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Wu X, Yang Z, Zhu Y, Zhan Y, Li Y, Teng W, Han Y, Zhao X. Bioinformatics Identification and Expression Analysis of Acetyl-CoA Carboxylase Reveal Its Role in Isoflavone Accumulation during Soybean Seed Development. Int J Mol Sci 2024; 25:10221. [PMID: 39337707 PMCID: PMC11432495 DOI: 10.3390/ijms251810221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2024] [Revised: 09/05/2024] [Accepted: 09/20/2024] [Indexed: 09/30/2024] Open
Abstract
Isoflavones belong to the class of flavonoid compounds, which are important secondary metabolites that play a crucial role in plant development and defense. Acetyl-CoA carboxylase (ACCase) is a biotin-dependent enzyme that catalyzes the conversion of Acetyl-CoA into Malonyl-CoA in plants. It is a key enzyme in fatty acid synthesis and also catalyzes the production of various secondary metabolites. However, information on the ACC gene family in the soybean (Glycine max L. Merr.) genome and the specific members involved in isoflavone biosynthesis is still lacking. In this study, we identified 20 ACC family genes (GmACCs) from the soybean genome and further characterized their evolutionary relationships and expression patterns. Phylogenetic analysis showed that the GmACCs could be divided into five groups, and the gene structures within the same groups were highly conserved, indicating that they had similar functions. The GmACCs were randomly distributed across 12 chromosomes, and collinearity analysis suggested that many GmACCs originated from tandem and segmental duplications, with these genes being under purifying selection. In addition, gene expression pattern analysis indicated that there was functional divergence among GmACCs in different tissues. The GmACCs reached their peak expression levels during the early or middle stages of seed development. Based on the transcriptome and isoflavone content data, a weighted gene co-expression network was constructed, and three candidate genes (Glyma.06G105900, Glyma.13G363500, and Glyma.13G057400) that may positively regulate isoflavone content were identified. These results provide valuable information for the further functional characterization and application of GmACCs in isoflavone biosynthesis in soybean.
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Affiliation(s)
- Xu Wu
- Key Laboratory of Soybean Biology in Chinese Education Ministry, Northeast Agricultural University, Harbin 150030, China
| | - Zhenhong Yang
- Key Laboratory of Soybean Biology in Chinese Education Ministry, Northeast Agricultural University, Harbin 150030, China
| | - Yina Zhu
- Key Laboratory of Soybean Biology in Chinese Education Ministry, Northeast Agricultural University, Harbin 150030, China
| | - Yuhang Zhan
- Key Laboratory of Soybean Biology in Chinese Education Ministry, Northeast Agricultural University, Harbin 150030, China
| | - Yongguang Li
- Key Laboratory of Soybean Biology in Chinese Education Ministry, Northeast Agricultural University, Harbin 150030, China
| | - Weili Teng
- Key Laboratory of Soybean Biology in Chinese Education Ministry, Northeast Agricultural University, Harbin 150030, China
| | - Yingpeng Han
- Key Laboratory of Soybean Biology in Chinese Education Ministry, Northeast Agricultural University, Harbin 150030, China
| | - Xue Zhao
- Key Laboratory of Soybean Biology in Chinese Education Ministry, Northeast Agricultural University, Harbin 150030, China
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Balech R, Maalouf F, Kaur S, Jighly A, Joukhadar R, Alsamman AM, Hamwieh A, Khater LA, Rubiales D, Kumar S. Identification of novel genes associated with herbicide tolerance in Lentil (Lens culinaris ssp. culinaris Medik.). Sci Rep 2024; 14:10215. [PMID: 38702403 PMCID: PMC11068770 DOI: 10.1038/s41598-024-59695-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 04/15/2024] [Indexed: 05/06/2024] Open
Abstract
Weeds pose a major constraint in lentil cultivation, leading to decrease farmers' revenues by reducing the yield and increasing the management costs. The development of herbicide tolerant cultivars is essential to increase lentil yield. Even though herbicide tolerant lines have been identified in lentils, breeding efforts are still limited and lack proper validation. Marker assisted selection (MAS) can increase selection accuracy at early generations. Total 292 lentil accessions were evaluated under different dosages of two herbicides, metribuzin and imazethapyr, during two seasons at Marchouch, Morocco and Terbol, Lebanon. Highly significant differences among accessions were observed for days to flowering (DF) and maturity (DM), plant height (PH), biological yield (BY), seed yield (SY), number of pods per plant (NP), as well as the reduction indices (RI) for PH, BY, SY and NP. A total of 10,271 SNPs markers uniformly distributed along the lentil genome were assayed using Multispecies Pulse SNP chip developed at Agriculture Victoria, Melbourne. Meta-GWAS analysis was used to detect marker-trait associations, which detected 125 SNPs markers associated with different traits and clustered in 85 unique quantitative trait loci. These findings provide valuable insights for initiating MAS programs aiming to enhance herbicide tolerance in lentil crop.
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Affiliation(s)
- Rind Balech
- International Center for Agricultural Research in the Dry Areas (ICARDA), Terbol, Lebanon.
| | - Fouad Maalouf
- International Center for Agricultural Research in the Dry Areas (ICARDA), Terbol, Lebanon.
| | - Sukhjiwan Kaur
- Department of Energy, AgriBio, Environment and Climate Action, Centre for AgriBioscience, 5 Ring Road, Bundoora, VIC, 3083, Australia
| | - Abdulqader Jighly
- Department of Energy, AgriBio, Environment and Climate Action, Centre for AgriBioscience, 5 Ring Road, Bundoora, VIC, 3083, Australia
| | - Reem Joukhadar
- Department of Energy, AgriBio, Environment and Climate Action, Centre for AgriBioscience, 5 Ring Road, Bundoora, VIC, 3083, Australia
| | | | | | - Lynn Abou Khater
- International Center for Agricultural Research in the Dry Areas (ICARDA), Terbol, Lebanon
| | - Diego Rubiales
- Institute for Sustainable Agriculture, CSIC, Córdoba, Spain
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Li H, Che R, Zhu J, Yang X, Li J, Fernie AR, Yan J. Multi-omics-driven advances in the understanding of triacylglycerol biosynthesis in oil seeds. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 117:999-1017. [PMID: 38009661 DOI: 10.1111/tpj.16545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 11/01/2023] [Indexed: 11/29/2023]
Abstract
Vegetable oils are rich sources of polyunsaturated fatty acids and energy as well as valuable sources of human food, animal feed, and bioenergy. Triacylglycerols, which are comprised of three fatty acids attached to a glycerol backbone, are the main component of vegetable oils. Here, we review the development and application of multiple-level omics in major oilseeds and emphasize the progress in the analysis of the biological roles of key genes underlying seed oil content and quality in major oilseeds. Finally, we discuss future research directions in functional genomics research based on current omics and oil metabolic engineering strategies that aim to enhance seed oil content and quality, and specific fatty acids components according to either human health needs or industrial requirements.
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Affiliation(s)
- Hui Li
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Ronghui Che
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Jiantang Zhu
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Xiaohong Yang
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China
| | - Jiansheng Li
- National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
| | - Jianbing Yan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China
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Peng Z, Yu S, Meng J, Jia KH, Zhang J, Li X, Gao W, Wan S. Alternative polyadenylation regulates acetyl-CoA carboxylase function in peanut. BMC Genomics 2023; 24:637. [PMID: 37875812 PMCID: PMC10594767 DOI: 10.1186/s12864-023-09696-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/21/2023] [Indexed: 10/26/2023] Open
Abstract
BACKGROUND Polyadenylation is a crucial process that terminates mRNA molecules at their 3'-ends. It has been observed that alternative polyadenylation (APA) can generate multiple transcripts from a single gene locus, each with different polyadenylation sites (PASs). This leads to the formation of several 3' untranslated regions (UTRs) that vary in length and composition. APA has a significant impact on approximately 60-70% of eukaryotic genes and has far-reaching implications for cell proliferation, differentiation, and tumorigenesis. RESULTS In this study, we conducted long-read, single-molecule sequencing of mRNA from peanut seeds. Our findings revealed that over half of all peanut genes possess over two PASs, with older developing seeds containing more PASs. This suggesting that the PAS exhibits high tissue specificity and plays a crucial role in peanut seed maturation. For the peanut acetyl-CoA carboxylase A1 (AhACCA1) gene, we discovered four 3' UTRs referred to UTR1-4. RT-PCR analysis showed that UTR1-containing transcripts are predominantly expressed in roots, leaves, and early developing seeds. Transcripts containing UTR2/3 accumulated mainly in roots, flowers, and seeds, while those carrying UTR4 were constitutively expressed. In Nicotiana benthamiana leaves, we transiently expressed all four UTRs, revealing that each UTR impacted protein abundance but not subcellular location. For functional validation, we introduced each UTR into yeast cells and found UTR2 enhanced AhACCA1 expression compared to a yeast transcription terminator, whereas UTR3 did not. Furthermore, we determined ACC gene structures in seven plant species and identified 51 PASs for 15 ACC genes across four plant species, confirming that APA of the ACC gene family is universal phenomenon in plants. CONCLUSION Our data demonstrate that APA is widespread in peanut seeds and plays vital roles in peanut seed maturation. We have identified four 3' UTRs for AhACCA1 gene, each showing distinct tissue-specific expression patterns. Through subcellular location experiment and yeast transformation test, we have determined that UTR2 has a stronger impact on gene expression regulation compared to the other three UTRs.
