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Cannon AE, Horn PJ. The Molecular Frequency, Conservation and Role of Reactive Cysteines in Plant Lipid Metabolism. PLANT & CELL PHYSIOLOGY 2024; 65:826-844. [PMID: 38113384 DOI: 10.1093/pcp/pcad163] [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: 08/04/2023] [Revised: 11/21/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
Cysteines (Cys) are chemically reactive amino acids containing sulfur that play diverse roles in plant biology. Recent proteomics investigations in Arabidopsis thaliana have revealed the presence of thiol post-translational modifications (PTMs) in several Cys residues. These PTMs are presumed to impact protein structure and function, yet mechanistic data regarding the specific Cys susceptible to modification and their biochemical relevance remain limited. To help address these limitations, we have conducted a wide-ranging analysis by integrating published datasets encompassing PTM proteomics (comparing S-sulfenylation, persulfidation, S-nitrosylation and S-acylation), genomics and protein structures, with a specific focus on proteins involved in plant lipid metabolism. The prevalence and distribution of modified Cys residues across all analyzed proteins is diverse and multifaceted. Nevertheless, by combining an evaluation of sequence conservation across 100+ plant genomes with AlphaFold-generated protein structures and physicochemical predictions, we have unveiled structural propensities associated with Cys modifications. Furthermore, we have identified discernible patterns in lipid biochemical pathways enriched with Cys PTMs, notably involving beta-oxidation, jasmonic acid biosynthesis, fatty acid biosynthesis and wax biosynthesis. These collective findings provide valuable insights for future investigations targeting the mechanistic foundations of Cys modifications and the regulation of modified proteins in lipid metabolism and other metabolic pathways.
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Affiliation(s)
- Ashley E Cannon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle, Denton, TX 76203, USA
| | - Patrick J Horn
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle, Denton, TX 76203, USA
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2
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Tao B, Ma Y, Wang L, He C, Chen J, Ge X, Zhao L, Wen J, Yi B, Tu J, Fu T, Shen J. Developmental pleiotropy of SDP1 from seedling to mature stages in B. napus. PLANT MOLECULAR BIOLOGY 2024; 114:49. [PMID: 38642182 DOI: 10.1007/s11103-024-01447-8] [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: 12/22/2023] [Accepted: 03/25/2024] [Indexed: 04/22/2024]
Abstract
Rapeseed, an important oil crop, relies on robust seedling emergence for optimal yields. Seedling emergence in the field is vulnerable to various factors, among which inadequate self-supply of energy is crucial to limiting seedling growth in early stage. SUGAR-DEPENDENT1 (SDP1) initiates triacylglycerol (TAG) degradation, yet its detailed function has not been determined in B. napus. Here, we focused on the effects of plant growth during whole growth stages and energy mobilization during seedling establishment by mutation in BnSDP1. Protein sequence alignment and haplotypic analysis revealed the conservation of SDP1 among species, with a favorable haplotype enhancing oil content. Investigation of agronomic traits indicated bnsdp1 had a minor impact on vegetative growth and no obvious developmental defects when compared with wild type (WT) across growth stages. The seed oil content was improved by 2.0-2.37% in bnsdp1 lines, with slight reductions in silique length and seed number per silique. Furthermore, bnsdp1 resulted in lower seedling emergence, characterized by a shrunken hypocotyl and poor photosynthetic capacity in the early stages. Additionally, impaired seedling growth, especially in yellow seedlings, was not fully rescued in medium supplemented with exogenous sucrose. The limited lipid turnover in bnsdp1 was accompanied by induced amino acid degradation and PPDK-dependent gluconeogenesis pathway. Analysis of the metabolites in cotyledons revealed active amino acid metabolism and suppressed lipid degradation, consistent with the RNA-seq results. Finally, we proposed strategies for applying BnSDP1 in molecular breeding. Our study provides theoretical guidance for understanding trade-off between oil accumulation and seedling energy mobilization in B. napus.
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Affiliation(s)
- Baolong Tao
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Yina Ma
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Liqin Wang
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Chao He
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Junlin Chen
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Xiaoyu Ge
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Lun Zhao
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Jing Wen
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Bin Yi
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Jinxing Tu
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Tingdong Fu
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China
| | - Jinxiong Shen
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement/National Engineering Research Center of Rapeseed, Wuhan, 430070, China.
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3
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Li L, Liu Z, Pan X, Yao K, Wang Y, Yang T, Huang G, Liao W, Wang C. Genome-Wide Identification and Characterization of Tomato Fatty Acid β-Oxidase Family Genes KAT and MFP. Int J Mol Sci 2024; 25:2273. [PMID: 38396949 PMCID: PMC10889323 DOI: 10.3390/ijms25042273] [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: 01/13/2024] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
Fatty acids and their derivatives play a variety of roles in living organisms. Fatty acids not only store energy but also comprise membrane lipids and act as signaling molecules. There are three main proteins involved in the fatty acid β-oxidation pathway in plant peroxisomes, including acyl-CoA oxidase (ACX), multifunctional protein (MFP), and 3-ketolipoyl-CoA thiolase (KAT). However, genome-scale analysis of KAT and MFP has not been systemically investigated in tomatoes. Here, we conducted a bioinformatics analysis of KAT and MFP genes in tomatoes. Their physicochemical properties, protein secondary structure, subcellular localization, gene structure, phylogeny, and collinearity were also analyzed. In addition, a conserved motif analysis, an evolutionary pressure selection analysis, a cis-acting element analysis, tissue expression profiling, and a qRT-PCR analysis were conducted within tomato KAT and MFP family members. There are five KAT and four MFP family members in tomatoes, which are randomly distributed on four chromosomes. By analyzing the conserved motifs of tomato KAT and MFP family members, we found that both KAT and MFP members are highly conserved. In addition, the results of the evolutionary pressure selection analysis indicate that the KAT and MFP family members have evolved mainly from purifying selection, which makes them more structurally stable. The results of the cis-acting element analysis show that SlKAT and SlMFP with respect may respond to light, hormones, and adversity stresses. The tissue expression analysis showed that KAT and MFP family members have important roles in regulating the development of floral organs as well as fruit ripening. The qRT-PCR analysis revealed that the expressions of SlKAT and SlMFP genes can be regulated by ABA, MeJA, darkness, NaCl, PEG, UV, cold, heat, and H2O2 treatments. These results provide a basis for the involvement of the SlKAT and SlMFP genes in tomato floral organ development and abiotic stress response, which lay a foundation for future functional study of SlKAT and SlMFP in tomatoes.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Chunlei Wang
- College of Horticulture, Gansu Agricultural University, Yinmen Village, Anning District, Lanzhou 730070, China; (L.L.); (Z.L.); (X.P.); (K.Y.); (Y.W.); (T.Y.); (G.H.); (W.L.)
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4
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Xiang F, Liu WC, Liu X, Song Y, Zhang Y, Zhu X, Wang P, Guo S, Song CP. Direct balancing of lipid mobilization and reactive oxygen species production by the epoxidation of fatty acid catalyzed by a cytochrome P450 protein during seed germination. THE NEW PHYTOLOGIST 2023; 237:2104-2117. [PMID: 36495066 DOI: 10.1111/nph.18669] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Fatty acid (FA) β-oxidation provides energy for oil seed germination but also produces massive byproduct reactive oxygen species (ROS), posing potential oxidative damage to plant cells. How plants overcome the contradiction between energy supply and ROS production during seed germination remains unclear. In this study, we identified an Arabidopsis mvs1 (methylviologen-sensitive) mutant that was hypersensitive to ROS and caused by a missense mutation (G1349 substituted as A) of a cytochrome P450 gene, CYP77A4. CYP77A4 was highly expressed in germinating seedling cotyledons, and its protein is localized in the endoplasmic reticulum. As CYP77A4 catalyzes the epoxidation of unsaturated FA, disruption of CYP77A4 resulted in increased unsaturated FA abundance and over accumulated ROS in the mvs1 mutant. Consistently, scavenging excess ROS or blocking FA β-oxidation could repress the ROS overaccumulation and hypersensitivity in the mvs1 mutant. Furthermore, H2 O2 transcriptionally upregulated CYP77A4 expression and post-translationally modified CYP77A4 by sulfenylating its Cysteine-456, which is necessary for CYP77A4's role in modulating FA abundance and ROS production. Together, our study illustrates that CYP77A4 mediates direct balancing of lipid mobilization and ROS production by the epoxidation of FA during seed germination.
