scholarly journals MdFRK2-mediated sugar metabolism accelerates cellulose accumulation in apple and poplar

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jing Su ◽  
Chunxia Zhang ◽  
Lingcheng Zhu ◽  
Nanxiang Yang ◽  
Jingjing Yang ◽  
...  
Keyword(s):  
Carbohydrate Metabolism ◽  
Carbon Flux ◽  
Sugar Metabolism ◽  
Economic Benefits ◽  
Phenotypic Traits ◽  
Cellulose Synthesis ◽  
Sink Strength ◽  
Cellulose Content ◽  
Common Component ◽  
Photosynthetic Carbon

Abstract Background Cellulose is not only a common component in vascular plants, but also has great economic benefits for paper, wood, and industrial products. In addition, its biosynthesis is highly regulated by carbohydrate metabolism and allocation in plant. MdFRK2, which encodes a key fructokinase (FRK) in apple, showed especially high affinity to fructose and regulated carbohydrate metabolism. Results It was observed that overexpression of MdFRK2 in apple decreased sucrose (Suc) and fructose (Fru) with augmented FRK activity in stems, and caused the alterations of many phenotypic traits that include increased cellulose content and an increase in thickness of the phloem region. To further investigate the involved mechanisms, we generated FRK2-OE poplar lines OE#1, OE#4 and OE#9 and discovered (1) that overexpression of MdFRK2 resulted in the huge increased cellulose level by shifting the fructose 6-phosphate or glucose 6-phsophate towards UDPG formation, (2) a direct metabolic pathway for the biosynthesis of cellulose is that increased cleavage of Suc into UDP-glucose (UDPG) for cellulose synthesis via the increased sucrose synthase (SUSY) activity and transcript levels of PtrSUSY1, (3) that the increased FRK activity increases the sink strength overall so there is more carbohydrate available to fuel increased cambial activity and that resulted in more secondary phloem. These results demonstrated that MdFRK2 overexpression would significantly changes the photosynthetic carbon flux from sucrose and hexose to UDPG for increased cellulose synthesis. Conclusions The present data indicated that MdFRK2 overexpression in apple and poplar changes the photosynthetic carbon flux from sucrose and hexose to UDPG for stem cellulose synthesis. A strategy is proposed to increase cellulose production by regulating sugar metabolism as a whole.

scholarly journals Overexpressing MdFRK2-mediated Sugar Metabolism Accelerates Cellulose Accumulation in Apple and Poplar

2021 ◽  
Author(s):  
Jing Su ◽  
Chunxia Zhang ◽  
Lingcheng Zhu ◽  
Nanyang Yang ◽  
Jingjing Yang ◽  
...  
Keyword(s):  
Carbohydrate Metabolism ◽  
Carbon Flux ◽  
Sugar Metabolism ◽  
Economic Benefits ◽  
Phenotypic Traits ◽  
Cellulose Synthesis ◽  
Cellulose Content ◽  
Common Component ◽  
Photosynthetic Carbon ◽  
New Strategy

Abstract Background: Cellulose is not only a common component in vascular plants, but also has great economic benefits for paper, wood, and industrial products. And its biosynthesis is highly regulated by carbohydrate metabolism and allocation in plant. MdFRK2, which encodes a key fructokinase (FRK) in apple, showed especially high affinity to fructose and regulated carbohydrate metabolism. Results: It was observed that overexpression of MdFRK2 in apple decreased sucrose (Suc) and fructose (Fru) with augmented FRK activity in stems, and caused the alterations of many phenotypic traits that include increased cellulose content and thickened primary phloem. To further investigate the involved mechanisms, we generated FRK2-OE poplar lines OE#1, OE#4 and OE#9 and discovered (1) a direct metabolic pathway for the biosynthesis of cellulose is that increased cleavage of Suc into UDP-glucose (UDPG) for cellulose synthesis via the increased sucrose synthase (SUSY) activity and transcript levels of PtrSUSY1, (2) another finding of this study is that overexpression of MdFRK2 resulted in the huge increased cellulose level by shifting the fructose 6-phosphate or glucose 6-phsophate towards UDPG formation, (3) that with increased UDPG in the sink tissue, and therefore more cellulose or hemicellulose can be used to thicker primary phloem. These results demonstrated that MdFRK2 overexpression would significantly changes the photosynthetic carbon flux from sucrose and hexose to UDPG for increased cellulose synthesis.Conclusions: The present data indicated that MdFRK2 overexpression in apple and poplar changes the photosynthetic carbon flux from sucrose and hexose to UDPG for stem cellulose synthesis. A new strategy is proposed to increase cellulose production by regulating sugar metabolism as a whole.