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Affiliation(s)
- Zhenying Peng
- Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Science, Jinan, 250100, China.
| | - Shuang Yu
- College of Agricultural, Xinjiang Agricultural University, Urumqi, 830052, China
| | - Jingjing Meng
- Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Science, Jinan, 250100, China
| | - Kai-Hua Jia
- Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Science, Jinan, 250100, China
| | - Jialei Zhang
- Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Science, Jinan, 250100, China
| | - Xinguo Li
- Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Science, Jinan, 250100, China
| | - Wenwei Gao
- College of Agricultural, Xinjiang Agricultural University, Urumqi, 830052, China.
| | - Shubo Wan
- Shandong Academy of Agricultural Science, Jinan, 250100, China.
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Megha S, Wang Z, Kav NNV, Rahman H. Genome-wide identification of biotin carboxyl carrier subunits of acetyl-CoA carboxylase in Brassica and their role in stress tolerance in oilseed Brassica napus. BMC Genomics 2022; 23:707. [PMID: 36253756 PMCID: PMC9578262 DOI: 10.1186/s12864-022-08920-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/23/2022] [Indexed: 11/22/2022] Open
Abstract
Background Biotin carboxyl carrier protein (BCCP) is a subunit of Acetyl CoA-carboxylase (ACCase) which catalyzes the conversion of acetyl-CoA to malonyl-CoA in a committed step during the de novo biosynthesis of fatty acids. Lipids, lipid metabolites, lipid-metabolizing and -modifying enzymes are known to play a role in biotic and abiotic stress tolerance in plants. In this regard, an understanding of the Brassica napus BCCP genes will aid in the improvement of biotic and abiotic stress tolerance in canola. Results In this study, we identified 43 BCCP genes in five Brassica species based on published genome data. Among them, Brassica rapa, Brassica oleracea, Brassica nigra, Brassica napus and Brassica juncea had six, seven, seven, 10 and 13 BCCP homologs, respectively. Phylogenetic analysis categorized them into five classes, each with unique conserved domains. The promoter regions of all BCCP genes contained stress-related cis-acting elements as determined by cis-element analysis. We identified four and three duplicated gene pairs (segmental) in B. napus and B. juncea respectively, indicating the role of segmental duplication in the expansion of this gene family. The Ka/Ks ratios of orthologous gene pairs between Arabidopsis thaliana and five Brassica species were mostly less than 1.0, implying that purifying selection, i.e., selective removal of deleterious alleles, played a role during the evolution of Brassica genomes. Analysis of 10 BnaBCCP genes using qRT-PCR showed a different pattern of expression because of exposure of the plants to biotic stresses, such as clubroot and sclerotinia diseases, and abiotic stresses such as drought, low temperature and salinity stresses. Conclusions The identification and functional analysis of the Brassica BCCPs demonstrated that some of these genes might play important roles in biotic and abiotic stress responses. Results from this study could lay the foundation for a better understanding of these genes for the improvement of Brassica crops for stress tolerance. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08920-y.
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Affiliation(s)
- Swati Megha
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Zhengping Wang
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Nat N V Kav
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Habibur Rahman
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
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Guo Q, Liu L, Rupasinghe TWT, Roessner U, Barkla BJ. Salt stress alters membrane lipid content and lipid biosynthesis pathways in the plasma membrane and tonoplast. PLANT PHYSIOLOGY 2022; 189:805-826. [PMID: 35289902 PMCID: PMC9157097 DOI: 10.1093/plphys/kiac123] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 02/22/2022] [Indexed: 05/25/2023]
Abstract
Plant cell membranes are the sites of sensing and initiation of rapid responses to changing environmental factors including salinity stress. Understanding the mechanisms involved in membrane remodeling is important for studying salt tolerance in plants. This task remains challenging in complex tissue due to suboptimal subcellular membrane isolation techniques. Here, we capitalized on the use of a surface charge-based separation method, free flow electrophoresis, to isolate the tonoplast (TP) and plasma membrane (PM) from leaf tissue of the halophyte ice plant (Mesembryanthemum crystallinum L.). Results demonstrated a membrane-specific lipidomic remodeling in this plant under salt conditions, including an increased proportion of bilayer forming lipid phosphatidylcholine in the TP and an increase in nonbilayer forming and negatively charged lipids (phosphatidylethanolamine and phosphatidylserine) in the PM. Quantitative proteomics showed salt-induced changes in proteins involved in fatty acid synthesis and desaturation, glycerolipid, and sterol synthesis, as well as proteins involved in lipid signaling, binding, and trafficking. These results reveal an essential plant mechanism for membrane homeostasis wherein lipidome remodeling in response to salt stress contributes to maintaining the physiological function of individual subcellular compartments.
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Affiliation(s)
- Qi Guo
- Faculty of Science and Engineering, Southern Cross Plant Science, Southern Cross University, Lismore, NSW 2480, Australia
| | - Lei Liu
- Faculty of Science and Engineering, Southern Cross Plant Science, Southern Cross University, Lismore, NSW 2480, Australia
| | - Thusitha W T Rupasinghe
- School of BioSciences, The University of Melbourne, Parkville 3010, Australia
- Sciex, Mulgrave, VIC 3170, Australia
| | - Ute Roessner
- School of BioSciences, The University of Melbourne, Parkville 3010, Australia
| | - Bronwyn J Barkla
- Faculty of Science and Engineering, Southern Cross Plant Science, Southern Cross University, Lismore, NSW 2480, Australia
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Raman G, Nam GH, Park S. Extensive reorganization of the chloroplast genome of Corydalis platycarpa: A comparative analysis of their organization and evolution with other Corydalis plastomes. FRONTIERS IN PLANT SCIENCE 2022; 13:1043740. [PMID: 37090468 PMCID: PMC10115153 DOI: 10.3389/fpls.2022.1043740] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/07/2022] [Indexed: 05/03/2023]
Abstract
Introduction The chloroplast (cp) is an autonomous plant organelle with an individual genome that encodes essential cellular functions. The genome architecture and gene content of the cp is highly conserved in angiosperms. The plastome of Corydalis belongs to the Papaveraceae family, and the genome is comprised of unusual rearrangements and gene content. Thus far, no extensive comparative studies have been carried out to understand the evolution of Corydalis chloroplast genomes. Methods Therefore, the Corydalis platycarpa cp genome was sequenced, and wide-scale comparative studies were conducted using publicly available twenty Corydalis plastomes. Results Comparative analyses showed that an extensive genome rearrangement and IR expansion occurred, and these events evolved independently in the Corydalis species. By contrast, the plastomes of its closely related subfamily Papaveroideae and other Ranunculales taxa are highly conserved. On the other hand, the synapomorphy characteristics of both accD and the ndh gene loss events happened in the common ancestor of the Corydalis and sub-clade of the Corydalis lineage, respectively. The Corydalis-sub clade species (ndh lost) are distributed predominantly in the Qinghai-Tibetan plateau (QTP) region. The phylogenetic analysis and divergence time estimation were also employed for the Corydalis species. Discussion The divergence time of the ndh gene in the Corydalis sub-clade species (44.31 - 15.71 mya) coincides very well with the uplift of the Qinghai-Tibet Plateau in Oligocene and Miocene periods, and maybe during this period, it has probably triggered the radiation of the Corydalis species. Conclusion To the best of the authors' knowledge, this is the first large-scale comparative study of Corydalis plastomes and their evolution. The present study may provide insights into the plastome architecture and the molecular evolution of Corydalis species.