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Affiliation(s)
- Fuyou Xiang
- State Key Laboratory of Crop Stress Adaptation and Improvement, College of Life Sciences, College of Agriculture, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, Henan, 475004, China
| | - Wen-Cheng Liu
- State Key Laboratory of Crop Stress Adaptation and Improvement, College of Life Sciences, College of Agriculture, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, Henan, 475004, China
| | - Xin Liu
- State Key Laboratory of Crop Stress Adaptation and Improvement, College of Life Sciences, College of Agriculture, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, Henan, 475004, China
| | - Yuwei Song
- State Key Laboratory of Crop Stress Adaptation and Improvement, College of Life Sciences, College of Agriculture, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, Henan, 475004, China
- College of Life Sciences and Agricultural Engineering, Nanyang Normal University, Nanyang, 473061, China
| | - Yu Zhang
- State Key Laboratory of Crop Stress Adaptation and Improvement, College of Life Sciences, College of Agriculture, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, Henan, 475004, China
| | - Xiaojing Zhu
- State Key Laboratory of Crop Stress Adaptation and Improvement, College of Life Sciences, College of Agriculture, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, Henan, 475004, China
| | - Pengtao Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, College of Life Sciences, College of Agriculture, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, Henan, 475004, China
| | - Siyi Guo
- State Key Laboratory of Crop Stress Adaptation and Improvement, College of Life Sciences, College of Agriculture, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, Henan, 475004, China
| | - Chun-Peng Song
- State Key Laboratory of Crop Stress Adaptation and Improvement, College of Life Sciences, College of Agriculture, Academy for Advanced Interdisciplinary Studies, Henan University, Kaifeng, Henan, 475004, China
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Xia L, Kong X, Song H, Han Q, Zhang S. Advances in proteome-wide analysis of plant lysine acetylation. PLANT COMMUNICATIONS 2022; 3:100266. [PMID: 35059632 PMCID: PMC8760137 DOI: 10.1016/j.xplc.2021.100266] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/21/2021] [Accepted: 11/22/2021] [Indexed: 06/14/2023]
Abstract
Lysine acetylation (LysAc) is a conserved and important post-translational modification (PTM) that plays a key role in plant physiological and metabolic processes. Based on advances in Lys-acetylated protein immunoenrichment and mass-spectrometric technology, LysAc proteomics studies have been performed in many species. Such studies have made substantial contributions to our understanding of plant LysAc, revealing that Lys-acetylated histones and nonhistones are involved in a broad spectrum of plant cellular processes. Here, we present an extensive overview of recent research on plant Lys-acetylproteomes. We provide in-depth insights into the characteristics of plant LysAc modifications and the mechanisms by which LysAc participates in cellular processes and regulates metabolism and physiology during plant growth and development. First, we summarize the characteristics of LysAc, including the properties of Lys-acetylated sites, the motifs that flank Lys-acetylated lysines, and the dynamic alterations in LysAc among different tissues and developmental stages. We also outline a map of Lys-acetylated proteins in the Calvin-Benson cycle and central carbon metabolism-related pathways. We then introduce some examples of the regulation of plant growth, development, and biotic and abiotic stress responses by LysAc. We discuss the interaction between LysAc and Nα-terminal acetylation and the crosstalk between LysAc and other PTMs, including phosphorylation and succinylation. Finally, we propose recommendations for future studies in the field. We conclude that LysAc of proteins plays an important role in the regulation of the plant life cycle.
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6
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Meng W, Xu L, Du ZY, Wang F, Zhang R, Song X, Lam SM, Shui G, Li Y, Chye ML. RICE ACYL-COA-BINDING PROTEIN6 Affects Acyl-CoA Homeostasis and Growth in Rice. RICE (NEW YORK, N.Y.) 2020; 13:75. [PMID: 33159253 PMCID: PMC7647982 DOI: 10.1186/s12284-020-00435-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/21/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUNDS Acyl-coenzyme A (CoA) esters are important intermediates in lipid metabolism with regulatory properties. Acyl-CoA-binding proteins bind and transport acyl-CoAs to fulfill these functions. RICE ACYL-COA-BINDING PROTEIN6 (OsACBP6) is currently the only one peroxisome-localized plant ACBP that has been proposed to be involved in β-oxidation in transgenic Arabidopsis. The role of the peroxisomal ACBP (OsACBP6) in rice (Oryza sativa) was investigated. RESULTS Here, we report on the function of OsACBP6 in rice. The osacbp6 mutant showed diminished growth with reduction in root meristem activity and leaf growth. Acyl-CoA profiling and lipidomic analysis revealed an increase in acyl-CoA content and a slight triacylglycerol accumulation caused by the loss of OsACBP6. Comparative transcriptomic analysis discerned the biological processes arising from the loss of OsACBP6. Reduced response to oxidative stress was represented by a decline in gene expression of a group of peroxidases and peroxidase activities. An elevation in hydrogen peroxide was observed in both roots and shoots/leaves of osacbp6. Taken together, loss of OsACBP6 not only resulted in a disruption of the acyl-CoA homeostasis but also peroxidase-dependent reactive oxygen species (ROS) homeostasis. In contrast, osacbp6-complemented transgenic rice displayed similar phenotype to the wild type rice, supporting a role for OsACBP6 in the maintenance of the acyl-CoA pool and ROS homeostasis. Furthermore, quantification of plant hormones supported the findings observed in the transcriptome and an increase in jasmonic acid level occurred in osacbp6. CONCLUSIONS In summary, OsACBP6 appears to be required for the efficient utilization of acyl-CoAs. Disruption of OsACBP6 compromises growth and led to provoked defense response, suggesting a correlation of enhanced acyl-CoAs content with defense responses.
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Affiliation(s)
- Wei Meng
- 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.
| | - Lijian Xu
- College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, China
| | - Zhi-Yan Du
- Department of Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, HI, 96822, USA
| | - Fang Wang
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Rui Zhang
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Xingshun Song
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Sin Man Lam
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Lipidall Technologies Company Limited, Changzhou, 213000, China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yuhua Li
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration (Northeast Forestry University), Ministry of Education, Harbin, 150040, China
| | - Mee-Len Chye
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
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7
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Barros JAS, Siqueira JAB, Cavalcanti JHF, Araújo WL, Avin-Wittenberg T. Multifaceted Roles of Plant Autophagy in Lipid and Energy Metabolism. TRENDS IN PLANT SCIENCE 2020; 25:1141-1153. [PMID: 32565020 DOI: 10.1016/j.tplants.2020.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
Together with sugars and proteins, lipids constitute the main carbon reserves in plants. Lipids are selectively recycled and catabolized for energy production during development and in response to environmental stresses. Autophagy is a major catabolic pathway, operating in the recycling of cellular components in eukaryotes. Although the autophagic degradation of lipids has been mainly characterized in mammals and yeast, growing evidence has highlighted the role of autophagy in several aspects of lipid metabolism in plants. Here, we summarize recent findings focusing on autophagy functions in lipid droplet (LD) metabolism. We further provide novel insights regarding the relevance of autophagy in the maintenance and clearance of mitochondria and peroxisomes and its consequences for proper lipid usage and energy homeostasis in plants.
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Affiliation(s)
- Jessica A S Barros
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil; Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - João A B Siqueira
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil
| | - João H F Cavalcanti
- Instituto de Educação, Agricultura e Ambiente, Universidade Federal do Amazonas, Humaitá, Amazonas, Brazil
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel.
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Chemical Genetics Approach Identifies Abnormal Inflorescence Meristem 1 as a Putative Target of a Novel Sulfonamide That Protects Catalase2-Deficient Arabidopsis against Photorespiratory Stress. Cells 2020; 9:cells9092026. [PMID: 32887516 PMCID: PMC7563276 DOI: 10.3390/cells9092026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/26/2020] [Accepted: 08/31/2020] [Indexed: 11/24/2022] Open
Abstract
Alterations of hydrogen peroxide (H2O2) levels have a profound impact on numerous signaling cascades orchestrating plant growth, development, and stress signaling, including programmed cell death. To expand the repertoire of known molecular mechanisms implicated in H2O2 signaling, we performed a forward chemical screen to identify small molecules that could alleviate the photorespiratory-induced cell death phenotype of Arabidopsisthaliana mutants lacking H2O2-scavenging capacity by peroxisomal catalase2. Here, we report the characterization of pakerine, an m-sulfamoyl benzamide from the sulfonamide family. Pakerine alleviates the cell death phenotype of cat2 mutants exposed to photorespiration-promoting conditions and delays dark-induced senescence in wild-type Arabidopsis leaves. By using a combination of transcriptomics, metabolomics, and affinity purification, we identified abnormal inflorescence meristem 1 (AIM1) as a putative protein target of pakerine. AIM1 is a 3-hydroxyacyl-CoA dehydrogenase involved in fatty acid β-oxidation that contributes to jasmonic acid (JA) and salicylic acid (SA) biosynthesis. Whereas intact JA biosynthesis was not required for pakerine bioactivity, our results point toward a role for β-oxidation-dependent SA production in the execution of H2O2-mediated cell death.
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Lefevere H, Bauters L, Gheysen G. Salicylic Acid Biosynthesis in Plants. FRONTIERS IN PLANT SCIENCE 2020; 11:338. [PMID: 32362901 PMCID: PMC7182001 DOI: 10.3389/fpls.2020.00338] [Citation(s) in RCA: 205] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/06/2020] [Indexed: 05/19/2023]
Abstract
Salicylic acid (SA) is an important plant hormone that is best known for mediating host responses upon pathogen infection. Its role in plant defense activation is well established, but its biosynthesis in plants is not fully understood. SA is considered to be derived from two possible pathways; the ICS and PAL pathway, both starting from chorismate. The importance of both pathways for biosynthesis differs between plant species, rendering it hard to make generalizations about SA production that cover the entire plant kingdom. Yet, understanding SA biosynthesis is important to gain insight into how plant pathogen responses function and how pathogens can interfere with them. In this review, we have taken a closer look at how SA is synthesized and the importance of both biosynthesis pathways in different plant species.
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Affiliation(s)
| | | | - Godelieve Gheysen
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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10
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Li Y, Xu J, Li G, Wan S, Batistič O, Sun M, Zhang Y, Scott R, Qi B. Protein S-acyl transferase 15 is involved in seed triacylglycerol catabolism during early seedling growth in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5205-5216. [PMID: 31199467 DOI: 10.1093/jxb/erz282] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 06/05/2019] [Indexed: 06/09/2023]
Abstract
Seeds of Arabidopsis contain ~40% oil, which is primarily in the form of triacylglycerol and it is converted to sugar to support post-germination growth. We identified an Arabidopsis T-DNA knockout mutant that is sugar-dependent during early seedling establishment and determined that the β-oxidation process involved in catabolising the free fatty acids released from the seed triacylglycerol is impaired. The mutant was confirmed to be transcriptional null for Protein Acyl Transferase 15, AtPAT15 (At5g04270), one of the 24 protein acyl transferases in Arabidopsis. Although it is the shortest, AtPAT15 contains the signature 'Asp-His-His-Cys cysteine-rich domain' that is essential for the enzyme activity of this family of proteins. The function of AtPAT15 was validated by the fact that it rescued the growth defect of the yeast protein acyl transferase mutant akr1 and it was also auto-acylated in vitro. Transient expression in Arabidopsis and tobacco localised AtPAT15 in the Golgi apparatus. Taken together, our data demonstrate that AtPAT15 is involved in β-oxidation of triacylglycerol, revealing the importance of protein S-acylation in the breakdown of seed-storage lipids during early seedling growth of Arabidopsis.
