scholarly journals Photoreceptor effects on plant biomass, resource allocation, and metabolic state

2016 ◽  
Vol 113 (27) ◽  
pp. 7667-7672 ◽  
Author(s):  
Deyue Yang ◽  
Daniel D. Seaton ◽  
Johanna Krahmer ◽  
Karen J. Halliday
Keyword(s):  
Biomass Production ◽  
Carbon Fixation ◽  
Carbon Allocation ◽  
Plant Biomass ◽  
Tricarboxylic Acid Cycle ◽  
Critical Role ◽  
Marker Genes ◽  
Adult Plant ◽  
Plant Signaling ◽  
Phytochrome Mutants

Plants sense the light environment through an ensemble of photoreceptors. Members of the phytochrome class of light receptors are known to play a critical role in seedling establishment, and are among the best-characterized plant signaling components. Phytochromes also regulate adult plant growth; however, our knowledge of this process is rather fragmented. This study demonstrates that phytochrome controls carbon allocation and biomass production in the developing plant. Phytochrome mutants have a reduced CO2 uptake, yet overaccumulate daytime sucrose and starch. This finding suggests that even though carbon fixation is impeded, the available carbon resources are not fully used for growth during the day. Supporting this notion, phytochrome depletion alters the proportion of day:night growth. In addition, phytochrome loss leads to sizeable reductions in overall growth, dry weight, total protein levels, and the expression of CELLULOSE SYNTHASE-LIKE genes. Because cellulose and protein are major constituents of plant biomass, our data point to an important role for phytochrome in regulating these fundamental components of plant productivity. We show that phytochrome loss impacts core metabolism, leading to elevated levels of tricarboxylic acid cycle intermediates, amino acids, sugar derivatives, and notably the stress metabolites proline and raffinose. Furthermore, the already growth-retarded phytochrome mutants are less responsive to growth-inhibiting abiotic stresses and have elevated expression of stress marker genes. This coordinated response appears to divert resources from energetically costly biomass production to improve resilience. In nature, this strategy may be activated in phytochrome-disabling, vegetation-dense habitats to enhance survival in potentially resource-limiting conditions.

scholarly journals Phytochrome light receptors control metabolic flux, and their action during seedling development sets the trajectory for biomass production

2019 ◽  
Author(s):  
Johanna Krahmer ◽  
Ammad Abbas ◽  
Virginie Mengin ◽  
Hirofumi Ishihara ◽  
Thiago A Moraes ◽  
...  
Keyword(s):  
Metabolic Flux ◽  
Carbon Fixation ◽  
Plant Biomass ◽  
Growth Dynamics ◽  
Biomass Accumulation ◽  
Adult Plant ◽  
Growth Responses ◽  
Cell Wall Polysaccharides ◽  
Stress Metabolites ◽  
Biomass Quantification

AbstractThe phytochromes (phys) photoreceptors are known to be major regulators of plastic growth responses to vegetation shade. Recent reports have begun to uncover an important role for phys in carbon resource management. Our earlier work showed that phy mutants had a distinct metabolic profile with elevated levels of metabolites including TCA intermediates, amino acids and sugars. Here we show that in seedlings phy regulates the balance between glucose and starch. Multi-allele phy mutants have excess glucose and low starch levels, which is conducive to hypocotyl elongation. 13C-CO2 labelling demonstrates that metabolic flux balance in adult plants is markedly altered in phy mutants. Phytochrome reduces synthesis rates of stress metabolites, including raffinose and proline and several typical stress-induced biosynthetic genes related to these metabolites show higher expression in phy mutants.Since growth and metabolism are typically inter-connected, we investigated why phy mutants have severely reduced biomass. Quantification of carbon fixation, biomass accumulation, and 13C labelling of cell wall polysaccharides established that relative growth rate is impaired in multi allele phy mutants for the first 2.5 weeks after germination but equivalent to the WT thereafter. Mathematical modelling predicts that the altered growth dynamics and final biomass deficit can be explained by the smaller cotyledon size of the multiple phy mutants. This indicates that the established role of phy in promoting seedling establishment has enduring effects that govern adult plant biomass.

