LED light gradient as a screening tool for light quality responses in model plant species

AbstractCurrent developments in light-emitting diodes (LEDs) technologies have opened new perspectives for sustainable and highly efficient indoor cultivation. The introduction of LEDs not only allows a reduction in the production costs on a quantitative level, it also offers opportunities to manipulate and optimise qualitative traits. Indeed, while plants respond strongest to red and blue lights for photosynthesis, the whole light spectrum has an effect on plant shape, development, and chemical composition. In order to evaluate LEDs as an alternative to traditional lighting sources, the species-specific plant responses to distinct wavelengths need to be evaluated under controlled conditions. Here, we tested the possibility to use light composition gradients in combination with semi-automated phenotyping to rapidly explore the phenotypic responses of different species to variations in the light spectrum provided by LED sources. Plants of seven different species (Arabidopsis thaliana, Ocimum basilicum, Solanum lycopersicum, Brachypodium distachyon, Oryza sativa, Euphorbia peplus, Setaria viridis) were grown under standard white fluorescent light for 30 days, then transferred to a Red:Blue gradient for another 30 days and finally returned to white light. In all species, differences in terms of dimension, shape, and color were rapidly observed across the gradient and the overall response was widely species-dependent. The experiment yielded large amounts of imaging-based phenotypic data and we suggest simple data analysis methods to aggregate the results and facilitate comparisons between species. Similar experimental setups will help achieve rapid environmental optimization, screen new crop species and genotypes, or develop new gene discovery strategies.

Download Full-text

Cross-species complementation reveals conserved functions for EARLY FLOWERING 3 between monocots and dicots

10.1101/131185 ◽

2017 ◽

Author(s):

He Huang ◽

Malia A. Gehan ◽

Sarah E. Huss ◽

Sophie Alvarez ◽

Cesar Lizarraga ◽

...

Keyword(s):

Circadian Clock ◽

Clock Genes ◽

Expression Profiles ◽

Affinity Purification ◽

Brachypodium Distachyon ◽

Sequence Divergence ◽

Plant Responses ◽

Crop Species ◽

Physiological Level ◽

High Sequence Divergence

ABSTRACTPlant responses to the environment are shaped by external stimuli and internal signaling pathways. In both the model plant Arabidopsis thaliana and crop species, circadian clock factors have been identified as critical for growth, flowering and circadian rhythms. Outside of A. thaliana, however, little is known about the molecular function of clock genes. Therefore, we sought to compare the function of Brachypodium distachyon and Seteria viridis orthologs of EARLY FLOWERING3, a key clock gene in A. thaliana. To identify both cycling genes and putative ELF3 functional orthologs in S. viridis, a circadian RNA-seq dataset and online query tool (Diel Explorer) was generated as a community resource to explore expression profiles of Setaria genes under constant conditions after photo- or thermo-entrainment. The function of ELF3 orthologs from A. thaliana, B. distachyon, and S. viridis were tested for complementation of an elf3 mutation in A. thaliana. Despite comparably low sequence identity versus AtELF3 (less than 37%), both monocot orthologs were capable of rescuing hypocotyl elongation, flowering time and arrhythmic clock phenotypes. Molecular analysis using affinity purification and mass spectrometry to compare physical interactions also found that BdELF3 and SvELF3 could be integrated into similar complexes and networks as AtELF3, including forming a composite evening complex. Thus, we find that, despite 180 million years of separation, BdELF3 and SvELF3 can functionally complement loss of ELF3 at the molecular and physiological level.One Sentence SummaryOrthologs of a key circadian clock component ELF3 from grasses functionally complement the Arabidopsis counterpart at the molecular and physiological level, in spite of high sequence divergence.