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Affiliation(s)
- Yaxiao Li
- Department of Biology and Biochemistry, University of Bath, Bath, UK
- Shanghai Center for Plant Stress Biology & National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jianfeng Xu
- Department of Biology and Biochemistry, University of Bath, Bath, UK
- College of Horticulture, Hebei Agricultural University, Baoding, China
| | - Gang Li
- College of Horticulture, Hebei Agricultural University, Baoding, China
| | - Si Wan
- Department of Biology and Biochemistry, University of Bath, Bath, UK
| | - Oliver Batistič
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Muenster, Germany
| | - Meihong Sun
- College of Horticulture, Shandong Agricultural University, Tai'an, China
| | - Yuxing Zhang
- College of Horticulture, Hebei Agricultural University, Baoding, China
| | - Rod Scott
- Department of Biology and Biochemistry, University of Bath, Bath, UK
| | - Baoxiu Qi
- Department of Biology and Biochemistry, University of Bath, Bath, UK
- College of Horticulture, Hebei Agricultural University, Baoding, China
- Pharmacy and Biomolecular Sciences, James Parsons Building, Byrom Street, Liverpool, UK
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11
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Charton L, Plett A, Linka N. Plant peroxisomal solute transporter proteins. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2019; 61:817-835. [PMID: 30761734 PMCID: PMC6767901 DOI: 10.1111/jipb.12790] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 02/11/2019] [Indexed: 05/18/2023]
Abstract
Plant peroxisomes are unique subcellular organelles which play an indispensable role in several key metabolic pathways, including fatty acid β-oxidation, photorespiration, and degradation of reactive oxygen species. The compartmentalization of metabolic pathways into peroxisomes is a strategy for organizing the metabolic network and improving pathway efficiency. An important prerequisite, however, is the exchange of metabolites between peroxisomes and other cell compartments. Since the first studies in the 1970s scientists contributed to understanding how solutes enter or leave this organelle. This review gives an overview about our current knowledge of the solute permeability of peroxisomal membranes described in plants, yeast, mammals and other eukaryotes. In general, peroxisomes contain in their bilayer membrane specific transporters for hydrophobic fatty acids (ABC transporter) and large cofactor molecules (carrier for ATP, NAD and CoA). Smaller solutes with molecular masses below 300-400 Da, like the organic acids malate, oxaloacetate, and 2-oxoglutarate, are shuttled via non-selective channels across the peroxisomal membrane. In comparison to yeast, human, mammals and other eukaryotes, the function of these known peroxisomal transporters and channels in plants are discussed in this review.
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Affiliation(s)
- Lennart Charton
- Institute for Plant Biochemistry and Cluster of Excellence on Plant Sciences (CEPLAS)Heinrich Heine UniversityUniversitätsstrasse 140225 DüsseldorfGermany
| | - Anastasija Plett
- Institute for Plant Biochemistry and Cluster of Excellence on Plant Sciences (CEPLAS)Heinrich Heine UniversityUniversitätsstrasse 140225 DüsseldorfGermany
| | - Nicole Linka
- Institute for Plant Biochemistry and Cluster of Excellence on Plant Sciences (CEPLAS)Heinrich Heine UniversityUniversitätsstrasse 140225 DüsseldorfGermany
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12
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Burkhart SE, Llinas RJ, Bartel B. PEX16 contributions to peroxisome import and metabolism revealed by viable Arabidopsis pex16 mutants. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2019; 61:853-870. [PMID: 30761735 PMCID: PMC6613983 DOI: 10.1111/jipb.12789] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/10/2019] [Indexed: 06/09/2023]
Abstract
Peroxisomes rely on peroxins (PEX proteins) for biogenesis, importing membrane and matrix proteins, and fission. PEX16, which is implicated in peroxisomal membrane protein targeting and forming nascent peroxisomes from the endoplasmic reticulum (ER), is unusual among peroxins because it is inserted co-translationally into the ER and localizes to both ER and peroxisomal membranes. PEX16 mutations in humans, yeast, and plants confer some common peroxisomal defects; however, apparent functional differences have impeded the development of a unified model for PEX16 action. The only reported pex16 mutant in plants, the Arabidopsis shrunken seed1 mutant, is inviable, complicating analysis of PEX16 function after embryogenesis. Here, we characterized two viable Arabidopsis pex16 alleles that accumulate negligible PEX16 protein levels. Both mutants displayed impaired peroxisome function - slowed consumption of stored oil bodies, decreased import of matrix proteins, and increased peroxisome size. Moreover, one pex16 allele exhibited reduced growth that could be alleviated by an external fixed carbon source, decreased responsiveness to peroxisomally processed hormone precursors, and worsened or improved peroxisome function in combination with other pex mutants. Because the mutations impact different regions of the PEX16 gene, these viable pex16 alleles allow assessment of the importance of Arabidopsis PEX16 and its functional domains.
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Peroxisomal β-oxidation regulates histone acetylation and DNA methylation in Arabidopsis. Proc Natl Acad Sci U S A 2019; 116:10576-10585. [PMID: 31064880 DOI: 10.1073/pnas.1904143116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Epigenetic markers, such as histone acetylation and DNA methylation, determine chromatin organization. In eukaryotic cells, metabolites from organelles or the cytosol affect epigenetic modifications. However, the relationships between metabolites and epigenetic modifications are not well understood in plants. We found that peroxisomal acyl-CoA oxidase 4 (ACX4), an enzyme in the fatty acid β-oxidation pathway, is required for suppressing the silencing of some endogenous loci, as well as Pro35S:NPTII in the ProRD29A:LUC/C24 transgenic line. The acx4 mutation reduces nuclear histone acetylation and increases DNA methylation at the NOS terminator of Pro35S:NPTII and at some endogenous genomic loci, which are also targeted by the demethylation enzyme REPRESSOR OF SILENCING 1 (ROS1). Furthermore, mutations in multifunctional protein 2 (MFP2) and 3-ketoacyl-CoA thiolase-2 (KAT2/PED1/PKT3), two enzymes in the last two steps of the β-oxidation pathway, lead to similar patterns of DNA hypermethylation as in acx4 Thus, metabolites from fatty acid β-oxidation in peroxisomes are closely linked to nuclear epigenetic modifications, which may affect diverse cellular processes in plants.
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Kataya ARA, Muench DG, Moorhead GB. A Framework to Investigate Peroxisomal Protein Phosphorylation in Arabidopsis. TRENDS IN PLANT SCIENCE 2019; 24:366-381. [PMID: 30683463 DOI: 10.1016/j.tplants.2018.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/11/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
Peroxisomes perform essential roles in a range of cellular processes, highlighted by lipid metabolism, reactive species detoxification, and response to a variety of stimuli. The ability of peroxisomes to grow, divide, respond to changing cellular needs, interact with other organelles, and adjust their proteome as required, suggest that, like other organelles, their specialized roles are highly regulated. Similar to most other cellular processes, there is an emerging role for protein phosphorylation to regulate these events. In this review, we establish a knowledge framework of key players that control protein phosphorylation events in the plant peroxisome (i.e., the protein kinases and phosphatases), and highlight a vastly expanded set of (phospho)substrates.
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Affiliation(s)
- Amr R A Kataya
- Department of Chemistry, Bioscience, and Environmental Engineering, University of Stavanger, Stavanger, 4036, Norway; Department of Biological Sciences, University of Calgary, Calgary, T2N 1N4, Canada; www.katayaproject.com.
| | - Douglas G Muench
- Department of Biological Sciences, University of Calgary, Calgary, T2N 1N4, Canada
| | - Greg B Moorhead
- Department of Biological Sciences, University of Calgary, Calgary, T2N 1N4, Canada
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15
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Hua Y, Wang C, Wang S, Liu Z, Liu X, Zou L, Gu W, Luo Y, Liu J. iTRAQ-Based Quantitative Proteomic Analysis of Pseudostellaria heterophylla from Geo-Authentic Habitat and Cultivated Bases. CURR PROTEOMICS 2019. [DOI: 10.2174/1570164616666181116124050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Pseudostellaria heterophylla is an important tonic traditional Chinese medicine.
However, the molecular changes in the herb from geo-authentic habitat and cultivated bases remain
to be explored.
Objective:
The purpose of this research was to study differences in P. heterophylla from geo-authentic
habitat and cultivated bases.
Methods:
High-throughput technologies of transcriptomic and proteomic were used to identify proteins.
Isobaric Tags for Relative and Absolute Quantification (iTRAQ) MS/MS has been utilized to
evaluate changes in P. heterophylla from geo-authentic habitat and cultivated bases.
Results:
In this study, a total of 3775 proteins were detected, and 140 differentially expressed proteins
were found in P. heterophylla from geo-authentic habitat and cultivated bases. 44 significantly differential
expressed proteins were identified based on functional analysis classified into nine categories.
Five differentially expressed proteins were confirmed at the gene expression level by Quantitative realtime
PCR. Catabolic metabolism, carbohydrate metabolism, and response to stress of oxidoreductases
and transferases in P. heterophylla from geo-authentic habitat were stronger than in those from cultivated
bases, but protein folding and response to stress of heat shock proteins, isomerases, rubisco large
subunit-binding proteins, chaperone proteins, and luminal-binding proteins in herbs from cultivated
bases were more active. ADG1 and TKTA could be the critical proteins to regulate sucrose; MFP2 and
CYS may be the crucial proteins that control the metabolism of fatty acids and amino acids.
Conclusion:
These results will provide the basic information for exploring the differences in secondary
metabolites in P. heterophylla from geo-authentic habitat and cultivated bases and the protein mechanism
of its quality formation.
