1
|
Molecular Cloning and Characterization of FAD6 Gene from Chia (Salvia hispanica L.). Biochem Genet 2021; 59:1295-1310. [PMID: 33797013 DOI: 10.1007/s10528-021-10063-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 03/16/2021] [Indexed: 12/13/2022]
Abstract
Plastidial Δ12 fatty acid desaturase (FAD6) is a key enzyme for linoleic acid (LA) and α-linolenic acid (ALA) biosynthesis. Chia (Salvia hispanica L.) is a revived omega-3 plant source that is richest in ALA level. In this study, based on the RACE method, one full-length cDNA sequence encoding FAD6, named ShFAD6, was isolated from chia. There exist three alternative transcription start sites and five alternative poly(A) tailing sites in ShFAD6. The 5'UTR of ShFAD6 contains a purine-stretch of 44 bp. ShFAD6 has an ORF of 1335 bp encoding a 444 aa protein of 51.33 kDa. ShFAD6 contains a conserved Delta12-FADS-like domain together with three strong trans-membrane helices and three histidine motifs. There also exists a chloroplast transmit peptide in ShFAD6 N-terminal. Phylogenetic analyses validated its identity of dicot FAD6 protein and suggested some critical evolutionary features of plant FAD6 genes. Heterologous yeast expression confirmed the catalytic activity of ShFAD6. The qRT-PCR assay showed that ShFAD6 is mainly expressed in leaves, stems, flowers, buds and early-stage seeds, and also responded to various stresses and hormone treatments. Under Sclerotinia infection, qRT-PCR and fluorescence imaging illustrated the possible correlation of ShFAD6 expression and photosynthesis. This study provides insight for further function study of ShFAD6 in oil quality improvement in staple oilseed crops as well as stress response and adaptation in plants.
Collapse
|
2
|
Luján MA, Soria-García Á, Claver A, Lorente P, Rubio MC, Picorel R, Alfonso M. Different Cis-Regulatory Elements Control the Tissue-Specific Contribution of Plastid ω-3 Desaturases to Wounding and Hormone Responses. FRONTIERS IN PLANT SCIENCE 2021; 12:727292. [PMID: 34777414 PMCID: PMC8578140 DOI: 10.3389/fpls.2021.727292] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/04/2021] [Indexed: 05/13/2023]
Abstract
Trienoic fatty acids are essential constituents of biomembranes and precursors of jasmonates involved in plant defense responses. Two ω-3 desaturases, AtFAD7 and AtFAD8, synthetize trienoic fatty acids in the plastid. Promoter:GUS and mutagenesis analysis was used to identify cis-elements controlling AtFAD7 and AtFAD8 basal expression and their response to hormones or wounding. AtFAD7 promoter GUS activity was much higher than that of AtFAD8 in leaves, with specific AtFAD7 expression in the flower stamen and pistil and root meristem and vasculature. This specific tissue and organ expression of AtFAD7 was controlled by different cis-elements. Thus, promoter deletion and mutagenesis analysis indicated that WRKY proteins might be essential for basal expression of AtFAD7 in leaves. Two MYB target sequences present in the AtFAD7 promoter might be responsible for its expression in the flower stamen and stigma of the pistil and in the root meristem, and for the AtFAD7 wound-specific response. Two MYB target sequences detected in the distal region of the AtFAD8 gene promoter seemed to negatively control AtFAD8 expression, particularly in true leaves and flowers, suggesting that MYB transcription factors act as repressors of AtFAD8 gene basal expression, modulating the different relative abundance of both plastid ω-3 desaturases at the transcriptional level. Our data showed that the two ABA repression sequences detected in the AtFAD7 promoter were functional, suggesting an ABA-dependent mechanism involved in the different regulation of both ω-3 plastid desaturases. These results reveal the implication of different signaling pathways for the concerted regulation of trienoic fatty acid content in Arabidopsis.
