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Koh Iba - One of the best experts on this subject based on the ideXlab platform.
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a temperature sensitive mechanism that regulates post translational stability of a plastidial ω 3 fatty acid desaturase fad8 in arabidopsis leaf tissues
Journal of Biological Chemistry, 2005Co-Authors: Osamu Matsuda, Hikaru Sakamoto, Tadafumi Hashimoto, Koh IbaAbstract:Trienoic fatty acids (TAs) are the major constituents in plant membrane lipids. In Arabidopsis, two plastidial isozymes of omega-3 fatty acid desaturase, FAD7 and FAD8, are the major contributors for TA production in leaf tissues. Despite a high degree of structural relatedness, activities of these two isozymes are regulated differentially in response to temperature. Elevated temperatures lead to decreases in leaf TA level due to temperature sensitivity of FAD8 activity. A series of FAD7-FAD8 chimeric genes, each encoding a functional plastidial omega-3 desaturase, were introduced into the Arabidopsis fad7fad8 double mutant. Constructs with or without a c-Myc epitope tag were tested. Functionality of each chimeric gene in response to temperature was assayed by Northern and Western analyses and by examining the fatty acid composition. All transformants harboring a chimeric gene containing the FAD8-derived C-terminal coding region (44 amino acids) showed a marked decrease in TA level when exposed to high temperature, similarly as transgenic lines complemented with the native form of FAD8. The reduction of TA level was accompanied by a decrease in the amount of omega-3 desaturase protein but not necessarily by a decrease in its transcript level. Analysis of the decay of c-Myc-tagged products after inhibiting protein synthesis revealed that the FAD8-derived C-terminal region acts in an autoregulatory fashion to destabilize the protein at high temperature. This suggests that the regulation of post-translational stability of FAD8 provides an important regulatory mechanism for modifying its activity in response to temperature, mediating a decrease in TA level at elevated temperatures.
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cloning of a temperature regulated gene encoding a chloroplast omega 3 desaturase from arabidopsis thaliana
Plant Physiology, 1994Co-Authors: Susan I Gibson, Vincent Arondel, Koh Iba, Chris SomervilleAbstract:Previous genetic evidence suggested that the fad8 and fad7 genes of Arabidopsis thaliana encode chloroplast membrane-associated omega-3 desaturases. A putative fad8 cDNA was isolated by heterologous hybridization using a gene encoding an endoplasmic reticulum-localized omega-3 desaturase (fad3) as a probe. The cDNA encodes a protein of 435 amino acid residues with a molecular mass of 50,134 D. Constitutive expression of the cDNA in transgenic plants of a fad7 mutant resulted in genetic complementation of the mutation, indicating that the fad7 and fad8 gene products are functionally equivalent. Expression of the fad8 cDNA in transgenic plants often resulted in the co-suppression of both the endogenous fad7 and fad8 genes in spite of the fact that these two genes share only about 75% nucleotide identity. In contrast to all other known plant desaturases, including fad7, the steady-state level of fad8 mRNA is strongly increased in plants grown at low temperature. This suggests that the role of fad8 is to provide increased omega-3 desaturase activity in plants that are exposed to low growth temperature. The fad8-1 mutation created a premature stop codon 149 amino acids from the amino-terminal end of the fad8 open reading frame, suggesting that this mutation results in a complete loss of fad8 activity.
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a gene encoding a chloroplast omega 3 fatty acid desaturase complements alterations in fatty acid desaturation and chloroplast copy number of the fad7 mutant of arabidopsis thaliana
Journal of Biological Chemistry, 1993Co-Authors: Koh Iba, Vincent Arondel, S Gibson, Takumi Nishiuchi, Takuichi Fuse, Mitsuo Nishimura, S Hugly, Chris SomervilleAbstract:Mutations at the fad7 locus of Arabidopsis thaliana (previously called fadD) cause decreased desaturation of dienoic fatty acids in chloroplast lipids in plants grown at elevated temperatures. This suggested that the fad7 locus encodes a chloroplast omega-3 desaturase that catalyzes the desaturation of lipid-linked 18:2 and 16:2 fatty acids. In order to clone the fad7 gene, it was first genetically mapped relative to the flanking restriction fragment length polymorphism markers 4547 and 2488A on chromosome 3, and yeast artificial chromosomes covering the locus were identified. A putative desaturase cDNA clone that was isolated by low stringency heterologous probing with a cDNA for an endoplasmic reticulum-localized omega-3 desaturase (fad3) hybridized to the yeast artificial chromosomes and could not be resolved from the locus by restriction fragment length polymorphism mapping. Expression of the cDNA in transgenic fad7 mutant plants resulted in restoration of wild type fatty acid composition and suppression of a previously observed effect of the fad7 mutation on chloroplast number, indicating genetic complementation. The structural gene contained seven introns within a coding sequence of 1338 base pairs, which encodes a 446-amino acid polypeptide of 51,172 daltons. The amino-terminal region of the fad7 gene product contained a consensus chloroplast transit peptide. Except for the amino-terminal domain, the deduced amino acid sequence of the fad7 gene product had high homology to the fad3 gene product, indicating that fad7 encodes an omega-3 desaturase and that the two genes arose from a common ancestral gene. There was no apparent effect of growth temperature on the steady-state levels of fad7 mRNA in wild type plants.