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Affiliation(s)
- Yujiao Hua
- School of Pharmacy, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing 210023, China
| | - Chengcheng Wang
- School of Pharmacy, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing 210023, China
| | - Shengnan Wang
- School of Pharmacy, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing 210023, China
| | - Zixiu Liu
- School of Pharmacy, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing 210023, China
| | - Xunhong Liu
- School of Pharmacy, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing 210023, China
| | - Lisi Zou
- School of Pharmacy, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing 210023, China
| | - Wei Gu
- School of Pharmacy, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing 210023, China
| | - Yiyuan Luo
- School of Pharmacy, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing 210023, China
| | - Juanxiu Liu
- School of Pharmacy, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing 210023, China
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Yoshitake Y, Ohta H, Shimojima M. Autophagy-Mediated Regulation of Lipid Metabolism and Its Impact on the Growth in Algae and Seed Plants. FRONTIERS IN PLANT SCIENCE 2019; 10:709. [PMID: 31214225 PMCID: PMC6558177 DOI: 10.3389/fpls.2019.00709] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 05/13/2019] [Indexed: 05/08/2023]
Abstract
Under nutrient starvation conditions, algae and seed-plant cells accumulate carbon metabolites such as storage lipids, triacylglycerols (TAGs), and starches. Recent research has suggested the involvement of autophagy in the regulation of carbon metabolites under nutrient starvation. When algae are grown under carbon starvation conditions, such as growth in darkness or in the presence of a photosynthesis inhibitor, lipid droplets are surrounded by phagophores. Indeed, the amount of TAGs in an autophagy-deficient mutant has been found to be greater than that in wild type under nitrogen starvation, and cerulenin, which is one of the inhibitors of fatty acid synthesis, induces autophagy. In land plants, TAGs accumulate predominantly in seeds and etiolated seedlings. These TAGs are degraded in peroxisomes via β-oxidation during germination as a source of carbon for growth without photosynthesis. A global analysis of the role of autophagy in Arabidopsis seedlings under carbon starvation revealed that a lack of autophagy enhances the accumulation of TAGs and fatty acids. In Oryza sativa, autophagy-mediated degradation of TAGs and diacylglycerols has been suggested to be important for pollen development. In this review, we introduce and summarize research findings demonstrating that autophagy affects lipid metabolism and discuss the role of autophagy in membrane and storage-lipid homeostasis, each of which affects the growth and development of seed plants and algae.
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Affiliation(s)
- Yushi Yoshitake
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroyuki Ohta
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
- Open Innovation Platform with Enterprises, Research Institute and Academia (OPERA), Japan Science and Technology Agency, Chiyoda, Japan
| | - Mie Shimojima
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
- *Correspondence: Mie Shimojima,
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Zhou W, Chen F, Zhao S, Yang C, Meng Y, Shuai H, Luo X, Dai Y, Yin H, Du J, Liu J, Fan G, Liu W, Yang W, Shu K. DA-6 promotes germination and seedling establishment from aged soybean seeds by mediating fatty acid metabolism and glycometabolism. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:101-114. [PMID: 29982626 PMCID: PMC6305204 DOI: 10.1093/jxb/ery247] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/27/2018] [Indexed: 05/17/2023]
Abstract
Soybean seeds contain higher concentrations of oil (triacylglycerol) and fatty acids than do cereal crop seeds, and the oxidation of these biomolecules during seed storage significantly shortens seed longevity and decreases germination ability. Here, we report that diethyl aminoethyl hexanoate (DA-6), a plant growth regulator, increases germination and seedling establishment from aged soybean seeds by increasing fatty acid metabolism and glycometabolism. Phenotypic analysis showed that DA-6 treatment markedly promoted germination and seedling establishment from naturally and artificially aged soybean seeds. Further analysis revealed that DA-6 increased the concentrations of soluble sugars during imbibition of aged soybean seeds. Consistently, the concentrations of several different fatty acids in DA-6-treated aged seeds were higher than those in untreated aged seeds. Subsequently, quantitative PCR analysis indicated that DA-6 induced the transcription of several key genes involved in the hydrolysis of triacylglycerol to sugars in aged soybean seeds. Furthermore, the activity of invertase in aged seeds, which catalyzes the hydrolysis of sucrose to form fructose and glucose, increased following DA-6 treatment. Taken together, DA-6 promotes germination and seedling establishment from aged soybean seeds by enhancing the hydrolysis of triacylglycerol and the conversion of fatty acids to sugars.
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Affiliation(s)
- Wenguan Zhou
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Feng Chen
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Sihua Zhao
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Caiqiong Yang
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Yongjie Meng
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Haiwei Shuai
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Xiaofeng Luo
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Yujia Dai
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Han Yin
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Junbo Du
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Jiang Liu
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Gaoqiong Fan
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Weiguo Liu
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Wenyu Yang
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Kai Shu
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
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18
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Huang J, Hao X, Jin Y, Guo X, Shao Q, Kumar KS, Ahlawat YK, Harry DE, Joshi CP, Zheng Y. Temporal transcriptome profiling of developing seeds reveals a concerted gene regulation in relation to oil accumulation in Pongamia (Millettia pinnata). BMC PLANT BIOLOGY 2018; 18:140. [PMID: 29986660 PMCID: PMC6038193 DOI: 10.1186/s12870-018-1356-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/28/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Pongamia (Millettia pinnata syn. Pongamia pinnata), an oilseed legume species, is emerging as potential feedstock for sustainable biodiesel production. Breeding Pongamia for favorable traits in commercial application will rely on a comprehensive understanding of molecular mechanism regulating oil accumulation during its seed development. To date, only limited genomic or transcript sequences are available for Pongamia, while a temporal transcriptome profiling of developing seeds is still lacking in this species. RESULTS In this work, we conducted a time-series analysis of morphological and physiological characters, oil contents and compositions, as well as global gene expression profiles in developing Pongamia seeds. Firstly, three major developmental phases were characterized based on the combined evidences from embryonic shape, seed weight, seed moisture content, and seed color. Then, the gene expression levels at these three phases were quantified by RNA-Seq analyses with three biological replicates from each phase. Nearly 94% of unigenes were expressed at all three phases, whereas only less than 2% of unigenes were exclusively expressed at one of these phases. A total of 8881 differentially expressed genes (DEGs) were identified between phases. Furthermore, the qRT-PCR analyses for 10 DEGs involved in lipid metabolism demonstrated a good reliability of our RNA-Seq data in temporal gene expression profiling. We observed a dramatic increase in seed oil content from the embryogenesis phase to the early seed-filling phase, followed by a steady and moderate increase towards the maximum at the desiccation phase. We proposed that a highly active expression of most genes related to fatty acid (FA) and triacylglycerol (TAG) biosynthesis at the embryogenesis phase might trigger both the substantial oil accumulation and the membrane lipid synthesis for rapid cell proliferation at this phase, while a concerted reactivation of TAG synthesis-related genes at the desiccation phase might further promote storage lipid synthesis to achieve the maximum content of seed oils. CONCLUSIONS This study not only built a bridge between gene expression profiles and oil accumulation in developing seeds, but also laid a foundation for future attempts on genetic engineering of Pongamia varieties to acquire higher oil yield or improved oil properties for biofuel applications.
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Affiliation(s)
- Jianzi Huang
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 China
| | - Xuehong Hao
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 China
| | - Ye Jin
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 China
| | - Xiaohuan Guo
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 China
| | - Qing Shao
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 China
| | - Kavitha S. Kumar
- Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931 USA
| | - Yogesh K. Ahlawat
- Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931 USA
| | | | - Chandrashekhar P. Joshi
- Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931 USA
| | - Yizhi Zheng
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 China
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Wong DCJ, Amarasinghe R, Rodriguez-Delgado C, Eyles R, Pichersky E, Peakall R. Tissue-Specific Floral Transcriptome Analysis of the Sexually Deceptive Orchid Chiloglottis trapeziformis Provides Insights into the Biosynthesis and Regulation of Its Unique UV-B Dependent Floral Volatile, Chiloglottone 1. FRONTIERS IN PLANT SCIENCE 2017; 8:1260. [PMID: 28769963 PMCID: PMC5515871 DOI: 10.3389/fpls.2017.01260] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/04/2017] [Indexed: 05/29/2023]
Abstract
The Australian sexually deceptive orchid, Chiloglottis trapeziformis, employs a unique UV-B-dependent floral volatile, chiloglottone 1, for specific male wasp pollinator attraction. Chiloglottone 1 and related variants (2,5-dialkylcyclohexane-1,3-diones), represent a unique class of specialized metabolites presumed to be the product of cyclization between two fatty acid (FA) precursors. However, the genes involved in the biosynthesis of precursors, intermediates, and transcriptional regulation remains to be discovered. Chiloglottone 1 production occurs in the aggregation of calli (callus) on the labellum under continuous UV-B light. Therefore, deep sequencing, transcriptome assembly, and differential expression (DE) analysis were performed across different tissue types and UV-B treatments. Transcripts expressed in the callus and labellum (∼23,000 transcripts) were highly specialized and enriched for a diversity of known and novel metabolic pathways. DE analysis between chiloglottone-emitting callus versus the remainder of the labellum showed strong coordinated induction of entire FA biosynthesis and β-oxidation pathways including genes encoding Ketoacyl-ACP Synthase, Acyl-CoA Oxidase, and Multifunctional Protein. Phylogenetic analysis revealed potential gene duplicates with tissue-specific differential regulation including two Acyl-ACP Thioesterase B and a Ketoacyl-ACP Synthase genes. UV-B treatment induced the activation of UVR8-mediated signaling and large-scale transcriptome changes in both tissues, however, neither FA biosynthesis/β-oxidation nor other lipid metabolic pathways showed clear indications of concerted DE. Gene co-expression network analysis identified three callus-specific modules enriched with various lipid metabolism categories. These networks also highlight promising candidates involved in the cyclization of chiloglottone 1 intermediates (e.g., Bet v I and dimeric α,β barrel proteins) and orchestrating regulation of precursor pathways (e.g., AP2/ERF) given a strong co-regulation with FA biosynthesis/β-oxidation genes. Possible alternative biosynthetic routes for precursors (e.g., aldehyde dehydrogenases) were also indicated. Our comprehensive study constitutes the first step toward understanding the biosynthetic pathways involved in chiloglottone 1 production in Chiloglottis trapeziformis - supporting the roles of FA metabolism in planta, gene duplication as a potential source of new genes, and co-regulation of novel pathway genes in a tissue-specific manner. This study also provides a new and valuable resource for future discovery and comparative studies in plant specialized metabolism of other orchids and non-model plants.