Mismatch between the optimal ages for ecosystem productivity and net CO2 sequestration in Norway spruce forests

2021 ◽  
Author(s):  
Junbin Zhao ◽  
Holger Lange ◽  
Helge Meissner
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
Norway Spruce ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Economic Benefits ◽  
Sink Strength ◽  
Climate Change Scenarios ◽  
Ecosystem Productivity ◽  
Spruce Forests

<p>Forests have climate change mitigation potential since they sequester carbon. However, their carbon sink strength might depend on management. As a result of the balance between CO<sub>2</sub> uptake and emission, forest net ecosystem exchange (NEE) reaches optimal values (maximum sink strength) at young stand ages, followed by a gradual NEE decline over many years. Traditionally, this peak of NEE is believed to be concurrent with the peak of primary production (e.g., gross primary production, GPP); however, in theory, this concurrence may potentially vary depending on tree species, site conditions and the patterns of ecosystem respiration (R<sub>eco</sub>). In this study, we used eddy-covariance (EC)-based CO<sub>2</sub> flux measurements from 8 forest sites that are dominated by Norway spruce (Picea abies L.) and built machine learning models to find the optimal age of ecosystem productivity and that of CO<sub>2</sub> sequestration. We found that the net CO<sub>2</sub> uptake of Norway spruce forests peaked at ages of 30-40 yrs. Surprisingly, this NEE peak did not overlap with the peak of GPP, which appeared later at ages of 60-90 yrs. The mismatch between NEE and GPP was a result of the R<sub>eco</sub> increase that lagged behind the GPP increase associated with the tree growth at early age. Moreover, we also found that newly planted Norway spruce stands had a high probability (up to 90%) of being a C source in the first year, while, at an age as young as 5 yrs, they were likely to be a sink already. Further, using common climate change scenarios, our model results suggest that net CO<sub>2</sub> uptake of Norway spruce forests will increase under the future climate with young stands in the high latitude areas being more beneficial. Overall, the results suggest that forest management practices should consider NEE and forest productivity separately and harvests should be performed only after the optimal ages of both the CO<sub>2</sub> sequestration and productivity to gain full ecological and economic benefits.</p>

scholarly journals Disruption of Very-Long-Chain-Fatty Acid Synthesis Has an Impact on the Dynamics of Cellulose Synthase in Arabidopsis thaliana

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1599
Author(s):  
Xiaoyu Zhu ◽  
Frédérique Tellier ◽  
Ying Gu ◽  
Shundai Li
Keyword(s):  
Fatty Acid ◽  
Cell Biology ◽  
Higher Plants ◽  
Threshold Level ◽  
Cellulose Synthase ◽  
Chain Fatty Acid ◽  
Cellulose Synthesis ◽  
Cellulose Content ◽  
Long Chain Fatty Acid ◽  
Long Chain

In higher plants, cellulose is synthesized by membrane-spanning large protein complexes named cellulose synthase complexes (CSCs). In this study, the Arabidopsis PASTICCINO2 (PAS2) was identified as an interacting partner of cellulose synthases. PAS2 was previously characterized as the plant 3-hydroxy-acyl-CoA dehydratase, an ER membrane-localized dehydratase that is essential for very-long-chain-fatty acid (VLCFA) elongation. The pas2-1 mutants show defective cell elongation and reduction in cellulose content in both etiolated hypocotyls and light-grown roots. Although disruption of VLCFA synthesis by a genetic alteration had a reduction in VLCFA in both etiolated hypocotyls and light-grown roots, it had a differential effect on cellulose content in the two systems, suggesting the threshold level of VLCFA for efficient cellulose synthesis may be different in the two biological systems. pas2-1 had a reduction in both CSC delivery rate and CSC velocity at the PM in etiolated hypocotyls. Interestingly, Golgi but not post-Golgi endomembrane structures exhibited a severe defect in motility. Experiments using pharmacological perturbation of VLCFA content in etiolated hypocotyls strongly indicate a novel function of PAS2 in the regulation of CSC and Golgi motility. Through a combination of genetic, biochemical and cell biology studies, our study demonstrated that PAS2 as a multifunction protein has an important role in the regulation of cellulose biosynthesis in Arabidopsis hypocotyl.

