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Miret JA, Griffiths CA, Paul MJ. Sucrose homeostasis: Mechanisms and opportunity in crop yield improvement. JOURNAL OF PLANT PHYSIOLOGY 2024; 294:154188. [PMID: 38295650 DOI: 10.1016/j.jplph.2024.154188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 03/10/2024]
Abstract
Sugar homeostasis is a critical feature of biological systems. In humans, raised and dysregulated blood sugar is a serious health issue. In plants, directed changes in sucrose homeostasis and allocation represent opportunities in crop improvement. Plant tissue sucrose varies more than blood glucose and is found at higher concentrations (cytosol and phloem ca. 100 mM v 3.9-6.9 mM for blood glucose). Tissue sucrose varies with developmental stage and environment, but cytosol and phloem exhibit tight sucrose control. Sucrose homeostasis is a consequence of the integration of photosynthesis, synthesis of storage end-products such as starch, transport of sucrose to sinks and sink metabolism. Trehalose 6-phosphate (T6P)-SnRK1 and TOR play central, still emerging roles in regulating and coordinating these processes. Overall, tissue sucrose levels are more strongly related to growth than to photosynthesis. As a key sucrose signal, T6P regulates sucrose levels, transport and metabolic pathways to coordinate source and sink at a whole plant level. Emerging evidence shows that T6P interacts with meristems. With careful targeting, T6P manipulation through exploiting natural variation, chemical intervention and genetic modification is delivering benefits for crop yields. Regulation of cereal grain set, filling and retention may be the most strategically important aspect of sucrose allocation and homeostasis for food security.
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Affiliation(s)
- Javier A Miret
- Sustainable Soils and Crops, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Cara A Griffiths
- Sustainable Soils and Crops, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Matthew J Paul
- Sustainable Soils and Crops, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
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2
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Richardson KA, de Bonth ACM, Beechey-Gradwell Z, Kadam S, Cooney LJ, Nelson KA, Cookson R, Winichayakul S, Reid M, Anderson P, Crowther T, Zou X, Maher D, Xue H, Scott RW, Allan A, Johnson RD, Card SD, Mace WJ, Roberts NJ, Bryan G. Epichloë fungal endophyte interactions in perennial ryegrass (Lolium perenne L.) modified to accumulate foliar lipids for increased energy density. BMC PLANT BIOLOGY 2023; 23:636. [PMID: 38072924 PMCID: PMC10712098 DOI: 10.1186/s12870-023-04635-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/26/2023] [Indexed: 12/18/2023]
Abstract
BACKGROUND Commercial cultivars of perennial ryegrass infected with selected Epichloë fungal endophytes are highly desirable in certain pastures as the resulting mutualistic association has the capacity to confer agronomic benefits (such as invertebrate pest deterrence) largely due to fungal produced secondary metabolites (e.g., alkaloids). In this study, we investigated T2 segregating populations derived from two independent transformation events expressing diacylglycerol acyltransferase (DGAT) and cysteine oleosin (CO) genes designed to increase foliar lipid and biomass accumulation. These populations were either infected with Epichloë festucae var. lolii strain AR1 or Epichloë sp. LpTG-3 strain AR37 to examine relationships between the introduced trait and the endophytic association. Here we report on experiments designed to investigate if expression of the DGAT + CO trait in foliar tissues of perennial ryegrass could negatively impact the grass-endophyte association and vice versa. Both endophyte and plant characters were measured under controlled environment and field conditions. RESULTS Expected relative increases in total fatty acids of 17-58% accrued as a result of DGAT + CO expression with no significant difference between the endophyte-infected and non-infected progeny. Hyphal growth in association with DGAT + CO expression appeared normal when compared to control plants in a growth chamber. There was no significant difference in mycelial biomass for both strains AR1 and AR37, however, Epichloë-derived alkaloid concentrations were significantly lower on some occasions in the DGAT + CO plants compared to the corresponding null-segregant progenies, although these remained within the reported range for bioactivity. CONCLUSIONS These results suggest that the mutualistic association formed between perennial ryegrass and selected Epichloë strains does not influence expression of the host DGAT + CO technology, but that endophyte performance may be reduced under some circumstances. Further investigation will now be required to determine the preferred genetic backgrounds for introgression of the DGAT + CO trait in combination with selected endophyte strains, as grass host genetics is a major determinant to the success of the grass-endophyte association in this species.
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Grants
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- contract C10X1603 Ministry of Business, Innovation and Employment
- AgResearch Strategic Science Investment Fund
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Affiliation(s)
- Kim A Richardson
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand.
| | | | | | - Suhas Kadam
- Division of Plant Sciences & Technology, University of Missouri, Columbia, 65201, MO, USA
- Present address: SGS North America, Crop Sciences, Brookings, SD, 57006, USA
| | - Luke J Cooney
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Kelly A Nelson
- Division of Plant Sciences & Technology, University of Missouri, Novelty, 63460, MO, USA
| | - Ruth Cookson
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | | | - Michele Reid
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Philip Anderson
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Tracey Crowther
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Xiuying Zou
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Dorothy Maher
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Hong Xue
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Richard W Scott
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Anne Allan
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Richard D Johnson
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Stuart D Card
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Wade J Mace
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Nicholas J Roberts
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
| | - Gregory Bryan
- Resilient Agriculture, AgResearch Ltd, Palmerston North, 4442, New Zealand
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3
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Cao VD, Luo G, Korynta S, Liu H, Liang Y, Shanklin J, Altpeter F. Intron-mediated enhancement of DIACYLGLYCEROL ACYLTRANSFERASE1 expression in energycane promotes a step change for lipid accumulation in vegetative tissues. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:153. [PMID: 37838699 PMCID: PMC10576891 DOI: 10.1186/s13068-023-02393-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 09/09/2023] [Indexed: 10/16/2023]
Abstract
BACKGROUND Metabolic engineering for hyperaccumulation of lipids in vegetative tissues is a novel strategy for enhancing energy density and biofuel production from biomass crops. Energycane is a prime feedstock for this approach due to its high biomass production and resilience under marginal conditions. DIACYLGLYCEROL ACYLTRANSFERASE (DGAT) catalyzes the last and only committed step in the biosynthesis of triacylglycerol (TAG) and can be a rate-limiting enzyme for the production of TAG. RESULTS In this study, we explored the effect of intron-mediated enhancement (IME) on the expression of DGAT1 and resulting accumulation of TAG and total fatty acid (TFA) in leaf and stem tissues of energycane. To maximize lipid accumulation these evaluations were carried out by co-expressing the lipogenic transcription factor WRINKLED1 (WRI1) and the TAG protect factor oleosin (OLE1). Including an intron in the codon-optimized TmDGAT1 elevated the accumulation of its transcript in leaves by seven times on average based on 5 transgenic lines for each construct. Plants with WRI1 (W), DGAT1 with intron (Di), and OLE1 (O) expression (WDiO) accumulated TAG up to a 3.85% of leaf dry weight (DW), a 192-fold increase compared to non-modified energycane (WT) and a 3.8-fold increase compared to the highest accumulation under the intron-less gene combination (WDO). This corresponded to TFA accumulation of up to 8.4% of leaf dry weight, a 2.8-fold or 6.1-fold increase compared to WDO or WT, respectively. Co-expression of WDiO resulted in stem accumulations of TAG up to 1.14% of DW or TFA up to 2.08% of DW that exceeded WT by 57-fold or 12-fold and WDO more than twofold, respectively. Constitutive expression of these lipogenic "push pull and protect" factors correlated with biomass reduction. CONCLUSIONS Intron-mediated enhancement (IME) of the expression of DGAT resulted in a step change in lipid accumulation of energycane and confirmed that under our experimental conditions it is rate limiting for lipid accumulation. IME should be applied to other lipogenic factors and metabolic engineering strategies. The findings from this study may be valuable in developing a high biomass feedstock for commercial production of lipids and advanced biofuels.