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Affiliation(s)
- Gurusamy Raman
- Department of Life Sciences, Yeungnam University, Gyeongsan, Gyeongsan-buk, Republic of Korea
| | - Gi-Heum Nam
- Plants Resource Division, Biological Resources Research Department, National Institute of Biological Resources, Seo-gu, Incheon, Republic of Korea
- *Correspondence: SeonJoo Park, ; Gi-Heum Nam,
| | - SeonJoo Park
- Department of Life Sciences, Yeungnam University, Gyeongsan, Gyeongsan-buk, Republic of Korea
- *Correspondence: SeonJoo Park, ; Gi-Heum Nam,
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Wang Y, Wang M, Ye X, Liu H, Takano T, Tsugama D, Liu S, Bu Y. Biotin plays an important role in Arabidopsis thaliana seedlings under carbonate stress. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 300:110639. [PMID: 33180716 DOI: 10.1016/j.plantsci.2020.110639] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/21/2020] [Accepted: 08/15/2020] [Indexed: 06/11/2023]
Abstract
Globally, many saline-alkali soils are rich in NaHCO3 and Na2CO3, which are characterized by a high pH Carbonate stress caused by this kind of soil severely damages plant cells and inhibits plant growth. Biotin and HCO3- participate in the first and rate-limiting reaction of the fatty acid biosynthesis pathway, but whether biotin contributes to plant responses to carbonate stress is unclear. In this study, we revealed that high carbonate and biotin concentrations inhibited Arabidopsis (Arabidopsis thaliana) seedling growth. However, specific concentrations of carbonate and biotin decreased the inhibitory effects of the other compound at the germination and seedling stages. Additionally, a carbonate treatment increased the endogenous biotin content and expression of AtBIO2, which encodes a biotin synthase. Moreover, phenotypic analyses indicated that the overexpression of AtBIO2 in Arabidopsis enhanced the tolerance to carbonate stress, whereas mutations to AtBIO2 had the opposite effect. Furthermore, the carbonate stress-induced accumulation of reactive oxygen species was lower in plants overexpressing AtBIO2 than in the wild-type and bio2 mutants. Accordingly, biotin, which is an essential vitamin for plants, can enhance the resistance to carbonate stress.
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Affiliation(s)
- Yao Wang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration (Northeast Forestry University), Ministry of Education, Harbin, 150040, China; College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Min Wang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration (Northeast Forestry University), Ministry of Education, Harbin, 150040, China; College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Xiaoxue Ye
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration (Northeast Forestry University), Ministry of Education, Harbin, 150040, China; College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Hua Liu
- Department of Silviculture, State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Lin'an, Zhejiang, 311300, China
| | - Tetsuo Takano
- Asian Natural Environmental Science Center (ANESC), University of Tokyo, Nishitokyo, Tokyo, 188-0002, Japan
| | - Daisuke Tsugama
- Asian Natural Environmental Science Center (ANESC), University of Tokyo, Nishitokyo, Tokyo, 188-0002, Japan
| | - Shenkui Liu
- Department of Silviculture, State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Lin'an, Zhejiang, 311300, China.
| | - Yuanyuan Bu
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration (Northeast Forestry University), Ministry of Education, Harbin, 150040, China; College of Life Science, Northeast Forestry University, Harbin, 150040, China.
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Hearn J, Blaxter M, Schönrogge K, Nieves-Aldrey JL, Pujade-Villar J, Huguet E, Drezen JM, Shorthouse JD, Stone GN. Genomic dissection of an extended phenotype: Oak galling by a cynipid gall wasp. PLoS Genet 2019; 15:e1008398. [PMID: 31682601 PMCID: PMC6855507 DOI: 10.1371/journal.pgen.1008398] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/14/2019] [Accepted: 10/23/2019] [Indexed: 12/13/2022] Open
Abstract
Galls are plant tissues whose development is induced by another organism for the inducer's benefit. 30,000 arthropod species induce galls, and in most cases the inducing effectors and target plant systems are unknown. Cynipid gall wasps are a speciose monophyletic radiation that induce structurally complex galls on oaks and other plants. We used a model system comprising the gall wasp Biorhiza pallida and the oak Quercus robur to characterise inducer and host plant gene expression at defined stages through the development of galled and ungalled plant tissues, and tested alternative hypotheses for the origin and type of galling effectors and plant metabolic pathways involved. Oak gene expression patterns diverged markedly during development of galled and normal buds. Young galls showed elevated expression of oak genes similar to legume root nodule Nod factor-induced early nodulin (ENOD) genes and developmental parallels with oak buds. In contrast, mature galls showed substantially different patterns of gene expression to mature leaves. While most oak transcripts could be functionally annotated, many gall wasp transcripts of interest were novel. We found no evidence in the gall wasp for involvement of third-party symbionts in gall induction, for effector delivery using virus-like-particles, or for gallwasp expression of genes coding for plant hormones. Many differentially and highly expressed genes in young larvae encoded secretory peptides, which we hypothesise are effector proteins exported to plant tissues. Specifically, we propose that host arabinogalactan proteins and gall wasp chitinases interact in young galls to generate a somatic embryogenesis-like process in oak tissues surrounding the gall wasp larvae. Gall wasp larvae also expressed genes encoding multiple plant cell wall degrading enzymes (PCWDEs). These have functional orthologues in other gall inducing cynipids but not in figitid parasitoid sister groups, suggesting that they may be evolutionary innovations associated with cynipid gall induction. Plant galls are induced by organisms that manipulate host plant development to produce novel structures. The organisms involved range from mutualistic (such as nitrogen fixing bacteria) to parasitic. In the case of parasites, the gall benefits only the gall-inducing partner. A wide range of organisms can induce galls, but the processes involved are understood only for some bacterial and fungal galls. Cynipid gall wasps induce diverse and structurally complex galls, particularly on oaks (Quercus). We used transcriptome and genome sequencing for one gall wasp and its host oak to identify genes active in gall development. On the plant side, when compared to normally developing bud tissues, young gall tissues showed elevated expression of loci similar to those found in nitrogen-fixing root nodules of leguminous plants. On the wasp side, we found no evidence for involvement of viruses or microorganisms carried by the insects in gall induction or delivery of inducing stimuli. We found that gall wasps express many genes whose products may be secreted to the host, including enzymes that degrade plant cell walls. Genome comparisons between galling and non-galling relatives showed cell wall-degrading enzymes are restricted to gall inducers, and hence potentially key components of a gall inducing lifestyle.