Effects of elevated temperature on sucrose metabolism and cellulose synthesis in cotton fibre during secondary cell wall development

2015 ◽  
Vol 42 (9) ◽  
pp. 909 ◽  
Author(s):  
Yanjiao Dai ◽  
Binglin Chen ◽  
Yali Meng ◽  
Wenqing Zhao ◽  
Zhiguo Zhou ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Sucrose Synthase ◽  
Field Experiments ◽  
Sucrose Metabolism ◽  
Cotton Fibre ◽  
Cellulose Synthesis ◽  
Cellulose Content ◽  
Sucrose Content ◽  
Formation Stage ◽  
Temperature Regimes

Global warming has the potential to increase air temperatures by 1.8 to 4.0°C by the end of the 21st century. In order to reveal the effects of increased temperatures on the sucrose metabolism and cellulose synthesis in cotton fibre during its flowering and boll formation stage, field experiments with elevated temperature regimes (32.6/28.6°C, mean daytime/night-time temperature during flowering and boll formation stage during 2010–12, the same below) and ambient temperature regimes (30.1/25.8°C) were conducted. Activities of sucrose synthase and acid/alkaline invertase decreased under elevated temperature in fibre, but activities of sucrose phosphate synthase were increased. Callose content increased, but sucrose content decreased within the cotton fibre under elevated temperature. The disparity of callose content and sucrose content between the two temperature regimes decreased with the number of days post anthesis, indicating that the effects of elevated temperature on both sucrose content and cellulose content were diminished as the boll matured. Due to the dynamics of the carbohydrate content and associated enzyme activities, we hypothesise that the restrained sucrose metabolism and cellulose biosynthesis under elevated temperatures were mainly attributed to the changed activities of sucrose synthase and invertase. Furthermore, 32.6/28.6°C had a negative effect on the cellulose synthesis compared with 30.1/25.8°C.

scholarly journals Differential Gene Expression of Brachypodium distachyon Roots Colonized by Gluconacetobacter diazotrophicus and the Role of BdCESA8 in the Colonization

2021 ◽  
Author(s):  
Xuan Yang ◽  
Kathleen A. Hill ◽  
Ryan S. Austin ◽  
Lining Tian
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Rna Sequencing ◽  
Crop Production ◽  
Brachypodium Distachyon ◽  
Cellulose Synthesis ◽  
Gibberellin Biosynthesis ◽  
Cellulose Content ◽  
Gluconacetobacter Diazotrophicus ◽  
Nitrogen Fixing

Alternatives to synthetic nitrogen fertilizer are needed to reduce the costs of crop production and offset environmental damage. Nitrogen-fixing bacterium Gluconacetobacter diazotrophicus has been proposed as a possible biofertilizer for monocot crop production. However, the colonization of G. diazotrophicus in most monocot crops is limited and deep understanding of the response of host plants to G. diazotrophicus colonization is still lacking. In this study, the molecular response of the monocot plant model Brachypodium distachyon was studied during G. diazotrophicus root colonization. The gene expression profiles of B. distachyon root tissues colonized by G. diazotrophicus were generated via next-generation RNA sequencing, and investigated through gene ontology and metabolic pathway analysis. The RNA sequencing results indicated that Brachypodium is actively involved in G. diazotrophicus colonization via cell wall synthesis. Jasmonic acid, ethylene, gibberellin biosynthesis. nitrogen assimilation, and primary and secondary metabolite pathways are also modulated to accommodate and control the extent of G. diazotrophicus colonization. Cellulose synthesis is significantly downregulated during colonization. The loss of function mutant for Brachypodium cellulose synthase 8 (BdCESA8) showed decreased cellulose content in xylem and increased resistance to G. diazotrophicus colonization. This result suggested that the cellulose synthesis of the secondary cell wall is involved in G. diazotrophicus colonization. The results of this study provide insights for future research in regard to gene manipulation for efficient colonization of nitrogen-fixing bacteria in Brachypodium and monocot crops. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals Investigation of PtSGT1 and PtSGT4 Function in Cellulose Biosynthesis in Populus tomentosa Using CRISPR/Cas9 Technology