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Affiliation(s)
- Viet Dang Cao
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Gainesville, FL, USA
| | - Guangbin Luo
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Gainesville, FL, USA
| | - Shelby Korynta
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Gainesville, FL, USA
| | - Hui Liu
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, USA
| | - Yuanxue Liang
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, USA
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA.
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, USA.
- Biosciences Department, Brookhaven National Laboratory, Upton, NY, USA.
| | - Fredy Altpeter
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA.
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Gainesville, FL, USA.
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4
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Van Gelder K, Oliveira-Filho ER, Messina CD, Venado RE, Wilker J, Rajasekar S, Ané JM, Amthor JS, Hanson AD. Running the numbers on plant synthetic biology solutions to global problems. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2023; 335:111815. [PMID: 37543223 DOI: 10.1016/j.plantsci.2023.111815] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/30/2023] [Accepted: 08/02/2023] [Indexed: 08/07/2023]
Abstract
Synthetic biology and metabolic engineering promise to deliver sustainable solutions to global problems such as phasing out fossil fuels and replacing industrial nitrogen fixation. While this promise is real, scale matters, and so do knock-on effects of implementing solutions. Both scale and knock-on effects can be estimated by 'Fermi calculations' (aka 'back-of-envelope calculations') that use uncontroversial input data plus simple arithmetic to reach rough but reliable conclusions. Here, we illustrate how this is done and how informative it can be using two cases: oilcane (sugarcane engineered to accumulate triglycerides instead of sugar) as a source of bio-jet fuel, and nitrogen fixation by bacteria in mucilage secreted by maize aerial roots. We estimate that oilcane could meet no more than about 1% of today's U.S. jet fuel demand if grown on all current U.S. sugarcane land and that, if cane land were expanded to meet two-thirds of this demand, the fertilizer and refinery requirements would create a large carbon footprint. Conversely, we estimate that nitrogen fixation in aerial-root mucilage could replace up to 10% of the fertilizer nitrogen applied to U.S. maize, that 2% of plant carbon income used for growth would suffice to fuel the fixation, and that this extra carbon consumption would likely reduce grain yield only slightly.
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Affiliation(s)
- Kristen Van Gelder
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA
| | | | - Carlos D Messina
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA
| | - Rafael E Venado
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jennifer Wilker
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Shanmugam Rajasekar
- Department of Agronomy, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jean-Michel Ané
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Agronomy, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jeffrey S Amthor
- Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Andrew D Hanson
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA.
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5
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Morley SA, Ma F, Alazem M, Frankfater C, Yi H, Burch-Smith T, Clemente TE, Veena V, Nguyen H, Allen DK. Expression of malic enzyme reveals subcellular carbon partitioning for storage reserve production in soybeans. THE NEW PHYTOLOGIST 2023. [PMID: 36829298 DOI: 10.1111/nph.18835] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Central metabolism produces amino and fatty acids for protein and lipids that establish seed value. Biosynthesis of storage reserves occurs in multiple organelles that exchange central intermediates including two essential metabolites, malate, and pyruvate that are linked by malic enzyme. Malic enzyme can be active in multiple subcellular compartments, partitioning carbon and reducing equivalents for anabolic and catabolic requirements. Prior studies based on isotopic labeling and steady-state metabolic flux analyses indicated malic enzyme provides carbon for fatty acid biosynthesis in plants, though genetic evidence confirming this role is lacking. We hypothesized that increasing malic enzyme flux would alter carbon partitioning and result in increased lipid levels in soybeans. Homozygous transgenic soybean plants expressing Arabidopsis malic enzyme alleles, targeting the translational products to plastid or outside the plastid during seed development, were verified by transcript and enzyme activity analyses, organelle proteomics, and transient expression assays. Protein, oil, central metabolites, cofactors, and acyl-acyl carrier protein (ACPs) levels were quantified overdevelopment. Amino and fatty acid levels were altered resulting in an increase in lipids by 0.5-2% of seed biomass (i.e. 2-9% change in oil). Subcellular targeting of a single gene product in central metabolism impacts carbon and reducing equivalent partitioning for seed storage reserves in soybeans.