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Affiliation(s)
- Jack Hearn
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Institute of Evolutionary Biology, University of Edinburgh, King’s Buildings, Edinburgh, United Kingdom
- * E-mail: (JH); (GNS)
| | - Mark Blaxter
- Institute of Evolutionary Biology, University of Edinburgh, King’s Buildings, Edinburgh, United Kingdom
| | | | - José-Luis Nieves-Aldrey
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), Madrid, Spain
| | | | - Elisabeth Huguet
- UMR 7261 CNRS, Institut de Recherche sur la Biologie de l’Insecte, Faculté des Sciences et Techniques, Université de Tours, France
| | - Jean-Michel Drezen
- UMR 7261 CNRS, Institut de Recherche sur la Biologie de l’Insecte, Faculté des Sciences et Techniques, Université de Tours, France
| | | | - Graham N. Stone
- Institute of Evolutionary Biology, University of Edinburgh, King’s Buildings, Edinburgh, United Kingdom
- * E-mail: (JH); (GNS)
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10
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Cui Y, Zhao Y, Wang Y, Liu Z, Ijaz B, Huang Y, Hua J. Genome-Wide Identification and Expression Analysis of the Biotin Carboxyl Carrier Subunits of Heteromeric Acetyl-CoA Carboxylase in Gossypium. FRONTIERS IN PLANT SCIENCE 2017; 8:624. [PMID: 28507552 PMCID: PMC5410604 DOI: 10.3389/fpls.2017.00624] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/06/2017] [Indexed: 05/27/2023]
Abstract
Acetyl-CoA carboxylase is an important enzyme, which catalyzes acetyl-CoA's carboxylation to produce malonyl-CoA and to serve as a committed step for de novo fatty acid biosynthesis in plastids. In this study, 24 putative cotton BCCP genes were identified based on the lately published genome data in Gossypium. Among them, 4, 4, 8, and 8 BCCP homologs were identified in Gossypium raimondii, G. arboreum, G. hirsutum, and G. barbadense, respectively. These genes were divided into two classes based on a phylogenetic analysis. In each class, these homologs were relatively conserved in gene structure and motifs. The chromosomal distribution pattern revealed that all the BCCP genes were distributed equally on corresponding chromosomes or scaffold in the four cotton species. Segmental duplication was a predominant duplication event in both of G. hirsutum and G. barbadense. The analysis of the expression profile showed that 8 GhBCCP genes expressed in all the tested tissues with changed expression levels, and GhBCCP genes belonging to class II were predominantly expressed in developing ovules. Meanwhile, the expression analysis for the 16 cotton BCCP genes from G. raimondii, G. arboreum and G. hirsutum showed that they were induced or suppressed by cold or salt stress, and their expression patterns varied among different tissues. These findings will help to determine the functional and evolutionary characteristics of the BCCP genes in Gossypium species.
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Affiliation(s)
- Yupeng Cui
- Laboratory of Cotton Genetics, Genomics and Breeding, College of Agronomy and Biotechnology/Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China
| | - Yanpeng Zhao
- Laboratory of Cotton Genetics, Genomics and Breeding, College of Agronomy and Biotechnology/Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China
| | - Yumei Wang
- Research Institute of Cash Crop, Hubei Academy of Agricultural SciencesWuhan, China
| | - Zhengjie Liu
- Laboratory of Cotton Genetics, Genomics and Breeding, College of Agronomy and Biotechnology/Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China
| | - Babar Ijaz
- Laboratory of Cotton Genetics, Genomics and Breeding, College of Agronomy and Biotechnology/Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China
| | - Yi Huang
- Oil Crops Research Institute, Chinese Academy of Agricultural SciencesWuhan, China
| | - Jinping Hua
- Laboratory of Cotton Genetics, Genomics and Breeding, College of Agronomy and Biotechnology/Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China
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11
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Kim HU, Lee KR, Jung SJ, Shin HA, Go YS, Suh MC, Kim JB. Senescence-inducible LEC2 enhances triacylglycerol accumulation in leaves without negatively affecting plant growth. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:1346-59. [PMID: 25790072 PMCID: PMC5448714 DOI: 10.1111/pbi.12354] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 12/28/2014] [Accepted: 01/30/2015] [Indexed: 05/08/2023]
Abstract
The synthesis of fatty acids and glycerolipids in wild-type Arabidopsis leaves does not typically lead to strong triacylglycerol (TAG) accumulation. LEAFY COTYLEDON2 (LEC2) is a master regulator of seed maturation and oil accumulation in seeds. Constitutive ectopic LEC2 expression causes somatic embryogenesis and defects in seedling growth. Here, we report that senescence-inducible LEC2 expression caused a threefold increase in TAG levels in transgenic leaves compared with that in the leaves of wild-type plants. Plant growth was not severely affected by the accumulation the TAG in response to LEC2 expression. The levels of plastid-synthesized lipids, mono- and di-galactosyldiacylglycerol and phosphatidylglycerol were reduced more in senescence-induced LEC2 than in endoplasmic reticulum-synthesized lipids, including phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol. Senescence-induced LEC2 up-regulated the expression of many genes involved in fatty acid and TAG biosynthesis at precise times in senescent leaves, including WRINKLED1 (WRI1), which encodes a fatty acid transcription factor. The expressions of glycerol-3-phosphate dehydrogenase 1 and phospholipid:diacylglycerol 2 were increased in the transgenic leaves. Five seed-type oleosin-encoding genes, expressed during oil-body formation, and the seed-specific FAE1 gene, which encodes the enzyme responsible for the synthesis of C20:1 and C22:1 fatty acids, were also expressed at higher levels in senescing transgenic leaves than in wild-type leaves. Senescence-inducible LEC2 triggers the key metabolic steps that increase TAG accumulation in vegetative tissues.
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Affiliation(s)
- Hyun Uk Kim
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea
- Corresponding author: Hyun Uk Kim, Tel: 82-031-299-1703, Fax: 82-031-299-1672,
| | - Kyeong-Ryeol Lee
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea
| | - Su-Jin Jung
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea
| | - Hyun A Shin
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea
| | - Young Sam Go
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Mi-Chung Suh
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Jong Bum Kim
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea
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12
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Hardré H, Kuhn L, Albrieux C, Jouhet J, Michaud M, Seigneurin-Berny D, Falconet D, Block MA, Maréchal E. The selective biotin tagging and thermolysin proteolysis of chloroplast outer envelope proteins reveals information on protein topology and association into complexes. FRONTIERS IN PLANT SCIENCE 2014; 5:203. [PMID: 24999344 PMCID: PMC4064156 DOI: 10.3389/fpls.2014.00203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 04/25/2014] [Indexed: 05/27/2023]
Abstract
The understanding of chloroplast function requires the precise localization of proteins in each of its sub-compartments. High-sensitivity mass spectrometry has allowed the inventory of proteins in thylakoid, stroma, and envelope fractions. Concerning membrane association, proteins can be either integral or peripheral or even soluble proteins bound transiently to a membrane complex. We sought a method providing information at the surface of the outer envelope membrane (OEM), based on specific tagging with biotin or proteolysis using thermolysin, a non-membrane permeable protease. To evaluate this method, envelope, thylakoid, and stroma proteins were separated by two-dimensional electrophoresis and analyzed by immunostaining and mass spectrometry. A short selection of proteins associated to the chloroplast envelope fraction was checked after superficial treatments of intact chloroplasts. We showed that this method could allow the characterization of OEM embedded proteins facing the cytosol, as well as peripheral and soluble proteins associated via tight or lose interactions. Some stromal proteins were associated with biotinylated spots and analyzes are still needed to determine whether polypeptides were tagged prior import or if they co-migrated with OEM proteins. This method also suggests that some proteins associated with the inner envelope membrane (IEM) might need the integrity of a trans-envelope (IEM-OEM) protein complex (e.g., division ring-forming components) or at least an intact OEM partner. Following this evaluation, proteomic analyzes should be refined and the putative role of inter-membrane space components stabilizing trans-envelope complexes demonstrated. For future comprehensive studies, perspectives include the dynamic analyses of OEM proteins and IEM-OEM complexes in various physiological contexts and using virtually any other purified membrane organelle.
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Affiliation(s)
- Hélène Hardré
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, iRTSVCEA Grenoble, Grenoble, France
| | - Lauriane Kuhn
- Laboratoire de Biologie à Grande Echelle, iRTSVCEA Grenoble, Grenoble, France
| | - Catherine Albrieux
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, iRTSVCEA Grenoble, Grenoble, France
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, iRTSVCEA Grenoble, Grenoble, France
| | - Morgane Michaud
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, iRTSVCEA Grenoble, Grenoble, France
| | - Daphné Seigneurin-Berny
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, iRTSVCEA Grenoble, Grenoble, France
| | - Denis Falconet
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, iRTSVCEA Grenoble, Grenoble, France
| | - Maryse A. Block
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, iRTSVCEA Grenoble, Grenoble, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, iRTSVCEA Grenoble, Grenoble, France
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13
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Gu K, Chiam H, Tian D, Yin Z. Molecular cloning and expression of heteromeric ACCase subunit genes from Jatropha curcas. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 180:642-9. [PMID: 21421413 DOI: 10.1016/j.plantsci.2011.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 01/08/2011] [Accepted: 01/11/2011] [Indexed: 05/08/2023]
Abstract
Acetyl-CoA carboxylase (ACCase) catalyzes the biotin-dependent carboxylation of acetyl-CoA to produce malonyl-CoA, which is the essential first step in the biosynthesis of long-chain fatty acids. ACCase exists as a multi-subunit enzyme in most prokaryotes and the chloroplasts of most plants and algae, while it is present as a multi-domain enzyme in the endoplasmic reticulum of most eukaryotes. The heteromeric ACCase of higher plants consists of four subunits: an α-subunit of carboxyltransferase (α-CT, encoded by accA gene), a biotin carboxyl carrier protein (BCCP, encoded by accB gene), a biotin carboxylase (BC, encoded by accC gene) and a β-subunit of carboxyltransferase (β-CT, encoded by accD gene). In this study, we cloned and characterized the genes accA, accB1, accC and accD that encode the subunits of heteromeric ACCase in Jatropha (Jatropha curcas), a potential biofuel plant. The full-length cDNAs of the four subunit genes were isolated from a Jatropha cDNA library and by using 5' RACE, whereas the genomic clones were obtained from a Jatropha BAC library. They encode a 771 amino acid (aa) α-CT, a 286-aa BCCP1, a 537-aa BC and a 494-aa β-CT, respectively. The single-copy accA, accB1 and accC genes are nuclear genes, while the accD gene is located in chloroplast genome. Jatropha α-CT, BCCP1, BC and β-CT show high identity to their homologues in other higher plants at amino acid level and contain all conserved domains for ACCase activity. The accA, accB1, accC and accD genes are temporally and spatially expressed in the leaves and endosperm of Jatropha plants, which are regulated by plant development and environmental factors.
