Functional and Predictive Structural Characterization of WRINKLED2, A Unique Oil Biosynthesis Regulator in Avocado

WRINKLED1 (WRI1), a member of the APETALA2 (AP2) class of transcription factors regulates fatty acid biosynthesis and triacylglycerol (TAG) accumulation in plants. Among the four known Arabidopsis WRI1 paralogs, only WRI2 was unable to complement and restore fatty acid content in wri1-1 mutant seeds. Avocado (Persea americana) mesocarp, which accumulates 60-70% dry weight oil content, showed high expression levels for orthologs of WRI2, along with WRI1 and WRI3, during fruit development. While the role of WRI1 as a master regulator of oil biosynthesis is well-established, the function of WRI1 paralogs is poorly understood. Comprehensive and comparative in silico analyses of WRI1 paralogs from avocado (a basal angiosperm) with higher angiosperms Arabidopsis (dicot), maize (monocot) revealed distinct features. Predictive structural analyses of the WRI orthologs from these three species revealed the presence of AP2 domains and other highly conserved features, such as intrinsically disordered regions associated with predicted PEST motifs and phosphorylation sites. Additionally, avocado WRI proteins also contained distinct features that were absent in the nonfunctional Arabidopsis ortholog AtWRI2. Through transient expression assays, we demonstrated that both avocado WRI1 and WRI2 are functional and drive TAG accumulation in Nicotiana benthamiana leaves. We predict that the unique features and activities of ancestral PaWRI2 were likely lost in orthologous genes such as AtWRI2 during evolution and speciation, leading to at least partial loss of function in some higher eudicots. This study provides us with new targets to enhance oil biosynthesis in plants.

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Genome-edited Camelina sativa with a unique fatty acid content and its potential impact on ecosystems

Environmental Sciences Europe ◽

10.1186/s12302-021-00482-2 ◽

2021 ◽

Vol 33 (1) ◽

Author(s):

Katharina Kawall

Keyword(s):

Fatty Acid ◽

Genome Editing ◽

Defense Mechanisms ◽

Fatty Acid Biosynthesis ◽

Fatty Acid Content ◽

Camelina Sativa ◽

Nutritional Composition ◽

Oilseed Crop ◽

Biotic And Abiotic Stress ◽

Multiple Copies

Abstract‘Genome editing’ is intended to accelerate modern plant breeding enabling a much faster and more efficient development of crops with improved traits such as increased yield, altered nutritional composition, as well as resistance to factors of biotic and abiotic stress. These traits are often generated by site-directed nuclease-1 (SDN-1) applications that induce small, targeted changes in the plant genomes. These intended alterations can be combined in a way to generate plants with genomes that are altered on a larger scale than it is possible with conventional breeding techniques. The power and the potential of genome editing comes from its highly effective mode of action being able to generate different allelic combinations of genes, creating, at its most efficient, homozygous gene knockouts. Additionally, multiple copies of functional genes can be targeted all at once. This is especially relevant in polyploid plants such as Camelina sativa which contain complex genomes with multiple chromosome sets. Intended alterations induced by genome editing have potential to unintentionally alter the composition of a plant and/or interfere with its metabolism, e.g., with the biosynthesis of secondary metabolites such as phytohormones or other biomolecules. This could affect diverse defense mechanisms and inter-/intra-specific communication of plants having a direct impact on associated ecosystems. This review focuses on the intended alterations in crops mediated by SDN-1 applications, the generation of novel genotypes and the ecological effects emerging from these intended alterations. Genome editing applications in C. sativa are used to exemplify these issues in a crop with a complex genome. C. sativa is mainly altered in its fatty acid biosynthesis and used as an oilseed crop to produce biofuels.