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Affiliation(s)
- Stewart A Morley
- United States Department of Agriculture, Agricultural Research Service, 975 N Warson Rd, St Louis, MO, 63132, USA
- Donald Danforth Plant Science Center, 975 N Warson Rd, St Louis, MO, 63132, USA
| | - Fangfang Ma
- Donald Danforth Plant Science Center, 975 N Warson Rd, St Louis, MO, 63132, USA
| | - Mazen Alazem
- Donald Danforth Plant Science Center, 975 N Warson Rd, St Louis, MO, 63132, USA
| | - Cheryl Frankfater
- United States Department of Agriculture, Agricultural Research Service, 975 N Warson Rd, St Louis, MO, 63132, USA
- Donald Danforth Plant Science Center, 975 N Warson Rd, St Louis, MO, 63132, USA
| | - Hochul Yi
- Donald Danforth Plant Science Center, 975 N Warson Rd, St Louis, MO, 63132, USA
| | - Tessa Burch-Smith
- Donald Danforth Plant Science Center, 975 N Warson Rd, St Louis, MO, 63132, USA
| | - Tom Elmo Clemente
- Department of Agronomy & Horticulture, University of Nebraska-Lincoln, 202 Keim Hall, Lincoln, NE, 68583, USA
| | - Veena Veena
- Donald Danforth Plant Science Center, 975 N Warson Rd, St Louis, MO, 63132, USA
| | - Hanh Nguyen
- Center for Plant Science Innovation, University of Nebraska, N300 Beadle Center, 1901 Vine St., Lincoln, NE, 68588, USA
| | - Doug K Allen
- United States Department of Agriculture, Agricultural Research Service, 975 N Warson Rd, St Louis, MO, 63132, USA
- Donald Danforth Plant Science Center, 975 N Warson Rd, St Louis, MO, 63132, USA
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6
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Liang Y, Yu X, Anaokar S, Shi H, Dahl WB, Cai Y, Luo G, Chai J, Cai Y, Mollá‐Morales A, Altpeter F, Ernst E, Schwender J, Martienssen RA, Shanklin J. Engineering triacylglycerol accumulation in duckweed (Lemna japonica). PLANT BIOTECHNOLOGY JOURNAL 2023; 21:317-330. [PMID: 36209479 PMCID: PMC9884027 DOI: 10.1111/pbi.13943] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 09/08/2022] [Accepted: 09/30/2022] [Indexed: 05/13/2023]
Abstract
Duckweeds are amongst the fastest growing of higher plants, making them attractive high-biomass targets for biofuel feedstock production. Their fronds have high rates of fatty acid synthesis to meet the demand for new membranes, but triacylglycerols (TAG) only accumulate to very low levels. Here we report on the engineering of Lemna japonica for the synthesis and accumulation of TAG in its fronds. This was achieved by expression of an estradiol-inducible cyan fluorescent protein-Arabidopsis WRINKLED1 fusion protein (CFP-AtWRI1), strong constitutive expression of a mouse diacylglycerol:acyl-CoA acyltransferase2 (MmDGAT), and a sesame oleosin variant (SiOLE(*)). Individual expression of each gene increased TAG accumulation by 1- to 7-fold relative to controls, while expression of pairs of these genes increased TAG by 7- to 45-fold. In uninduced transgenics containing all three genes, TAG accumulation increased by 45-fold to 3.6% of dry weight (DW) without severely impacting growth, and by 108-fold to 8.7% of DW after incubation on medium containing 100 μm estradiol for 4 days. TAG accumulation was accompanied by an increase in total fatty acids of up to three-fold to approximately 15% of DW. Lipid droplets from fronds of all transgenic lines were visible by confocal microscopy of BODIPY-stained fronds. At a conservative 12 tonnes (dry matter) per acre and 10% (DW) TAG, duckweed could produce 350 gallons of oil/acre/year, approximately seven-fold the yield of soybean, and similar to that of oil palm. These findings provide the foundation for optimizing TAG accumulation in duckweed and present a new opportunity for producing biofuels and lipidic bioproducts.
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Affiliation(s)
- Yuanxue Liang
- Biology DepartmentBrookhaven National LaboratoryUptonNYUSA
| | - Xiao‐Hong Yu
- Biology DepartmentBrookhaven National LaboratoryUptonNYUSA
| | - Sanket Anaokar
- Biology DepartmentBrookhaven National LaboratoryUptonNYUSA
| | - Hai Shi
- Biology DepartmentBrookhaven National LaboratoryUptonNYUSA
| | | | - Yingqi Cai
- Biology DepartmentBrookhaven National LaboratoryUptonNYUSA
| | - Guangbin Luo
- Agronomy Department, Genetics InstituteUniversity of FloridaGainesvilleFLUSA
| | - Jin Chai
- Biology DepartmentBrookhaven National LaboratoryUptonNYUSA
| | - Yuanheng Cai
- Biology DepartmentBrookhaven National LaboratoryUptonNYUSA
| | | | - Fredy Altpeter
- Agronomy Department, Genetics InstituteUniversity of FloridaGainesvilleFLUSA
| | - Evan Ernst
- Cold Spring Harbor LaboratoryCold Spring HarborNYUSA
- Howard Hughes Medical InstituteCold Spring Harbor LaboratoryCold Spring HarborNYUSA
| | - Jorg Schwender
- Biology DepartmentBrookhaven National LaboratoryUptonNYUSA
| | - Robert A. Martienssen
- Cold Spring Harbor LaboratoryCold Spring HarborNYUSA
- Howard Hughes Medical InstituteCold Spring Harbor LaboratoryCold Spring HarborNYUSA
| | - John Shanklin
- Biology DepartmentBrookhaven National LaboratoryUptonNYUSA
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7
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Winichayakul S, Macknight R, Le Lievre L, Beechey-Gradwell Z, Lee R, Cooney L, Xue H, Crowther T, Anderson P, Richardson K, Zou X, Maher D, Bryan G, Roberts N. Insight into the regulatory networks underlying the high lipid perennial ryegrass growth under different irradiances. PLoS One 2022; 17:e0275503. [PMID: 36227922 PMCID: PMC9560171 DOI: 10.1371/journal.pone.0275503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/18/2022] [Indexed: 11/19/2022] Open
Abstract
Under favourable conditions, perennial ryegrass (Lolium perenne) engineered to accumulated high lipid (HL) carbon sink in their leaves was previously shown to also enhance photosynthesis and growth. The greater aboveground biomass was found to be diminished in a dense canopy compared to spaced pots. Besides, the underlying genetic regulatory network linking between leaf lipid sinks and these physiological changes remains unknown. In this study, we demonstrated that the growth advantage was not displayed in HL Lolium grown in spaced pots under low lights. Under standard lights, analysis of differentiating transcripts in HL Lolium reveals that the plants had elevated transcripts involved in lipid metabolism, light capturing, photosynthesis, and sugar signalling while reduced expression of genes participating in sugar biosynthesis and transportation. The plants also had altered several transcripts involved in mitochondrial oxidative respiration and redox potential. Many of the above upregulated or downregulated transcript levels were found to be complemented by growing the plants under low light. Overall, this study emphasizes the importance of carbon and energy homeostatic regulatory mechanisms to overall productivity of the HL Lolium through photosynthesis, most of which are significantly impacted by low irradiances.
