Antisense expression of a ω-3 fatty acid desaturase gene in tobacco plants enhances susceptibility against pathogens

2004 ◽  
Vol 82 (3) ◽  
pp. 297-303 ◽  
Author(s):  
Yang Ju Im ◽  
Mi Seong Kim ◽  
Kwang Yeol Yang ◽  
Yong Hwan Kim ◽  
Kyoungwhan Back ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Pseudomonas Syringae ◽  
Membrane Lipids ◽  
Fatty Acid Desaturase ◽  
Powdery Mildew Fungus ◽  
Transgenic Lines ◽  
Tobacco Mosaic Virus Infection

Membrane lipids in higher plants contain a high proportion of trienoic fatty acids. ω-3 Fatty acid desaturases act on membrane lipids to catalyze the formation of trienoic acids. We isolated a wound-inducible Arabidopsis plastid ω-3 fatty acid desaturase (fad7) gene, and generated transgenic tobacco plants constitutively expressing the antisense fad7 RNA. Selected transgenic lines showed significant reductions in the content of trienoic fatty acids compared with control plants. The transgenic lines showed enhanced susceptibility against Tobacco mosaic virus infection, where necrotic lesions with brown halos developed much earlier and were larger in the transgenic lines than in control plants. After Tobacco mosaic virus infection, expression and protein accumulations of the wound-inducible protein kinase WIPK, as well as defense-response gene expressions such as lipoxygenase (lox) and defensin (pdf1.2), were retarded in the transgenic lines compared with control plants. Increased susceptibility of the transgenic lines was also demonstrated by infections with Pseudomonas syringae pv. tabaci (van Hall) Ash et al., which caused wildfire disease, and with a powdery mildew fungus (Erysiphe cichoracearum DC). These findings support the concept that trienoic fatty acids are involved in plant defense signaling.Key words: ω-3 fatty acid desaturase, linolenic acid, Nicotiana tabacum 'Xanthi', Pseudomonas syringae pv. tabaci, powdery mildew fungus, Tobacco mosaic virus.

scholarly journals Heat stress elicits remodeling in the anther lipidome of peanut

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zolian S. Zoong Lwe ◽  
Ruth Welti ◽  
Daniel Anco ◽  
Salman Naveed ◽  
Sachin Rustgi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Heat Stress ◽  
Fatty Acid ◽  
Membrane Lipids ◽  
Fatty Acid Desaturase ◽  
Susceptible Genotype ◽  
Unsaturated Lipid ◽  
Lipid Species ◽  
Lipid Unsaturation ◽  
Fatty Acid Amount

AbstractUnderstanding the changes in peanut (Arachis hypogaea L.) anther lipidome under heat stress (HT) will aid in understanding the mechanisms of heat tolerance. We profiled the anther lipidome of seven genotypes exposed to ambient temperature (AT) or HT during flowering. Under AT and HT, the lipidome was dominated by phosphatidylcholine (PC), phosphatidylethanolamine (PE), and triacylglycerol (TAG) species (> 50% of total lipids). Of 89 lipid analytes specified by total acyl carbons:total carbon–carbon double bonds, 36:6, 36:5, and 34:3 PC and 34:3 PE (all contain 18:3 fatty acid and decreased under HT) were the most important lipids that differentiated HT from AT. Heat stress caused decreases in unsaturation indices of membrane lipids, primarily due to decreases in highly-unsaturated lipid species that contained 18:3 fatty acids. In parallel, the expression of Fatty Acid Desaturase 3-2 (FAD3-2; converts 18:2 fatty acids to 18:3) decreased under HT for the heat-tolerant genotype SPT 06-07 but not for the susceptible genotype Bailey. Our results suggested that decreasing lipid unsaturation levels by lowering 18:3 fatty-acid amount through reducing FAD3 expression is likely an acclimation mechanism to heat stress in peanut. Thus, genotypes that are more efficient in doing so will be relatively more tolerant to HT.