Collapse
|
3
|
Soria-Garcï A ÏN, Rubio MAC, Lagunas B, Lï Pez-Gomollï N S, Lujï N MADLÏN, Dï Az-Guerra RL, Picorel R, Alfonso M. Tissue Distribution and Specific Contribution of Arabidopsis FAD7 and FAD8 Plastid Desaturases to the JA- and ABA-Mediated Cold Stress or Defense Responses. PLANT & CELL PHYSIOLOGY 2019; 60:1025-1040. [PMID: 30690505 DOI: 10.1093/pcp/pcz017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 01/18/2019] [Indexed: 05/27/2023]
Abstract
To overcome the difficulties to analyze membrane desaturases at the protein level, transgenic Arabidopsis plants expressing the plastidial AtFAD7 and AtFAD8 ω-3 desaturases fused to green fluorescent protein, under the control of their endogenous promoters, were generated and their tissue relative abundance was studied. Gene expression, glucuronidase promoter activity, immunoblot and confocal microscopy analyses indicated that AtFAD7 is the major ω-3 desaturase in leaves when compared to AtFAD8. This higher abundance of AtFAD7 was consistent with its higher promoter activity and could be related with its specificity for the abundant leaf galactolipids. AtFAD7 was also present in roots but at much lower level than leaves. AtFAD8 expression and protein abundance in leaves was consistent with its lower promoter activity, suggesting that transcriptional control modulates the abundance of both desaturases in leaves. AtFAD7 protein levels increased in response to wounding but not to jasmonate (JA), and decreased upon abscisic acid (ABA) treatment. Conversely, AtFAD8 protein levels increased upon cold or JA exposure and decreased at high temperatures, but did not respond to ABA or wounding. These results indicated specific and non-redundant roles for the plastidial ω-3 desaturases in defense, temperature stress or phytohormone mediated responses and a tight coordination of their activities between biotic and abiotic stress signaling pathways. Our data suggested that transcriptional regulation was crucial for this coordination. Finally, bimolecular fluorescence complementation analysis showed that both AtFAD7 and AtFAD8 interact with the AtFAD6 ω-6 desaturase in vivo, suggesting that quaternary complexes are involved in trienoic fatty acid production within the plastid membranes.
Collapse
Affiliation(s)
- Ï Ngel Soria-Garcï A
- Department of Plant Nutrition, Estaci�n Experimental Aula Dei (EEAD-CSIC), Avda. Monta�ana 1005, Zaragoza, Spain
| | - Marï A C Rubio
- Department of Plant Nutrition, Estaci�n Experimental Aula Dei (EEAD-CSIC), Avda. Monta�ana 1005, Zaragoza, Spain
| | - Beatriz Lagunas
- School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Sara Lï Pez-Gomollï N
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, UK
| | - Marï A de Los Ï Ngeles Lujï N
- Department of Plant Nutrition, Estaci�n Experimental Aula Dei (EEAD-CSIC), Avda. Monta�ana 1005, Zaragoza, Spain
| | - Raï L Dï Az-Guerra
- Department of Plant Nutrition, Estaci�n Experimental Aula Dei (EEAD-CSIC), Avda. Monta�ana 1005, Zaragoza, Spain
| | - Rafael Picorel
- Department of Plant Nutrition, Estaci�n Experimental Aula Dei (EEAD-CSIC), Avda. Monta�ana 1005, Zaragoza, Spain
| | - Miguel Alfonso
- Department of Plant Nutrition, Estaci�n Experimental Aula Dei (EEAD-CSIC), Avda. Monta�ana 1005, Zaragoza, Spain
| |
Collapse
|
4
|
Hernández ML, Sicardo MD, Alfonso M, Martínez-Rivas JM. Transcriptional Regulation of Stearoyl-Acyl Carrier Protein Desaturase Genes in Response to Abiotic Stresses Leads to Changes in the Unsaturated Fatty Acids Composition of Olive Mesocarp. FRONTIERS IN PLANT SCIENCE 2019; 10:251. [PMID: 30891055 PMCID: PMC6411816 DOI: 10.3389/fpls.2019.00251] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 02/15/2019] [Indexed: 05/21/2023]
Abstract
In higher plants, the stearoyl-acyl carrier protein desaturase (SAD) catalyzes the first desaturation step leading to oleic acid, which can be further desaturated to linoleic and α-linolenic acids. Therefore, SAD plays an essential role in determining the overall content of unsaturated fatty acids (UFA). We have investigated how SAD genes expression and UFA composition are regulated in olive (Olea europaea) mesocarp tissue from Picual and Arbequina cultivars in response to different abiotic stresses. The results showed that olive SAD genes are transcriptionally regulated by temperature, darkness and wounding. The increase in SAD genes expression levels observed in Picual mesocarp exposed to low temperature brought about a modification in the UFA content of microsomal membrane lipids. In addition, darkness caused the down-regulation of SAD genes transcripts, together with a decrease in the UFA content of chloroplast lipids. The differential role of olive SAD genes in the wounding response was also demonstrated. These data point out that different environmental stresses can modify the UFA composition of olive mesocarp through the transcriptional regulation of SAD genes, affecting olive oil quality.