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Affiliation(s)
- Darren C. J. Wong
- Ecology and Evolution, Research School of Biology, The Australian National University, CanberraACT, Australia
| | - Ranamalie Amarasinghe
- Ecology and Evolution, Research School of Biology, The Australian National University, CanberraACT, Australia
| | - Claudia Rodriguez-Delgado
- Ecology and Evolution, Research School of Biology, The Australian National University, CanberraACT, Australia
| | - Rodney Eyles
- Ecology and Evolution, Research School of Biology, The Australian National University, CanberraACT, Australia
| | - Eran Pichersky
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann ArborMI, United States
| | - Rod Peakall
- Ecology and Evolution, Research School of Biology, The Australian National University, CanberraACT, Australia
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Corpas FJ, Barroso JB, Palma JM, Rodriguez-Ruiz M. Plant peroxisomes: A nitro-oxidative cocktail. Redox Biol 2017; 11:535-542. [PMID: 28092771 PMCID: PMC5238456 DOI: 10.1016/j.redox.2016.12.033] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/28/2016] [Accepted: 12/30/2016] [Indexed: 12/16/2022] Open
Abstract
Although peroxisomes are very simple organelles, research on different species has provided us with an understanding of their importance in terms of cell viability. In addition to the significant role played by plant peroxisomes in the metabolism of reactive oxygen species (ROS), data gathered over the last two decades show that these organelles are an endogenous source of nitric oxide (NO) and related molecules called reactive nitrogen species (RNS). Molecules such as NO and H2O2 act as retrograde signals among the different cellular compartments, thus facilitating integral cellular adaptation to physiological and environmental changes. However, under nitro-oxidative conditions, part of this network can be overloaded, possibly leading to cellular damage and even cell death. This review aims to update our knowledge of the ROS/RNS metabolism, whose important role in plant peroxisomes is still underestimated. However, this pioneering approach, in which key elements such as β-oxidation, superoxide dismutase (SOD) and NO have been mainly described in relation to plant peroxisomes, could also be used to explore peroxisomes from other organisms.
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Affiliation(s)
- Francisco J Corpas
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda, 1, 18008 Granada, Spain.
| | - Juan B Barroso
- Biochemistry and Cell Signaling in Nitric Oxide Group, Department of Experimental Biology, Center for Advanced Studies in Olive Grove and Olive Oils, Faculty of Experimental Sciences, Campus Universitario "Las Lagunillas" s/n, University of Jaén, E-23071 Jaén, Spain
| | - José M Palma
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda, 1, 18008 Granada, Spain
| | - Marta Rodriguez-Ruiz
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda, 1, 18008 Granada, Spain
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Xia Y, Jing D, Kong L, Zhang J, OuYang F, Zhang H, Wang J, Zhang S. Global Lysine Acetylome Analysis of Desiccated Somatic Embryos of Picea asperata. FRONTIERS IN PLANT SCIENCE 2016; 7:1927. [PMID: 28066480 PMCID: PMC5179564 DOI: 10.3389/fpls.2016.01927] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 12/05/2016] [Indexed: 05/22/2023]
Abstract
Partial desiccation treatment (PDT) promotes the germination capacity of conifer somatic embryos. Lysine acetylation (LysAc) is a dynamic and reversible post-translational modification that plays a key role in many biological processes including metabolic pathways and stress response. To investigate the functional impact of LysAc in the response of Picea asperata somatic embryos to PDT, we performed a global lysine acetylome analysis. Here, combining antibody-based affinity enrichment and high-resolution mass spectrometry, we identified and validated 1079 acetylation sites in 556 acetylated proteins from P. asperata somatic embryos during PDT. These data represent a novel large-scale dataset of lysine-acetylated proteins from the conifer family. Intensive bioinformatics analysis of the Gene Ontology of molecular functions demonstrated that lysine-acetylated proteins were mainly associated with binding, catalytic activities, and structural molecular activities. Functional characterization of the acetylated proteins revealed that in the desiccated somatic embryos, LysAc is mainly involved in the response to stress and central metabolism. Accordingly, the majority of these interacting proteins were also highly enriched in ribosome, proteasome, spliceosome, and carbon metabolism clusters. This work provides the most comprehensive profile of LysAc for a coniferous species obtained to date and facilitates the systematic study of the physiological role of LysAc in desiccated somatic embryos of P. asperata.
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Affiliation(s)
- Yan Xia
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Danlong Jing
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Lisheng Kong
- Centre for Forest Biology, Department of Biology, University of VictoriaVictoria, BC, Canada
| | - Jianwei Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Fangqun OuYang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Hanguo Zhang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry UniversityHarbin, China
| | - Junhui Wang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Shougong Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
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22
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The Roles of β-Oxidation and Cofactor Homeostasis in Peroxisome Distribution and Function in Arabidopsis thaliana. Genetics 2016; 204:1089-1115. [PMID: 27605050 DOI: 10.1534/genetics.116.193169] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/06/2016] [Indexed: 11/18/2022] Open
Abstract
Key steps of essential metabolic pathways are housed in plant peroxisomes. We conducted a microscopy-based screen for anomalous distribution of peroxisomally targeted fluorescence in Arabidopsis thaliana This screen uncovered 34 novel alleles in 15 genes affecting oil body mobilization, fatty acid β-oxidation, the glyoxylate cycle, peroxisome fission, and pexophagy. Partial loss-of-function of lipid-mobilization enzymes conferred peroxisomes clustered around retained oil bodies without other notable defects, suggesting that this microscopy-based approach was sensitive to minor perturbations, and that fatty acid β-oxidation rates in wild type are higher than required for normal growth. We recovered three mutants defective in PECTIN METHYLESTERASE31, revealing an unanticipated role in lipid mobilization for this cytosolic enzyme. Whereas mutations reducing fatty acid import had peroxisomes of wild-type size, mutations impairing fatty acid β-oxidation displayed enlarged peroxisomes, possibly caused by excess fatty acid β-oxidation intermediates in the peroxisome. Several fatty acid β-oxidation mutants also displayed defects in peroxisomal matrix protein import. Impairing fatty acid import reduced the large size of peroxisomes in a mutant defective in the PEROXISOMAL NAD+ TRANSPORTER (PXN), supporting the hypothesis that fatty acid accumulation causes pxn peroxisome enlargement. The diverse mutants isolated in this screen will aid future investigations of the roles of β-oxidation and peroxisomal cofactor homeostasis in plant development.
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He D, Damaris RN, Fu J, Tu J, Fu T, Xi C, Yi B, Yang P. Differential Molecular Responses of Rapeseed Cotyledons to Light and Dark Reveal Metabolic Adaptations toward Autotrophy Establishment. FRONTIERS IN PLANT SCIENCE 2016; 7:988. [PMID: 27471506 PMCID: PMC4944393 DOI: 10.3389/fpls.2016.00988] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/22/2016] [Indexed: 05/23/2023]
Abstract
Photosynthesis competent autotrophy is established during the postgerminative stage of plant growth. Among the multiple factors, light plays a decisive role in the switch from heterotrophic to autotrophic growth. Under dark conditions, the rapeseed hypocotyl extends quickly with an apical hook, and the cotyledon is yellow and folded, and maintains high levels of the isocitrate lyase (ICL). By contrast, in the light, the hypocotyl extends slowly, the cotyledon unfolds and turns green, the ICL content changes in parallel with cotyledon greening. To reveal metabolic adaptations during the establishment of postgerminative autotrophy in rapeseed, we conducted comparative proteomic and metabolomic analyses of the cotyledons of seedlings grown under light versus dark conditions. Under both conditions, the increase in proteases, fatty acid β-oxidation and glyoxylate-cycle related proteins was accompanied by rapid degradation of the stored proteins and lipids with an accumulation of the amino acids. While light condition partially retarded these conversions. Light significantly induced the expression of chlorophyll-binding and photorespiration related proteins, resulting in an increase in reducing-sugars. However, the levels of some chlorophyllide conversion, Calvin-cycle and photorespiration related proteins also accumulated in dark grown cotyledons, implying that the transition from heterotrophy to autotrophy is programmed in the seed rather than induced by light. Various anti-stress systems, e.g., redox related proteins, salicylic acid, proline and chaperones, were employed to decrease oxidative stress, which was mainly derived from lipid oxidation or photorespiration, under both conditions. This study provides a comprehensive understanding of the differential molecular responses of rapeseed cotyledons to light and dark conditions, which will facilitate further study on the complex mechanism underlying the transition from heterotrophy to autotrophy.