Download Full-text

Disentangling transcriptional responses in plant defense against arthropod herbivores

Scientific Reports ◽

10.1038/s41598-021-92468-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Alejandro Garcia ◽

M. Estrella Santamaria ◽

Isabel Diaz ◽

Manuel Martinez

Keyword(s):

Regulatory Networks ◽

Pieris Rapae ◽

Meta Analysis ◽

Plant Response ◽

Plant Responses ◽

Transcriptional Responses ◽

Crop Species ◽

Physiological Processes ◽

Meta Analyses ◽

Plant Herbivore

AbstractThe success in the response of a plant to a pest depends on the regulatory networks that connect plant perception and plant response. Meta-analyses of transcriptomic responses are valuable tools to discover novel mechanisms in the plant/herbivore interplay. Considering the quantity and quality of available transcriptomic analyses, Arabidopsis thaliana was selected to test the ability of comprehensive meta-analyses to disentangle plant responses. The analysis of the transcriptomic data showed a general induction of biological processes commonly associated with the response to herbivory, like jasmonate signaling or glucosinolate biosynthesis. However, an uneven induction of many genes belonging to these biological categories was found, which was likely associated with the particularities of each specific Arabidopsis-herbivore interaction. A thorough analysis of the responses to the lepidopteran Pieris rapae and the spider mite Tetranychus urticae highlighted specificities in the perception and signaling pathways associated with the expression of receptors and transcription factors. This information was translated to a variable alteration of secondary metabolic pathways. In conclusion, transcriptomic meta-analysis has been revealed as a potent way to sort out relevant physiological processes in the plant response to herbivores. Translation of these transcriptomic-based analyses to crop species will permit a more appropriate design of biotechnological programs.

Download Full-text

High-Throughput Phenotyping Methods for Breeding Drought-Tolerant Crops

International Journal of Molecular Sciences ◽

10.3390/ijms22158266 ◽

2021 ◽

Vol 22 (15) ◽

pp. 8266

Author(s):

Minsu Kim ◽

Chaewon Lee ◽

Subin Hong ◽

Song Lim Kim ◽

Jeong-Ho Baek ◽

...

Keyword(s):

Drought Stress ◽

High Throughput ◽

Large Scale ◽

Crop Yields ◽

Plant Traits ◽

Rapid Development ◽

Plant Responses ◽

Phenotypic Data ◽

Agricultural Technologies ◽

High Throughput Phenotyping

Drought is a main factor limiting crop yields. Modern agricultural technologies such as irrigation systems, ground mulching, and rainwater storage can prevent drought, but these are only temporary solutions. Understanding the physiological, biochemical, and molecular reactions of plants to drought stress is therefore urgent. The recent rapid development of genomics tools has led to an increasing interest in phenomics, i.e., the study of phenotypic plant traits. Among phenomic strategies, high-throughput phenotyping (HTP) is attracting increasing attention as a way to address the bottlenecks of genomic and phenomic studies. HTP provides researchers a non-destructive and non-invasive method yet accurate in analyzing large-scale phenotypic data. This review describes plant responses to drought stress and introduces HTP methods that can detect changes in plant phenotypes in response to drought.

Download Full-text

A Bayesian hierarchical approach to improve model parameter estimates and predictions of silage maize phenology in Germany

10.5194/egusphere-egu21-7962 ◽

2021 ◽

Author(s):

Michelle Viswanathan ◽

Tobias KD Weber ◽

Andreas Scheidegger ◽

Thilo Streck

Keyword(s):