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Transcriptome, Biochemical and Growth Responses of the Marine Phytoplankter Phaeodactylum Tricornutum Bohlin (Bacillariophyta) to Copepod Grazer Presence

Cellular Physiology and Biochemistry ◽

10.1159/000488839 ◽

2018 ◽

Vol 46 (3) ◽

pp. 1091-1111 ◽

Cited By ~ 4

Author(s):

Si Li ◽

Stefanie M.H. Ismar

Keyword(s):

Fatty Acid ◽

Phaeodactylum Tricornutum ◽

Fatty Acid Biosynthesis ◽

Fatty Acid Content ◽

Model Organism ◽

Cellular Responses ◽

Pathogen Resistance ◽

Nutritional Composition ◽

Growth Responses ◽

Transcriptomic Response

Background/Aims: As a model organism for a pleiomorphic marine planktonic primary producer, Phaeodactylum tricornutum has been studied on a molecular level under diverse cultural conditions. But little is known about its morphological, nutritional or transcriptomic responses under grazing stress. Methods: To assess microalgal molecular and cellular responses to grazer presence, we conducted transcriptome profiling in combination with growth rate, biovolume, fatty acid content, carbon and nitrogen content measurements in the model diatom Phaeodactylum tricornutum. RNA-sequencing was used to evaluate the transcriptomic response to grazing stress for P. tricornutum strain CCAP 1055/1. Results: Among the differentially expressed genes, we found down-regulation of genes involved in pathogen resistance, and in fatty acid biosynthesis pathways, while mitosis-involved genes were up-regulated. Experimentally testing morphological and biochemical responses in five strains of the species, we detected strain-specific significant effects of simulated grazing pressure in altered growth rates, biovolume and nutritional composition. Conclusion: Our research reveals the associated molecular and cellular responses to grazing effects in P. tricornutum and extends the understanding of co-evolutionary roles in regulating grazing defence between P. tricornutum and its grazer.

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Overexpression of Avocado (Persea americana Mill.) PaRAP2.1 Promotes Fatty Acid Accumulation in Arabidopsis thaliana

Journal of Agricultural Science ◽

10.5539/jas.v13n6p1 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1

Author(s):

Weihong Ma ◽

Xiaoping Zang ◽

Yuanzheng Liu ◽

Lixia Wang ◽

Jiashui Wang ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Fatty Acid ◽

Fatty Acid Biosynthesis ◽

Persea Americana ◽

Wild Type ◽

Acid Biosynthesis ◽

Fatty Acid Accumulation ◽

Avocado Fruit ◽

Acid Accumulation ◽

Mature Seeds

Fatty acids in avocado fruit (Persea americana Mill.) are vital composition affecting flavour and nutritive value. Hence, horticulturalists are interested in illustrating the functions of transcription factors on fatty acid accumulation in avocado fruit. In the present study, the APETALA2/ethylene-responsive transcription factor gene, PaRAP2.1, was cloned from avocado mesocarp, and the subcellular localization demonstrated that PaRAP2.1 was located in the cytoplasm and nucleus. The PaRAP2.1 was introduced into Arabidopsis thaliana by Agrobacterium-mediated transformation. Furthermore, PaRAP2.1 were functionally verified its effect on fatty acid biosynthesis. Histological analyses of lipid droplets displayed that the striking difference in the lipid droplets in the mature seeds between PaRAP2.1-overexpressing transgenic and wild-type Arabidopsis thaliana lines were revealed based on confocal microscopy images. Subsequently, fatty acid analyses of PaRAP2.1-overexpressing Arabidopsis thaliana lines displayed the significantly higher contents of fatty acids than those in the wild-type plants. Meanwhile, expression amount of ten genes involving in fatty acid biosynthesis dramatically up-regulated in the mature seeds of PaRAP2.1-overexpressing lines than those of wild-type plants. These results provide a theoretical basis for future research in regard to the function of PaRAP2.1 on fatty acid biosynthesis.

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The biosynthesis of triacylglycerols in microsomal preparations of developing cotyledons of sunflower (Helianthus annuus L.)