TOTAL LIPID, FREE STEROL, FREE FATTY ACID, AND TRIACYLGLYCEROL FATTY ACID CONTENT OF TOBACCO MOSAIC VIRUS-INFECTED TOBACCO

1982 ◽  
Vol 62 (3) ◽  
pp. 771-776 ◽  
Author(s):  
L. E. TREVATHAN ◽  
S. A. TOLIN ◽  
L. D. MOORE ◽  
D. M. ORCUTT
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Total Lipid ◽  
Free Sterol ◽  
Fatty Acid Content ◽  
Free Sterols ◽  
Significant Difference ◽  
Infected Tobacco

North Carolina 88 tobacco, a systemic host of tobacco mosaic virus (TMV), was inoculated at the third leaf stage with purified TMV. Inoculated, asymptomatic, and systemically infected, symptomatic leaves were harvested 24 days after inoculation and analyzed for total lipids, free sterols, free fatty acids and triacylglycerol fatty acids. Infection resulted in significant quantitative increases in free sterol and decreases in both free and triacylglycerol fatty acid concentrations, but no changes in total lipid concentrations. Changes in all lipid components assayed occurred in TMV-inoculated leaves as well as in systemically infected leaves, with the only significant difference between them being a lower concentration of the triacylglycerol fatty acid, linolenic acid, in systemically infected leaves.

scholarly journals (290) Increased Tolerance to Dark, Cold Storage in Double Transgenic Plants Expressing FAD7 and IPT Genes under the Control of a Cold-inducible Promoter

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1081B-1081
Author(s):  
Mariya Khodakovskaya ◽  
Richard McAvoy ◽  
Hao Wu ◽  
Jeanne Peters ◽  
Yi Li
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Transgenic Plants ◽  
Fatty Acid Desaturase ◽  
Inducible Promoter ◽  
Omega 3 ◽  
Wild Type ◽  
Molecular Fraction ◽  
Transgenic Lines ◽  
Fatty Acid Species

Chill injury and leaf senescence occur in plants held in prolonged cold, dark storage. To increase tolerance to these conditions, Nicotiana alata and N. tabacum were transformed with either the FAD7 or IPT genes under the control of a cold-inducible promoter (cor15a). FAD7 encodes for omega-3-fatty acid desaturase and was used to resist cold-stress. IPT encodes the cytokinin-pathway enzyme isopentenyl transferase and was used to delay senescence. Independent FAD7 and IPT lines were crossed to produce double transgenic seed. Seedlings from single transgenic (cor15a-IPT or cor15a-FAD7) lines, double transgenic lines, and the wild-type were exposed to prolonged cold, dark conditions. After 3 months in the dark at 2 °C, survival of independent double transgenic N. tabacum lines ranged up to 80% to 90%. However only 40% of FAD7 seedlings survived, 10% of IPT seedlings survived, and no wild-type plants survived. Double transgenic N. alata seedlings average 90% survival under similar conditions and RT-PCR revealed expression of both the IPT and FAD7 genes. Omega-3-FAD enzyme activity increases desaturation in chloroplast membrane fatty acids. When exposed to prolonged cold, the molecular fraction of polyunsaturated fatty acids (18:3 and 16:3) in leaves of wild-type N. alata decreased while monounsaturated (16:1 and 18:1) and saturated fatty acid species (16:0 and 18:0) increased dramatically. In double transgenic N. alata lines exposed to prolonged cold, the molecular fraction of 18:3 and 16:3 increased, while the 16:0 and 18:0 species decreased dramatically compared to nonchilled double transgenic plants.

Saccharomyces kluyveri FAD3 encodes an ω3 fatty acid desaturase

Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1983-1990 ◽  
Author(s):  
Takahiro Oura ◽  
Susumu Kajiwara
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Functional Characterization ◽  
Fatty Acid Desaturase ◽  
Fatty Acid Desaturases ◽  
Desaturase Gene ◽  
Saccharomyces Kluyveri ◽  
Fatty Acid Desaturase Gene