Nilanjan Pal Chowdhury - One of the best experts on this subject based on the ideXlab platform.
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modulations of the reduction potentials of flavin based electron bifurcation complexes and semiquinone stabilities are key to control directional electron flow
FEBS Journal, 2020Co-Authors: Jeerus Sucharitakul, Supacha Buttranon, Thanyaporn Wongnate, Methinee Prongjit, Nilanjan Pal Chowdhury, Wolfgang Buckel, Pimchai ChaiyenAbstract:: The flavin-based electron bifurcation (FBEB) system from Acidaminococcus fermentans is composed of the electron transfer flavoprotein (EtfAB) and butyryl-CoA dehydrogenase (Bcd). α-FAD binds to domain II of the A-subunit of EtfAB, β-FAD to the B-subunit of EtfAB and δ-FAD to Bcd. NADH reduces β-FAD to β-FADH. , which bifurcates one electron to the high potential α-FAD•- semiquinone followed by the other to the low potential ferredoxin (Fd). As deduced from crystal structures, upon interaction of EtfAB with Bcd, the formed α-FADH. approaches δ-FAD by rotation of domain II, yielding δ-FAD•- . Repetition of this process leads to a second reduced ferredoxin (Fd- ) and δ-FADH. , which reduces crotonyl-CoA to butyryl-CoA. In this study, we measured the redox properties of the components EtfAB, EtfaB (Etf without α-FAD), Bcd, and Fd, as well as of the complexes EtfaB:Bcd, EtfAB:Bcd, EtfaB:Fd, and EftAB:Fd. In agreement with the structural studies, we have shown for the first time that the interaction of EtfAB with Bcd drastically decreases the midpoint reduction potential of α-FAD to be within the same range of that of β-FAD and to destabilize the semiquinone of α-FAD. This finding clearly explains that these interactions facilitate the passing of electrons from β-FADH. via α-FAD•- to the final electron acceptor δ-FAD•- on Bcd. The interactions modulate the semiquinone stability of δ-FAD in an opposite way by having a greater semiquinone stability than in free Bcd.
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studies on the mechanism of electron bifurcation catalyzed by electron transferring flavoprotein etf and butyryl coa dehydrogenase bcd of acidaminococcus fermentans
Journal of Biological Chemistry, 2014Co-Authors: Nilanjan Pal Chowdhury, Jörg Kahnt, Julius K Demmer, Amr M Mowafy, Vikrant Upadhyay, Sebastian Koelzer, Elamparithi Jayamani, Marco Hornung, Ulrike DemmerAbstract:Abstract Electron bifurcation is a fundamental strategy of energy coupling originally discovered in the Q-cycle of many organisms. Recently a flavin-based electron bifurcation has been detected in anaerobes, first in clostridia and later in acetogens and methanogens. It enables anaerobic bacteria and archaea to reduce the two [4Fe-4S] cluster-containing ferredoxin, an energy rich compound that is used to conduct difficult reductions as well as to increase the efficiency of substrate level and electron transport phosphorylations (SLP and ETP). Here we characterize the bifurcating electron transferring flavoprotein (EtfAf) and butyryl-CoA dehydrogenase (BcdAf) from Acidaminococcus fermentans which couple the exergonic reduction of crotonyl-CoA to butyryl-CoA to the endergonic reduction of ferredoxin both with NADH. EtfAf contains one FAD (α-FAD) in subunit α and a second FAD (β-FAD) in subunit β. The distance between the two isoalloxazine rings is 18 Angstrom. The EtfAf-NAD+ complex structure revealed β-FAD as acceptor of the hydride of NADH. The formed β-FADH. is considered as the bifurcating electron donor. Due to a conformational change, α-FAD is able to approach β-FADH. by ca. 5 Angstrom and take up one electron yielding a stable anionic semiquinone, α-FAD●−, which due to a second conformational change donates this electron further to FAD of BcdAf. The remaining non-stabilized neutral semiquinone, β-FADH., immediately reduces ferredoxin. Repetition of this process affords a second reduced ferredoxin and FADH. of BcdAf that converts crotonyl-CoA to butyryl-CoA.