scholarly journals Efficiency of Recycled Biogas Digestates as Phosphorus Fertilizers for Maize

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 553
Author(s):  
Inga-Mareike Bach ◽  
Lisa Essich ◽  
Torsten Müller
Keyword(s):  
Biomass Production ◽  
Plant Biomass ◽  
Nutrient Content ◽  
Phosphorus Concentration ◽  
Available Phosphorus ◽  
Phosphorus Fertilizers ◽  
Future Supply ◽  
Application Techniques ◽  
Phosphorus Recycling ◽  
Fertilizing Effect

Despite phosphorus resources on Earth being limited, over fertilization in many agricultural situations causes significant resource consumption. Phosphorus-recycling within agricultural production can reduce global dilution into the environment and is thus essential to secure sustainable future supply. This study investigated the fertilization efficacy of phosphorus fertilizers recycled from biogas digestates in maize shoots grown under controlled greenhouse conditions, in two soils, in a pot experiment. Variables investigated were plant-available phosphorus in soil, plant biomass production, and concentration of phosphorus, calcium, and magnesium in shoots. Soils were treated with three different fertilizer fractions, separated from biogas digestates, at equivalent phosphorus concentrations, using different combinations and application techniques, isolated or in combination, and compared to triple superphosphate (TSP) as a reference. One of the fractions (P-Salt) had effects on biomass production and plant phosphorus concentration equivalent to TSP in agricultural surface soil. In the second soil (with less active soil life and nutrient content), equivalence to TSP was achieved with combinations of two recycled fractions (P-Salt and dried solids). The enhancement of the phosphorus fertilizing effect by the solids was synergistic, indicating that the solids had a soil conditioning effect. The results show that biogas digestates are a valuable source for phosphorus recycling of fractions that have equivalent or even superior fertilizing properties compared to TSP.

scholarly journals Mangrove diversity enhances plant biomass production and carbon storage in Hainan island, China

2021 ◽  
Vol 35 (3) ◽  
pp. 774-786
Author(s):  
Jiankun Bai ◽  
Yuchen Meng ◽  
Ruikun Gou ◽  
Jiacheng Lyu ◽  
Zheng Dai ◽  
...  
Keyword(s):  
Carbon Storage ◽  
Biomass Production ◽  
Plant Biomass ◽  
Hainan Island ◽  
Plant Biomass Production

Can repeated soil amendment with biogas digestates increase soil suppressiveness toward non-specific soil-borne pathogens in agricultural lands?

2020 ◽  
pp. 1-12
Author(s):  
L. M. Manici ◽  
F. Caputo ◽  
G. A. Cappelli ◽  
E. Ceotto
Keyword(s):  
Plant Growth ◽  
Biomass Production ◽  
Soil Amendment ◽  
Plant Biomass ◽  
Amended Soils ◽  
Soil Suppressiveness ◽  
Soil Microbial ◽  
Soil Borne Pathogens ◽  
The Impact ◽  
Plant Biomass Production