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Affiliation(s)
- Keyu Gu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore
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14
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Li X, Ilarslan H, Brachova L, Qian HR, Li L, Che P, Wurtele ES, Nikolau BJ. Reverse-genetic analysis of the two biotin-containing subunit genes of the heteromeric acetyl-coenzyme A carboxylase in Arabidopsis indicates a unidirectional functional redundancy. PLANT PHYSIOLOGY 2011; 155:293-314. [PMID: 21030508 PMCID: PMC3075786 DOI: 10.1104/pp.110.165910] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2010] [Accepted: 10/26/2010] [Indexed: 05/19/2023]
Abstract
The heteromeric acetyl-coenzyme A carboxylase catalyzes the first and committed reaction of de novo fatty acid biosynthesis in plastids. This enzyme is composed of four subunits: biotin carboxyl-carrier protein (BCCP), biotin carboxylase, α-carboxyltransferase, and β-carboxyltransferase. With the exception of BCCP, single-copy genes encode these subunits in Arabidopsis (Arabidopsis thaliana). Reverse-genetic approaches were used to individually investigate the physiological significance of the two paralogous BCCP-coding genes, CAC1A (At5g16390, codes for BCCP1) and CAC1B (At5g15530, codes for BCCP2). Transfer DNA insertional alleles that completely eliminate the accumulation of BCCP2 have no perceptible effect on plant growth, development, and fatty acid accumulation. In contrast, transfer DNA insertional null allele of the CAC1A gene is embryo lethal and deleteriously affects pollen development and germination. During seed development the effect of the cac1a null allele first becomes apparent at 3-d after flowering, when the synchronous development of the endosperm and embryo is disrupted. Characterization of CAC1A antisense plants showed that reducing BCCP1 accumulation to 35% of wild-type levels, decreases fatty acid accumulation and severely affects normal vegetative plant growth. Detailed expression analysis by a suite of approaches including in situ RNA hybridization, promoter:reporter transgene expression, and quantitative western blotting reveal that the expression of CAC1B is limited to a subset of the CAC1A-expressing tissues, and CAC1B expression levels are only about one-fifth of CAC1A expression levels. Therefore, a likely explanation for the observed unidirectional redundancy between these two paralogous genes is that whereas the BCCP1 protein can compensate for the lack of BCCP2, the absence of BCCP1 cannot be tolerated as BCCP2 levels are not sufficient to support heteromeric acetyl-coenzyme A carboxylase activity at a level that is required for normal growth and development.
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MESH Headings
- Acetyl-CoA Carboxylase/genetics
- Acetyl-CoA Carboxylase/metabolism
- Alleles
- Arabidopsis/embryology
- Arabidopsis/enzymology
- Arabidopsis/genetics
- Arabidopsis/growth & development
- Arabidopsis/ultrastructure
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/metabolism
- Biotin/metabolism
- DNA, Bacterial
- Endosperm/enzymology
- Endosperm/growth & development
- Endosperm/ultrastructure
- Fatty Acid Synthase, Type II/genetics
- Fatty Acid Synthase, Type II/metabolism
- Fatty Acids/metabolism
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Gene Knockout Techniques
- Genes, Plant/genetics
- Genes, Recessive/genetics
- Genetic Complementation Test
- Genetic Techniques
- Germination
- Mutation/genetics
- Pollen Tube/enzymology
- Pollen Tube/growth & development
- Pollen Tube/ultrastructure
- Protein Subunits/genetics
- Protein Subunits/metabolism
- RNA, Antisense/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
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15
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Hajduch M, Casteel JE, Hurrelmeyer KE, Song Z, Agrawal GK, Thelen JJ. Proteomic analysis of seed filling in Brassica napus. Developmental characterization of metabolic isozymes using high-resolution two-dimensional gel electrophoresis. PLANT PHYSIOLOGY 2006; 141:32-46. [PMID: 16543413 PMCID: PMC1459325 DOI: 10.1104/pp.105.075390] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Brassica napus (cultivar Reston) seed proteins were analyzed at 2, 3, 4, 5, and 6 weeks after flowering in biological quadruplicate using two-dimensional gel electrophoresis. Developmental expression profiles for 794 protein spot groups were established and hierarchical cluster analysis revealed 12 different expression trends. Tryptic peptides from each spot group were analyzed in duplicate using matrix-assisted laser desorption ionization time-of-flight mass spectrometry and liquid chromatography-tandem mass spectrometry. The identity of 517 spot groups was determined, representing 289 nonredundant proteins. These proteins were classified into 14 functional categories based upon the Arabidopsis (Arabidopsis thaliana) genome classification scheme. Energy and metabolism related proteins were highly represented in developing seed, accounting for 24.3% and 16.8% of the total proteins, respectively. Analysis of subclasses within the metabolism group revealed coordinated expression during seed filling. The influence of prominently expressed seed storage proteins on relative quantification data is discussed and an in silico subtraction method is presented. The preponderance of energy and metabolic proteins detected in this study provides an in-depth proteomic view on carbon assimilation in B. napus seed. These data suggest that sugar mobilization from glucose to acetyl-coenzyme A [corrected] is a collaboration between the cytosol and plastids and that temporal control of enzymes and pathways extends beyond transcription. This study provides a systematic analysis of metabolic processes operating in developing B. napus seed from the perspective of protein expression. Data generated from this study have been deposited into a web database (http://oilseedproteomics.missouri.edu) that is accessible to the public domain.
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Affiliation(s)
- Martin Hajduch
- Department of Biochemistry, Life Sciences Center , University of Missouri, Columbia, Missouri 65211, USA
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16
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Kode V, Mudd EA, Iamtham S, Day A. The tobacco plastid accD gene is essential and is required for leaf development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 44:237-44. [PMID: 16212603 DOI: 10.1111/j.1365-313x.2005.02533.x] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Angiosperm plastid genomes typically encode approximately 80 polypeptides, mainly specifying plastid-localized functions such as photosynthesis and gene expression. Plastid protein synthesis and expression of the plastid clpP1 gene are essential for development in tobacco, indicating the presence of one or more plastid genes whose influence extends beyond the plastid compartment. The plastid accD gene encodes the beta-carboxyl transferase subunit of acetyl-CoA carboxylase and is present in the plastids of most flowering plants, including non-photosynthetic parasitic plants. We replaced the wild-type accD gene with an aadA-disrupted mutant allele using homologous recombination. Persistent heteroplasmy in the presence of antibiotics indicated that the wild-type accD allele was essential. The phenotype of the accD knockout was revealed in plastid transformants grown in the absence of antibiotics. Leaves contained pale green sectors and lacked part or all of the leaf lamina due to arrested division or loss of cells. Abnormal structures were present in plastids found in mutant plants, indicating that accD might be required to maintain the plastid compartment. Loss of the plastid compartment would be expected to be lethal. These results provide genetic evidence showing the essential role of plastid ACCase in the pathway leading to the synthesis of products required for the extra-plastidic processes needed for leaf development.