Collapse
Affiliation(s)
- M. Luisa Hernández
- Instituto de la Grasa (IG-CSIC), Seville, Spain
- Estación Experimental de Aula Dei (EEAD-CSIC), Zaragoza, Spain
- *Correspondence: M. Luisa Hernández, ;
| | | | - Miguel Alfonso
- Estación Experimental de Aula Dei (EEAD-CSIC), Zaragoza, Spain
| | | |
Collapse
|
5
|
Lagunas B, Román Á, Andreu V, Picorel R, Alfonso M. A temporal regulatory mechanism controls the different contribution of endoplasmic reticulum and plastidial ω-3 desaturases to trienoic fatty acid content during leaf development in soybean (Glycine max cv Volania). PHYTOCHEMISTRY 2013; 95:158-67. [PMID: 23928132 DOI: 10.1016/j.phytochem.2013.07.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 07/12/2013] [Accepted: 07/16/2013] [Indexed: 06/02/2023]
Abstract
We analyzed the molecular mechanism controlling ω-3 fatty acid desaturases during seed germination and leaf development in soybean. During germination, soybean seeds were characterized by a high 18:2(Δ9,12) level (more than 50%) and reduced 18:3(Δ9,12,15) content (10%). Interestingly, transcripts from all endoplasmic reticulum (GmFAD3A and GmFAD3B) and plastidial (GmFAD7-1/GmFAD7-2 or GmFAD8-1/GmFAD8-2) desaturase genes were detected during seed germination. Upon germination, soybean trifoliate leaf development was accompanied by an increase in linolenic acid (18:3(Δ9,12,15)). Our data showed that transcripts corresponding to the endoplasmic reticulum ω-3 desaturases GmFAD3A and GmFAD3B decreased with leaf development. No changes in the expression profile of the plastidial ω-3 desaturases GmFAD7-1 and GmFAD7-2 genes were detected. On the contrary, GmFAD8-2 transcript levels increased while GmFAD8-1 transcripts decreased during leaf development. Given this expression profile, our data suggested the existence of a temporal regulatory mechanism controlling ω-3 desaturases during leaf development in which the endoplasmic reticulum ω-3 desaturases would be more important in young leaves while plastidial ω-3 desaturases might contribute to 18:3(Δ9,12,15) production in mature leaves. Photosynthetic cell cultures showed 18:3(Δ9,12,15) levels similar to those from leaves. No changes in the 18:3(Δ9,12,15) content or expression of the ω-3 desaturase genes were detected along the cell culture cycle. A comparison of our data with those available in Arabidopsis or wheat suggested that the regulatory mechanism controlling the expression and activity of both endoplasmic reticulum and plastidial desaturases during leaf development might differ among plant species.