Environmental Conditions ◽

Plant Phenology ◽

Parameter Estimates ◽

Crop Species ◽

Bayesian Hierarchical ◽

Crop Models ◽

Hierarchical Framework ◽

Silage Maize ◽

Parameterized Model ◽

Species Specific

Crop models are used to evaluate the impact of climate change on food security by simulating plant phenology, yield, biomass and leaf area index. Plant phenology defines the timing of crucial growth stages and physiological processes that influence organ appearance and assimilate partitioning. It is governed by environmental factors such as solar radiation, temperature and water availability. Plant phenology is not only specific for the crop species, but also depends on the cultivar. Additionally, growth of a cultivar could vary depending on the environment. Common crop models cannot fully capture the influence of the environment on phenology, resulting in cultivar-specific parameters that are environment-dependent. These parameter estimates may be unreliable in case of limited data. Moreover, crucial species-specific information is ignored. On the other hand, in large regional-scale models covering multiple cultivars and environments, information about the cultivars grown is generally not available. In this case, a shared set of parameters for the crop species would suppress within-species differences leading to unreliable predictions.A Bayesian hierarchical framework enables us to alleviate these problems by honouring the multi-level data structure. Additionally, we can reflect the uncertainty from different sources, for example, model inputs and measurements. In this study we implement a Bayesian hierarchical framework to estimate parameters of the Soil-Plant-Atmosphere System Simulation (SPASS) model for simulating phenological development of different cultivars of silage maize grown over all the contrasting climatological regions of Germany.We used data from the German weather service on the phenological development stages of silage maize grown across Germany between 2009 and 2019. During this period, silage maize was grown in over 3000 unique location-year combinations. Maize crops were differentiated into early, mid-early, mid-late and late ripening groups and were further classified into cultivars within each ripening group. Within the hierarchical framework, we estimate maize species-specific parameters as well as parameters per ripening group and cultivar, through Bayesian model calibration. We analyse the influence of environmental conditions on parameter estimates, to further develop the hierarchical structure. We perform cross-validation to assess the prediction quality of the parameterized model.With this approach, we show that robust parameter estimates account for differences between cultivars, ripening groups as well as different environmental conditions. The parameterized model can be used for large-scale phenology predictions of silage maize grown across Germany. These parameter estimates may perform better than independent species- or cultivar-specific estimates, in predicting phenology of future cultivars where specific cultivar characteristics are not known.

Download Full-text

Reaching Natural Growth: Light Quality Effects on Plant Performance in Indoor Growth Facilities

Plants ◽

10.3390/plants9101273 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1273

Author(s):

Camilo Chiang ◽

Daniel Bånkestad ◽

Günter Hoch

Keyword(s):

Plant Growth ◽

Field Trial ◽

Light Quality ◽

Plant Traits ◽

Principal Component ◽

Biomass Productivity ◽

Plant Performance ◽

Plant Responses ◽

Natural Ecosystems ◽

Species Specific

To transfer experimental findings in plant research to natural ecosystems it is imperative to reach near to natural-like plant performance. Previous studies propose differences in temperature and light quantity as main sources of deviations between indoor and outdoor plant growth. With increasing implementation of light emitting diodes (LED) in plant growth facilities, light quality is yet another factor that can be optimised to prevent unnatural plant performance. We investigated the effects of different wavelength combinations in phytotrons (i.e., indoor growth chambers) on plant growth and physiology in seven different plant species from different plant functional types (herbs, grasses and trees). The results from these experiments were compared against a previous field trial with the same set of species. While different proportions of blue (B) and red (R) light were applied in the phytotrons, the mean environmental conditions (photoperiod, total radiation, red to far red ratio and day/night temperature and air humidity) from the field trial were used in the phytotrons in order to assess which wavelength combinations result in the most natural-like plant performance. Different plant traits and physiological parameters, including biomass productivity, specific leaf area (SLA), leaf pigmentation, photosynthesis under a standardised light, and the respective growing light and chlorophyll fluorescence, were measured at the end of each treatment. The exposure to different B percentages induced species-specific dose response reactions for most of the analysed parameters. Compared with intermediate B light treatments (25 and/or 35% B light), extreme R or B light enriched treatments (6% and 62% of B respectively) significantly affected the height, biomass, biomass allocation, chlorophyll content, and photosynthesis parameters, differently among species. Principal component analyses (PCA) confirmed that 6% and 62% B light quality combinations induce more extreme plant performance in most cases, indicating that light quality needs to be adjusted to mitigate unnatural plant responses under indoor conditions.

Download Full-text

Blue light reduces organ injury from ischemia and reperfusion

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1515296113 ◽

2016 ◽

Vol 113 (19) ◽

pp. 5239-5244 ◽

Cited By ~ 14

Author(s):

Du Yuan ◽

Richard D. Collage ◽

Hai Huang ◽

Xianghong Zhang ◽

Benjamin C. Kautza ◽

...