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Affiliation(s)
- Dongli He
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
| | - Rebecca N. Damaris
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- University of Chinese Academy of SciencesBeijing, China
| | - Jinlei Fu
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- University of Chinese Academy of SciencesBeijing, China
| | - Jinxing Tu
- National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement in Wuhan, Huazhong Agricultural UniversityWuhan, China
| | - Tingdong Fu
- National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement in Wuhan, Huazhong Agricultural UniversityWuhan, China
| | - Chen Xi
- Wuhan Institute of BiotechnologyWuhan, China
| | - Bin Yi
- National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement in Wuhan, Huazhong Agricultural UniversityWuhan, China
- *Correspondence: Bin Yi, Pingfang Yang,
| | - Pingfang Yang
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- Sino-African Joint Research Center, Chinese Academy of SciencesWuhan, China
- *Correspondence: Bin Yi, Pingfang Yang,
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Peng H, Wei D, Chen G, Chen F. Transcriptome analysis reveals global regulation in response to CO2 supplementation in oleaginous microalga Coccomyxa subellipsoidea C-169. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:151. [PMID: 27453726 PMCID: PMC4957332 DOI: 10.1186/s13068-016-0571-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 07/12/2016] [Indexed: 05/05/2023]
Abstract
BACKGROUND Microalgae are emerging as suitable feedstock for renewable biofuel production and providing a promising way to alleviate green house gas CO2. Characterizing the metabolic pathways involved in the biosynthesis of energy-rich compounds and their global regulation upon elevated CO2 is necessary to explore the mechanism underlying rapid growth and lipid accumulation, so as to realize the full potential of these organisms as energy resources. RESULTS In the present study, 2 and 5 % CO2 increased growth rate and lipid accumulation in autotrophically cultured green alga Coccomyxa subellipsoidea C-169. Overall biomass productivity as 222 mg L(-1) day(-1) and fatty acid content as 48.5 % dry cell weight were attained in 2 % CO2, suggesting C-169 as a great candidate for lipid production via CO2 supplementation. Transcriptomic analysis of 2 % against 0.04 % CO2-cultured C-169 unveiled the global regulation of important metabolic processes. Other than enhancing gene expression in the Calvin cycle, C-169 upregulated the expression of phosphoenolpyruvate carboxylase, pyruvate carboxylase and carbamoyl-phosphate synthetase II to enhance the anaplerotic carbon assimilation reactions upon elevated CO2. Upregulation of ferredoxin and ferredoxin-NADP(+) reductase implied that plentiful energy captured through photosynthesis was transferred through ferredoxin to sustain rapid growth and lipid accumulation. Genes involved in the glycolysis, TCA cycle and oxidative phosphorylation were predominantly upregulated presumably to provide abundant intermediates and metabolic energy for anabolism. Coordinated upregulation of nitrogen acquisition and assimilation genes, together with activation of specific carbamoyl-phosphate synthetase and ornithine pathway genes, might help C-169 to maintain carbon/nitrogen balance upon elevated CO2. Significant downregulation of fatty acid degradation genes, as well as the upregulation of fatty acid synthesis genes at the later stage might contribute to the tremendous lipid accumulation. CONCLUSION Global and collaborative regulation was employed by C-169 to assimilate more carbon and maintain carbon/nitrogen balance upon elevated CO2, which provide abundant carbon skeleton and affluent metabolic energy to sustain rapid growth and lipid accumulation. Data here for the first time bring significant insights into the regulatory profile of metabolism and acclimation to elevated CO2 in C-169, which provide important information for future metabolic engineering in the development of sustainable microalgae-based biofuels.
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Affiliation(s)
- Huifeng Peng
- />School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640 People’s Republic of China
| | - Dong Wei
- />School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640 People’s Republic of China
| | - Gu Chen
- />School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640 People’s Republic of China
| | - Feng Chen
- />School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640 People’s Republic of China
- />Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871 People’s Republic of China
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Xu HM, Kong XD, Chen F, Huang JX, Lou XY, Zhao JY. Transcriptome analysis of Brassica napus pod using RNA-Seq and identification of lipid-related candidate genes. BMC Genomics 2015; 16:858. [PMID: 26499887 PMCID: PMC4619414 DOI: 10.1186/s12864-015-2062-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 10/10/2015] [Indexed: 11/25/2022] Open
Abstract
Background Brassica napus is an important oilseed crop. Dissection of the genetic architecture underlying oil-related biological processes will greatly facilitates the genetic improvement of rapeseed. The differential gene expression during pod development offers a snapshot on the genes responsible for oil accumulation in. To identify candidate genes in the linkage peaks reported previously, we used RNA sequencing (RNA-Seq) technology to analyze the pod transcriptomes of German cultivar Sollux and Chinese inbred line Gaoyou. Methods The RNA samples were collected for RNA-Seq at 5-7, 15-17 and 25-27 days after flowering (DAF). Bioinformatics analysis was performed to investigate differentially expressed genes (DEGs). Gene annotation analysis was integrated with QTL mapping and Brassica napus pod transcriptome profiling to detect potential candidate genes in oilseed. Results Four hundred sixty five and two thousand, one hundred fourteen candidate DEGs were identified, respectively, between two varieties at the same stages and across different periods of each variety. Then, 33 DEGs between Sollux and Gaoyou were identified as the candidate genes affecting seed oil content by combining those DEGs with the quantitative trait locus (QTL) mapping results, of which, one was found to be homologous to Arabidopsis thaliana lipid-related genes. Discussion Intervarietal DEGs of lipid pathways in QTL regions represent important candidate genes for oil-related traits. Integrated analysis of transcriptome profiling, QTL mapping and comparative genomics with other relative species leads to efficient identification of most plausible functional genes underlying oil-content related characters, offering valuable resources for bettering breeding program of Brassica napus. Conclusions This study provided a comprehensive overview on the pod transcriptomes of two varieties with different oil-contents at the three developmental stages. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2062-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hai-Ming Xu
- Institute of Bioinformatics, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Xiang-Dong Kong
- Institute of Bioinformatics, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Fei Chen
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, 198 Shiqiao Road, Hangzhou, 310021, China
| | - Ji-Xiang Huang
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, 198 Shiqiao Road, Hangzhou, 310021, China
| | - Xiang-Yang Lou
- Department of Biostatistics and Bioinformatics, Tulane University, 1440 Canal St., Suite 2001, New Orleans, LA, 70112-2632, USA.
| | - Jian-Yi Zhao
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, 198 Shiqiao Road, Hangzhou, 310021, China.
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Avin-Wittenberg T, Bajdzienko K, Wittenberg G, Alseekh S, Tohge T, Bock R, Giavalisco P, Fernie AR. Global analysis of the role of autophagy in cellular metabolism and energy homeostasis in Arabidopsis seedlings under carbon starvation. THE PLANT CELL 2015; 27:306-22. [PMID: 25649436 PMCID: PMC4456922 DOI: 10.1105/tpc.114.134205] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/29/2014] [Accepted: 01/19/2015] [Indexed: 05/18/2023]
Abstract
Germination and early seedling establishment are developmental stages in which plants face limited nutrient supply as their photosynthesis mechanism is not yet active. For this reason, the plant must mobilize the nutrient reserves provided by the mother plant in order to facilitate growth. Autophagy is a catabolic process enabling the bulk degradation of cellular constituents in the vacuole. The autophagy mechanism is conserved among eukaryotes, and homologs of many autophagy-related (ATG) genes have been found in Arabidopsis thaliana. T-DNA insertion mutants (atg mutants) of these genes display higher sensitivity to various stresses, particularly nutrient starvation. However, the direct impact of autophagy on cellular metabolism has not been well studied. In this work, we used etiolated Arabidopsis seedlings as a model system for carbon starvation. atg mutant seedlings display delayed growth in response to carbon starvation compared with wild-type seedlings. High-throughput metabolomic, lipidomic, and proteomic analyses were performed, as well as extensive flux analyses, in order to decipher the underlying causes of the phenotype. Significant differences between atg mutants and wild-type plants have been demonstrated, suggesting global effects of autophagy on central metabolism during carbon starvation as well as severe energy deprivation, resulting in a morphological phenotype.
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Affiliation(s)
| | - Krzysztof Bajdzienko
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Gal Wittenberg
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Saleh Alseekh
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Takayuki Tohge
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Patrick Giavalisco
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
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Wiszniewski AAG, Bussell JD, Long RL, Smith SM. Knockout of the two evolutionarily conserved peroxisomal 3-ketoacyl-CoA thiolases in Arabidopsis recapitulates the abnormal inflorescence meristem 1 phenotype. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:6723-33. [PMID: 25297549 PMCID: PMC4246196 DOI: 10.1093/jxb/eru397] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A specific function for peroxisomal β-oxidation in inflorescence development in Arabidopsis thaliana is suggested by the mutation of the abnormal inflorescence meristem 1 gene, which encodes one of two peroxisomal multifunctional proteins. Therefore, it should be possible to identify other β-oxidation mutants that recapitulate the aim1 phenotype. Three genes encode peroxisomal 3-ketoacyl-CoA thiolase (KAT) in Arabidopsis. KAT2 and KAT5 are present throughout angiosperms whereas KAT1 is a Brassicaceae-specific duplication of KAT2 expressed at low levels in Arabidopsis. KAT2 plays a dominant role in all known aspects of peroxisomal β-oxidation, including that of fatty acids, pro-auxins, jasmonate precursor oxophytodienoic acid, and trans-cinnamic acid. The functions of KAT1 and KAT5 are unknown. Since KAT5 is conserved throughout vascular plants and expressed strongly in flowers, kat2 kat5 double mutants were generated. These were slow growing, had abnormally branched inflorescences, and ectopic organ growth. They made viable pollen, but produced no seed indicating that infertility was due to defective gynaecium function. These phenotypes are strikingly similar to those of aim1. KAT5 in the Brassicaceae encodes both cytosolic and peroxisomal proteins and kat2 kat5 defects could be complemented by the re-introduction of peroxisomal (but not cytosolic) KAT5. It is concluded that peroxisomal KAT2 and KAT5 have partially redundant functions and operate downstream of AIM1 to provide β-oxidation functions essential for inflorescence development and fertility.
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Affiliation(s)
- Andrew A G Wiszniewski
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia Max-Planck Institute for Molecular Plant Physiology, Wissenschaftpark Golm, Am Mühlenberg 1, D-14476 Potsdam, Germany
| | - John D Bussell
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Rowena L Long
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Steven M Smith
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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Hsiao AS, Haslam RP, Michaelson LV, Liao P, Napier JA, Chye ML. Gene expression in plant lipid metabolism in Arabidopsis seedlings. PLoS One 2014; 9:e107372. [PMID: 25264899 PMCID: PMC4180049 DOI: 10.1371/journal.pone.0107372] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 08/09/2014] [Indexed: 11/18/2022] Open
Abstract
Events in plant lipid metabolism are important during seedling establishment. As it has not been experimentally verified whether lipid metabolism in 2- and 5-day-old Arabidopsis thaliana seedlings is diurnally-controlled, quantitative real-time PCR analysis was used to investigate the expression of target genes in acyl-lipid transfer, β-oxidation and triacylglycerol (TAG) synthesis and hydrolysis in wild-type Arabidopsis WS and Col-0. In both WS and Col-0, ACYL-COA-BINDING PROTEIN3 (ACBP3), DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1) and DGAT3 showed diurnal control in 2- and 5-day-old seedlings. Also, COMATOSE (CTS) was diurnally regulated in 2-day-old seedlings and LONG-CHAIN ACYL-COA SYNTHETASE6 (LACS6) in 5-day-old seedlings in both WS and Col-0. Subsequently, the effect of CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) from the core clock system was examined using the cca1lhy mutant and CCA1-overexpressing (CCA1-OX) lines versus wild-type WS and Col-0, respectively. Results revealed differential gene expression in lipid metabolism between 2- and 5-day-old mutant and wild-type WS seedlings, as well as between CCA1-OX and wild-type Col-0. Of the ACBPs, ACBP3 displayed the most significant changes between cca1lhy and WS and between CCA1-OX and Col-0, consistent with previous reports that ACBP3 is greatly affected by light/dark cycling. Evidence of oil body retention in 4- and 5-day-old seedlings of the cca1lhy mutant in comparison to WS indicated the effect of cca1lhy on storage lipid reserve mobilization. Lipid profiling revealed differences in primary lipid metabolism, namely in TAG, fatty acid methyl ester and acyl-CoA contents amongst cca1lhy, CCA1-OX, and wild-type seedlings. Taken together, this study demonstrates that lipid metabolism is subject to diurnal regulation in the early stages of seedling development in Arabidopsis.