Collapse
Affiliation(s)
- Beatriz Lagunas
- Department of Plant Nutrition, Estación Experimental Aula Dei (EEAD-CSIC), Avda. Montañana 1005, 50059 Zaragoza, Spain
| | | | | | | | | |
Collapse
|
6
|
Andreu V, Lagunas B, Collados R, Picorel R, Alfonso M. The GmFAD7 gene family from soybean: identification of novel genes and tissue-specific conformations of the FAD7 enzyme involved in desaturase activity. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:3371-84. [PMID: 20547564 PMCID: PMC2905200 DOI: 10.1093/jxb/erq158] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 05/14/2010] [Accepted: 05/14/2010] [Indexed: 05/03/2023]
Abstract
The FAD7 gene encodes a omega3 fatty acid desaturase which catalyses the production of trienoic fatty acids (TAs) in plant chloroplasts. A novel GmFAD7 gene (named GmFAD7-2) has been identified in soybean, with high homology to the previously annotated GmFAD7 gene. Genomic sequencing analysis together with searches at the soybean genome database further confirmed that both GmFAD7 genes were located in two different loci within the soybean genome, suggesting that the soybean omega3 plastidial desaturase FAD7 is encoded by two different paralogous genes. Both GmFAD7-1 and GmFAD7-2 genes were expressed in all soybean tissues examined, displaying their highest mRNA accumulation in leaves. This expression profile contrasted with GmFAD3A and GmFAD3B mRNA accumulation, which was very low in this tissue. These results suggested a concerted control of plastidial and reticular omega3 desaturase gene expression in soybean mature leaves. Analysis of GmFAD7 protein distribution in different soybean tissues showed that, in mature leaves, two bands were detected, coincident with the higher expression level of both GmFAD7 genes and the highest 18:3 fatty acid accumulation. By contrast, in seeds, where FAD7 activity is low, specific GmFAD7 protein conformations were observed. These GmFAD7 protein conformations were affected in vitro by changes in the redox conditions of thiol groups and iron availability. These results suggest the existence of tissue-specific post-translational regulatory mechanisms affecting the distribution and conformation of the FAD7 enzymes related with the control of its activity.
Collapse
Affiliation(s)
| | | | | | | | - Miguel Alfonso
- Department of Plant Nutrition, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, E-50059 Zaragoza, Spain
| |
Collapse
|
7
|
Teixeira MC, Carvalho IS, Brodelius M. Omega-3 fatty acid desaturase genes isolated from purslane (Portulaca oleracea L.): expression in different tissues and response to cold and wound stress. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:1870-1877. [PMID: 20070085 DOI: 10.1021/jf902684v] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Two full-length cDNA clones PoleFAD7 and PoleFAD8, encoding plastidial omega-3 fatty acid desaturases were isolated from purslane (Portulaca oleracea). The encoded enzymes convert linoleic to alpha-linolenic acid (C18:3n-3). Three histidine clusters characteristic of fatty acid desaturases, a putative chloroplast transit peptide in the N-terminal, and three putative transmembrane domains were identified in the sequence. Both genes were expressed in all analyzed tissues showing different levels of expression. PoleFAD7 was up-regulated by wounding but not by low temperature. PoleFAD8 was up-regulated by cold stress but not by wounding. Total fatty acid and linolenic acid content were higher both, in wounded and intact leaves of plants exposed to low temperature.
Collapse
|
8
|
Bruce German J, Watkins S. Unsaturated Fatty Acids. FOOD SCIENCE AND TECHNOLOGY 2008. [DOI: 10.1201/9781420046649.ch20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
9
|
Tang S, Guan R, Zhang H, Huang J. Cloning and expression analysis of three cDNAs encoding omega-3 fatty acid desaturases from Descurainia sophia. Biotechnol Lett 2007; 29:1417-24. [PMID: 17479217 DOI: 10.1007/s10529-007-9391-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 04/03/2007] [Accepted: 04/03/2007] [Indexed: 10/23/2022]
Abstract
Three cDNAs of DsFAD3, DsFAD7 and DsFAD8, encoding omega-3 fatty acid desaturases, which are the key enzymes for the conversion of linoleic to alpha-linolenic acid (18:3n-3), were isolated from Descurainia sophia using RACE-PCR. Tissue-specific expression analysis revealed that DsFAD3 and DsFAD7 genes were expressed in all tissues and at a high level in stems, leaves and young siliques, whereas DsFAD8 was moderately expressed in photosynthetic tissues including stems, leaves and young siliques. All three genes were significantly induced by wounding stress and DsFAD3 and DsFAD7 transcript levels were down-regulated by cold, whereas DsFAD8 was increased upon cold stress.