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Affiliation(s)
- Vasumathi Kode
- Faculty of Life Sciences, The University of Manchester, Manchester M13 9PT, UK
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17
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Price LJ, Herbert D, Moss SR, Cole DJ, Harwood JL. Graminicide insensitivity correlates with herbicide-binding co-operativity on acetyl-CoA carboxylase isoforms. Biochem J 2003; 375:415-23. [PMID: 12859251 PMCID: PMC1223688 DOI: 10.1042/bj20030665] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2003] [Revised: 07/09/2003] [Accepted: 07/15/2003] [Indexed: 11/17/2022]
Abstract
The sensitivity of grass species to important classes of graminicide herbicides inhibiting ACCase (acetyl-CoA carboxylase) is associated with a specific inhibition of the multifunctional ACCase located in the plastids of grasses. In contrast, the multisubunit form of ACCase found in the chloroplasts of dicotyledonous plants is insensitive and the minor cytosolic multifunctional isoforms of the enzyme in both types of plants are also less sensitive to inhibition. We have isolated, separated and characterized the multifunctional ACCase isoforms found in exceptional examples of grasses that are either inherently insensitive to these graminicides, or from biotypes showing acquired resistance to their use. Major and minor multifunctional enzymes were isolated from cell suspension cultures of Festuca rubra and the 'Notts A1'-resistant biotype of Alopecurus myosuroides, and their properties compared with those isolated from cells of wild-type sensitive A. myosuroides or from sensitive maize. Purifications of up to 300-fold were necessary to separate the two isoforms. The molecular masses (200-230 kDa) and K(m) values for all three substrates (ATP, bicarbonate and acetyl-CoA) were similar for the different ACCases, irrespective of their graminicide sensitivity. Moreover, we found no correlation between the ability of isoforms to carboxylate propionyl-CoA and their sensitivity to graminicides. However, insensitive purified forms of ACCase were characterized by herbicide-binding co-operativity, whereas, in contrast, sensitive forms of the enzymes were not. Our studies on isolated individual isoforms of ACCase from grasses support and extend previous indications that herbicide binding co-operativity is the only kinetic property that differentiates naturally or selected insensitive enzymes from the typical sensitive forms usually found in grasses.
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Affiliation(s)
- Lindsey J Price
- School of Biosciences, Cardiff University, P.O. Box 911, Cardiff CF10 3US, UK
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18
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Abstract
Biotin-containing proteins are found in all forms of life, and they catalyze carboxylation, decarboxylation, or transcarboxylation reactions that are central to metabolism. In plants, five biotin-containing proteins have been characterized. Of these, four are catalysts, namely the two structurally distinct acetyl-CoA carboxylases (heteromeric and homomeric), 3-methylcrotonyl-CoA carboxylase and geranoyl-CoA carboxylase. In addition, plants contain a noncatalytic biotin protein that accumulates in seeds and is thought to play a role in storing biotin. Acetyl-CoA carboxylases generate two pools of malonyl-CoA, one in plastids that is the precursor for de novo fatty acid biosynthesis and the other in the cytosol that is the precursor for fatty acid elongation and a large number of secondary metabolites. 3-Methylcrotonyl-CoA carboxylase catalyzes a reaction in the mitochondrial pathway for leucine catabolism. The exact metabolic function of geranoyl-CoA carboxylase is as yet unknown, but it may be involved in isoprenoid metabolism. This minireview summarizes the recent developments in our understanding of the structure, regulation, and metabolic functions of these proteins in plants.
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19
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Abstract
Acetyl-CoA carboxylase (ACC) catalyses the first committed step of fatty acid synthesis, the carboxylation of acetyl-CoA to malonyl-CoA. Two physically distinct types of enzymes are found in nature. Bacterial and most plant chloroplasts contain a multi-subunit ACC (MS-ACC) enzyme that is readily dissociated into its component proteins. Mammals, fungi, and plant cytosols contain the second type of ACC, a single large multifunctional polypeptide. This review will focus on the structures, regulation, and enzymatic mechanisms of the bacterial and plant MS-ACCs.
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Affiliation(s)
- John E Cronan
- Department of Microbiology, B103 Chemical and Life Sciences Laboratory, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL 61801, USA.
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20
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Thelen JJ, Ohlrogge JB. The multisubunit acetyl-CoA carboxylase is strongly associated with the chloroplast envelope through non-ionic interactions to the carboxyltransferase subunits. Arch Biochem Biophys 2002; 400:245-57. [PMID: 12054435 DOI: 10.1016/s0003-9861(02)00025-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The committed step for de novo fatty acid biosynthesis is the carboxylation of acetyl-CoA catalyzed by acetyl-CoA carboxylase (ACCase). Plastidial ACCase from most plants is a multisubunit complex composed of multiple copies of four different polypeptides, biotin carboxyl carrier protein (BCCP), biotin carboxylase (BC), and carboxyltransferase (alpha-CT and beta-CT). Immunoblot analyses revealed these four proteins were mostly (69% of total) associated with a 17,000 g insoluble fraction from lysed pea chloroplasts. Under the same conditions only 8% of ribulose-1,5-bisphosphate carboxylase was associated with this insoluble fraction. BCCP and biotin carboxylase BC subunits freely dissociated from 17 kg insoluble fractions under high ionic strength conditions, whereas alpha-CT and beta-CT subunits remained tightly associated. Both CT subunits were highly enriched in envelope versus stroma and thylakoid preparations whereas BC and BCCP subunits were predominantly stromal-localized due to partial dissociation. Rapid solubilization of intact chloroplasts with Triton X-100 followed by centrifugation at 30 kg resulted in a pellet that was up to 8-fold enriched in ACCase activity and 21-fold enriched in BC activity. Triton-insoluble 30 kg pellets were reduced in lipid and chlorophyll content but enriched in chloroplast DNA due to the isolation of nucleoid particles. However, ACCase was not directly associated with nucleoids since enzymatic digestion of DNA or RNA had no effect on the association with Triton-insoluble matter. The amount of Triton-insoluble ACCase was similar in chloroplasts isolated from dark- or light-adapted leaves suggesting transitory starch granules were also not involved in this association. It is proposed that ACCase is associated with envelope membranes through interactions with an unidentified integral membrane protein.
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Affiliation(s)
- Jay J Thelen
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
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21
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Pongdontri P, Hills M. Characterization of a novel plant acyl-coA synthetase that is expressed in lipogenic tissues of Brassica napus L. PLANT MOLECULAR BIOLOGY 2001; 47:717-26. [PMID: 11785933 DOI: 10.1023/a:1013652014744] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
A cDNA encoding a novel isoform of acyl-CoA synthetase (ACS6) was isolated from embryos of oilseed rape. Homology searches show it is most closely related to ACS4 from rat and human brain rather than the other oilseed rape ACSs. The ACS6 is strongly expressed in embryos and flowers, tissues of Brassica napus that synthesize lipids at high rates. The activity of recombinantly expressed ACS6 was recovered in the insoluble fraction (214,000 x g, 1 h pellet). CHAPS-solubilized recombinant ACS6 protein preferred utilising long-chain fatty acids that contained a cis-9 double bond, i.e. palmitoleic, oleic, linoleic and linolenic acids. Western blot analysis showed that the ACS6 protein is membrane-bound.