2021 ◽  
Vol 22 (24) ◽  
pp. 13200
Author(s):  
Yinxuan Xue ◽  
Siyan Li ◽  
Deyu Miao ◽  
Sai Huang ◽  
Bin Guo ◽  
...  
Keyword(s):  
Sugar Metabolism ◽  
Populus Tomentosa ◽  
Expression Vectors ◽  
Cellulose Synthesis ◽  
Sequencing Analysis ◽  
Reading Frame ◽  
Glucose Levels ◽  
Wood Processing ◽  
Transgenic Lines ◽  
Metabolism Analysis

Cellulose synthesis is a complex process in plant cells that is important for wood processing, pulping, and papermaking. Cellulose synthesis begins with the glycosylation of sitosterol by sitosterol glycosyltransferase (SGT) to produce sitosterol-glucoside (SG), which acts as the guiding primer for cellulose production. However, the biological functions of SGTs in Populus tomentosa (P. tomentosa) remain largely unknown. Two full-length PtSGT genes (PtSGT1 and PtSGT4) were previously isolated from P. tomentosa and characterized. In the present study, CRISPR/Cas9 gene-editing technology was used to construct PtSGT1-sgRNA and PtSGT4-sgRNA expression vectors, which were genetically transformed into P. tomentosa using the Agrobacterium-mediated method to obtain transgenic lines. Nucleic acid and amino acid sequencing analysis revealed both base insertions and deletions, in addition to reading frame shifts and early termination of translation in the transgenic lines. Sugar metabolism analysis indicated that sucrose and fructose were significantly downregulated in stems and leaves of mutant PtSGT1-1 and PtSGT4-1. Glucose levels did not change significantly in roots and stems of PtSGT1-1 mutants; however, glucose was significantly upregulated in stems and downregulated in leaves of the PtSGT4-1 mutants. Dissection of the plants revealed disordered and loosely arranged xylem cells in the PtSGT4-1 mutant, which were larger and thinner than those of the wild-type. This work will enhance our understanding of cellulose synthesis in the cell walls of woody plants.

scholarly journals Exogenous Application of Low-Concentration Sugar Enhances Brassinosteroid Signaling for Skotomorphogenesis by Promoting BIN2 Degradation

2021 ◽  
Vol 22 (24) ◽  
pp. 13588
Author(s):  
Huachun Sheng ◽  
Shuangxi Zhang ◽  
Yanping Wei ◽  
Shaolin Chen
Keyword(s):  
Plant Growth ◽  
Molecular Mechanisms ◽  
Cellulose Synthesis ◽  
Cellulose Content ◽  
Growth Responses ◽  
Phenotypic Analysis ◽  
Triple Mutant ◽  
Low Concentration ◽  
Etiolated Seedlings ◽  
Dependent Growth

In plants, seedling growth is subtly controlled by multiple environmental factors and endogenous phytohormones. The cross-talk between sugars and brassinosteroid (BR) signaling is known to regulate plant growth; however, the molecular mechanisms that coordinate hormone-dependent growth responses with exogenous sucrose in plants are incompletely understood. Skotomorphogenesis is a plant growth stage with rapid elongation of the hypocotyls. In the present study, we found that low-concentration sugars could improve skotomorphogenesis in a manner dependent on BR biosynthesis and TOR activation. However, accumulation of BZR1 in bzr1-1D mutant plants partially rescued the defects of skotomorphogenesis induced by the TOR inhibitor AZD, and these etiolated seedlings displayed a normal phenotype like that of wild-type seedlings in response to both sucrose and non-sucrose treatments, thereby indicating that accumulated BZR1 sustained, at least partially, the sucrose-promoted growth of etiolated seedlings (skotomorphogenesis). Moreover, genetic evidence based on a phenotypic analysis of bin2-3bil1bil2 triple-mutant and gain-of-function bin2–1 mutant plant indicated that BIN2 inactivation was conducive to skotomorphogenesis in the dark. Subsequent biochemical and molecular analyses enabled us to confirm that sucrose reduced BIN2 levels via the TOR–S6K2 pathway in etiolated seedlings. Combined with a determination of the cellulose content, our results indicated that sucrose-induced BIN2 degradation led to the accumulation of BZR1 and the enhancement of cellulose synthesis, thereby promoting skotomorphogenesis, and that BIN2 is the converging node that integrates sugar and BR signaling.