Biochemical Journal ◽

10.1042/bj2200481 ◽

1984 ◽

Vol 220 (2) ◽

pp. 481-488 ◽

Cited By ~ 31

Author(s):

S Stymne ◽

A K Stobart

Keyword(s):

Fatty Acid ◽

Helianthus Annuus ◽

Unsaturated Fatty Acid ◽

Fatty Acid Content ◽

Acid Synthesis ◽

Carthamus Tinctorius ◽

Persea Americana ◽

Acyl Exchange ◽

The Relationship ◽

Continuous Enrichment

The synthesis of triacylglycerols was investigated in microsomes (microsomal fractions) prepared from the developing cotyledons of sunflower (Helianthus annuus). Particular emphasis was placed on the mechanisms involved in controlling the C18- unsaturated-fatty-acid content of the oils. We have demonstrated that the microsomes were capable of: the transfer of oleate from acyl-CoA to position 2 of sn-phosphatidylcholine for its subsequent desaturation and the return of the polyunsaturated products to the acyl-CoA pool by further acyl exchange; the acylation of sn-glycerol 3-phosphate with acyl-CoA to yield phosphatidic acid, which was further utilized in diacyl- and tri-acylglycerol synthesis; and (3) the equilibrium of a diacylglycerol pool with phosphatidylcholine. The acyl exchange between acyl-CoA and position 2 of sn-phosphatidylcholine coupled to the equilibration of diacylglycerol and phosphatidylcholine brings about the continuous enrichment of the glycerol backbone with C18 polyunsaturated fatty acids for triacylglycerol production. Similar reactions were found to operate in another oilseed plant, safflower (Carthamus tinctorius L.). On the other hand, the microsomes of avocado (Persea americana) mesocarp, which synthesize triacylglycerol via the Kennedy [(1961) Fed. Proc. Fed. Am. Soc. Exp. Biol. 20, 934-940] pathway, were deficient in acyl exchange and the diacylglycerol in equilibrium phosphatidylcholine interconversion. The results provide a working model that helps to explain the relationship between C18- unsaturated-fatty-acid synthesis and triacylglycerol production in oilseeds.

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Oil biosynthesis in a basal angiosperm: transcriptome analysis of Persea Americana mesocarp

BMC Plant Biology ◽

10.1186/s12870-015-0586-2 ◽

2015 ◽

Vol 15 (1) ◽

Cited By ~ 47

Author(s):

Aruna Kilaru ◽

Xia Cao ◽

Parker B. Dabbs ◽

Ha-Jung Sung ◽

Md. Mahbubur Rahman ◽

...

Keyword(s):

Transcriptome Analysis ◽

Persea Americana ◽

Basal Angiosperm ◽

Oil Biosynthesis

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The effect of cadmium on lipid and fatty acid biosynthesis in tomato leaves

Biologia ◽

10.2478/s11756-008-0002-6 ◽

2008 ◽

Vol 63 (1) ◽

Cited By ~ 4

Author(s):

Wided Ben Ammar ◽

Issam Nouairi ◽

Mokhtar Zarrouk ◽

Fatma Jemal

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Acid Content ◽

Fatty Acid Biosynthesis ◽

Fatty Acid Content ◽

Lipid Biosynthesis ◽

Lipid Classes ◽

Acetate Incorporation ◽

Acid Biosynthesis ◽

Tomato Plants

AbstractThis research aims to examine the effect of cadmium uptake on lipid composition and fatty acid biosynthesis, in young leaves of tomato treated seedlings (Lycopersicon esculentum cv. Ibiza F1). Results in membrane lipids investigations revealed that high cadmium concentrations affect the main lipid classes, leading to strong changes in their composition and fatty acid content. Thus, the exposure of tomato plants to cadmium caused a concentration-related decrease in the unsaturated fatty acid content, resulting in a lower degree of fatty acid unsaturation. The level of lipid peroxides was significantly enhanced at high Cd concentrations. Studies of the lipid metabolism using radioactive labelling with [1-14C]acetate as a major precursor of lipid biosynthesis, showed that levels of radioactivity incorporation in total lipids as well as in all lipid classes were lowered by Cd doses. In total lipid fatty acids, [1-14C]acetate incorporation was reduced in tri-unsaturated fatty acids (C16:3 and C18:3); While it was enhanced in the palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0) and linoleic (C18:2) acids. [1-14C]acetate incorporation into C16:3 and C18:3 of galactolipids [monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG)] and some phospholipids [phosphatidylcholine (PC) and phosphatidylglycerol (PG)] was inhibited by Cd stress. Our results showed that in tomato plants, cadmium stress provoked an inhibition of polar lipid biosynthesis and reduced fatty acid desaturation process.