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studies on the mechanism of electron bifurcation catalyzed by electron transferring flavoprotein etf and butyryl coa dehydrogenase bcd of acidaminococcus fermentans
Journal of Biological Chemistry, 2014Co-Authors: Julius K Demmer, Amr M Mowafy, Vikrant Upadhyay, Sebastian Koelzer, Elamparithi Jayamani, Nilanjan Pal Chowdhury, Jörg KahntAbstract:Electron bifurcation is a fundamental strategy of energy coupling originally discovered in the Q-cycle of many organisms. Recently a flavin-based electron bifurcation has been detected in anaerobes, first in clostridia and later in acetogens and methanogens. It enables anaerobic bacteria and archaea to reduce the low-potential [4Fe-4S] clusters of ferredoxin, which increases the efficiency of the substrate level and electron transport phosphorylations. Here we characterize the bifurcating electron transferring flavoprotein (EtfAf) and butyryl-CoA dehydrogenase (BcdAf) of Acidaminococcus fermentans, which couple the exergonic reduction of crotonyl-CoA to butyryl-CoA to the endergonic reduction of ferredoxin both with NADH. EtfAf contains one FAD (α-FAD) in subunit α and a second FAD (β-FAD) in subunit β. The distance between the two isoalloxazine rings is 18 Å. The EtfAf-NAD+ complex structure revealed β-FAD as acceptor of the hydride of NADH. The formed β-FADH. is considered as the bifurcating electron donor. As a result of a domain movement, α-FAD is able to approach β-FADH. by about 4 Å and to take up one electron yielding a stable anionic semiquinone, α-FAD⨪, which donates this electron further to Dh-FAD of BcdAf after a second domain movement. The remaining non-stabilized neutral semiquinone, β-FADH., immediately reduces ferredoxin. Repetition of this process affords a second reduced ferredoxin and Dh-FADH. that converts crotonyl-CoA to butyryl-CoA.
Klaus Brettel - One of the best experts on this subject based on the ideXlab platform.
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reaction mechanisms of dna photolyase
Current Opinion in Structural Biology, 2010Co-Authors: Klaus Brettel, Martin ByrdinAbstract:DNA photolyase uses visible light and a fully reduced flavin cofactor FADH. to repair major UV-induced lesions in DNA, the cyclobutane pyrimidine dimers (CPDs). Electron transfer from photoexcited FADH. to CPD, splitting of the two intradimer bonds, and back electron transfer to the transiently formed flavin radical FADH. occur in overall 1 ns. Whereas the kinetics of FADH. was resolved, the DNA-based intermediates escaped unambiguous detection yet. Another light reaction, named photoactivation, reduces catalytically inactive FADH. to FADH. without implication of DNA. It involves electron hopping along a chain of three tryptophan residues in 30 ps, as elucidated in detail by transient absorption spectroscopy. The same triple tryptophan chain is found in cryptochrome blue-light photoreceptors and may be involved in their primary photoreaction.
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quantum yield measurements of short lived photoactivation intermediates in dna photolyase toward a detailed understanding of the triple tryptophan electron transfer chain
Journal of Physical Chemistry A, 2010Co-Authors: Martin Byrdin, Klaus Brettel, Andre P M Eker, Andras Lukacs, Viruthachalam Thiagarajan, Marten H VosAbstract:The light-dependent DNA repair enzyme photolyase contains a unique evolutionary conserved triple tryptophan electron transfer chain (W382−W359−W306 in photolyase from E. coli) that bridges the ∼15 A distance between the buried flavin adenine dinucleotide (FAD) cofactor and the surface of the protein. Upon excitation of the semireduced flavin (FADH.), electron transfer through the chain leads to formation of fully reduced flavin (FADH.; required for DNA repair) and oxidation of the most remote tryptophan residue W306, followed by its deprotonation. The thus-formed tryptophanyl radical W306°+ is reduced either by an extrinsic reductant or by reverse electron transfer from FADH.. Altogether the kinetics of these charge transfer reactions span 10 orders of magnitude, from a few picoseconds to tens of milliseconds. We investigated electron transfer processes in the picosecond−nanosecond time window bridging the time domains covered by ultrafast pump−probe and “classical” continuous probe techniques. Using a re...
