scholarly journals Channeling of Eukaryotic Diacylglycerol into the Biosynthesis of Plastidial Phosphatidylglycerol

2006 ◽  
Vol 282 (7) ◽  
pp. 4613-4625 ◽  
Author(s):  
Markus Fritz ◽  
Heiko Lokstein ◽  
Dieter Hackenberg ◽  
Ruth Welti ◽  
Mary Roth ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Double Bond ◽  
Transgenic Plants ◽  
Phosphatidic Acid ◽  
Lipid Analysis ◽  
Photosynthetic Apparatus ◽  
Hexadecenoic Acid ◽  
Transgenic Tobacco Plants ◽  
Tobacco Plants

Plastidial glycolipids contain diacylglycerol (DAG) moieties, which are either synthesized in the plastids (prokaryotic lipids) or originate in the extraplastidial compartment (eukaryotic lipids) necessitating their transfer into plastids. In contrast, the only phospholipid in plastids, phosphatidylglycerol (PG), contains exclusively prokaryotic DAG backbones. PG contributes in several ways to the functions of chloroplasts, but it is not known to what extent its prokaryotic nature is required to fulfill these tasks. As a first step toward answering this question, we produced transgenic tobacco plants that contain eukaryotic PG in thylakoids. This was achieved by targeting a bacterial DAG kinase into chloroplasts in which the heterologous enzyme was also incorporated into the envelope fraction. From lipid analysis we conclude that the DAG kinase phosphorylated eukaryotic DAG forming phosphatidic acid, which was converted into PG. This resulted in PG with 2–3 times more eukaryotic than prokaryotic DAG backbones. In the newly formed PG the unique Δ3-trans-double bond, normally confined to 3-trans-hexadecenoic acid, was also found in sn-2-bound cis-unsaturated C18 fatty acids. In addition, a lipidomics technique allowed the characterization of phosphatidic acid, which is assumed to be derived from eukaryotic DAG precursors in the chloroplasts of the transgenic plants. The differences in lipid composition had only minor effects on measured functions of the photosynthetic apparatus, whereas the most obvious phenotype was a significant reduction in growth.

scholarly journals Overexpression of the pitaya phosphoethanolamine N-methyltransferase gene (HpPEAMT) enhanced simulated drought stress in tobacco

2021 ◽  
Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen
Keyword(s):  
Drought Stress ◽  
Stress Response ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Transgenic Tobacco ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Transgenic Tobacco Plants ◽  
Wild Type ◽  
Tobacco Plants

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.

Characterization of Aeromonas genomic species by using quinone, polyamine, and fatty acid patterns

1994 ◽  
Vol 40 (10) ◽  
pp. 844-850 ◽  
Author(s):  
Peter Kämpfer ◽  
Klaus Blasczyk ◽  
Georg Auling
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Octadecenoic Acid ◽  
Hexadecenoic Acid ◽  
Genomic Species ◽  
Great Homogeneity ◽  
Hydroxylated Fatty Acids ◽  
Fatty Acid Patterns ◽  
Chemotaxonomic Study

A chemotaxonomic study was carried out on representative strains of 13 Aeromonas genomic species. Quinone, polyamine, and fatty acid patterns were found to be very useful for an improved characterization of the genus and an improved differentiation from members of the families Enterobacteriaceae and Vibrionaceae. The Q-8-benzoquinone was the predominant ubiquinone, and putrescine and diaminopropane were the major poly amines of the genus. The fatty acid patterns of 181 strains, all characterized by DNA–DNA hybridization, showed a great homogeneity within the genus, with major amounts of hexadecanoic acid (16:0), hexadecenoic acid (16:1), and octadecenoic acid (18:1), and minor amounts of the hydroxylated fatty acids (3-OH 13:0, 2-OH 14:0, 3-OH 14:0) in addition to some iso and anteiso branched fatty acids (i-13:0, i-17:1, i-17:0, and a-17:0). Although some differences in fatty acid profiles between the genomic species could be observed, a clearcut differentiation of all species was not possible.Key words: Aeromonas, polyamines, quinones, fatty acids, differentiation.

Transgenic tobacco expressing an Arisaema heterophyllum agglutinin gene displays enhanced resistance to aphids

2004 ◽  
Vol 84 (3) ◽  
pp. 785-790 ◽  
Author(s):  
Jianhong Yao, Xiuyun Zhao ◽  
Huaxiong Qi, Bingliang Wan ◽  
Fei Chen, Xiaofen Sun ◽  
Shanqian Yu ◽  
Kexuan Tang
Keyword(s):  
Transgenic Plants ◽  
Transgenic Tobacco ◽  
Myzus Persicae ◽  
Transgenic Tobacco Plants ◽  
Insect Bioassay ◽  
Tobacco Plants ◽  
Potato Aphid ◽  
Enhanced Resistance ◽  
Multiple Copies ◽  
Peach Potato Aphid

Tobacco leaf discs were transformed with a plasmid, pBIAHA, containing the selectable marker neomycin phosphotransferase gene (nptII) and an Arisaema heterophyllum agglutinin gene (aha) via Agrobacterium tumefaciens-mediated transformation. Thirty-two independent transgenic tobacco plants were regenerated. PCR and Southern blot analyses confirmed that multiple copies of the aha gene had integrated into the plant genome. Northern blot analysis revealed that the aha gene was expressed at various levels in the transgenic plants. Insect bioassay test showed that transgenic plants expressing multiple copies of the aha gene reduced the rate of population increase of the peach potato aphid (Myzus persicae Sulzer). This is the first report that transgenic tobacco plants expressing the aha gene display enhanced resistance to aphids. Key words: Insect bioassay, Arisaema heterophyllum agglutinin, transformation, transgenic tobacco, peach potato aphid (Myzus persicae Sulzer)

scholarly journals The Arabidopsis expansin gene (AtEXPA18) is capable to ameliorate drought stress tolerance in transgenic tobacco plants

