Fluorescent g-C3N4 nanosheets enhanced photosynthetic efficiency in maize

This research focuses on the potential use of Canna hybrida `King Humbert' for removing simazine from contaminated water generated at golf courses and ornamental nurseries. Because of simazine's herbicidal activity, it is important for levels in solution not to exceed plant tolerance levels. Tolerance levels for C. hybrida were determined by dosing plants for 7 d with 0, 0.01, 0.03, 0.1, 0.3, 1.0, or 3.0 mg simazine/L nutrient media. Measurements of 7-d fresh mass production and photosynthetic efficiency (Fv/Fm) were taken. Simazine uptake and distribution within the plant was determined by dosing plants with 2.03 mCi 14C-simazine (0.243 mg/L) for 1, 3, 5, or 7 d. Plant tissues were analyzed by combustion and liquid scintillation counting. Fresh mass production was reduced 66% and 78% for plants exposed to 1.0 and 3.0 mg/L, respectively. Likewise, photosynthetic efficiency was reduced to 66% and 40% of the controls at the same respective concentrations. Plant uptake of simazine accounted for 13%, 34%, 48%, and 65% of the original simazine in the dosing solution after 1-, 3-, 5-, and 7-d exposure, respectively. This simazine was distributed primarily between roots and leaves.

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Studies of the Physiological Basis for Yields Differences. III. Genetic Variation in Photosynthetic Efficiency of Phaseolus vulgaris L. 1

Crop Science ◽

10.2135/cropsci1967.0011183x000700050015x ◽

1967 ◽

Vol 7 (5) ◽

pp. 457-460 ◽

Cited By ~ 36

Author(s):

S. Izhar ◽

D. H. Wallace

Keyword(s):

Genetic Variation ◽

Phaseolus Vulgaris ◽

Photosynthetic Efficiency ◽

Phaseolus Vulgaris L ◽

Physiological Basis

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Prevalence and Photobiology of Photosynthetic Dinoflagellate Endosymbionts in the Nudibranch Berghia stephanieae

Animals ◽

10.3390/ani11082200 ◽

2021 ◽

Vol 11 (8) ◽

pp. 2200

Author(s):

Ruben X. G. Silva ◽

Paulo Cartaxana ◽

Ricardo Calado

Keyword(s):

Food Deprivation ◽

Photosynthetic Efficiency ◽

Rapid Decrease ◽

Complete Loss ◽

Symbiotic Association ◽

Non Invasive ◽

Sea Slugs ◽

Non Destructive ◽

Over Time

Berghia stephanieae is a stenophagous sea slug that preys upon glass anemones, such as Exaiptasia diaphana. Glass anemones host photosynthetic dinoflagellate endosymbionts that sea slugs ingest when consuming E. diaphana. However, the prevalence of these photosynthetic dinoflagellate endosymbionts in sea slugs appears to be short-lived, particularly if B.stephanieae is deprived of prey that host these microalgae (e.g., during bleaching events impacting glass anemones). In the present study, we investigated this scenario, along with food deprivation, and validated the use of a non-invasive and non-destructive approach employing chlorophyll fluorescence as a proxy to monitor the persistence of the association between sea slugs and endosymbiotic photosynthetic dinoflagellates acquired through the consumption of glass anemones. Berghia stephanieae deprived of a trophic source hosting photosynthetic dinoflagellate endosymbionts (e.g., through food deprivation or by feeding on bleached E. diaphana) showed a rapid decrease in minimum fluorescence (Fo) and photosynthetic efficiency (Fv/Fm) when compared to sea slugs fed with symbiotic anemones. A complete loss of endosymbionts was observed within 8 days, confirming that no true symbiotic association was established. The present work opens a new window of opportunity to rapidly monitor in vivo and over time the prevalence of associations between sea slugs and photosynthetic dinoflagellate endosymbionts, particularly during bleaching events that prevent sea slugs from incorporating new microalgae through trophic interactions.

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Ethylene Supplementation Combined with Split Application of Nitrogen and Sulfur Protects Salt-Inhibited Photosynthesis through Optimization of Proline Metabolism and Antioxidant System in Mustard (Brassica juncea L.)

Plants ◽

10.3390/plants10071303 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1303

Author(s):

Badar Jahan ◽

Noushina Iqbal ◽

Mehar Fatma ◽

Zebus Sehar ◽

Asim Masood ◽

...

Keyword(s):

Salt Stress ◽

Brassica Juncea ◽

Antioxidant System ◽

Photosynthetic Efficiency ◽

Growth Potential ◽

Proline Metabolism ◽

Sowing Time ◽

Stress Effects ◽

Nutrient Assimilation ◽

S Application

In the present study, the potential of ethylene as ethephon (an ethylene source) was investigated individually and in combination with split doses of nitrogen (N) and sulfur (S) soil treatments for removal of the damaging effects of salt stress (100 mM NaCl) in mustard (Brassica juncea L.). Plants were grown with 50 mg N plus 50 mg S kg−1 soil at sowing time and an equivalent dose at 20 days after sowing [N50 + S50]0d and 20d. Ethephon at 200 μL L‒1 was applied to combined split doses of N and S with or without NaCl. Plants subjected to NaCl showed a decrease in growth and photosynthetic characteristics as well as N and S assimilation, whereas proline metabolism and antioxidants increased. The application of ethephon to plants grown with split N and S doses significantly enhanced photosynthetic efficiency by increasing the assimilation of N and S, improving the concentration of proline and induction of the antioxidant system with or without NaCl. The regulation of ethylene and/or split forms of N and S application may be potential tools for not just overcoming salt stress effects in this species and in related Brassicaceae but also enhancing their photosynthesis and growth potential through increased nutrient assimilation.

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Effect of caffeine on the growth and photosynthetic efficiency of marine macroalgae

Botanica Marina ◽

10.1515/bot-2020-0055 ◽

2021 ◽

Vol 64 (1) ◽

pp. 13-18

Author(s):

Ira Gray ◽

Lindsay A. Green-Gavrielidis ◽

Carol Thornber

Keyword(s):

Growth Rate ◽

Photosynthetic Efficiency ◽

Sublethal Effects ◽

Marine Species ◽

Marine Organisms ◽

Marine Macroalgae ◽

Chondrus Crispus ◽

Coastal Environments ◽

Codium Fragile ◽

High Concentrations

Abstract Caffeine is present in coastal environments worldwide and there is a need to assess its impact on marine organisms. Here, we exposed two species of ecologically important marine macroalgae (Chondrus crispus and Codium fragile subsp. fragile) to a suite of caffeine concentrations and measured their response. Caffeine concentrations of 10–100 ng L−1 had no significant effect on the growth rate or photosynthetic efficiency of either algae. Extremely high concentrations (100–200 mg L−1), which may occur acutely, produced sublethal effects for both species and mortality in C. fragile subsp. fragile. Our results highlight the need to understand how caffeine impacts marine species.

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