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Intraprotein electron transfer and proton dynamics during photoactivation of DNA photolyase from E. coli: Review and new insights from an "inverse" deuterium isotope effect.
Biochimica biophysica acta (BBA) - Bioenergetics, 2004Co-Authors: Martin Byrdin, Klaus Brettel, Corinne Aubert, Valérie Sartor, André Eker, Marten Vos, Paul MathisAbstract:We review our work on electron transfer and proton dynamics during photoactivation in DNA photolyase from E. coli and discuss a recent theoretical study on this issue. In addition, we present unpublished data on the charge recombination between the fully reduced FADH. and the neutral (deprotonated) radical of the solvent exposed tryptophan W306. We found a pronounced acceleration with decreasing pH and an inverse deuterium isotope effect (kH/kD=0.35 at pL 6.5) and interpret it in a model of a fast protonation equilibrium for the W306 radical. Due to this fast equilibrium, two parallel recombination channels contribute differently at different pH values: one where reprotonation of the W306 radical is followed by electron transfer from FADH. (electron transfer time constant tet in the order of 10-50 µs), and one where electron transfer from FADH. (tet=25 ms) is followed by reprotonation of the W306 anion. Cop. 2004 Elsevier B.V. All rights reserved.
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dissection of the triple tryptophan electron transfer chain in escherichia coli dna photolyase trp382 is the primary donor in photoactivation
Proceedings of the National Academy of Sciences of the United States of America, 2003Co-Authors: Martin Byrdin, Andre P M Eker, Marten H Vos, Klaus BrettelAbstract:In Escherichia coli photolyase, excitation of the FAD cofactor in its semireduced radical state (FADH.) induces an electron transfer over approximately 15 A from tryptophan W306 to the flavin. It has been suggested that two additional tryptophans are involved in an electron transfer chain FADH. <-- W382 <-- W359 <-- W306. To test this hypothesis, we have mutated W382 into redox inert phenylalanine. Ultrafast transient absorption studies showed that, in WT photolyase, excited FADH. decayed with a time constant tau approximately 26 ps to fully reduced flavin and a tryptophan cation radical. In W382F mutant photolyase, the excited flavin was much longer lived (tau approximately 80 ps), and no significant amount of product was detected. We conclude that, in WT photolyase, excited FADH. is quenched by electron transfer from W382. On a millisecond scale, a product state with extremely low yield ( approximately 0.5% of WT) was detected in W382F mutant photolyase. Its spectral and kinetic features were similar to the fully reduced flavin/neutral tryptophan radical state in WT photolyase. We suggest that, in W382F mutant photolyase, excited FADH. is reduced by W359 at a rate that competes only poorly with the intrinsic decay of excited FADH. (tau approximately 80 ps), explaining the low product yield. Subsequently, the W359 cation radical is reduced by W306. The rate constants of electron transfer from W382 to excited FADH. in WT and from W359 to excited FADH. in W382F mutant photolyase were estimated and related to the donor-acceptor distances.