scholarly journals Engineering of Primary Carbohydrate Metabolism for Increased Production of Actinorhodin in Streptomyces coelicolor

2006 ◽  
Vol 72 (11) ◽  
pp. 7132-7139 ◽  
Author(s):  
Yong-Gu Ryu ◽  
Michael J. Butler ◽  
Keith F. Chater ◽  
Kye Joon Lee
Keyword(s):  
Carbohydrate Metabolism ◽  
Carbon Metabolism ◽  
Carbon Flux ◽  
Streptomyces Coelicolor ◽  
Central Carbon Metabolism ◽  
Acetyl Coenzyme A ◽  
Central Carbon ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Acetyl Coenzyme A Carboxylase ◽  
Central Carbohydrate Metabolism

ABSTRACT The objectives of the current studies were to determine the roles of key enzymes in central carbon metabolism in the context of increased production of antibiotics in Streptomyces coelicolor. Genes for glucose-6-phosphate dehydrogenase and phosphoglucomutase (Pgm) were deleted and those for the acetyl coenzyme A carboxylase (ACCase) were overexpressed. Under the conditions tested, glucose-6-phosphate dehydrogenase encoded by zwf2 plays a more important role than that encoded by zwf1 in determining the carbon flux to actinorhodin (Act), while the function of Pgm encoded by SCO7443 is not clearly understood. The pgm-deleted mutant unexpectedly produced abundant glycogen but was impaired in Act production, the exact reverse of what had been anticipated. Overexpression of the ACCase resulted in more rapid utilization of glucose and sharply increased the efficiency of its conversion to Act. From the current experiments, it is concluded that carbon storage metabolism plays a significant role in precursor supply for Act production and that manipulation of central carbohydrate metabolism can lead to an increased production of Act in S. coelicolor.

scholarly journals Microbiome and Metagenome Analysis Reveals Huanglongbing Affects the Abundance of Citrus Rhizosphere Bacteria Associated with Resistance and Energy Metabolism

Horticulturae ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 151
Author(s):  
Hongfei Li ◽  
Fang Song ◽  
Qiang Xu ◽  
Shu’ang Peng ◽  
Zhiyong Pan ◽  
...  
Keyword(s):  
Microbial Community ◽  
Energy Metabolism ◽  
Carbohydrate Metabolism ◽  
Plant Resistance ◽  
Sugar Metabolism ◽  
Amino Sugar ◽  
Vital Role ◽  
Phosphoinositide Metabolism ◽  
Metagenome Analysis ◽  
Rhizosphere Microbial Community

The plant rhizosphere microbiome is known to play a vital role in plant health by competing with pathogens or inducing plant resistance. This study aims to investigate rhizosphere microorganisms responsive to a devastating citrus disease caused by ‘Candidatus Liberibacter asiaticus’ (CLas) infection, by using 16S rRNA sequencing and metagenome technologies. The results show that 30 rhizosphere and 14 root bacterial genera were significantly affected by CLas infection, including 9 plant resistance-associated bacterial genera. Among these, Amycolatopsis, Sphingopyxis, Chryseobacterium, Flavobacterium, Ralstonia, Stenotrophomonas, Duganella, and Streptacidiphilus were considerably enriched in CLas-infected roots, while Rhizobium was significantly decreased. Metagenome analysis revealed that the abundance of genes involved in carbohydrate metabolism, such as glycolysis, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, was significantly reduced in the CLas-infected citrus rhizosphere microbial community. Likewise, the abundance of genes involved in phosphoinositide signaling and phosphoinositide metabolism, which play important roles in energy metabolism (such as carbohydrate metabolism and lipid metabolism), was also decreased in the CLas-infected samples. Taken together, our results indicate that CLas infection could affect the resistance potential and energy metabolism of the citrus rhizosphere microbial community, which may help us to understand the rhizosphere responses to plant disease and thus facilitate the development and application of antagonistic microorganism products in citrus industry.

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