Collapse
Affiliation(s)
- Sanyuan Tang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing, 210095, P. R. China
| | | | | | | |
Collapse
|
10
|
Hamada T, Iba K, Shimada T. Reduction of trienoic fatty acid content by expression of a double-stranded RNA of a plastid omega-3 fatty acid desaturase gene in transgenic tobacco. Biotechnol Lett 2006; 28:779-85. [PMID: 16786241 DOI: 10.1007/s10529-006-9009-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Accepted: 02/15/2006] [Indexed: 10/24/2022]
Abstract
Plastid omega-3 fatty acid desaturase catalyzes the conversion of dienoic fatty acids (16:2 and 18:2) to trienoic fatty acids (16:3 and alpha-18:3) in glycerolipids which are the main constituents of chloroplast membranes. We produced transgenic tobacco plants that express the transcript of a double-stranded RNA (dsRNA) of tobacco plastid omega-3 fatty acid desaturase gene, NtFAD7. In these transgenic plants, 16:3 and alpha-18:3 content in leaves decreased to less than 2.7% and 7.5-10.4%, respectively, when compared with the control plant. The steady-state NtFAD7 mRNA was not detected in the transgenic plants. These results indicate that down-regulation of the transcript level in the NtFAD7 by introduction of NtFAD7 dsRNA constructs is useful to decrease the trienoic fatty acid contents of the vegetative tissues in higher plants.
Collapse
Affiliation(s)
- Tatsuro Hamada
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichimachi, Ishikawa 921-8836, Japan.
| | | | | |
Collapse
|
11
|
Poghosyan ZP, Giannoulia K, Katinakis P, Murphy DJ, Hatzopoulos P. Temporal and transient expression of olive enoyl-ACP reductase gene during flower and fruit development. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2005; 43:37-44. [PMID: 15763664 DOI: 10.1016/j.plaphy.2004.12.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Accepted: 12/12/2004] [Indexed: 05/02/2023]
Abstract
Enoyl-ACP reductase is a catalytic component of the fatty acid synthetase (FAS) type II system in plants that is involved in the de novo fatty acid biosynthesis in plastids. A cDNA encoding an enoyl-ACP reductase responsible for the removal of the trans-unsaturated double bonds to form saturated acyl-ACP has been isolated from a library made from ripening fruits of Olea europaea L. The predicted protein contains 393 amino acid residues including a consensus chloroplast specific transit peptide. A strong homology was observed when olive enoyl-ACP reductase aligned with other plant sequences. Southern hybridization analysis revealed that enoyl-ACP reductase is encoded by a single gene in olives. Northern hybridization showed a transient expression of the enoyl-ACP reductase (ENR) gene at early stages of drupe (5-7 weeks after flowering, WAF), embryo and endosperm (13-16 WAF) while in mesocarp (13-19 WAF) the expression remained at high levels. In situ hybridization showed particularly prominent expression in the palisade and vascular tissue of young leaves, the tapetum, developing pollen grains and vascular tissue of anthers and to less extent in the embryo sac and transmitting tissue of the carpel. The distinctive spatial and temporal regulation of the ENR gene is consistent with major roles, not only in thylakoid membrane formation and fatty acid deposition, but also in the provision of precursor molecules for the biosynthesis of oxilipins that are important in plant tissues involved in transportation and reproduction.
Collapse
Affiliation(s)
- Zaruhi P Poghosyan
- Laboratory of Molecular Biology, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece
| | | | | | | | | |
Collapse
|
12
|
Iba K. Acclimative response to temperature stress in higher plants: approaches of gene engineering for temperature tolerance. ANNUAL REVIEW OF PLANT BIOLOGY 2002; 53:225-45. [PMID: 12221974 DOI: 10.1146/annurev.arplant.53.100201.160729] [Citation(s) in RCA: 286] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Temperature stresses experienced by plants can be classified into three types: those occurring at (a) temperatures below freezing, (b) low temperatures above freezing, and (c) high temperatures. This review outlines how biological substances that are deeply related to these stresses, such as heat-shock proteins, glycinebetaine as a compatible solute, membrane lipids, etc., and also detoxifiers of active oxygen species, contribute to temperature stress tolerance in plants. Also presented here are the uses of genetic engineering techniques to improve the adaptability of plants to temperature stress by altering the levels and composition of these substances in the living organism. Finally, the future prospects for molecular breeding are discussed.