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intraprotein electron transfer between tyrosine and tryptophan in dna photolyase from anacystis nidulans
Proceedings of the National Academy of Sciences of the United States of America, 1999Co-Authors: Corinne Aubert, Andre P M Eker, Paul Mathis, Klaus BrettelAbstract:Abstract Light-induced electron transfer reactions leading to the fully reduced, catalytically competent state of the flavin adenine dinucleotide (FAD) cofactor have been studied by flash absorption spectroscopy in DNA photolyase from Anacystis nidulans. The protein, overproduced in Escherichia coli, was devoid of the antenna cofactor, and the FAD chromophore was present in the semireduced form, FADH., which is inactive for DNA repair. We show that after selective excitation of FADH. by a 7-ns laser flash, fully reduced FAD (FADH.) is formed in less than 500 ns by electron abstraction from a tryptophan residue. Subsequently, a tyrosine residue is oxidized by the tryptophanyl radical with t = 50 μs. The amino acid radicals were identified by their characteristic absorption spectra, with maxima at 520 nm for Trp⋅ and 410 nm for TyrO⋅. The newly discovered electron transfer between tyrosine and tryptophan occurred for ≈40% of the tryptophanyl radicals, whereas 60% decayed by charge recombination with FADH. (t = 1 ms). The tyrosyl radical can also recombine with FADH. but at a much slower rate (t = 76 ms) than Trp⋅. In the presence of an external electron donor, however, TyrO⋅ is rereduced efficiently in a bimolecular reaction that leaves FAD in the fully reduced state FADH.. These results show that electron transfer from tyrosine to Trp⋅ is an essential step in the process leading to the active form of photolyase. They provide direct evidence that electron transfer between tyrosine and tryptophan occurs in a native biological reaction.
Chris Somerville - One of the best experts on this subject based on the ideXlab platform.
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cloning of a temperature regulated gene encoding a chloroplast omega 3 desaturase from arabidopsis thaliana
Plant Physiology, 1994Co-Authors: Susan I Gibson, Vincent Arondel, Koh Iba, Chris SomervilleAbstract:Previous genetic evidence suggested that the fad8 and fad7 genes of Arabidopsis thaliana encode chloroplast membrane-associated omega-3 desaturases. A putative fad8 cDNA was isolated by heterologous hybridization using a gene encoding an endoplasmic reticulum-localized omega-3 desaturase (fad3) as a probe. The cDNA encodes a protein of 435 amino acid residues with a molecular mass of 50,134 D. Constitutive expression of the cDNA in transgenic plants of a fad7 mutant resulted in genetic complementation of the mutation, indicating that the fad7 and fad8 gene products are functionally equivalent. Expression of the fad8 cDNA in transgenic plants often resulted in the co-suppression of both the endogenous fad7 and fad8 genes in spite of the fact that these two genes share only about 75% nucleotide identity. In contrast to all other known plant desaturases, including fad7, the steady-state level of fad8 mRNA is strongly increased in plants grown at low temperature. This suggests that the role of fad8 is to provide increased omega-3 desaturase activity in plants that are exposed to low growth temperature. The fad8-1 mutation created a premature stop codon 149 amino acids from the amino-terminal end of the fad8 open reading frame, suggesting that this mutation results in a complete loss of fad8 activity.
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a gene encoding a chloroplast omega 3 fatty acid desaturase complements alterations in fatty acid desaturation and chloroplast copy number of the fad7 mutant of arabidopsis thaliana
Journal of Biological Chemistry, 1993Co-Authors: Koh Iba, Vincent Arondel, S Gibson, Takumi Nishiuchi, Takuichi Fuse, Mitsuo Nishimura, S Hugly, Chris SomervilleAbstract:Mutations at the fad7 locus of Arabidopsis thaliana (previously called fadD) cause decreased desaturation of dienoic fatty acids in chloroplast lipids in plants grown at elevated temperatures. This suggested that the fad7 locus encodes a chloroplast omega-3 desaturase that catalyzes the desaturation of lipid-linked 18:2 and 16:2 fatty acids. In order to clone the fad7 gene, it was first genetically mapped relative to the flanking restriction fragment length polymorphism markers 4547 and 2488A on chromosome 3, and yeast artificial chromosomes covering the locus were identified. A putative desaturase cDNA clone that was isolated by low stringency heterologous probing with a cDNA for an endoplasmic reticulum-localized omega-3 desaturase (fad3) hybridized to the yeast artificial chromosomes and could not be resolved from the locus by restriction fragment length polymorphism mapping. Expression of the cDNA in transgenic fad7 mutant plants resulted in restoration of wild type fatty acid composition and suppression of a previously observed effect of the fad7 mutation on chloroplast number, indicating genetic complementation. The structural gene contained seven introns within a coding sequence of 1338 base pairs, which encodes a 446-amino acid polypeptide of 51,172 daltons. The amino-terminal region of the fad7 gene product contained a consensus chloroplast transit peptide. Except for the amino-terminal domain, the deduced amino acid sequence of the fad7 gene product had high homology to the fad3 gene product, indicating that fad7 encodes an omega-3 desaturase and that the two genes arose from a common ancestral gene. There was no apparent effect of growth temperature on the steady-state levels of fad7 mRNA in wild type plants.