2021 ◽  
Author(s):  
Alireza Abbasi ◽  
Meysam Malekpour ◽  
Sajjad Sobhanverdi
Keyword(s):  
Drought Stress ◽  
Transgenic Plants ◽  
Transgenic Tobacco ◽  
Dry Weight ◽  
Conventional Polymerase Chain Reaction ◽  
Specific Gene ◽  
Severe Drought ◽  
Transgenic Tobacco Plants ◽  
Tobacco Plants ◽  
Reverse Transcription Pcr

Abstract Expansins are cell wall proteins that, due to changes in pH, causing the expansion of the cell walls. In this study, a previously gene construct designed based on a root-specific gene, AtEXPA18, was utilized to assess its potential roles on different morphological, physiological, and cellular levels of generated transgenic tobacco plants in response to moderate and severe drought stress. AtEXPA18 gene was successfully transferred to the tobacco plants through an agrobacterium-mediate transformation system. Upon obtaining the second generation, tobacco transgenic plants were confirmed by conventional polymerase chain reaction (PCR) technique alongside reverse transcription PCR (RT-PCR) using specific primers. Under drought stress, the transgenic lines showed remarkable growth and significantly improved based on morphological traits such as height and stem diameter, leaf area, leaf number, root dry weight, and Abscisic acid (ABA) levels of leaves compared control plants. As a result, the Cytokinin content of transgenic plants has increased under severe stress levels. Notably, the area's expansion for abaxial epidermal cells under the microscope confirmed in transgene cells compared with the -transgene cells. These results, altogether, could support the AtEXPA18 gene implication in cell expansion and improving tolerance capacity of transgenic crops under drought stress.

scholarly journals Overexpression of Grapevine VvIAA18 Gene Enhanced Salt Tolerance in Tobacco

2020 ◽  
Vol 21 (4) ◽  
pp. 1323 ◽  
Author(s):  
Wei Li ◽  
Changxi Dang ◽  
Yuxiu Ye ◽  
Zunxin Wang ◽  
Laibao Hu ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Transgenic Plants ◽  
Transgenic Tobacco ◽  
Transcriptional Activation ◽  
Late Embryogenesis Abundant Protein ◽  
Pcr Analysis ◽  
Vitis Vinifera L ◽  
Transgenic Tobacco Plants ◽  
Tobacco Plants

In plants, auxin/indoleacetic acid (Aux/IAA) proteins are transcriptional regulators that regulate developmental process and responses to phytohormones and stress treatments. However, the regulatory functions of the Vitis vinifera L. (grapevine) Aux/IAA transcription factor gene VvIAA18 have not been reported. In this study, the VvIAA18 gene was successfully cloned from grapevine. Subcellular localization analysis in onion epidermal cells indicated that VvIAA18 was localized to the nucleus. Expression analysis in yeast showed that the full length of VvIAA18 exhibited transcriptional activation. Salt tolerance in transgenic tobacco plants and Escherichia. coli was significantly enhanced by VvIAA18 overexpression. Real-time quantitative PCR analysis showed that overexpression of VvIAA18 up-regulated the salt stress-responsive genes, including pyrroline-5-carboxylate synthase (NtP5CS), late embryogenesis abundant protein (NtLEA5), superoxide dismutase (NtSOD), and peroxidase (NtPOD) genes, under salt stress. Enzymatic analyses found that the transgenic plants had higher SOD and POD activities under salt stress. Meanwhile, component analysis showed that the content of proline in transgenic plants increased significantly, while the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) decreased significantly. Based on the above results, the VvIAA18 gene is related to improving the salt tolerance of transgenic tobacco plants. The VvIAA18 gene has the potential to be applied to enhance plant tolerance to abiotic stress.

Characterization of branched and unsaturated fatty acids in Mycobacterium vaccae strain JOB5

1975 ◽  
Vol 21 (4) ◽  
pp. 510-512 ◽  
Author(s):  
D. H. King ◽  
J. J. Perry
Keyword(s):  
Fatty Acids ◽  
Double Bond ◽  
Unsaturated Fatty Acids ◽  
Mycobacterium Vaccae ◽  
Mass Spectral ◽  
Cellular Fatty Acids ◽  
Branched Chain ◽  
Chain Synthesis ◽  
Chromatographic Mass

After growth of Mycobacterium vaccae strain JOB5 on acetate or propane, the cellular fatty acids were isolated and identified by a combination of gas-chromatographic, mass-spectral, and chemical means. The fatty acids ranged from C12 to C19 and were a mixture of saturated, monounsaturated, and methyl-branched components. The double bond was in the Δ9 position in the C15 to C18 unsaturated acids. The single methyl branch was located on the C10 position of Br-C17, Br-C18, and Br-C19 fatty acids. Branched-chain synthesis occurs at the expense of an unsaturated precursor fatty acid; the double bond serves as the site of methylation. Results suggest that S-adenosylmethionine is the methyl donor involved.

Sign in / Sign up

Export Citation Format

Share Document