Collapse
Affiliation(s)
- Koh Iba
- Department of Biology, Kyushu University, Fukuoka 812-8581, Japan.
| |
Collapse
|
13
|
Horiguchi G, Fuse T, Kawakami N, Kodama H, Iba K. Temperature-dependent translational regulation of the ER omega-3 fatty acid desaturase gene in wheat root tips. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2000; 24:805-813. [PMID: 11135114 DOI: 10.1111/j.1365-313x.2000.00925.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The proportion of alpha-linolenic acid (18:3) among the total fatty acids in root tissue increases as the growth temperature decreases. Endoplasmic reticulum omega-3 fatty acid desaturase is responsible for the production of most of the 18:3 in root tissue. In this study, the effect of temperature on expression of the TaFAD3 gene, which encodes endoplasmic reticulum omega-3 desaturase in wheat (Triticum aestivum L. cv. Chihoku), was analysed at the mRNA and protein levels. In wheat root tips grown at 30 and 10 degrees C, the proportions of 18:3 among total fatty acids were 22% and 55%, respectively. The level of TaFAD3 protein in microsomal preparations of the root tips grown at 10 degrees C was approximately 7.5 times higher than that of the root tips grown at 30 degrees C. The increased level of TaFAD3 protein at the lower temperature was accompanied by enhanced association of TaFAD3 mRNA with polyribosomes. In contrast, the level of TaFAD3 mRNA in root tips grown at 10 degrees C was slightly higher than in those grown at 30 degrees C. These results suggest that, in root tips, the increase in the 18:3 level at low temperature is achieved directly by an increase in the amount of TaFAD3 protein, and that temperature-dependent translational regulation of the TaFAD3 gene, rather than its transcriptional regulation, contributes to modulation of the TaFAD3 protein accumulation.
Collapse
Affiliation(s)
- G Horiguchi
- Department of Biology, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | | | | | | | | |
Collapse
|
14
|
Horiguchi G, Fuse T, Kawakami N, Kodama H, Iba K. Temperature-dependent translational regulation of the ER omega-3 fatty acid desaturase gene in wheat root tips. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2000; 24:805-813. [PMID: 11135114 DOI: 10.1046/j.1365-313x.2000.00925.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The proportion of alpha-linolenic acid (18:3) among the total fatty acids in root tissue increases as the growth temperature decreases. Endoplasmic reticulum omega-3 fatty acid desaturase is responsible for the production of most of the 18:3 in root tissue. In this study, the effect of temperature on expression of the TaFAD3 gene, which encodes endoplasmic reticulum omega-3 desaturase in wheat (Triticum aestivum L. cv. Chihoku), was analysed at the mRNA and protein levels. In wheat root tips grown at 30 and 10 degrees C, the proportions of 18:3 among total fatty acids were 22% and 55%, respectively. The level of TaFAD3 protein in microsomal preparations of the root tips grown at 10 degrees C was approximately 7.5 times higher than that of the root tips grown at 30 degrees C. The increased level of TaFAD3 protein at the lower temperature was accompanied by enhanced association of TaFAD3 mRNA with polyribosomes. In contrast, the level of TaFAD3 mRNA in root tips grown at 10 degrees C was slightly higher than in those grown at 30 degrees C. These results suggest that, in root tips, the increase in the 18:3 level at low temperature is achieved directly by an increase in the amount of TaFAD3 protein, and that temperature-dependent translational regulation of the TaFAD3 gene, rather than its transcriptional regulation, contributes to modulation of the TaFAD3 protein accumulation.