Keyword(s):

Blue Light ◽

Ischemia Reperfusion ◽

High Mobility ◽

Kidney Injury ◽

Organ Injury ◽

Fluorescent Light ◽

Protective Mechanism ◽

Hepatocellular Injury ◽

Light Spectrum ◽

Bright Blue

Evidence suggests that light and circadian rhythms profoundly influence the physiologic capacity with which an organism responds to stress. However, the ramifications of light spectrum on the course of critical illness remain to be determined. Here, we show that acute exposure to bright blue spectrum light reduces organ injury by comparison with bright red spectrum or ambient white fluorescent light in two murine models of sterile insult: warm liver ischemia/reperfusion (I/R) and unilateral renal I/R. Exposure to bright blue light before I/R reduced hepatocellular injury and necrosis and reduced acute kidney injury and necrosis. In both models, blue light reduced neutrophil influx, as evidenced by reduced myeloperoxidase (MPO) within each organ, and reduced the release of high-mobility group box 1 (HMGB1), a neutrophil chemotactant and key mediator in the pathogenesis of I/R injury. The protective mechanism appeared to involve an optic pathway and was mediated, in part, by a sympathetic (β3 adrenergic) pathway that functioned independent of significant alterations in melatonin or corticosterone concentrations to regulate neutrophil recruitment. These data suggest that modifying the spectrum of light may offer therapeutic utility in sterile forms of cellular injury.

Download Full-text

Bamboos flower after the return of an appropriate sun-moon phasing

10.1101/2021.06.11.448081 ◽

2021 ◽

Author(s):

Benoit Clerget

Keyword(s):

Full Moon ◽

Seedling Emergence ◽

Economic Importance ◽

Plant Responses ◽

Time Intervals ◽

Lunar Cycles ◽

Short Period ◽

Highly Correlated ◽

Species Specific ◽

Unique Species

All Asian woody bamboo species of economic importance are semelparous. They remain vegetative during time intervals that are specific to each species and range from three to 120 years, with notable concentrations around a series of values (3, 7-8, 14-17, 29-36, 42-48, 61-64, and 120 years). Then, they flower gregariously within a short period. As with all grasses, they are monocarpic and produce a large quantity of seeds before dying. Entire forests temporarily disappear during these periods, and the dates of these dramatic events have been recorded over the last 200 years. I have found that the concentrations of flowering cycles were highly correlated with the series of successive returns of almost the same sun-moon phasing as at seedling emergence. On basis of knowledge on plant photoperiod sensitivity, I hypothesize that bamboo plants i) run a lunar cellular clock that is set at the full moon, ii) retain in their cellular memory the exact sun-moon phasing of the year of their emergence as seedlings, and iii) inhibit flowering until the occurrence of a unique, species-specific sun-moon phasing that is shifted by a precise amount from the sun-moon phasing at their emergence. Recent evidence of plant responses to lunar cycles supports this hypothesis, for which experimental evidence is now anticipated.

Download Full-text

Long-term effects of snowmelt timing and climate warming on phenology, growth and reproductive effort of arctic tundra plant species

Arctic Science ◽

10.1139/as-2021-0028 ◽

2021 ◽

Author(s):

Esther R. Frei ◽

Greg H.R. Henry

Keyword(s):

Plant Species ◽

Reproductive Effort ◽

High Arctic ◽

Snow Accumulation ◽

The Arctic ◽

Plant Responses ◽

Long Term Effects ◽

Passive Warming ◽

Species Specific

Arctic regions are particularly affected by rapidly rising temperatures and altered snow regimes. Snowmelt timing depends on spring temperatures and winter snow accumulation. Scenarios for the Arctic include both decreases and increases in snow accumulation. Predictions of future snowmelt timing are thus difficult and experimental evidence for ecological consequences is scarce. In 1995, a long-term factorial experiment was set up in a High Arctic evergreen shrub heath community on Ellesmere Island, Canada. We investigated how snow removal, snow addition and passive warming affected phenology, growth and reproductive effort of the four common tundra plant species Cassiope tetragona, Dryas integrifolia, Luzula arctica and Papaver radicatum. Timing of flowering and seed maturation as well as flower production were more strongly influenced by the combined effects of snowmelt timing and warming in the two shrub species than in the two herbaceous species. Warming effects persisted over the course of the growing season and resulted in increased shrub growth. Moreover, the long-term trend of increasing growth in two species suggests that ambient warming promotes tundra plant growth. Our results confirm the importance of complex interactions between temperature and snowmelt timing in driving species-specific plant responses to climate change in the Arctic.