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Affiliation(s)
| | - Richard Macknight
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Liam Le Lievre
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | | | - Robyn Lee
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Luke Cooney
- AgResearch Ltd., Palmerston North, New Zealand
| | - Hong Xue
- AgResearch Ltd., Palmerston North, New Zealand
| | | | | | | | - Xiuying Zou
- AgResearch Ltd., Palmerston North, New Zealand
| | | | | | - Nick Roberts
- AgResearch Ltd., Palmerston North, New Zealand
- * E-mail: (SW); (NR)
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8
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Kannan B, Liu H, Shanklin J, Altpeter F. Towards oilcane: preliminary field evaluation of metabolically engineered sugarcane with hyper-accumulation of triacylglycerol in vegetative tissues. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2022; 42:64. [PMID: 37313011 PMCID: PMC10248597 DOI: 10.1007/s11032-022-01333-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/24/2022] [Indexed: 06/15/2023]
Abstract
We recently generated oilcane, a metabolically engineered sugarcane with hyper-accumulation of energy dense triacylglycerol in vegetative tissues. Refinement of this strategy in high biomass crops like sugarcane may result in elevated lipid yields that exceed traditional oilseed crops for biodiesel production. This is the first report of agronomic performance, stable co-expression of lipogenic factors, and TAG accumulation in transgenic sugarcane under field conditions. Co-expression of WRI1; DGAT1, OLE1, and RNAi suppression of PXA1 was stable during the 2-year field evaluation and resulted in TAG accumulation up to 4.4% of leaf DW. This TAG accumulation was 70-fold higher than in non-transgenic sugarcane and more than 2-fold higher than previously reported for the same line under greenhouse conditions. TAG accumulation correlated highest with the expression of WRI1. However, constitutive expression of WRI1 was negatively correlated with biomass accumulation. Transgenic lines without WRI1 expression accumulated TAG up to 1.6% of leaf DW and displayed no biomass yield penalty in the plant cane. These findings confirm sugarcane as a promising platform for the production of vegetative lipids and will be used to inform strategies to maximize future biomass and lipid yields. The main conclusion is that constitutive expression of WRI1 in combination with additional lipogenic factors (DGAT1-2, OLE1, PXA1) in sugarcane under field conditions leads to hyper-accumulation of TAG and reduces biomass yield. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-022-01333-5.
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Affiliation(s)
- Baskaran Kannan
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL USA
| | - Hui Liu
- Biosciences Department, Brookhaven National Laboratory, Upton, Brookhaven, NY USA
| | - John Shanklin
- Biosciences Department, Brookhaven National Laboratory, Upton, Brookhaven, NY USA
| | - Fredy Altpeter
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL USA
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9
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Winichayakul S, Curran A, Moraga R, Cookson R, Xue H, Crowther T, Roldan M, Bryan G, Roberts N. An alternative angiosperm DGAT1 topology and potential motifs in the N-terminus. FRONTIERS IN PLANT SCIENCE 2022; 13:951389. [PMID: 36186081 PMCID: PMC9523541 DOI: 10.3389/fpls.2022.951389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 08/05/2022] [Indexed: 06/16/2023]
Abstract
The highly variable cytoplasmic N-terminus of the plant diacylglycerol acyltransferase 1 (DGAT1) has been shown to have roles in oligomerization as well as allostery; however, the biological significance of the variation within this region is not understood. Comparing the coding sequences over the variable N-termini revealed the Poaceae DGAT1s contain relatively high GC compositional gradients as well as numerous direct and inverted repeats in this region. Using a variety of reciprocal chimeric DGAT1s from angiosperms we show that related N-termini had similar effects (positive or negative) on the accumulation of the recombinant protein in Saccharomyces cerevisiae. When expressed in Camelina sativa seeds the recombinant proteins of specific chimeras elevated total lipid content of the seeds as well as increased seed size. In addition, we combine N- and C-terminal as well as internal tags with high pH membrane reformation, protease protection and differential permeabilization. This led us to conclude the C-terminus is in the ER lumen; this contradicts earlier reports of the cytoplasmic location of plant DGAT1 C-termini.
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Affiliation(s)
- Somrutai Winichayakul
- Resilient Agriculture Innovation Centre of Excellence, AgResearch Ltd., Palmerston North, New Zealand
| | - Amy Curran
- ZeaKal Inc., San Diego, CA, United States
| | - Roger Moraga
- Bioinformatics and Statistics, AgResearch Ltd., Palmerston North, New Zealand
| | - Ruth Cookson
- Resilient Agriculture Innovation Centre of Excellence, AgResearch Ltd., Palmerston North, New Zealand
| | - Hong Xue
- Resilient Agriculture Innovation Centre of Excellence, AgResearch Ltd., Palmerston North, New Zealand
| | - Tracey Crowther
- Resilient Agriculture Innovation Centre of Excellence, AgResearch Ltd., Palmerston North, New Zealand
| | - Marissa Roldan
- Resilient Agriculture Innovation Centre of Excellence, AgResearch Ltd., Palmerston North, New Zealand
| | - Greg Bryan
- Resilient Agriculture Innovation Centre of Excellence, AgResearch Ltd., Palmerston North, New Zealand
- ZeaKal Inc., San Diego, CA, United States
| | - Nick Roberts
- Resilient Agriculture Innovation Centre of Excellence, AgResearch Ltd., Palmerston North, New Zealand
- ZeaKal Inc., San Diego, CA, United States
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10
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Luo G, Cao VD, Kannan B, Liu H, Shanklin J, Altpeter F. Metabolic engineering of energycane to hyperaccumulate lipids in vegetative biomass. BMC Biotechnol 2022; 22:24. [PMID: 36042455 PMCID: PMC9425976 DOI: 10.1186/s12896-022-00753-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 08/18/2022] [Indexed: 11/24/2022] Open
Abstract
Background The metabolic engineering of high-biomass crops for lipid production in their vegetative biomass has recently been proposed as a strategy to elevate energy density and lipid yields for biodiesel production. Energycane and sugarcane are highly polyploid, interspecific hybrids between Saccharum officinarum and Saccharum spontaneum that differ in the amount of ancestral contribution to their genomes. This results in greater biomass yield and persistence in energycane, which makes it the preferred target crop for biofuel production. Results Here, we report on the hyperaccumulation of triacylglycerol (TAG) in energycane following the overexpression of the lipogenic factors Diacylglycerol acyltransferase1-2 (DGAT1-2) and Oleosin1 (OLE1) in combination with RNAi suppression of SUGAR-DEPENDENT1 (SDP1) and Trigalactosyl diacylglycerol1 (TGD1). TAG accumulated up to 1.52% of leaf dry weight (DW,) a rate that was 30-fold that of non-modified energycane, in addition to almost doubling the total fatty acid content in leaves to 4.42% of its DW. Pearson’s correlation analysis showed that the accumulation of TAG had the highest correlation with the expression level of ZmDGAT1-2, followed by the level of RNAi suppression for SDP1. Conclusions This is the first report on the metabolic engineering of energycane and demonstrates that this resilient, high-biomass crop is an excellent target for the further optimization of the production of lipids from vegetative tissues. Supplementary Information The online version contains supplementary material available at 10.1186/s12896-022-00753-7.