Collapse
Affiliation(s)
- G Horiguchi
- Department of Biology, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | | | | | | | | |
Collapse
|
15
|
Kodama H, Nishiuchi T, Seo S, Ohashi Y, Iba K. Possible involvement of protein phosphorylation in the wound-responsive expression of Arabidopsis plastid omega-3 fatty acid desaturase gene. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2000; 155:153-160. [PMID: 10814818 DOI: 10.1016/s0168-9452(00)00210-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The plastid omega-3 fatty acid desaturase (FAD7) catalyzes the conversion of linoleic acid to linolenic acid. Wounding enhances the expression of the FAD7 gene in leaves and induces its expression in stems and roots. The wound-induced expression of the FAD7 promoter was investigated in transgenic tobacco plants carrying the -825 Arabidopsis FAD7 promoter::beta-glucuronidase (GUS) fusion gene. The protein kinase inhibitor, staurosporine, and the protein phosphatase inhibitor, calyculin A, suppressed the wound induction of the FAD7 gene in stems. A tobacco mitogen-activated protein kinase (WIPK) was rapidly activated upon wounding not only in leaves but also in stems and roots, indicating that WIPK probably mediates the wound signals in most vegetative organs. The FAD7 promoter::GUS fusion gene was introduced into the transgenic tobacco plants in which the wipk gene was expressed constitutively at a high level or into the transgenic plants in which the wipk gene was suppressed possibly due to the transgene-induced gene silencing. The wound-induced expression of the FAD7 gene in stems was enhanced in the former transgenic tobacco plants and suppressed in the latter plants. These results suggest that the wound activation of the FAD7 promoter depends on both protein phosphorylation and dephosphorylation events especially in stems, and also that WIPK is involved in such signaling cascades.
Collapse
Affiliation(s)
- H Kodama
- Department of Biology, Kyushu University, Fukuoka, Japan
| | | | | | | | | |
Collapse
|
16
|
Nishiuchi T, Kodama H, Yanagisawa S, Iba K. Wound-induced expression of the FAD7 gene is mediated by different regulatory domains of its promoter in leaves/stems and roots. PLANT PHYSIOLOGY 1999; 121:1239-46. [PMID: 10594110 PMCID: PMC59490 DOI: 10.1104/pp.121.4.1239] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/1999] [Accepted: 08/19/1999] [Indexed: 05/23/2023]
Abstract
The FAD7 gene is expressed preferentially in the chlorophyllous tissues of unwounded plants. Wounding activates the expression of the FAD7 gene not only in chlorophyllous tissues, but also in nonchlorophyllous tissues of stems and roots. Our previous study suggested that wound-responsive transcriptional activation by the FAD7 promoter in leaves/stems and roots is brought about by a jasmonic acid (JA)-independent and JA-dependent signaling pathway, respectively. In this paper, we show that a specific region (from -259 to -198) in the FAD7 promoter is required for wound-activated expression of this gene in leaves and stems, while another region (from -521 to -363) is necessary not only for wound-activated but also for JA-responsive expression of this gene in roots. Thus, different regulatory regions of the FAD7 promoter mediate distinct wound-induced expression of this gene in leaves/stems and roots. Gel mobility shift assays revealed the wound-inducible DNA-binding activity to the -242/-223 region in both stem and leaf nuclear extracts. In fact, deletion of this region abolished wound response of the FAD7 promoter, suggesting the in vivo role of this site. Furthermore, we detected root nuclear factors interacting with the region from -433 to -363 of this promoter. Wounding and methyl jasmonate treatments induced differently these DNA-binding activities. These results suggest that different regulatory mechanisms mediate the wound-induced expression of the FAD7 gene in aerial and subterranean organs.
Collapse
Affiliation(s)
- T Nishiuchi
- Department of Biology, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | | | | | | |
Collapse
|
17
|
Martín M, León J, Dammann C, Albar JP, Griffiths G, Sánchez-Serrano JJ. Antisense-mediated depletion of potato leaf omega3 fatty acid desaturase lowers linolenic acid content and reduces gene activation in response to wounding. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 262:283-90. [PMID: 10336609 DOI: 10.1046/j.1432-1327.1999.00382.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fatty acid omega3 desaturases act on membrane lipids to catalyse the formation of trienoic fatty acids, the most abundant in plant tissues being alpha-linolenic acid. This fatty acid is a precursor of jasmonic acid, a plant growth regulator involved in the control of wound-induced gene activation in plants and in the induction of tuberization in potato. We isolated a potato omega3 desaturase cDNA, possibly encoding a plastidial isoform, and used it to investigate its expression pattern throughout plant development and in response to wounding. Plastidial omega3 desaturase gene transcripts accumulate rapidly upon wounding, preceding the jasmonate-dependent induction of the wound-responsive proteinase inhibitor II gene. We generated transgenic potato plants constitutively expressing an antisense RNA to this plastidial omega3 desaturase. Selected transgenic lines in which the cognate omega3 desaturase mRNA is largely depleted show a marked reduction, of up to 60%, in trienoic acids in leaves and tubers. In these lines, a corresponding reduction in jasmonate content and proteinase inhibitor II expression is observed upon wounding. Our results indicate that a reduction in omega3 desaturase mRNA levels compromises the wound-induced activation of proteinase inhibitor II, suggesting that wound-induced synthesis of linolenic acid is required for jasmonic acid production. The antisense-mediated depletion of fatty acid omega3 desaturases is a viable alternative for reducing trienoic fatty acid content in plant species in which a mutant screening approach is not applicable.