Download Full-text

Distinct Arabidopsis Responses to Two Generalist Caterpillar Species Differing in Host Breadth

PhytoFrontiers™ ◽

10.1094/phytofr-07-20-0002-r ◽

2020 ◽

pp. PHYTOFR-07-20-0

Author(s):

Zhihong Zhang ◽

Andreas Schedl ◽

Rebekka Sontowski ◽

Brian T. Driscoll ◽

Nicole M. van Dam ◽

...

Keyword(s):

Host Range ◽

Trichoplusia Ni ◽

Marker Gene ◽

Cabbage Looper ◽

Beet Armyworm ◽

Induced Response ◽

Plant Responses ◽

Plant Host ◽

Temporal Differences ◽

Species Specific

In general, caterpillar herbivores with a narrow host preference (specialists) have evolved mechanisms to circumvent specific plant defenses. In contrast, caterpillars with a broader host range (generalists) may manipulate phytohormone pathways common to many plant species to attenuate induced defenses. Many studies have compared plant responses to specialist versus generalist caterpillars. In contrast, this study evaluates the induced response of Arabidopsis thaliana to two generalist caterpillar species, the cabbage looper, Trichoplusia ni, and the beet armyworm, Spodoptera exigua. Although both caterpillars are considered generalists, S. exigua has a broader plant host range, whereas T. ni prefers Brassicaceous plants. Our study shows that most responses to caterpillar herbivory, such as the jasmonate burst, are similar in plants attacked by either insect species; however, we do observe dynamic and temporal differences in specific responses. Expression of AtZAT10, a 12-oxo-phytodienoic acid-responsive gene, is only induced in response to T. ni damage. In comparison, only S. exigua herbivory activates the salicylic acid/NPR1-dependent pathway, as observed by the expression of the marker gene AtPR1. Even though both species induce AtPDF1.2 expression, we found caterpillar-specific temporal differences: T. ni herbivory results in sustained expression over time, whereas gene expression is sharply downregulated at 36 h in S. exigua-attacked plants. Although damage by these two caterpillar species induced AtMYB28 and AtMYB34 expression, specific short- and long-chain aliphatic and indolic glucosinolates accumulate only in response to S. exigua herbivory. These species-specific, plant-induced responses likely reflect differences in effectors found in caterpillar oral secretions. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Download Full-text

Cargo Recognition and Function of Selective Autophagy Receptors in Plants

International Journal of Molecular Sciences ◽

10.3390/ijms22031013 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1013

Author(s):

Shuwei Luo ◽

Xifeng Li ◽

Yan Zhang ◽

Yunting Fu ◽

Baofang Fan ◽

...

Keyword(s):

Cellular Response ◽

Plant Responses ◽

Biological Functions ◽

Biotic And Abiotic Stresses ◽

Selective Autophagy ◽

Evolutionarily Conserved ◽

Autophagic Degradation ◽

Species Specific ◽

And Function ◽

Cellular Components

Autophagy is a major quality control system for degradation of unwanted or damaged cytoplasmic components to promote cellular homeostasis. Although non-selective bulk degradation of cytoplasm by autophagy plays a role during cellular response to nutrient deprivation, the broad roles of autophagy are primarily mediated by selective clearance of specifically targeted components. Selective autophagy relies on cargo receptors that recognize targeted components and recruit them to autophagosomes through interaction with lapidated autophagy-related protein 8 (ATG8) family proteins anchored in the membrane of the forming autophagosomes. In mammals and yeast, a large collection of selective autophagy receptors have been identified that mediate the selective autophagic degradation of organelles, aggregation-prone misfolded proteins and other unwanted or nonnative proteins. A substantial number of selective autophagy receptors have also been identified and functionally characterized in plants. Some of the autophagy receptors in plants are evolutionarily conserved with homologs in other types of organisms, while a majority of them are plant-specific or plant species-specific. Plant selective autophagy receptors mediate autophagic degradation of not only misfolded, nonactive and otherwise unwanted cellular components but also regulatory and signaling factors and play critical roles in plant responses to a broad spectrum of biotic and abiotic stresses. In this review, we summarize the research on selective autophagy in plants, with an emphasis on the cargo recognition and the biological functions of plant selective autophagy receptors.

Download Full-text