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Affiliation(s)
- Guangbin Luo
- Plant Molecular and Cellular Biology Program, Agronomy Department, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
| | - Viet Dang Cao
- Plant Molecular and Cellular Biology Program, Agronomy Department, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
| | - Baskaran Kannan
- Plant Molecular and Cellular Biology Program, Agronomy Department, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
| | - Hui Liu
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA.
| | - Fredy Altpeter
- Plant Molecular and Cellular Biology Program, Agronomy Department, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA.
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11
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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12
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Clark TJ, Schwender J. Elucidation of Triacylglycerol Overproduction in the C 4 Bioenergy Crop Sorghum bicolor by Constraint-Based Analysis. FRONTIERS IN PLANT SCIENCE 2022; 13:787265. [PMID: 35251073 PMCID: PMC8892208 DOI: 10.3389/fpls.2022.787265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Upregulation of triacylglycerols (TAGs) in vegetative plant tissues such as leaves has the potential to drastically increase the energy density and biomass yield of bioenergy crops. In this context, constraint-based analysis has the promise to improve metabolic engineering strategies. Here we present a core metabolism model for the C4 biomass crop Sorghum bicolor (iTJC1414) along with a minimal model for photosynthetic CO2 assimilation, sucrose and TAG biosynthesis in C3 plants. Extending iTJC1414 to a four-cell diel model we simulate C4 photosynthesis in mature leaves with the principal photo-assimilatory product being replaced by TAG produced at different levels. Independent of specific pathways and per unit carbon assimilated, energy content and biosynthetic demands in reducing equivalents are about 1.3 to 1.4 times higher for TAG than for sucrose. For plant generic pathways, ATP- and NADPH-demands per CO2 assimilated are higher by 1.3- and 1.5-fold, respectively. If the photosynthetic supply in ATP and NADPH in iTJC1414 is adjusted to be balanced for sucrose as the sole photo-assimilatory product, overproduction of TAG is predicted to cause a substantial surplus in photosynthetic ATP. This means that if TAG synthesis was the sole photo-assimilatory process, there could be an energy imbalance that might impede the process. Adjusting iTJC1414 to a photo-assimilatory rate that approximates field conditions, we predict possible daily rates of TAG accumulation, dependent on varying ratios of carbon partitioning between exported assimilates and accumulated oil droplets (TAG, oleosin) and in dependence of activation of futile cycles of TAG synthesis and degradation. We find that, based on the capacity of leaves for photosynthetic synthesis of exported assimilates, mature leaves should be able to reach a 20% level of TAG per dry weight within one month if only 5% of the photosynthetic net assimilation can be allocated into oil droplets. From this we conclude that high TAG levels should be achievable if TAG synthesis is induced only during a final phase of the plant life cycle.
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Affiliation(s)
- Teresa J. Clark
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
| | - Jorg Schwender
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
- Department of Energy Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, United States
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13
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Chu KL, Koley S, Jenkins LM, Bailey SR, Kambhampati S, Foley K, Arp JJ, Morley SA, Czymmek KJ, Bates PD, Allen DK. Metabolic flux analysis of the non-transitory starch tradeoff for lipid production in mature tobacco leaves. Metab Eng 2022; 69:231-248. [PMID: 34920088 PMCID: PMC8761171 DOI: 10.1016/j.ymben.2021.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 10/12/2021] [Accepted: 12/11/2021] [Indexed: 12/19/2022]
Abstract
The metabolic plasticity of tobacco leaves has been demonstrated via the generation of transgenic plants that can accumulate over 30% dry weight as triacylglycerols. In investigating the changes in carbon partitioning in these high lipid-producing (HLP) leaves, foliar lipids accumulated stepwise over development. Interestingly, non-transient starch was observed to accumulate with plant age in WT but not HLP leaves, with a drop in foliar starch concurrent with an increase in lipid content. The metabolic carbon tradeoff between starch and lipid was studied using 13CO2-labeling experiments and isotopically nonstationary metabolic flux analysis, not previously applied to the mature leaves of a crop. Fatty acid synthesis was investigated through assessment of acyl-acyl carrier proteins using a recently derived quantification method that was extended to accommodate isotopic labeling. Analysis of labeling patterns and flux modeling indicated the continued production of unlabeled starch, sucrose cycling, and a significant contribution of NADP-malic enzyme to plastidic pyruvate production for the production of lipids in HLP leaves, with the latter verified by enzyme activity assays. The results suggest an inherent capacity for a developmentally regulated carbon sink in tobacco leaves and may in part explain the uniquely successful leaf lipid engineering efforts in this crop.
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Affiliation(s)
- Kevin L Chu
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Somnath Koley
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Lauren M Jenkins
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Sally R Bailey
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA; United States Department of Agriculture-Agriculture Research Service, Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | | | - Kevin Foley
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Jennifer J Arp
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Stewart A Morley
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA; United States Department of Agriculture-Agriculture Research Service, Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Kirk J Czymmek
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Philip D Bates
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164-6340, USA
| | - Doug K Allen
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA; United States Department of Agriculture-Agriculture Research Service, Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA.
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14
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Ojha R, Kaur S, Sinha K, Chawla K, Kaur S, Jadhav H, Kaur M, Bhunia RK. Characterization of oleosin genes from forage sorghum in Arabidopsis and yeast reveals their role in storage lipid stability. PLANTA 2021; 254:97. [PMID: 34655341 DOI: 10.1007/s00425-021-03744-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
Overexpression of forage sorghum oleosin genes in Arabidopsis oleosin-deficient mutant and yeast showed increased germination rate, triacylglycerol content, and protection against lipase-mediated TAG degradation. Plant lipids are an important source of ration for cattle or other livestock animals to fulfil their energy needs. Poor energy containing green forages are still one of the major sources of food for livestock animals, leaving the animals undernourished. This lowers the milk and meat production efficiency, thereby affecting human consumption. Oleosin, an essential oil body surface protein, is capable of enhancing and stabilizing the lipid content in plants. We identified and functionally characterized three forage sorghum oleosin genes (SbOle1, SbOle2, and SbOle3) in Arabidopsis and yeast. Phylogenetic analysis of SbOle proteins showed a close relationship with rice and maize oleosins. Expression analysis of SbOle genes determined a higher expression pattern in embryo followed by endosperm, while its expression in the non-seed tissues remained negligible. Overexpression of SbOle genes in Arabidopsis ole1-deficient mutants showed restoration of normal germination whereas control mutant seeds showed lower germination rates. Heterologous overexpression of SbOle in yeast cells resulted in increased TAG accumulation. Additionally, the TAG turnover assay showed the effectiveness of SbOle genes in reducing the yeast endogenous and rumen bacterial lipase-mediated TAG degradation. Taken together, our findings not only provide insights into forage sorghum oleosin for increasing the energy content in non-seed organs but also opened up the direction towards implication of oleosin in rumen protection of fodders.