Collapse
Affiliation(s)
- M Martín
- Plant Molecular Genetics, Centro Nacional de Biotecnología CSIC, Madrid, Spain
| | | | | | | | | | | |
Collapse
|
18
|
Tocher DR, Leaver MJ, Hodgson PA. Recent advances in the biochemistry and molecular biology of fatty acyl desaturases. Prog Lipid Res 1998; 37:73-117. [PMID: 9829122 DOI: 10.1016/s0163-7827(98)00005-8] [Citation(s) in RCA: 227] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- D R Tocher
- NERC Unit of Aquatic Biochemistry, School of Natural Sciences, University of Stirling, Scotland, U.K
| | | | | |
Collapse
|
19
|
Kirsch C, Takamiya-Wik M, Reinold S, Hahlbrock K, Somssich IE. Rapid, transient, and highly localized induction of plastidial omega-3 fatty acid desaturase mRNA at fungal infection sites in Petroselinum crispum. Proc Natl Acad Sci U S A 1997; 94:2079-84. [PMID: 9050908 PMCID: PMC20046 DOI: 10.1073/pnas.94.5.2079] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Parsley (Petroselinum crispum) plants and suspension-cultured cells have been used extensively for studies of non-host-resistance mechanisms in plant/pathogen interactions. We now show that treatment of cultured parsley cells with a defined peptide elicitor of fungal origin causes rapid and large changes in the levels of various unsaturated fatty acids. While linoleic acid decreased and linolenic acid increased steadily for several hours, comparatively sharp increases in oleic acid followed a biphasic time course. In contrast, the overall level of stearic acid remained unaffected. Using a PCR-based approach, a parsley cDNA was isolated sharing high sequence similarity with omega-3 fatty acid desaturases. Subsequent isolation and characterization of a full-length cDNA enabled its functional identification as a plastid-localized omega-3 fatty acid desaturase by complementation of the Arabidopsis thaliana fad7/8 double mutant which is low in trienoic fatty acids. omega-3 Fatty acid desaturase mRNA accumulated rapidly and transiently in elicitor-treated cultured parsley cells, protoplasts, and leaves, as well as highly localized around fungal infection sites in parsley leaf buds. These results indicate that unsaturated fatty acid metabolism is yet another component of the highly complex, transcriptionally regulated pathogen defense response in plants.
Collapse
MESH Headings
- Amino Acid Sequence
- Arabidopsis/genetics
- Blotting, Northern
- Cells, Cultured
- Cloning, Molecular
- Fatty Acid Desaturases/genetics
- Fatty Acid Desaturases/metabolism
- Fatty Acids, Unsaturated/metabolism
- Fungal Proteins/pharmacology
- Gene Expression Regulation, Plant
- Genetic Complementation Test
- In Situ Hybridization
- Membrane Glycoproteins/pharmacology
- Microscopy, Fluorescence
- Molecular Sequence Data
- Phytophthora/physiology
- Plants/enzymology
- Plants/genetics
- Plants/metabolism
- Plants/microbiology
- Plastids/enzymology
- RNA, Antisense/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Sequence Homology
Collapse
Affiliation(s)
- C Kirsch
- Max-Planck-Institut für Züchtungsforschung, Abteilung Biochemie, Cologne, Germany
| | | | | | | | | |
Collapse
|