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Affiliation(s)
- An-Shan Hsiao
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Richard P. Haslam
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Louise V. Michaelson
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Pan Liao
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Johnathan A. Napier
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Mee-Len Chye
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
- * E-mail:
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Geigenberger P, Fernie AR. Metabolic control of redox and redox control of metabolism in plants. Antioxid Redox Signal 2014; 21:1389-421. [PMID: 24960279 PMCID: PMC4158967 DOI: 10.1089/ars.2014.6018] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
SIGNIFICANCE Reduction-oxidation (Redox) status operates as a major integrator of subcellular and extracellular metabolism and is simultaneously itself regulated by metabolic processes. Redox status not only dominates cellular metabolism due to the prominence of NAD(H) and NADP(H) couples in myriad metabolic reactions but also acts as an effective signal that informs the cell of the prevailing environmental conditions. After relay of this information, the cell is able to appropriately respond via a range of mechanisms, including directly affecting cellular functioning and reprogramming nuclear gene expression. RECENT ADVANCES The facile accession of Arabidopsis knockout mutants alongside the adoption of broad-scale post-genomic approaches, which are able to provide transcriptomic-, proteomic-, and metabolomic-level information alongside traditional biochemical and emerging cell biological techniques, has dramatically advanced our understanding of redox status control. This review summarizes redox status control of metabolism and the metabolic control of redox status at both cellular and subcellular levels. CRITICAL ISSUES It is becoming apparent that plastid, mitochondria, and peroxisome functions influence a wide range of processes outside of the organelles themselves. While knowledge of the network of metabolic pathways and their intraorganellar redox status regulation has increased in the last years, little is known about the interorganellar redox signals coordinating these networks. A current challenge is, therefore, synthesizing our knowledge and planning experiments that tackle redox status regulation at both inter- and intracellular levels. FUTURE DIRECTIONS Emerging tools are enabling ever-increasing spatiotemporal resolution of metabolism and imaging of redox status components. Broader application of these tools will likely greatly enhance our understanding of the interplay of redox status and metabolism as well as elucidating and characterizing signaling features thereof. We propose that such information will enable us to dissect the regulatory hierarchies that mediate the strict coupling of metabolism and redox status which, ultimately, determine plant growth and development.
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Affiliation(s)
- Peter Geigenberger
- 1 Department of Biology I, Ludwig Maximilian University Munich , Planegg-Martinsried, Germany
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Yoshimoto K, Shibata M, Kondo M, Oikawa K, Sato M, Toyooka K, Shirasu K, Nishimura M, Ohsumi Y. Organ-specific quality control of plant peroxisomes is mediated by autophagy. J Cell Sci 2014; 127:1161-8. [PMID: 24463818 DOI: 10.1242/jcs.139709] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Peroxisomes are essential organelles that are characterized by the possession of enzymes that produce hydrogen peroxide (H2O2) as part of their normal catalytic cycle. During the metabolic process, peroxisomal proteins are inevitably damaged by H2O2 and the integrity of the peroxisomes is impaired. Here, we show that autophagy, an intracellular process for vacuolar degradation, selectively degrades dysfunctional peroxisomes. Marked accumulation of peroxisomes was observed in the leaves but not roots of autophagy-related (ATG)-knockout Arabidopsis thaliana mutants. The peroxisomes in leaf cells contained markedly increased levels of catalase in an insoluble and inactive aggregate form. The chemically inducible complementation system in ATG5-knockout Arabidopsis provided the evidence that these accumulated peroxisomes were delivered to vacuoles for degradation by autophagy. Interestingly, autophagosomal membrane structures specifically recognized the abnormal peroxisomes at the site of the aggregates. Thus, autophagy is essential for the quality control of peroxisomes in leaves and for proper plant development under natural growth conditions.
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Affiliation(s)
- Kohki Yoshimoto
- RIKEN Plant Science Center, Tsurumi-ku, Yokohama 230-0045, Japan
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Brown LA, Larson TR, Graham IA, Hawes C, Paudyal R, Warriner SL, Baker A. An inhibitor of oil body mobilization in Arabidopsis. THE NEW PHYTOLOGIST 2013; 200:641-649. [PMID: 24033128 DOI: 10.1111/nph.12467] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/25/2013] [Indexed: 05/12/2023]
Abstract
Fatty acid β-oxidation is an essential process in many aspects of plant development, and storage oil in the form of triacylglycerol (TAG) is an important food source for humans and animals, for biofuel and for industrial feedstocks. In this study we characterize the effects of a small molecule, diphenyl methylphosphonate, on oil mobilization in Arabidopsis thaliana. Confocal laser scanning microscopy, transmission electron microscopy and quantitative lipid profiling were used to examine the effects of diphenyl methylphosphonate treatment on seedlings. Diphenyl methylphosphonate causes peroxisome clustering around oil bodies but does not affect morphology of other cellular organelles. We show that this molecule blocks the breakdown of pre-existing oil bodies resulting in retention of TAG and accumulation of acyl CoAs. The biochemical and phenotypic effects are consistent with a block in the early part of the β-oxidation pathway. Diphenyl methylphosphonate appears to be a fairly specific inhibitor of TAG mobilization in plants and whilst further work is required to identify the molecular target of the compound it should prove a useful tool to interrogate and manipulate these pathways in a controlled and reproducible manner.
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Affiliation(s)
- Laura-Anne Brown
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Tony R Larson
- Centre for Novel Agricultural Products, Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK
| | - Ian A Graham
- Centre for Novel Agricultural Products, Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK
| | - Chris Hawes
- Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK
| | - Rupesh Paudyal
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Stuart L Warriner
- School of Chemistry, Faculty of Mathematics and Physical Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Alison Baker
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
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Li-Beisson Y, Shorrosh B, Beisson F, Andersson MX, Arondel V, Bates PD, Baud S, Bird D, DeBono A, Durrett TP, Franke RB, Graham IA, Katayama K, Kelly AA, Larson T, Markham JE, Miquel M, Molina I, Nishida I, Rowland O, Samuels L, Schmid KM, Wada H, Welti R, Xu C, Zallot R, Ohlrogge J. Acyl-lipid metabolism. THE ARABIDOPSIS BOOK 2013; 11:e0161. [PMID: 23505340 PMCID: PMC3563272 DOI: 10.1199/tab.0161] [Citation(s) in RCA: 699] [Impact Index Per Article: 63.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables.
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León J. Role of plant peroxisomes in the production of jasmonic acid-based signals. Subcell Biochem 2013; 69:299-313. [PMID: 23821155 DOI: 10.1007/978-94-007-6889-5_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
Jasmonates are a family of oxylipins derived from linolenic acid that control plant responses to biotic and abiotic stress factors and also regulate plant growth and development. Jasmonic acid (JA) is synthesized through the octadecanoid pathway that involves the translocation of lipid intermediates from the chloroplast membranes to the cytoplasm and later on into peroxisomes. The peroxisomal steps of the pathway involve the reduction of cis-(+)-12-oxophytodienoic acid (12-OPDA) and dinor-OPDA, which are the final products of the choroplastic phase of the biosynthetic pathway acting on 18:3 and 16:3 fatty acids, respectively. Further shortening of the carbon side-chain by successive rounds of β-oxidation reactions are required to complete JA biosynthesis. After peroxisomal reactions are completed, (+)-7-iso-JA is synthesized and then transported to the cytoplasm where is conjugated to the amino acid isoleucine to form the bioactive form of the hormone (+)-7-iso-JA-Ile (JA-Ile). Further regulatory activity of JA-Ile triggering gene activation in the jasmonate-dependent signaling cascades is exerted through a process mediated by the perception via the E3 ubiquitin ligase COI1 and further ligand-activated interaction with the family of JAZ repressor proteins. Upon interaction, JAZ are ubiquitinated and degraded by the proteasome, thus releasing transcription factors such as MYC2 from repression and allowing the activation of JA-responsive genes.
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Affiliation(s)
- José León
- Instituto de Biología Molecular y Celular de Plantas, CSIC - Universidad Politécnica de Valencia, Valencia, Spain,
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Abstract
Peroxisomes house many metabolic processes that allow organisms to safely sequester reactions with potentially damaging byproducts. Peroxisomes also produce signaling molecules; in plants, these include the hormones indole-3-acetic acid (IAA) and jasmonic acid (JA). Indole-3-butyric acid (IBA) is a chain-elongated form of the active auxin IAA and is a key tool for horticulturists and plant breeders for inducing rooting in plant cultures and callus. IBA is both made from and converted to IAA, providing a mechanism to maintain optimal IAA levels. Based on genetic analysis and studies of IBA metabolism, IBA conversion to IAA occurs in peroxisomes, and the timing and activity of peroxisomal import and metabolism thereby contribute to the IAA pool in a plant. Four enzymes have been hypothesized to act specifically in peroxisomal IBA conversion to IAA. Loss of these enzymes results in decreased IAA levels, a reduction in auxin-induced gene expression, and strong disruptions in cell elongation resulting in developmental abnormalities. Additional activity by known fatty acid β-oxidation enzymes also may contribute to IBA β-oxidation via direct activity or indirect effects. This review will discuss the peroxisomal enzymes that have been implicated in auxin homeostasis and the importance of IBA-derived IAA in plant growth and development.