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Affiliation(s)
- Rabishankar Ojha
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), Mohali, Punjab, 140306, India
| | - Simranjit Kaur
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), Mohali, Punjab, 140306, India
| | - Kshitija Sinha
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), Mohali, Punjab, 140306, India
- Department of Biotechnology, Panjab University, Sector-25, Chandigarh, 160014, India
| | - Kirti Chawla
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), Mohali, Punjab, 140306, India
| | - Sumandeep Kaur
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), Mohali, Punjab, 140306, India
- Department of Biotechnology, Panjab University, Sector-25, Chandigarh, 160014, India
| | - Harish Jadhav
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), Mohali, Punjab, 140306, India
| | - Manmehar Kaur
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), Mohali, Punjab, 140306, India
- Department of Biotechnology, Panjab University, Sector-25, Chandigarh, 160014, India
| | - Rupam Kumar Bhunia
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), Mohali, Punjab, 140306, India.
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15
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Paul MJ. Improving Photosynthetic Metabolism for Crop Yields: What Is Going to Work? FRONTIERS IN PLANT SCIENCE 2021; 12:743862. [PMID: 34621287 PMCID: PMC8490674 DOI: 10.3389/fpls.2021.743862] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 08/24/2021] [Indexed: 05/05/2023]
Affiliation(s)
- Matthew J. Paul
- Plant Science, Rothamsted Research, Harpenden, United Kingdom
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16
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Singh R, Arora A, Singh V. Biodiesel from oil produced in vegetative tissues of biomass - A review. BIORESOURCE TECHNOLOGY 2021; 326:124772. [PMID: 33551280 DOI: 10.1016/j.biortech.2021.124772] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 06/12/2023]
Abstract
Biodiesel is a green, renewable alternative to petroleum-derived diesel. However, using vegetable oil for biodiesel production significantly challenges the food security. Progress in metabolic engineering, understanding of lipid biosynthesis and storage have enabled engineering of vegetative tissues of plants such as sugarcane, sorghum, and tobacco for lipid production. Such sources could be cultivated on land resources, which are currently not suitable for row crops. Besides achieving significant lipid accumulation, it is imperative to maintain the fatty acid and lipid profile ideal for biodiesel production and engine performance. In this study, genetic modifications used to induce lipid accumulation in transgenic crops and the proposed strategies for efficient recovery of oil from these crops have been presented. This paper highlights that lipids sourced from vegetative biomass in their native form would pose significant challenges in biodiesel production. Therefore, different strategies have been presented for improving feedstock quality to achieve high-quality biodiesel production.
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Affiliation(s)
- Ramkrishna Singh
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, 1304 W. Pennsylvania Avenue, Urbana, IL 61801, USA; Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Amit Arora
- Indian Institute of Technology Bombay, Powai, Mumbai 400076, India; Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Vijay Singh
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, 1304 W. Pennsylvania Avenue, Urbana, IL 61801, USA; Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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17
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Cooney LJ, Beechey-Gradwell Z, Winichayakul S, Richardson KA, Crowther T, Anderson P, Scott RW, Bryan G, Roberts NJ. Changes in Leaf-Level Nitrogen Partitioning and Mesophyll Conductance Deliver Increased Photosynthesis for Lolium perenne Leaves Engineered to Accumulate Lipid Carbon Sinks. FRONTIERS IN PLANT SCIENCE 2021; 12:641822. [PMID: 33897730 PMCID: PMC8063613 DOI: 10.3389/fpls.2021.641822] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/11/2021] [Indexed: 06/12/2023]
Abstract
Diacylglycerol acyl-transferase (DGAT) and cysteine oleosin (CO) expression confers a novel carbon sink (of encapsulated lipid droplets) in leaves of Lolium perenne and has been shown to increase photosynthesis and biomass. However, the physiological mechanism by which DGAT + CO increases photosynthesis remains unresolved. To evaluate the relationship between sink strength and photosynthesis, we examined fatty acids (FA), water-soluble carbohydrates (WSC), gas exchange parameters and leaf nitrogen for multiple DGAT + CO lines varying in transgene accumulation. To identify the physiological traits which deliver increased photosynthesis, we assessed two important determinants of photosynthetic efficiency, CO2 conductance from atmosphere to chloroplast, and nitrogen partitioning between different photosynthetic and non-photosynthetic pools. We found that DGAT + CO accumulation increased FA at the expense of WSC in leaves of L. perenne and for those lines with a significant reduction in WSC, we also observed an increase in photosynthesis and photosynthetic nitrogen use efficiency. DGAT + CO L. perenne displayed no change in rubisco content or Vcmax but did exhibit a significant increase in specific leaf area (SLA), stomatal and mesophyll conductance, and leaf nitrogen allocated to photosynthetic electron transport. Collectively, we showed that increased carbon demand via DGAT+CO lipid sink accumulation can induce leaf-level changes in L. perenne which deliver increased rates of photosynthesis and growth. Carbon sinks engineered within photosynthetic cells provide a promising new strategy for increasing photosynthesis and crop productivity.