Abstract Soil suppressiveness which is the natural ability of soil to support optimal plant growth and health is the resultant of multiple soil microbial components; which implies many difficulties when estimating this soil condition. Microbial benefits for plant health from repeated digestate applications were assessed in three experimental sites surrounding anaerobic biogas plants in an intensively cultivated area of northern Italy. A 2-yr trial was performed in 2017 and 2018 by performing an in-pot plant growth assay, using soil samples taken from two fields for each experimental site, of which one had been repeatedly amended with anaerobic biogas digestate and the other had not. These fields were similar in management and crop sequences (maize was the recurrent crop) for the last 10 yr. Plant growth response in the bioassay was expressed as plant biomass production, root colonization frequency by soil-borne fungi were estimated to evaluate the impact of soil-borne pathogens on plant growth, abundance of Pseudomonas and actinomycetes populations in rhizosphere were estimated as beneficial soil microbial indicators. Repeated soil amendment with digestate increased significantly soil capacity to support plant biomass production as compared to unamended control in both the years. Findings supported evidence that this increase was principally attributable to a higher natural ability of digestate-amended soils to reduce root infection by saprophytic soil-borne pathogens whose inoculum was increased by the recurrent maize cultivation. Pseudomonas and actinomycetes were always more abundant in digestate-amended soils suggesting that both these large bacterial groups were involved in the increase of their natural capacity to control soil-borne pathogens (soil suppressiveness).

scholarly journals Study of expression analysis of SIRT4 and the coordinate regulation of bovine adipocyte differentiation by SIRT4 and its transcription factors

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Jieyun Hong ◽  
Shijun Li ◽  
Xiaoyu Wang ◽  
Chugang Mei ◽  
Linsen Zan
Keyword(s):  
Transcriptional Regulation ◽  
Transcription Factors ◽  
Adipocyte Differentiation ◽  
Binding Protein ◽  
Core Promoter ◽  
Critical Role ◽  
Luciferase Reporter ◽  
Marker Genes ◽  
Gene Assay ◽  
Bovine Adipocytes

Sirtuins, NAD+-dependent deacylases and ADP-ribosyltransferases, are critical regulators of metabolism involved in many biological processes, and are involved in mediating adaptive responses to the cellular environment. SIRT4 is a mitochondrial sirtuin and has been shown to play a critical role in maintaining insulin secretion and glucose homeostasis. As a regulator of lipid homeostasis, SIRT4 can repress fatty acid oxidation and promote lipid anabolism in nutrient-replete conditions. Using real-time quantitative PCR (qPCR) to explore the molecular mechanisms of transcriptional regulation of bovine SIRT4 during adipocyte differentiation, we found that bovine SIRT4 is expressed at high levels in bovine subcutaneous adipose tissue. SIRT4 knockdown led to decreased expression of adipogenic differentiation marker genes during adipocyte differentiation. The core promoter of bovine SIRT4 was identified in the −402/−60 bp region of the cloned 2-kb fragment containing the 5′-regulatory region. Binding sites were identified in this region for E2F transcription factor-1 (E2F1), CCAAT/enhancer-binding protein β (CEBPβ), homeobox A5 (HOXA5), interferon regulatory factor 4 (IRF4), paired box 4 (PAX4), and cAMP responsive element-binding protein 1 (CREB1) by using Electrophoretic mobility shift assay (EMSA) and luciferase reporter gene assay. We also found that E2F1, CEBPβ, and HOXA5 transcriptionally activate SIRT4 expression, whereas, IRF4, PAX4, and CREB1 transcriptionally repress SIRT4 expression. We further verified that SIRT4 knockdown could affect the ability of these transcription factors (TFs) to regulate the differentiation of bovine adipocytes. In conclusion, our results shed light on the mechanisms underlying the transcriptional regulation of SIRT4 expression in bovine adipocytes.

The remarkable diversity of plant PEPC (phosphoenolpyruvate carboxylase): recent insights into the physiological functions and post-translational controls of non-photosynthetic PEPCs

2011 ◽  
Vol 436 (1) ◽  
pp. 15-34 ◽  
Author(s):  
Brendan O'Leary ◽  
Joonho Park ◽  
William C. Plaxton
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Tricarboxylic Acid Cycle ◽  
Critical Role ◽  
Subcellular Location ◽  
Serine Phosphorylation ◽  
Regulatory Subunit ◽  
Physiological Functions ◽  
Intrinsically Disordered ◽  
Class 1

