats. During land plant evolution, a variety of different tree constructions evolved and their constructional principles are a subject of ongoing research. Understanding the “natural construction” of trees benefits strongly from methods and approaches from physics and engineering. Plant water transport is a good example for the ongoing demand for interdisciplinary efforts to unravel form-function relationships on vastly differing scales. Identification of the unique mechanism of water long-distance transport requires a solid basis of interfacial physics and thermodynamics. Studying tree functions by using theoretical approaches is, however, not a one-sided affair: The complex interrelationships between traits, functionality, trade-offs and phylogeny inspire engineers, physicists and architects until today.

scholarly journals Leaf-derived ABA regulates rice seed development via a transporter-mediated and temperature-sensitive mechanism

2021 ◽  
Vol 7 (3) ◽  
pp. eabc8873
Author(s):  
Peng Qin ◽  
Guohua Zhang ◽  
Binhua Hu ◽  
Jie Wu ◽  
Weilan Chen ◽  
...  
Keyword(s):  
Seed Development ◽  
Starch Synthesis ◽  
Biological Significance ◽  
Grain Filling ◽  
Temperature Sensitive ◽  
Rice Seed ◽  
Dependent Manner ◽  
Long Distance ◽  
Long Distance Transport ◽  
Mechanistic Basis

Long-distance transport of the phytohormone abscisic acid (ABA) has been studied for ~50 years, yet its mechanistic basis and biological significance remain very poorly understood. Here, we show that leaf-derived ABA controls rice seed development in a temperature-dependent manner and is regulated by defective grain-filling 1 (DG1), a multidrug and toxic compound extrusion transporter that effluxes ABA at nodes and rachilla. Specifically, ABA is biosynthesized in both WT and dg1 leaves, but only WT caryopses accumulate leaf-derived ABA. Our demonstration that leaf-derived ABA activates starch synthesis genes explains the incompletely filled and floury seed phenotypes in dg1. Both the DG1-mediated long-distance ABA transport efficiency and grain-filling phenotypes are temperature sensitive. Moreover, we extended these mechanistic insights to other cereals by observing similar grain-filling defects in a maize DG1 ortholog mutant. Our study demonstrates that rice uses a leaf-to-caryopsis ABA transport–based mechanism to ensure normal seed development in response to variable temperatures.

scholarly journals New evidence of arsenic translocation and accumulation in Pteris vittata from real-time imaging using positron-emitting 74As tracer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yi Huang-Takeshi Kohda ◽  
Zhaojie Qian ◽  
Mei-Fang Chien ◽  
Keisuke Miyauchi ◽  
Ginro Endo ◽  
...  
Keyword(s):  
Imaging System ◽  
Pteris Vittata ◽  
Long Distance ◽  
Long Distance Transport ◽  
Hydroponic Cultivation ◽  
Tracer Imaging ◽  
Serial Images ◽  
First Time ◽  
New Evidence ◽  
Hyperaccumulator Plant

AbstractPteris vittata is an arsenic (As) hyperaccumulator plant that accumulates a large amount of As into fronds and rhizomes (around 16,000 mg/kg in both after 16 weeks hydroponic cultivation with 30 mg/L arsenate). However, the sequence of long-distance transport of As in this hyperaccumulator plant is unclear. In this study, we used a positron-emitting tracer imaging system (PETIS) for the first time to obtain noninvasive serial images of As behavior in living plants with positron-emitting 74As-labeled tracer. We found that As kept accumulating in rhizomes as in fronds of P. vittata, whereas As was retained in roots of a non-accumulator plant Arabidopsis thaliana. Autoradiograph results of As distribution in P. vittata showed that with low As exposure, As was predominantly accumulated in young fronds and the midrib and rachis of mature fronds. Under high As exposure, As accumulation shifted from young fronds to mature fronds, especially in the margin of pinna, which resulted in necrotic symptoms, turning the marginal color to gray and then brown. Our results indicated that the function of rhizomes in P. vittata was As accumulation and the regulation of As translocation to the mature fronds to protect the young fronds under high As exposure.

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