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18
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Ji H, Liu D, Yang Z. High oil accumulation in tuber of yellow nutsedge compared to purple nutsedge is associated with more abundant expression of genes involved in fatty acid synthesis and triacylglycerol storage. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:54. [PMID: 33653389 PMCID: PMC7923336 DOI: 10.1186/s13068-021-01909-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/18/2021] [Indexed: 05/10/2023]
Abstract
BACKGROUND Yellow nutsedge is a unique plant species that can accumulate up to 35% oil of tuber dry weight, perhaps the highest level observed in the tuber tissues of plant kingdom. To gain insight into the molecular mechanism that leads to high oil accumulation in yellow nutsedge, gene expression profiles of oil production pathways involved carbon metabolism, fatty acid synthesis, triacylglycerol synthesis, and triacylglycerol storage during tuber development were compared with purple nutsedge, the closest relative of yellow nutsedge that is poor in oil accumulation. RESULTS Compared with purple nutsedge, high oil accumulation in yellow nutsedge was associated with significant up-regulation of specific key enzymes of plastidial RubisCO bypass as well as malate and pyruvate metabolism, almost all fatty acid synthesis enzymes, and seed-like oil-body proteins. However, overall transcripts for carbon metabolism toward carbon precursor for fatty acid synthesis were comparable and for triacylglycerol synthesis were similar in both species. Two seed-like master transcription factors ABI3 and WRI1 were found to display similar transcript patterns but were expressed at 6.5- and 14.3-fold higher levels in yellow nutsedge than in purple nutsedge, respectively. A weighted gene co-expression network analysis revealed that ABI3 was in strong transcriptional coordination with WRI1 and other key oil-related genes. CONCLUSIONS These results implied that pyruvate availability and fatty acid synthesis in plastid, along with triacylglycerol storage in oil bodies, rather than triacylglycerol synthesis in endoplasmic reticulum, are the major factors responsible for high oil production in tuber of yellow nutsedge, and ABI3 most likely plays a critical role in regulating oil accumulation. This study is of significance with regard to understanding the molecular mechanism controlling carbon partitioning toward oil production in oil-rich tuber and provides a valuable reference for enhancing oil accumulation in non-seed tissues of crops through genetic breeding or metabolic engineering.
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Affiliation(s)
- Hongying Ji
- Key Lab of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Dantong Liu
- Key Lab of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Zhenle Yang
- Key Lab of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093 China
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19
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Anaokar S, Liu H, Keereetaweep J, Zhai Z, Shanklin J. Mobilizing Vacuolar Sugar Increases Vegetative Triacylglycerol Accumulation. FRONTIERS IN PLANT SCIENCE 2021; 12:708902. [PMID: 34456949 PMCID: PMC8388850 DOI: 10.3389/fpls.2021.708902] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/02/2021] [Indexed: 05/11/2023]
Abstract
Photosynthetically derived sugars provide carbon skeletons for metabolism and carbon signals that favor anabolism. The amount of sugar available for fatty acid (FA) and triacylglycerol (TAG) synthesis depends on sugar compartmentation, transport, and demands from competing pathways. We are exploring the influence of sugar partitioning between the vacuole and cytoplasm on FA synthesis in Arabidopsis by building on our previous finding that reduced leaf sugar export in the sucrose-proton symporter2 (suc2) mutant, in combination with impaired starch synthesis in the ADP-glucose pyrophosphorylase (adg1) mutant, accumulates higher sugar levels and increased total FA and TAG compared to the wild type parent. Here we sought to relocalize sugar from the vacuole to the cytoplasm to drive additional FA/TAG synthesis and growth. Arabidopsis suc2 adg1 was therefore crossed with tonoplast monosaccharide transporter mutants tmt1 and tmt2 and overexpression of the sucrose/proton cotransporter SUC4 in which tmt1 tmt2 impairs sugar transport to the vacuole from the cytoplasm and SUC4 overexpression enhances sugar transport in the reverse direction from the vacuole to the cytoplasm. A resulting homozygous suc2 adg1 tmt1 tmt2 SUC4 line was used to test the hypothesis that increased intracellular carbon supply in the form of sugars would increase both FA and TAG accumulation. The data shows that relative to suc2 adg1, suc2 adg1 tmt1 tmt2 SUC4 significantly increases leaf total FA content by 1.29-fold to 10.9% of dry weight and TAG by 2.4-fold to 2.88%, supporting the hypothesis that mobilizing vacuolar sugar is a valid strategy for increasing vegetative oil accumulation.
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20
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Geddes-McAlister J, Sukumaran A, Patchett A, Hager HA, Dale JCM, Roloson JL, Prudhomme N, Bolton K, Muselius B, Powers J, Newman JA. Examining the Impacts of CO 2 Concentration and Genetic Compatibility on Perennial Ryegrass- Epichloë festucae var lolii Interactions. J Fungi (Basel) 2020; 6:jof6040360. [PMID: 33322591 PMCID: PMC7770580 DOI: 10.3390/jof6040360] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 12/12/2022] Open
Abstract
Perennial ryegrass (Lolium perenne) is the most cultivated cool-season grass worldwide with crucial roles in carbon fixation, turfgrass applications, and fodder for livestock. Lolium perenne forms a mutualism with the strictly vertically transmitted fungal endophyte, Epichloë festucae var lolii. The fungus produces alkaloids that protect the grass from herbivory, as well as conferring protection from drought and nutrient stress. The rising concentration of atmospheric CO2, a proximate cause of climatic change, is known to have many direct and indirect effects on plant growth. There is keen interest in how the nature of this plant-fungal interaction will change with climate change. Lolium perenne is an obligately outcrossing species, meaning that the genetic profile of the host is constantly being reshuffled. Meanwhile, the fungus is asexual implying both a relatively constant genetic profile and the potential for incompatible grass-fungus pairings. In this study, we used a single cultivar, "Alto", of L. perenne. Each plant was infected with one of four strains of the endophyte: AR1, AR37, NEA2, and Lp19 (the "common strain"). We outcrossed the Alto mothers with pollen from a number of individuals from different ryegrass cultivars to create more genetic diversity in the hosts. We collected seed such that we had replicate maternal half-sib families. Seed from each family was randomly allocated into the two levels of the CO2 treatment, 400 and 800 ppm. Elevated CO2 resulted in an c. 18% increase in plant biomass. AR37 produced higher fungal concentrations than other strains; NEA2 produced the lowest fungal concentrations. We did not find evidence of genetic incompatibility between the host plants and the fungal strains. We conducted untargeted metabolomics and quantitative proteomics to investigate the grass-fungus interactions between and within family and treatment groups. We identified a number of changes in both the proteome and metabalome. Taken together, our data set provides new understanding into the intricacy of the interaction between endophyte and host from multiple molecular levels and suggests opportunity to promote plant robustness and survivability in rising CO2 environmental conditions through application of bioprotective epichloid strains.
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Affiliation(s)
- Jennifer Geddes-McAlister
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.S.); (N.P.); (B.M.)
- Mass Spectrometry Facility—Advanced Analysis Centre, University of Guelph, Guelph, ON N1G 2W1, Canada
- Correspondence: (J.G.-M.); (J.A.N.)
| | - Arjun Sukumaran
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.S.); (N.P.); (B.M.)
| | - Aurora Patchett
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Heather A. Hager
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Jenna C. M. Dale
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Jennifer L. Roloson
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Nicholas Prudhomme
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.S.); (N.P.); (B.M.)
| | - Kim Bolton
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Benjamin Muselius
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.S.); (N.P.); (B.M.)
| | - Jacqueline Powers
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Jonathan A. Newman
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
- Correspondence: (J.G.-M.); (J.A.N.)