Fungi, like plants, are capable of producing the 18-carbon polyunsaturated fatty acids linoleic acid and α-linolenic acid. These fatty acids are synthesized by catalytic reactions of Δ12 and ω3 fatty acid desaturases. This paper describes the first cloning and functional characterization of a yeast ω3 fatty acid desaturase gene. The deduced protein encoded by the Saccharomyces kluyveri FAD3 gene (Sk-FAD3) consists of 419 amino acids, and shows 30–60 % identity with Δ12 fatty acid desaturases of several eukaryotic organisms and 29–31 % identity with ω3 fatty acid desaturases of animals and plants. During Sk-FAD3 expression in Saccharomyces cerevisiae, α-linolenic acid accumulated only when linoleic acid was added to the culture medium. The disruption of Sk-FAD3 led to the disappearance of α-linolenic acid in S. kluyveri. These findings suggest that Sk-FAD3 is the only ω3 fatty acid desaturase gene in this yeast. Furthermore, transcriptional expression of Sk-FAD3 appears to be regulated by low-temperature stress in a manner different from the other fatty acid desaturase genes in S. kluyveri.

scholarly journals Identification of Novel Inhibitors for Tobacco Mosaic Virus Infection in Solanaceae Plants

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Archana Prabahar ◽  
Subashini Swaminathan ◽  
Arul Loganathan ◽  
Ramalingam Jegadeesan
Keyword(s):  
Virtual Screening ◽  
Rna Polymerase ◽  
Tobacco Mosaic Virus ◽  
Small Molecules ◽  
Mosaic Virus ◽  
Catalytic Domain ◽  
Docking Analysis ◽  
Catalytic Sites ◽  
Capping Enzyme ◽  
Tobacco Mosaic Virus Infection

Tobacco mosaic virus (TMV) infects several crops of economic importance (e.g., tomato) and remains as one of the major concerns to the farmers. TMV enters the host cell and produces the capping enzyme RNA polymerase. The viral genome replicates further to produce multiple mRNAs which encodes several proteins, including the coat protein and an RNA-dependent RNA polymerase (RdRp), as well as the movement protein. TMV replicase domain was chosen for the virtual screening studies against small molecules derived from ligand databases such as PubChem and ChemBank. Catalytic sites of the RdRp domain were identified and subjected to docking analysis with screened ligands derived from virtual screening LigandFit. Small molecules that interact with the target molecule at the catalytic domain region amino acids, GDD, were chosen as the best inhibitors for controlling the TMV replicase activity.

scholarly journals Deficiency of Linolenic Acid in Lefad7 Mutant Tomato Changes the Volatile Profile and Sensory Perception of Disrupted Leaf and Fruit Tissue

2006 ◽  
Vol 131 (2) ◽  
pp. 284-289 ◽  
Author(s):  
Mauricio A. Cañoles ◽  
Randolph M. Beaudry ◽  
Chuanyou Li ◽  
Gregg Howe
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linolenic Acid ◽  
Fatty Acid Desaturase ◽  
Primary Source ◽  
Mutant Line ◽  
Volatile Profile ◽  
Omega 3 ◽  
Line Production ◽  
Fruit Tissue

Six-carbon aldehydes and alcohols formed by tomato (Lycopersicon esculentum Mill.) leaf and fruit tissue following disruption are believed to be derived from the degradation of lipids and free fatty acids. Collectively, these C-6 volatiles comprise some of the most important aroma impact compounds. If fatty acids are the primary source of tomato volatiles, then an alteration in the fatty acid composition such as that caused by a mutation in the chloroplastic omega-3-fatty acid desaturase (ω-3 FAD), referred to as LeFAD7, found in the mutant line of `Castlemart' termed Lefad7, would be reflected in the volatile profile of disrupted leaf and fruit tissue. Leaves and fruit of the Lefad7 mutant had ≈10% to 15% of the linolenic acid (18:3) levels and about 1.5- to 3-fold higher linoleic acid (18:2) levels found in the parent line. Production of unsaturated C-6 aldehydes Z-3-hexenal, Z-3-hexenol, and E-2-hexenal and the alcohol Z-3-hexenol derived from 18:3 was markedly reduced in disrupted leaf and fruit tissue of the Lefad7 mutant line. Conversely, the production of the saturated C-6 aldehyde hexanal and its alcohol, hexanol, were markedly higher in the mutant line. The shift in the volatile profile brought about by the loss of chloroplastic FAD activity in the Lefad7 line was detected by sensory panels at high significance levels (P < 0.0005) and detrimentally affected fruit sensory quality. The ratios and amounts of C-6 saturated and unsaturated aldehydes and alcohols produced by tomato were dependent on substrate levels, suggesting that practices that alter the content of linoleic and linolenic acids or change their ratios can influence tomato flavor.

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