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Activating de novo triacylglycerol synthesis in oleaginous yeast for improved bio-diesel quality

WEENTECH Proceedings in Energy ◽

10.32438/wpe.8218 ◽

2018 ◽

Vol 4 (2) ◽

pp. 16-24

Author(s):

Farha Deeba ◽

Ruchir Priyadarshi ◽

Vikas Pruthi ◽

Yuvraj Singh Negi

Keyword(s):

Fatty Acid ◽

Sodium Bicarbonate ◽

Acid Content ◽

Oleaginous Yeast ◽

De Novo ◽

Fatty Acid Content ◽

Biodiesel Production ◽

Nitrogen Base ◽

Triacylglycerol Synthesis ◽

Tag Accumulation

The economic production of yeast biofuels requires several strategies, such as multiomics techniques to gain insights into lipid biosynthesis pathway. Hence, metabolomic studies for amelioration of triacylglycerol (TAG) accumulation in oleaginous yeast strain to reveal potential targets in fatty acid synthesis pathway should be explored. The aim of this research experiment was to boost TAG agglomeration in novel isolated oleaginous yeast Cryptococcus psychrotolerans IITRFD using sodium bicarbonate as supplement for biodiesel production. Enhanced biomass productivity (83.5 ± 0.32 mg/L/h) and lipid productivity (56.8 ± 0.34 mg/L/h) have been estimated as compared to yeast nitrogen base media (YNB) used as control. Also, the bicarbonate supplementation (25 mM) leads to decrease in phospholipids (23.6 %) while increase in TAG amount (75.4 %) signifying that it redirects the phospholipids synthesis pathway in the direction of de novo TAG pathway. The fatty acid profile obtained revealed rise in monounsaturated fatty acid content and decrease in polyunsaturated fatty acid content demonstrating better oxidative stability (19 h) and cold flow behaviour (- 12 °C) of biodiesel produced. This novel strategy of utilizing bicarbonate as a triggering system may possibly revamp the commercial use of C. psychrotolerans IITRFD for high quality biodiesel production. This is the first study to augment TAG accumulation in this oleaginous yeast using sodium bicarbonate with improved fuel properties.

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A Soybean Acyl Carrier Protein, GmACP, Is Important for Root Nodule Symbiosis

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-09-13-0269-r ◽

2014 ◽

Vol 27 (5) ◽

pp. 415-423 ◽

Cited By ~ 11

Author(s):

Jun Wang ◽

Katalin Tóth ◽

Kiwamu Tanaka ◽

Cuong T. Nguyen ◽

Zhe Yan ◽

...

Keyword(s):

Fatty Acid ◽

Fatty Acid Biosynthesis ◽

Fluorescent Protein ◽

De Novo ◽

Acyl Carrier Protein ◽

Fatty Acid Content ◽

Gas Chromatography Mass Spectrometry ◽

Carrier Protein ◽

Acid Biosynthesis ◽

Transgenic Roots

Legumes (members of family Fabaceae) establish a symbiotic relationship with nitrogen-fixing soil bacteria (rhizobia) to overcome nitrogen source limitation. Single root hair epidermal cells serve as the entry point for bacteria to infect the host root, leading to development of a new organ, the nodule, which the bacteria colonize. In the present study, the putative role of a soybean acyl carrier protein (ACP), GmACP (Glyma18g47950), was examined in nodulation. ACP represent an essential cofactor protein in fatty acid biosynthesis. Phylogenetic analysis of plant ACP protein sequences showed that GmACP was classified in a legume-specific clade. Quantitative reverse-transcription polymerase chain reaction analysis demonstrated that GmACP was expressed in all soybean tissues but showed higher transcript accumulation in nodule tissue. RNA interference-mediated gene silencing of GmACP resulted in a significant reduction in nodule numbers on soybean transgenic roots. Fluorescent protein-labeled GmACP was localized to plastids in planta, the site of de novo fatty acid biosynthesis in plants. Analysis of the fatty acid content of root tissue silenced for GmACP expression, as determined by gas chromatography–mass spectrometry, showed an approximately 22% reduction, specifically in palmitic and stearic acid. Taken together, our data provide evidence that GmACP plays an important role in nodulation.