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22
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Slabas AR, Simon JW, Brown AP. Biosynthesis and regulation of fatty acids and triglycerides in oil seed rape. Current status and future trends. EUR J LIPID SCI TECH 2001. [DOI: 10.1002/1438-9312(200107)103:7<455::aid-ejlt455>3.0.co;2-u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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23
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Plank DW, Gengenbach BG, Gronwald JW. Effect of iron on activity of soybean multi-subunit acetyl-coenzyme A carboxylase. PHYSIOLOGIA PLANTARUM 2001; 112:183-194. [PMID: 11454223 DOI: 10.1034/j.1399-3054.2001.1120206.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Multi-subunit acetyl-coenzyme A carboxylase (MS-ACCase; EC 6.4.1.2) isolated from soybean chloroplasts is a labile enzyme that loses activity during purification. We found that incubating the chloroplast stromal fraction under anaerobic conditions or in the presence of 5 mM FeSO4 stimulated ACCase (acetyl-CoA-->malonyl-CoA) and carboxyltransferase (malonyl-CoA-->acetyl-CoA) activity. Fe-stimulation of activity was associated with 59Fe binding to a stromal protein fraction. ACCase and carboxyltransferase activities measured in the stromal protein fraction containing bound 59Fe were 2-fold and 6-fold greater, respectively, than the control (stromal fraction not pretreated with FeSO4). Superose 6 gel filtration chromatography indicated 59Fe comigrated with stromal protein of approximately 180 kDa that exhibited carboxyltransferase activity, but lacked ACCase activity. Anion exchange (Mono-Q) chromatography of the Superose 6 fraction yielded a protein peak that was enriched in carboxyltransferase activity and contained protein-bound 59Fe. Denaturing gels of the Mono-Q fraction indicated that the 180-kDa protein was composed of a 56-kDa subunit that was bound by an antibody raised against a synthetic beta-carboxyltransferase (beta-CTase) peptide. Incubation of the Mono-Q carboxyltransferase fraction with increasing concentrations of iron at a fixed substrate concentration resulted in increased initial velocities that fit well to a single rectangular three parameter hyperbola (v=vo+Vmax[FeSO4]/Km+[FeSO4]) consistent with iron functioning as a bound activator of catalysis. UV/Vis spectroscopy of the partially purified fraction before and after iron incubation yielded spectra consistent with a protein-bound metal cluster. These results suggest that the beta-CTase subunit of MS-ACCase in soybean chloroplasts is an iron-containing enzyme, which may in part explain its labile nature.
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Affiliation(s)
- David W. Plank
- Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108, USA Plant Science Research Unit, USDA-ARS, St. Paul, MN 55108, USA
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24
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Thelen JJ, Mekhedov S, Ohlrogge JB. Brassicaceae express multiple isoforms of biotin carboxyl carrier protein in a tissue-specific manner. PLANT PHYSIOLOGY 2001; 125:2016-28. [PMID: 11299381 PMCID: PMC88857 DOI: 10.1104/pp.125.4.2016] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2000] [Revised: 11/01/2000] [Accepted: 11/17/2000] [Indexed: 05/21/2023]
Abstract
Plastidial acetyl-coenzyme A carboxylase from most plants is a multi-enzyme complex comprised of four different subunits. One of these subunits, the biotin carboxyl carrier protein (BCCP), was previously proposed to be encoded by a single gene in Arabidopsis. We report and characterize here a second Arabidopsis BCCP (AtBCCP2) cDNA with 42% amino acid identity to AtBCCP1 and 75% identity to a class of oilseed rape (Brassica napus) BCCPs. Both Arabidopsis BCCP isoforms were expressed in Escherichia coli and found to be biotinylated and supported carboxylation activity when reconstituted with purified, recombinant Arabidopsis biotin carboxylase. In vitro translated AtBCCP2 was competent for import into pea (Pisum sativum) chloroplasts and processed to a 25-kD polypeptide. Extracts of Arabidopsis seeds contained biotinylated polypeptides of 35 and 25 kD, in agreement with the masses of recombinant AtBCCP1 and 2, respectively. AtBCCP1 protein was present in developing tissues from roots, leaves, flowers, siliques, and seeds, whereas AtBCCP2 protein was primarily expressed in 7 to 10 d-after-flowering seeds at levels approximately 2-fold less abundant than AtBCCP1. AtBCCP1 transcript reflected these protein expression profiles present in all developing organs and highest in 14-d leaves and siliques, whereas AtBCCP2 transcript was present in flowers and siliques. In protein blots, four different BCCP isoforms were detected in developing seeds from oilseed rape. Of these, a 35-kD BCCP was detected in immature leaves and developing seeds, whereas developing seeds also contained 22-, 25-, and 37-kD isoforms highly expressed 21 d after flowering. These data indicate that oilseed plants in the family Brassicaceae contain at least one to three seed-up-regulated BCCP isoforms, depending upon genome complexity.
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Affiliation(s)
- J J Thelen
- Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824, USA.
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Abstract
Biotin is an essential cofactor for a small number of enzymes involved mainly in the transfer of CO2 during HCO-3-dependent carboxylation reactions. This review highlights progress in plant biotin research by focusing on the four major areas of recent investigation: the structure, enzymology, and localization of two important biotinylated proteins (methylcrotonoyl-CoA carboxylase involved in the catabolism of leucine and noncyclic isoprenoids; acetyl-CoA carboxylase isoforms involved in a number of biosynthetic pathways); the biosynthesis of biotin; the biotinylation of biotin-dependent carboxylases, including the characterization of biotin holocarboxylase synthetase isoforms; and the detailed characterization of a novel, seed-specific biotinylated protein. A central challenge for plant biotin research is to determine in molecular terms how plant cells regulate the flow of biotin to sustain the biotinylation of biotin-dependent carboxylases during biosynthetic reactions.
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Affiliation(s)
- Claude Alban
- Laboratoire Mixte CNRS/Aventis (UMR 1932), Aventis CropScience, Lyon, France; e-mail:
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Ke J, Wen TN, Nikolau BJ, Wurtele ES. Coordinate regulation of the nuclear and plastidic genes coding for the subunits of the heteromeric acetyl-coenzyme A carboxylase. PLANT PHYSIOLOGY 2000; 122:1057-71. [PMID: 10759501 PMCID: PMC58940 DOI: 10.1104/pp.122.4.1057] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/1999] [Accepted: 12/17/1999] [Indexed: 05/20/2023]
Abstract
Plastidic acetyl-coenzyme A (CoA) carboxylase (ACCase) catalyzes the first committed reaction of de novo fatty acid biosynthesis. This heteromeric enzyme is composed of one plastid-coded subunit (beta-carboxyltransferase) and three nuclear-coded subunits (biotin carboxy-carrier, biotin carboxylase, and alpha-carboxyltransferase). We report the primary structure of the Arabidopsis alpha-carboxyltransferase and beta-carboxyltransferase subunits deduced from nucleotide sequences of the respective genes and/or cDNA. Co-immunoprecipitation experiments confirm that the alpha-carboxyltransferase and beta-carboxyltransferase subunits are physically associated. The plant alpha-carboxyltransferases have gained a C-terminal domain relative to eubacteria, possibly via the evolutionary acquisition of a single exon. This C-terminal domain is divergent among plants and may have a structural function rather than being essential for catalysis. The four ACCase subunit mRNAs accumulate to the highest levels in tissues and cells that are actively synthesizing fatty acids, which are used either for membrane biogenesis in rapidly growing tissues or for oil accumulation in developing embryos. Development coordinately affects changes in the accumulation of the ACCase subunit mRNAs so that these four mRNAs maintain a constant molar stoichiometric ratio. These data indicate that the long-term, developmentally regulated expression of the heteromeric ACCase is in part controlled by a mechanism(s) that coordinately affects the steady-state concentrations of each subunit mRNA.
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Affiliation(s)
- J Ke
- Department of Botany, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
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Mekhedov S, de Ilárduya OM, Ohlrogge J. Toward a functional catalog of the plant genome. A survey of genes for lipid biosynthesis. PLANT PHYSIOLOGY 2000; 122:389-402. [PMID: 10677432 PMCID: PMC58876 DOI: 10.1104/pp.122.2.389] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/1999] [Accepted: 11/02/1999] [Indexed: 05/20/2023]
Abstract
Public databases now include vast amounts of recently acquired DNA sequences that are only partially annotated and, furthermore, are often annotated by automated methods that are subject to errors. Maximum information value of these databases can be derived only by further detailed analyses that frequently require careful examination of records in the context of biological functions. In this study we present an example of such an analysis focused on plant glycerolipid synthesis. Public databases were searched for sequences corresponding to 65 plant polypeptides involved in lipid metabolism. Comprehensive search results and analysis of genes, cDNAs and expressed sequence tags (ESTs) are available online (http://www.canr.msu.edu/lgc). Multiple alignments provided a method to estimate the number of genes in gene families. Further analysis of sequences allowed us to tentatively identify several previously undescribed genes in Arabidopsis. For example, two genomic sequences were identified as candidates for the palmitate-specific monogalactosyldiacylglycerol desaturase (FAD5). A candidate genomic sequence for 3-ketoacyl-acyl-carrier protein (ACP) synthase involved in mitochondrial fatty acid biosynthesis was also identified. Biotin carboxyl carrier protein (BCCP) in Arabidopsis is encoded by at least two genes, but the most abundant BCCP transcript so far has not been characterized. The large number (>165,000) of plant ESTs also provides an opportunity to perform "digital northern" comparisons of gene expression levels across many genes. EST abundance in general correlated with biochemical and flux characteristics of the enzymes in Arabidopsis leaf tissue. In a few cases, statistically significant differences in EST abundance levels were observed for enzymes that catalyze similar reactions in fatty acid metabolism. For example, ESTs for the FatB acyl-ACP thioesterase occur 21 times compared with 7 times for FatA acyl-ACP thioesterase, although flux through the FatA reaction is several times higher than through FatB. Such comparisons may provide initial clues toward previously undescribed regulatory phenomena. The abundance of ESTs for ACP compared with that of stearoyl-ACP desaturase and FatB acyl-ACP thioesterase suggests that concentrations of some enzymes of fatty acid synthesis may be higher than their acyl-ACP substrates.