Kent D Chapman - One of the best experts on this subject based on the ideXlab platform.
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three dimensional visualization of membrane phospholipid distributions in arabidopsis thaliana seeds a spatial perspective of molecular heterogeneity
Biochimica et Biophysica Acta, 2017Co-Authors: Drew Sturtevant, Maria Emilia Duenas, Young Jin Lee, Kent D ChapmanAbstract:Arabidopsis thaliana has been widely used as a model plant to study acyl lipid metabolism. Seeds of A. thaliana are quite small (approximately 500×300μm and weigh ~20μg), making lipid compositional analyses of single seeds difficult to achieve. Here we have used matrix assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) to map and visualize the three-dimensional spatial distributions of two common membrane phospholipid classes, phosphatidylcholine (PC) and phosphatidylinositol (PI), in single A. thaliana seeds. The 3D images revealed distinct differences in distribution of several molecular species of both phospholipids among different seed tissues. Using data from these 3D reconstructions, the PC and PI mol% lipid profiles were calculated for the embryonic axis, cotyledons, and peripheral endosperm, and these data agreed well with overall quantification of these lipids in bulk seed extracts analyzed by conventional electrospray ionization-mass spectrometry (ESI-MS). In addition, MALDI-MSI was used to profile PC and PI molecular species in seeds of wild type, fad2-1, fad3-2, fad6-1, and fae1-1 acyl lipid mutants. The resulting distributions revealed previously unobserved changes in spatial distribution of several lipid molecular species, and were used to suggest new insights into biochemical heterogeneity of seed lipid metabolism. These studies highlight the value of mass spectrometry imaging to provide unprecedented spatial and chemical resolution of metabolites directly in samples even as small as a single A. thaliana seeds, and allow for expanded imaging of plant metabolites to improve our understanding of plant lipid metabolism from a spatial perspective.
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genome wide analysis of the omega 3 fatty acid desaturase gene family in gossypium
BMC Plant Biology, 2014Co-Authors: Olga Yurchenko, Sunjung Park, Daniel C Ilut, Jay J Inmon, Jon C Millhollon, Zach S Liechty, Justin T Page, Matthew A Jenks, Kent D ChapmanAbstract:Background: The majority of commercial cotton varieties planted worldwide are derived from Gossypium hirsutum, which is a naturally occurring allotetraploid produced by interspecific hybridization of A- and D-genome diploid progenitor species. While most cotton species are adapted to warm, semi-arid tropical and subtropical regions, and thus perform well in these geographical areas, cotton seedlings are sensitive to cold temperature, which can significantly reduce crop yields. One of the common biochemical responses of plants to cold temperatures is an increase in omega-3 fatty acids, which protects cellular function by maintaining membrane integrity. The purpose of our study was to identify and characterize the omega-3 fatty acid desaturase (FAD) gene family in G. hirsutum, with an emphasis on identifying omega-3 FADs involved in cold temperature adaptation. Results: Eleven omega-3 FAD genes were identified in G. hirsutum, and characterization of the gene family in extant A and D diploid species (G. herbaceum and G. raimondii, respectively) allowed for unambiguous genome assignment of all homoeologs in tetraploid G. hirsutum. The omega-3 FAD family of cotton includes five distinct genes, two of which encode endoplasmic reticulum-type enzymes (FAD3-1 and FAD3-2) and three that encode chloroplast-type enzymes (FAD7/8-1, FAD7/8-2, and FAD7/8-3). The FAD3-2 gene was duplicated in the A genome progenitor species after the evolutionary split from the D progenitor, but before the interspecific hybridization event that gave rise to modern tetraploid cotton. RNA-seq analysis revealed conserved, gene-specific expression patterns in various organs and cell types and semi-quantitative RT-PCR further revealed that FAD7/8-1 was specifically induced during cold temperature treatment of G. hirsutum seedlings. Conclusions: The omega-3 FAD gene family in cotton was characterized at the genome-wide level in three species, showing relatively ancient establishment of the gene family prior to the split of A and D diploid progenitor species. The FAD genes are differentially expressed in various organs and cell types, including fiber, and expression of the FAD7/8-1 gene was induced by cold temperature. Collectively, these data define the genetic and functional genomic properties of this important gene family in cotton and provide a foundation for future efforts to improve cotton abiotic stress tolerance through molecular breeding approaches.
