Fluctuating light experiments and semi-automated plant phenotyping enabled by self-built growth racks and simple upgrades to the IMAGING-PAM

AbstractBackgroundOver the last years, several plant science labs have started to employ fluctuating growth light conditions to simulate natural light regimes more closely. Many plant mutants reveal quantifiable effects under fluctuating light despite being indistinguishable from wild-type plants under standard constant light. Moreover, many subtle plant phenotypes become intensified and thus can be studied in more detail. This observation has caused a paradigm shift within the photosynthesis research community and an increasing number of scientists are interested in using fluctuating light growth conditions. However, high installation costs for commercial controllable LED setups as well as costly phenotyping equipment can make it hard for small academic groups to compete in this emerging field.ResultsWe show a simple do-it-yourself approach to enable fluctuating light growth experiments. Our results using previously published fluctuating light sensitive mutants, stn7 and pgr5, confirm that our low-cost setup yields similar results as top-prized commercial growth regimes. Moreover, we show how we increased the throughput of our Walz IMAGING-PAM, also found in many other departments around the world. We have designed a Python and R-based open source toolkit that allows for semi-automated sample segmentation and data analysis thereby reducing the processing bottleneck of large experimental datasets. We provide detailed instructions on how to build and functionally test each setup.ConclusionsWith material costs well below USD$1000, it is possible to setup a fluctuating light rack including a constant light control shelf for comparison. This allows more scientists to perform experiments closer to natural light conditions and contribute to an emerging research field. A small addition to the IMAGING-PAM hardware not only increases sample throughput but also enables larger-scale plant phenotyping with automated data analysis.

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Fluctuating light experiments and semi-automated plant phenotyping enabled by self-built growth racks and simple upgrades to the IMAGING-PAM

Plant Methods ◽

10.1186/s13007-019-0546-1 ◽

2019 ◽

Vol 15 (1) ◽

Cited By ~ 1

Author(s):

Dominik Schneider ◽

Laura S. Lopez ◽

Meng Li ◽

Joseph D. Crawford ◽

Helmut Kirchhoff ◽

...

Keyword(s):

Data Analysis ◽

Low Cost ◽

Growth Conditions ◽

Research Field ◽

Constant Light ◽

Plant Phenotyping ◽

Natural Light ◽

Light Conditions ◽

Fluctuating Light ◽

Science Labs

Abstract Background Over the last years, several plant science labs have started to employ fluctuating growth light conditions to simulate natural light regimes more closely. Many plant mutants reveal quantifiable effects under fluctuating light despite being indistinguishable from wild-type plants under standard constant light. Moreover, many subtle plant phenotypes become intensified and thus can be studied in more detail. This observation has caused a paradigm shift within the photosynthesis research community and an increasing number of scientists are interested in using fluctuating light growth conditions. However, high installation costs for commercial controllable LED setups as well as costly phenotyping equipment can make it hard for small academic groups to compete in this emerging field. Results We show a simple do-it-yourself approach to enable fluctuating light growth experiments. Our results using previously published fluctuating light sensitive mutants, stn7 and pgr5, confirm that our low-cost setup yields similar results as top-prized commercial growth regimes. Moreover, we show how we increased the throughput of our Walz IMAGING-PAM, also found in many other departments around the world. We have designed a Python and R-based open source toolkit that allows for semi-automated sample segmentation and data analysis thereby reducing the processing bottleneck of large experimental datasets. We provide detailed instructions on how to build and functionally test each setup. Conclusions With material costs well below USD$1000, it is possible to setup a fluctuating light rack including a constant light control shelf for comparison. This allows more scientists to perform experiments closer to natural light conditions and contribute to an emerging research field. A small addition to the IMAGING-PAM hardware not only increases sample throughput but also enables larger-scale plant phenotyping with automated data analysis.

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LHCSR3-Type NPQ Prevents Photoinhibition and Slowed Growth under Fluctuating Light in Chlamydomonas reinhardtii

Plants ◽

10.3390/plants9111604 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1604

Author(s):

Thomas Roach

Keyword(s):

Chlamydomonas Reinhardtii ◽

Nonphotochemical Quenching ◽

Constant Light ◽

Natural Light ◽

Wild Type ◽

Actinic Light ◽

Fluctuating Light ◽

Related Proteins ◽

Very High

Natural light intensities can rise several orders of magnitude over subsecond time spans, posing a major challenge for photosynthesis. Fluctuating light tolerance in the green alga Chlamydomonas reinhardtii requires alternative electron pathways, but the role of nonphotochemical quenching (NPQ) is not known. Here, fluctuating light (10 min actinic light followed by 10 min darkness) led to significant increase in NPQ/qE-related proteins, LHCSR1 and LHCSR3, relative to constant light of the same subsaturating or saturating intensity. Elevated levels of LHCSR1/3 increased the ability of cells to safely dissipate excess light energy to heat (i.e., qE-type NPQ) during dark to light transition, as measured with chlorophyll fluorescence. The low qE phenotype of the npq4 mutant, which is unable to produce LHCSR3, was abolished under fluctuating light, showing that LHCSR1 alone enables very high levels of qE. Photosystem (PS) levels were also affected by light treatments; constant light led to lower PsbA levels and Fv/Fm values, while fluctuating light led to lower PsaA and maximum P700+ levels, indicating that constant and fluctuating light induced PSII and PSI photoinhibition, respectively. Under fluctuating light, npq4 suffered more PSI photoinhibition and significantly slower growth rates than parental wild type, whereas npq1 and npq2 mutants affected in xanthophyll carotenoid compositions had identical growth under fluctuating and constant light. Overall, LHCSR3 rather than total qE capacity or zeaxanthin is shown to be important in C. reinhardtii in tolerating fluctuating light, potentially via preventing PSI photoinhibition.