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Growth Medium-Dependent Regulation ofMyxococcus xanthus Fatty Acid Content Is Controlled by theesg Locus

Journal of Bacteriology ◽

10.1128/jb.180.19.5269-5272.1998 ◽

1998 ◽

Vol 180 (19) ◽

pp. 5269-5272 ◽

Cited By ~ 6

Author(s):

Geoffrey Bartholomeusz ◽

Yanglong Zhu ◽

John Downard

Keyword(s):

Fatty Acid ◽

Growth Medium ◽

Acid Content ◽

Fatty Acid Biosynthesis ◽

Fatty Acid Content ◽

Defined Medium ◽

Chain Fatty Acid ◽

Complex Medium ◽

Chemically Defined Medium ◽

Branched Chain

ABSTRACT We compared the cellular fatty acid profiles of Myxococcus xanthus cells grown in either a Casitone-based complex medium or a chemically defined medium. The cells grown in the complex medium had a much higher content of the abundant branched-chain fatty acidiso-15:0 and several other branched-chain species. The higher branched-chain fatty acid content of the cells grown in the complex medium was dependent on the esg locus, which encodes the E1α and E1β components of a branched-chain keto acid dehydrogenase (BCKAD) multienzyme complex involved in branched-chain fatty acid biosynthesis. Cells grown in the complex medium were also found to have a higher level of esg transcription and more BCKAD enzyme activity than cells from the chemically defined medium. The level of esg transcription appears to be an important factor in the growth medium-dependent regulation of the M. xanthus branched-chain fatty acid content.

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Fatty acid content of avocados (Persea americana Mill. cv. Hass) in relation to orchard altitude and fruit maturity stage

Agronomía Colombiana ◽

10.15446/agron.colomb.v33n2.49902 ◽

2015 ◽

Vol 33 (2) ◽

pp. 220-227 ◽

Cited By ~ 12

Author(s):

Catarina Pedro Carvalho ◽

Jorge Bernal E. ◽

María Alejandra Velásquez ◽

José Régulo Cartagena V.

Keyword(s):

Fatty Acid ◽

Acid Content ◽

Fatty Acid Content ◽

Matter Content ◽

Persea Americana ◽

Maturity Stage ◽

Dry Matter Content ◽

Protected Designation Of Origin ◽

Fruit Maturity ◽

Close Relationship

The objective of this research was to study the relationship between the fatty acid content and the altitude of orchards and fruit maturity stage of avocados (Persea americana Mill. cv. Hass) at different locations in the department of Antioquia (Colombia). Orchards between 1,340 and 2,420 m a.s.l. were selected and the fatty acid profile and content of the fruits were analyzed. Oleic acid showed the highest percentage for all of the locations and its percentage decreased drastically at lower altitudes, meanwhile the percentage of palmitoleic and linoleic acids increased in these orchards. The oleic/palmitoleic, linoleic/palmitoleic, and oleic/linoleic indexes increased significantly at higher altitudes. Palmitoleic acid increased significantly with the maturity stage (dry matter content) of the avocados for all of the locations. Some fatty acids showed a high linear correlation with the fruit maturity stage, varying the type of acid or index with altitude. The fatty acid content is a variable to consider in future studies for a protected designation of origin (PDO), due to the close relationship observed with the geographical growing area and its importance to human health. More assessments must be taken over the course of years and harvests with more contrasting environments in order to obtain more robust information and feed the model.

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