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Affiliation(s)
- S Mekhedov
- Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824, USA
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de Boer GJ, Testerink C, Pielage G, Nijkamp HJ, Stuitje AR. Sequences surrounding the transcription initiation site of the Arabidopsis enoyl-acyl carrier protein reductase gene control seed expression in transgenic tobacco. PLANT MOLECULAR BIOLOGY 1999; 39:1197-207. [PMID: 10380806 DOI: 10.1023/a:1006129924683] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The NADH-specific enoyl-acyl carrier protein (ACP) reductase, which catalyses the last reducing step during the fatty acid biosynthesis cycle, is encoded in Arabidopsis thaliana encoded by a single housekeeping gene (ENR-A) which is differentially expressed during plant development. To identify elements involved in its tissue-specific transcriptional control, a fragment comprising the 1470 bp region directly upstream of the ATG start codon of the ENR-A gene was fused to the uidA (GUS) reporter gene and analysed in transgenic Nicotiana tabacum plants. GUS activity found during development of the transgenic plants was similar to endogenous ENR protein levels found in both tobacco and Arabidopsis plants, except for developing flowers. In floral tissue the promoter fragment showed very little activity in contrast to the relatively high level of endogenous ENR expression. Successive deletions from the 5' and 3' regions of the promoter fragment revealed the presence of at least three elements which control GUS expression in different stages of development in the transgenic tobacco plants. First, expression in young developing leaves required both the presence of sequences between -329 to -201 relative to the transcription start and part of the untranslated leader comprising the first intron. Second, root-specific GUS expression was still observed after deletion of the 5'-upstream sequences up to 19 bp of the transcription initiation site. Further, the additional removal of the intron from the untranslated leader increased root-specific expression by ca. 4- to 5-fold. Third, high expression in seeds was still observed with the minimal upstream promoter segment of 19 bp. This seed expression level was found to be independent of the presence or absence of the intron in the untranslated leader. Finally, 3' deletion of the leader sequence up to 17 bp of the transcription start greatly impaired GUS activity during all stages of plant development, suggesting that the deleted sequence of the leader either functions as an enhancer for transcription initiation or stabilizes the mRNA.
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MESH Headings
- 5' Untranslated Regions/genetics
- Arabidopsis/enzymology
- Arabidopsis/genetics
- Base Sequence
- Blotting, Western
- Enoyl-(Acyl-Carrier-Protein) Reductase (NADH)
- Gene Expression Regulation, Plant
- Genes, Plant/genetics
- Genes, Reporter/genetics
- Introns/genetics
- Oxidoreductases/genetics
- Plant Leaves/enzymology
- Plant Leaves/genetics
- Plant Leaves/growth & development
- Plant Roots/enzymology
- Plant Roots/genetics
- Plants, Genetically Modified
- Plants, Toxic
- Promoter Regions, Genetic/genetics
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Seeds/genetics
- Sequence Deletion/genetics
- Nicotiana/genetics
- Transgenes/genetics
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Affiliation(s)
- G J de Boer
- Department of Genetics, Institute for Molecular Biological Sciences, Vrije Universiteit, BioCentrum Amsterdam, Netherlands
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Reverdatto S, Beilinson V, Nielsen NC. A multisubunit acetyl coenzyme A carboxylase from soybean. PLANT PHYSIOLOGY 1999; 119:961-78. [PMID: 10069834 PMCID: PMC32110 DOI: 10.1104/pp.119.3.961] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/1998] [Accepted: 11/11/1998] [Indexed: 05/18/2023]
Abstract
A multisubunit form of acetyl coenzyme A (CoA) carboxylase (ACCase) from soybean (Glycine max) was characterized. The enzyme catalyzes the formation of malonyl CoA from acetyl CoA, a rate-limiting step in fatty acid biosynthesis. The four known components that constitute plastid ACCase are biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), and the alpha- and beta-subunits of carboxyltransferase (alpha- and beta-CT). At least three different cDNAs were isolated from germinating soybean seeds that encode BC, two that encode BCCP, and four that encode alpha-CT. Whereas BC, BCCP, and alpha-CT are products of nuclear genes, the DNA that encodes soybean beta-CT is located in chloroplasts. Translation products from cDNAs for BC, BCCP, and alpha-CT were imported into isolated pea (Pisum sativum) chloroplasts and became integrated into ACCase. Edman microsequence analysis of the subunits after import permitted the identification of the amino-terminal sequence of the mature protein after removal of the transit sequences. Antibodies specific for each of the chloroplast ACCase subunits were generated against products from the cDNAs expressed in bacteria. The antibodies permitted components of ACCase to be followed during fractionation of the chloroplast stroma. Even in the presence of 0.5 M KCl, a complex that contained BC plus BCCP emerged from Sephacryl 400 with an apparent molecular mass greater than about 800 kD. A second complex, which contained alpha- and beta-CT, was also recovered from the column, and it had an apparent molecular mass of greater than about 600 kD. By mixing the two complexes together at appropriate ratios, ACCase enzymatic activity was restored. Even higher ACCase activities were recovered by mixing complexes from pea and soybean. The results demonstrate that the active form of ACCase can be reassembled and that it could form a high-molecular-mass complex.
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Affiliation(s)
- S Reverdatto
- United States Department of Agriculture, Agricultural Research Service, Purdue University, West Lafayette, Indiana 47907-1150, USA
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Schulte W, Töpfer R, Stracke R, Schell J, Martini N. Multi-functional acetyl-CoA carboxylase from Brassica napus is encoded by a multi-gene family: indication for plastidic localization of at least one isoform. Proc Natl Acad Sci U S A 1997; 94:3465-70. [PMID: 9096417 PMCID: PMC20393 DOI: 10.1073/pnas.94.7.3465] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Three genes coding for different multifunctional acetyl-CoA carboxylase (ACCase; EC 6.4.1.2) isoenzymes from Brassica napus were isolated and divided into two major classes according to structural features in their 5' regions: class I comprises two genes with an additional coding exon of approximately 300 bp at the 5' end, and class II is represented by one gene carrying an intron of 586 bp in its 5' untranslated region. Fusion of the peptide sequence encoded by the additional first exon of a class I ACCase gene to the jellyfish Aequorea victoria green fluorescent protein (GFP) and transient expression in tobacco protoplasts targeted GFP to the chloroplasts. In contrast to the deduced primary structure of the biotin carboxylase domain encoded by the class I gene, the corresponding amino acid sequence of the class II ACCase shows higher identity with that of the Arabidopsis ACCase, both lacking a transit peptide. The Arabidopsis ACCase has been proposed to be a cytosolic isoenzyme. These observations indicate that the two classes of ACCase genes encode plastidic and cytosolic isoforms of multi-functional, eukaryotic type, respectively, and that B. napus contains at least one multi-functional ACCase besides the multi-subunit, prokaryotic type located in plastids. Southern blot analysis of genomic DNA from B. napus, Brassica rapa, and Brassica oleracea, the ancestors of amphidiploid rapeseed, using a fragment of a multi-functional ACCase gene as a probe revealed that ACCase is encoded by a multi-gene family of at least five members.
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Affiliation(s)
- W Schulte
- Max-Planck-Institut für Zuchtungsforschung, Cologne, Germany
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