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Thioredoxin-dependent regulatory networks in chloroplasts under fluctuating light conditions

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2013.0224 ◽

2014 ◽

Vol 369 (1640) ◽

pp. 20130224 ◽

Cited By ~ 54

Author(s):

Lauri Nikkanen ◽

Eevi Rintamäki

Keyword(s):

Regulatory Networks ◽

Redox Homeostasis ◽

Thioredoxin Reductase ◽

Reducing Power ◽

Growth Conditions ◽

Light Conditions ◽

Environmental Signals ◽

Fluctuating Light ◽

Thioredoxin System ◽

Thiol Redox

Plants have adopted a number of mechanisms to restore redox homeostasis in the chloroplast under fluctuating light conditions in nature. Chloroplast thioredoxin systems are crucial components of this redox network, mediating environmental signals to chloroplast proteins. In the reduced state, thioredoxins control the structure and function of proteins by reducing disulfide bridges in the redox active site of a protein. Subsequently, an oxidized thioredoxin is reduced by a thioredoxin reductase, the two enzymes together forming a thioredoxin system. Plant chloroplasts have versatile thioredoxin systems, including two reductases dependent on ferredoxin and NADPH as reducing power, respectively, several types of thioredoxins, and the system to deliver thiol redox signals to the thylakoid membrane and lumen. Light controls the activity of chloroplast thioredoxin systems in two ways. First, light reactions activate the thioredoxin systems via donation of electrons to oxidized ferredoxin and NADP + , and second, light induces production of reactive oxygen species in chloroplasts which deactivate the components of the thiol redox network. The diversity and partial redundancy of chloroplast thioredoxin systems enable chloroplast metabolism to rapidly respond to ever-changing environmental conditions and to raise plant fitness in natural growth conditions.

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Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118692 ◽

1985 ◽

Vol 43 ◽

pp. 364-365

Author(s):

K.M. Hones ◽

P. Sheldon ◽

B.G. Yacobi ◽

A. Mason

Keyword(s):

High Efficiency ◽

Lattice Mismatch ◽

Low Cost ◽

Growth Conditions ◽

Nonradiative Recombination ◽

Device Structure ◽

Si Substrates ◽

Transmission Electron ◽

Dislocation Densities ◽

Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

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Glycans in scaffold design in tissue reconstruction

Journal of Bioactive and Compatible Polymers ◽

10.1177/0883911521997847 ◽

2021 ◽

pp. 088391152199784

Author(s):

Nipun Jain ◽

Shashi Singh

Keyword(s):

Cell Attachment ◽

Low Cost ◽

Growth Conditions ◽

Downstream Signaling ◽

Cell Carrier ◽

Wide Range ◽

Proliferation And Differentiation ◽

Different Types ◽

Tissue Reconstruction ◽

A Cell

Development of an artificial tissue by tissue engineering is witnessed to be one of the long lasting clarified solutions for the damaged tissue function restoration. To accomplish this, a scaffold is designed as a cell carrier in which the extracellular matrix (ECM) performs a prominent task of controlling the inoculated cell’s destiny. ECM composition, topography and mechanical properties lead to different types of interactions between cells and ECM components that trigger an assortment of cellular reactions via diverse sensing mechanisms and downstream signaling pathways. The polysaccharides in the form of proteoglycans and glycoproteins yield better outcomes when included in the designed matrices. Glycosaminoglycan (GAG) chains present on proteoglycans show a wide range of operations such as sequestering of critical effector morphogens which encourage proficient nutrient contribution toward the growing stem cells for their development and endurance. In this review we discuss how the glycosylation aspects are of considerable importance in everyday housekeeping functions of a cell especially when placed in a controlled environment under ideal growth conditions. Hydrogels made from these GAG chains have been used extensively as a resorbable material that mimics the natural ECM functions for an efficient control over cell attachment, permeability, viability, proliferation, and differentiation processes. Also the incorporation of non-mammalian polysaccharides can elicit specific receptor responses which authorize the creation of numerous vigorous frameworks while prolonging the low cost and immunogenicity of the substance.

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Growth and biochemical composition of Chlorella vulgaris in different growth media

Anais da Academia Brasileira de Ciências ◽

10.1590/0001-3765201393312 ◽

2013 ◽

Vol 85 (4) ◽

pp. 1427-1438 ◽

Cited By ~ 49

Author(s):

MATHIAS A. CHIA ◽

ANA T. LOMBARDI ◽

MARIA DA GRACA G. MELAO

Keyword(s):

Biomass Production ◽

Chlorella Vulgaris ◽

Biochemical Composition ◽

Physiological Response ◽

Low Cost ◽

Cost Effective ◽

Growth Conditions ◽

Growth Media ◽

Continuous Cultures ◽

The Cost

The need for clean and low-cost algae production demands for investigations on algal physiological response under different growth conditions. In this research, we investigated the growth, biomass production and biochemical composition of Chlorella vulgaris using semi-continuous cultures employing three growth media (LC Oligo, Chu 10 and WC media). The highest cell density was obtained in LC Oligo, while the lowest in Chu medium. Chlorophyll a, carbohydrate and protein concentrations and yield were highest in Chu and LC Oligo media. Lipid class analysis showed that hydrocarbons (HC), sterol esthers (SE), free fatty acids (FFA), aliphatic alcohols (ALC), acetone mobile polar lipids (AMPL) and phospholipids (PL) concentrations and yields were highest in the Chu medium. Triglyceride (TAG) and sterol (ST) concentrations were highest in the LC Oligo medium. The results suggested that for cost effective cultivation, LC Oligo medium is the best choice among those studied, as it saved the cost of buying vitamins and EDTA associated with the other growth media, while at the same time resulted in the best growth performance and biomass production.

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