PEPC [PEP (phosphoenolpyruvate) carboxylase] is a tightly controlled enzyme located at the core of plant C-metabolism that catalyses the irreversible β-carboxylation of PEP to form oxaloacetate and Pi. The critical role of PEPC in assimilating atmospheric CO2 during C4 and Crassulacean acid metabolism photosynthesis has been studied extensively. PEPC also fulfils a broad spectrum of non-photosynthetic functions, particularly the anaplerotic replenishment of tricarboxylic acid cycle intermediates consumed during biosynthesis and nitrogen assimilation. An impressive array of strategies has evolved to co-ordinate in vivo PEPC activity with cellular demands for C4–C6 carboxylic acids. To achieve its diverse roles and complex regulation, PEPC belongs to a small multigene family encoding several closely related PTPCs (plant-type PEPCs), along with a distantly related BTPC (bacterial-type PEPC). PTPC genes encode ~110-kDa polypeptides containing conserved serine-phosphorylation and lysine-mono-ubiquitination sites, and typically exist as homotetrameric Class-1 PEPCs. In contrast, BTPC genes encode larger ~117-kDa polypeptides owing to a unique intrinsically disordered domain that mediates BTPC's tight interaction with co-expressed PTPC subunits. This association results in the formation of unusual ~900-kDa Class-2 PEPC hetero-octameric complexes that are desensitized to allosteric effectors. BTPC is a catalytic and regulatory subunit of Class-2 PEPC that is subject to multi-site regulatory phosphorylation in vivo. The interaction between divergent PEPC polypeptides within Class-2 PEPCs adds another layer of complexity to the evolution, physiological functions and metabolic control of this essential CO2-fixing plant enzyme. The present review summarizes exciting developments concerning the functions, post-translational controls and subcellular location of plant PTPC and BTPC isoenzymes.

scholarly journals Light-driven carbon−carbon bond formation via CO2reduction catalyzed by complexes of CdS nanorods and a 2-oxoacid oxidoreductase

2019 ◽  
Vol 117 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Hayden Hamby ◽  
Bin Li ◽  
Katherine E. Shinopoulos ◽  
Helena R. Keller ◽  
Sean J. Elliott ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Enzyme Catalysis ◽  
Transient Absorption ◽  
Tricarboxylic Acid Cycle ◽  
Semiconductor Nanocrystals ◽  
Bond Formation ◽  
Critical Role ◽  
Transient Absorption Spectroscopy ◽  
Carbon Bond ◽  
Carbon Carbon Bond

Redox enzymes are capable of catalyzing a vast array of useful reactions, but they require redox partners that donate or accept electrons. Semiconductor nanocrystals provide a mechanism to convert absorbed photon energy into redox equivalents for enzyme catalysis. Here, we describe a system for photochemical carbon−carbon bond formation to make 2-oxoglutarate by coupling CO2with a succinyl group. Photoexcited electrons from cadmium sulfide nanorods (CdS NRs) transfer to 2-oxoglutarate:ferredoxin oxidoreductase fromMagnetococcus marinusMC-1 (MmOGOR), which catalyzes a carbon−carbon bond formation reaction. We thereby decouple MmOGOR from its native role in the reductive tricarboxylic acid cycle and drive it directly with light. We examine the dependence of 2-oxoglutarate formation on a variety of factors and, using ultrafast transient absorption spectroscopy, elucidate the critical role of electron transfer (ET) from CdS NRs to MmOGOR. We find that the efficiency of this ET depends strongly on whether the succinyl CoA (SCoA) cosubstrate is bound at the MmOGOR active site. We hypothesize that the conformational changes due to SCoA binding impact the CdS NR−MmOGOR interaction in a manner that decreases ET efficiency compared to the enzyme with no cosubstrate bound. Our work reveals structural considerations for the nano−bio interfaces involved in light-driven enzyme catalysis and points to the competing factors of enzyme catalysis and ET efficiency that may arise when complex enzyme reactions are driven by artificial light absorbers.

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