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21
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Andrews M, Condron LM, Kemp PD, Topping JF, Lindsey K, Hodge S, Raven JA. Will rising atmospheric CO 2 concentration inhibit nitrate assimilation in shoots but enhance it in roots of C 3 plants? PHYSIOLOGIA PLANTARUM 2020; 170:40-45. [PMID: 32198758 DOI: 10.1111/ppl.13096] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/17/2020] [Indexed: 05/13/2023]
Abstract
Bloom et al. proposed that rising atmospheric CO2 concentrations 'inhibit malate production in chloroplasts and thus impede assimilation of nitrate into protein of C3 plants, a phenomenon that will strongly influence primary productivity and food security under the environmental conditions anticipated during the next few decades'. Previously we argued that the weight of evidence in the literature indicated that elevated atmospheric [CO2 ] does not inhibit NO3 - assimilation in C3 plants. New data for common bean (Phaseolus vulgaris) and wheat (Triticum aestivum) were presented that supported this view and indicated that the effects of elevated atmospheric [CO2 ] on nitrogen (N) assimilation and growth of C3 vascular plants were similar regardless of the form of N assimilated. Bloom et al. strongly criticised the arguments presented in Andrews et al. Here we respond to these criticisms and again conclude that the available data indicate that elevated atmospheric [CO2 ] does not inhibit NO3 - assimilation of C3 plants. Measurement of the partitioning of NO3 - assimilation between root and shoot of C3 species under different NO3 - supply, at ambient and elevated CO2 would determine if their NO3 - assimilation is inhibited in shoots but enhanced in roots at elevated atmospheric CO2 .
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Affiliation(s)
- Mitchell Andrews
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln, 7647, New Zealand
| | - Leo M Condron
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln, 7647, New Zealand
| | - Peter D Kemp
- Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Jennifer F Topping
- The Integrative Cell Biology Laboratory, Department of Biosciences, Durham University, Durham, DH1 3LE, UK
| | - Keith Lindsey
- The Integrative Cell Biology Laboratory, Department of Biosciences, Durham University, Durham, DH1 3LE, UK
| | - Simon Hodge
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln, 7647, New Zealand
| | - John A Raven
- Division of Plant Science, University of Dundee at the James Hutton Institute, Dundee, DD2 5DA, UK
- School of Plant Biology, University of Western Australia, Crawley, WA, 6009, Australia
- Climate Change Cluster, University of Technology, Sydney, NSW, 2007, Australia
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22
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Lechowicz K, Pawłowicz I, Perlikowski D, Arasimowicz-Jelonek M, Blicharz S, Skirycz A, Augustyniak A, Malinowski R, Rapacz M, Kosmala A. Adjustment of Photosynthetic and Antioxidant Activities to Water Deficit Is Crucial in the Drought Tolerance of Lolium multiflorum/Festuca arundinacea Introgression Forms. Int J Mol Sci 2020; 21:ijms21165639. [PMID: 32781659 PMCID: PMC7460672 DOI: 10.3390/ijms21165639] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 07/28/2020] [Accepted: 07/31/2020] [Indexed: 01/03/2023] Open
Abstract
Lolium multiflorum/Festuca arundinacea introgression forms have been proved several times to be good models to identify key components of grass metabolism involved in the mechanisms of tolerance to water deficit. Here, for the first time, a relationship between photosynthetic and antioxidant capacities with respect to drought tolerance of these forms was analyzed in detail. Two closely related L. multiflorum/F. arundinacea introgression forms distinct in their ability to re-grow after cessation of prolonged water deficit in the field were selected and subjected to short-term drought in pots to dissect precisely mechanisms of drought tolerance in this group of plants. The studies revealed that the form with higher drought tolerance was characterized by earlier and higher accumulation of abscisic acid, more stable cellular membranes, and more balanced reactive oxygen species metabolism associated with a higher capacity of the antioxidant system under drought conditions. On the other hand, both introgression forms revealed the same levels of stomatal conductance, CO2 assimilation, and consequently, intrinsic water use efficiency under drought and recovery conditions. However, simultaneous higher adjustment of the Calvin cycle to water deficit and reduced CO2 availability, with respect to the accumulation and activity of plastid fructose-1,6-bisphosphate aldolase, were clearly visible in the form with higher drought tolerance.
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Affiliation(s)
- Katarzyna Lechowicz
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (K.L.); (D.P.); (S.B.); (A.A.); (R.M.); (A.K.)
| | - Izabela Pawłowicz
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (K.L.); (D.P.); (S.B.); (A.A.); (R.M.); (A.K.)
- Correspondence:
| | - Dawid Perlikowski
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (K.L.); (D.P.); (S.B.); (A.A.); (R.M.); (A.K.)
| | - Magdalena Arasimowicz-Jelonek
- Department of Plant Ecophysiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland;
| | - Sara Blicharz
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (K.L.); (D.P.); (S.B.); (A.A.); (R.M.); (A.K.)
| | - Aleksandra Skirycz
- Department of Molecular Physiology, Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany;
| | - Adam Augustyniak
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (K.L.); (D.P.); (S.B.); (A.A.); (R.M.); (A.K.)
| | - Robert Malinowski
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (K.L.); (D.P.); (S.B.); (A.A.); (R.M.); (A.K.)
| | - Marcin Rapacz
- Department of Plant Breeding, Physiology and Seed Science, University of Agriculture in Kraków, Podłużna 3, 30-239 Kraków, Poland;
| | - Arkadiusz Kosmala
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (K.L.); (D.P.); (S.B.); (A.A.); (R.M.); (A.K.)
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23
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Evans JR, Lawson T. From green to gold: agricultural revolution for food security. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2211-2215. [PMID: 32251509 DOI: 10.1093/jxb/eraa110] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- John R Evans
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Tracy Lawson
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, UK
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24
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Paul MJ, Eastmond PJ. Turning sugar into oil: making photosynthesis blind to feedback inhibition. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2216-2218. [PMID: 32251510 PMCID: PMC7134900 DOI: 10.1093/jxb/erz504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
This article comments on: Beechey-Gradwell Z, Cooney L, Winichayakul S, Andrews M, Hea SY, Crowther T, Roberts N. 2020. Storing carbon in leaf lipid sinks enhanced perennial ryegrass carbon capture especially under high N and elevated CO2. Journal of Experimental Botany 71, 2351–2361.
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Affiliation(s)
| | - Peter J Eastmond
- Plant Science, Rothamsted Research, Harpenden, Hertfordshire, UK
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