scholarly journals A high-throughput method for measuring critical thermal limits of leaves by chlorophyll imaging fluorescence

2021 ◽  
Author(s):  
Pieter A. Arnold ◽  
Verónica F. Briceño ◽  
Kelli M. Gowland ◽  
Alexandra A. Catling ◽  
León A. Bravo ◽  
...  
2020 ◽  
Author(s):  
Pieter A. Arnold ◽  
Verónica F. Briceño ◽  
Kelli M. Gowland ◽  
Alexandra A. Catling ◽  
León A. Bravo ◽  
...  

AbstractPlant thermal tolerance is a crucial research area as the climate warms and extreme weather events become more frequent. We developed and tested a high-throughput method for measuring photosynthetic critical thermal limits at low (CTMIN) and high (CTMAX) temperatures to achieve pragmatic and robust measures of thermal tolerance limits using a Maxi-Imaging fluorimeter and a thermoelectric Peltier plate temperature ramping system. Leaves exposed to temperature extremes accumulate damage to photosystem II (PSII). Temperature-dependent changes in basal chlorophyll fluorescence (T-F0) can be used to identify the critical temperature at which PSII is damaged. We examined how experimental conditions: wet vs dry surfaces for leaves and temperature ramp rate, affect CTMIN and CTMAX across four species. CTMAX estimates were not different whether measured on wet or dry surfaces, but leaves were apparently less cold tolerant when on wet surfaces. Temperature ramp rate had a strong effect on both CTMAX and CTMIN that was species-specific. We discuss potential mechanisms for these results and recommend settings for researchers to use when measuring T-F0. The system described and tested here allows high-throughput measurement of critical temperature thresholds of leaf photosynthetic performance for characterising plant function in response to thermal extremes.


Author(s):  
David N. Awde ◽  
Tatum E. Fowler ◽  
Fernan Pérez-Gálvez ◽  
Mark J. Garcia ◽  
Nicholas M. Teets

Planta Medica ◽  
2016 ◽  
Vol 82 (05) ◽  
Author(s):  
C Avonto ◽  
AG Chittiboyina ◽  
D Rua ◽  
IA Khan

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1313
Author(s):  
Andreas Hoffmann ◽  
Alexander J. C. Kuehne

Carbon nanofiber nonwovens are promising materials for electrode or filtration applications; however, their utilization is obviated by a lack of high throughput production methods. In this study, we utilize a highly effective high-throughput method for the fabrication of polyacrylonitrile (PAN) nanofibers as a nonwoven on a dedicated substrate. The method employs rotational-, air pressure- and electrostatic forces to produce fibers from the inner edge of a rotating bell towards a flat collector. We investigate the impact of all above-mentioned forces on the fiber diameter, morphology, and bundling of the carbon-precursor PAN fibers. The interplay of radial forces with collector-facing forces has an influence on the uniformity of fiber deposition. Finally, the obtained PAN nanofibers are converted to carbon nonwovens by thermal treatment.


Soft Matter ◽  
2021 ◽  
Author(s):  
Tao Lin ◽  
Zhen Wang ◽  
Wen Wang ◽  
Yi Sui

We have developed a high-throughput method, by combining a hybrid neural network with a mechanistic capsule model, to predict membrane elasticity and viscosity of microcapsules from their dynamic deformation in a branched microchannel.


Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1466
Author(s):  
Lisard Iglesias-Carres ◽  
Lauren A. Essenmacher ◽  
Kathryn C. Racine ◽  
Andrew P. Neilson

Choline is metabolized by the gut microbiota into trimethylamine (TMA), the precursor of pro-atherosclerotic molecule trimethylamine N-oxide (TMAO). A reduction in TMA formation has shown cardioprotective effects, and some phytochemicals may reduce TMA formation. This study aimed to develop an optimized, high-throughput anaerobic fermentation methodology to study the inhibition of choline microbial metabolism into TMA by phenolic compounds with healthy human fecal starter. Optimal fermentation conditions were: 20% fecal slurry (1:10 in PBS), 100 µM choline, and 12 h fermentation. Additionally, 10 mM of 3,3-dimethyl-1-butanol (DMB) was defined as a positive TMA production inhibitor, achieving a ~50% reduction in TMA production. Gallic acid and chlorogenic acid reported higher TMA inhibitory potential (maximum of 80–90% TMA production inhibition), with IC50 around 5 mM. Neither DMB nor gallic acid or chlorogenic acid reduced TMA production through cytotoxic effects, indicating mechanisms such as altered TMA-lyase activity or expression.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Belinda van Heerwaarden ◽  
Carla M. Sgrò

AbstractForecasting which species/ecosystems are most vulnerable to climate warming is essential to guide conservation strategies to minimize extinction. Tropical/mid-latitude species are predicted to be most at risk as they live close to their upper critical thermal limits (CTLs). However, these assessments assume that upper CTL estimates, such as CTmax, are accurate predictors of vulnerability and ignore the potential for evolution to ameliorate temperature increases. Here, we use experimental evolution to assess extinction risk and adaptation in tropical and widespread Drosophila species. We find tropical species succumb to extinction before widespread species. Male fertility thermal limits, which are much lower than CTmax, are better predictors of species’ current distributions and extinction in the laboratory. We find little evidence of adaptive responses to warming in any species. These results suggest that species are living closer to their upper thermal limits than currently presumed and evolution/plasticity are unlikely to rescue populations from extinction.


Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 398
Author(s):  
Yusuke Aono ◽  
Yonathan Asikin ◽  
Ning Wang ◽  
Denise Tieman ◽  
Harry Klee ◽  
...  

Flavor and nutritional quality has been negatively impacted during the course of domestication and improvement of the cultivated tomato (Solanum lycopersicum). Recent emphasis on consumers has emphasized breeding strategies that focus on flavor-associated chemicals, including sugars, acids, and aroma compounds. Carotenoids indirectly affect flavor as precursors of aroma compounds, while chlorophylls contribute to sugar production through photosynthesis. However, the relationships between these pigments and flavor content are still unclear. In this study, we developed a simple and high-throughput method to quantify chlorophylls and carotenoids. This method was applied to over one hundred tomato varieties, including S. lycopersicum and its wild relatives (S. l. var. cerasiforme and S. pimpinellifolium), for quantification of these pigments in fruits. The results obtained by integrating data of the pigments, soluble solids, sugars, and aroma compounds indicate that (i) chlorophyll-abundant varieties have relatively higher sugar accumulations and (ii) prolycopene is associated with an abundance of linear carotenoid-derived aroma compounds in one of the orange-fruited varieties, “Dixie Golden Giant”. Our results suggest the importance of these pigments not only as components of fruit color but also as factors influencing flavor traits, such as sugars and aroma.


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