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Affiliation(s)
- Gretchen M Spiess
- Department of Biology, University of Missouri - St. Louis, St. Louis, USA
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35
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Wiszniewski AAG, Smith SM, Bussell JD. Conservation of two lineages of peroxisomal (Type I) 3-ketoacyl-CoA thiolases in land plants, specialization of the genes in Brassicaceae, and characterization of their expression in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:6093-103. [PMID: 23066143 PMCID: PMC3481203 DOI: 10.1093/jxb/ers260] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Arabidopsis thaliana has three genes encoding type I 3-ketoacyl-CoA thiolases (KAT1, KAT2, and KAT5), one of which (KAT5) is alternatively transcribed to produce both peroxisomal and cytosolic proteins. To evaluate the potential importance of these four gene products, their evolutionary history in plants and their expression patterns in Arabidopsis were investigated. Land plants as a whole have gene lineages corresponding to KAT2 and KAT5, implying conservation of distinct functions for these two genes. By contrast, analysis of synteny shows that KAT1 arose by duplication of the KAT2 locus. KAT1 is found in the Brassicaceae family, including in the genera Arabidopsis, Capsella, Thellungiella (=Eutrema) and Brassica, but not in the more distantly related Caricaceae (order Brassicales), or other plants. Gene expression analysis using qRT-PCR and β-glucuronidase reporter genes showed strong expression of KAT2 during germination and in many plant tissues throughout the life cycle, consistent with its observed dominant function in fatty acid β-oxidation. KAT1 was expressed very weakly while KAT5 was most strongly expressed during flower development and in seedlings after germination. Isoform-specific qRT-PCR analysis and promoter β-glucuronidase reporters revealed that the two splicing variants of KAT5 have similar expression profiles. Alternative splicing of KAT5 to produce cytosolic and peroxisomal proteins is specific to and ubiquitous in the Brassicaceae, and possibly had an earlier origin in the order Brassicales. This implies that an additional function for KAT5 arose between 43 and 115 mybp. We speculate that this KAT5 mutation was recruited for a cytosolic function in secondary metabolism.
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Affiliation(s)
| | - Steven M Smith
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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Completion of the core β-oxidative pathway of benzoic acid biosynthesis in plants. Proc Natl Acad Sci U S A 2012; 109:16383-8. [PMID: 22988098 DOI: 10.1073/pnas.1211001109] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Despite the importance of benzoic acid (BA) as a precursor for a wide array of primary and secondary metabolites, its biosynthesis in plants has not been fully elucidated. BA formation from phenylalanine requires shortening of the C(3) side chain by two carbon units, which can occur by a non-β-oxidative route and/or a β-oxidative pathway analogous to the catabolism of fatty acids. Enzymes responsible for the first and last reactions of the core BA β-oxidative pathway (cinnamic acid → cinnamoyl-CoA → 3-hydroxy-3-phenylpropanoyl-CoA → 3-oxo-3-phenylpropanoyl-CoA → BA-CoA) have previously been characterized in petunia, a plant with flowers rich in phenylpropanoid/benzenoid volatile compounds. Using a functional genomics approach, we have identified a petunia gene encoding cinnamoyl-CoA hydratase-dehydrogenase (PhCHD), a bifunctional peroxisomal enzyme responsible for two consecutively occurring unexplored intermediate steps in the core BA β-oxidative pathway. PhCHD spatially, developmentally, and temporally coexpresses with known genes in the BA β-oxidative pathway, and correlates with emission of benzenoid volatiles. Kinetic analysis of recombinant PhCHD revealed it most efficiently converts cinnamoyl-CoA to 3-oxo-3-phenylpropanoyl-CoA, thus forming the substrate for the final step in the pathway. Down-regulation of PhCHD expression in petunia flowers resulted in reduced CHD enzyme activity, as well as decreased formation of BA-CoA, BA and their derived volatiles. Moreover, transgenic lines accumulated the PhCHD substrate cinnamoyl-CoA and the upstream pathway intermediate cinnamic acid. Discovery of PhCHD completes the elucidation of the core BA β-oxidative route in plants, and together with the previously characterized CoA-ligase and thiolase enzymes, provides evidence that the whole pathway occurs in peroxisomes.
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Hernández ML, Whitehead L, He Z, Gazda V, Gilday A, Kozhevnikova E, Vaistij FE, Larson TR, Graham IA. A cytosolic acyltransferase contributes to triacylglycerol synthesis in sucrose-rescued Arabidopsis seed oil catabolism mutants. PLANT PHYSIOLOGY 2012; 160:215-25. [PMID: 22760209 PMCID: PMC3440200 DOI: 10.1104/pp.112.201541] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 07/02/2012] [Indexed: 05/19/2023]
Abstract
Triacylglycerol (TAG) levels and oil bodies persist in sucrose (Suc)-rescued Arabidopsis (Arabidopsis thaliana) seedlings disrupted in seed oil catabolism. This study set out to establish if TAG levels persist as a metabolically inert pool when downstream catabolism is disrupted, or if other mechanisms, such as fatty acid (FA) recycling into TAG are operating. We show that TAG composition changes significantly in Suc-rescued seedlings compared with that found in dry seeds, with 18:2 and 18:3 accumulating. However, 20:1 FA is not efficiently recycled back into TAG in young seedlings, instead partitioning into the membrane lipid fraction and diacylglycerol. In the lipolysis mutant sugar dependent1and the β-oxidation double mutant acx1acx2 (for acyl-Coenzyme A oxidase), levels of TAG actually increased in seedlings growing on Suc. We performed a transcriptomic study and identified up-regulation of an acyltransferase gene, DIACYLGLYCEROL ACYLTRANSFERASE3 (DGAT3), with homology to a peanut (Arachis hypogaea) cytosolic acyltransferase. The acyl-Coenzyme A substrate for this acyltransferase accumulates in mutants that are blocked in oil breakdown postlipolysis. Transient expression in Nicotiana benthamiana confirmed involvement in TAG synthesis and specificity toward 18:3 and 18:2 FAs. Double-mutant analysis with the peroxisomal ATP-binding cassette transporter mutant peroxisomal ABC transporter1 indicated involvement of DGAT3 in the partitioning of 18:3 into TAG in mutant seedlings growing on Suc. Fusion of the DGAT3 protein with green fluorescent protein confirmed localization to the cytosol of N. benthamiana. This work has demonstrated active recycling of 18:2 and 18:3 FAs into TAG when seed oil breakdown is blocked in a process involving a soluble cytosolic acyltransferase.
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Affiliation(s)
| | | | - Zhesi He
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Valeria Gazda
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Alison Gilday
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Ekaterina Kozhevnikova
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Fabián E. Vaistij
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Tony R. Larson
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Ian A. Graham
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom
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De Rybel B, Audenaert D, Xuan W, Overvoorde P, Strader LC, Kepinski S, Hoye R, Brisbois R, Parizot B, Vanneste S, Liu X, Gilday A, Graham IA, Nguyen L, Jansen L, Njo MF, Inzé D, Bartel B, Beeckman T. A role for the root cap in root branching revealed by the non-auxin probe naxillin. Nat Chem Biol 2012; 8:798-805. [PMID: 22885787 DOI: 10.1038/nchembio.1044] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 06/26/2012] [Indexed: 01/06/2023]
Abstract
The acquisition of water and nutrients by plant roots is a fundamental aspect of agriculture and strongly depends on root architecture. Root branching and expansion of the root system is achieved through the development of lateral roots and is to a large extent controlled by the plant hormone auxin. However, the pleiotropic effects of auxin or auxin-like molecules on root systems complicate the study of lateral root development. Here we describe a small-molecule screen in Arabidopsis thaliana that identified naxillin as what is to our knowledge the first non-auxin-like molecule that promotes root branching. By using naxillin as a chemical tool, we identified a new function for root cap-specific conversion of the auxin precursor indole-3-butyric acid into the active auxin indole-3-acetic acid and uncovered the involvement of the root cap in root branching. Delivery of an auxin precursor in peripheral tissues such as the root cap might represent an important mechanism shaping root architecture.
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Affiliation(s)
- Bert De Rybel
- Department of Plant Systems Biology, VIB, Gent, Belgium
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Theodoulou FL, Eastmond PJ. Seed storage oil catabolism: a story of give and take. CURRENT OPINION IN PLANT BIOLOGY 2012; 15:322-8. [PMID: 22516438 DOI: 10.1016/j.pbi.2012.03.017] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 03/27/2012] [Indexed: 05/21/2023]
Abstract
The transition from seed to seedling is an important step in the life cycle of plants, which is fuelled primarily by the breakdown of triacylglycerol (TAG) in 'oilseed' species. TAG is stored within cytosolic oil bodies, while the pathway for fatty acid β-oxidation resides in the peroxisome. Although the enzymology of fatty acid β-oxidation has been relatively well characterised, the processes by which fatty acids are liberated from oil bodies and enter the peroxisome are less well understood and, together with metabolite, cofactor and co-substrate transporters, represent key targets for future research in order to understand co-ordination of peroxisomal metabolism with that of other subcellular compartments.
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Affiliation(s)
- Frederica L Theodoulou
- Biological Chemistry and Crop Protection Department, Rothamsted Research, West Common, Harpenden, Hertfordshire, UK
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40
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Khan BR, Adham AR, Zolman BK. Peroxisomal Acyl-CoA oxidase 4 activity differs between Arabidopsis accessions. PLANT MOLECULAR BIOLOGY 2012; 78:45-58. [PMID: 22048901 DOI: 10.1007/s11103-011-9843-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 10/20/2011] [Indexed: 05/24/2023]
Abstract
In plants, peroxisomes are the primary site of fatty acid β-oxidation. Following substrate activation, fatty acids are oxidized by Acyl-CoA Oxidase (ACX) enzymes. Arabidopsis has six ACX genes, although ACX6 is not expressed. Biochemical characterization has revealed that each ACX enzyme acts on specific chain-length targets, but in a partially overlapping manner, indicating a degree of functional redundancy. Genetic analysis of acx single and double mutants in the Columbia (Col-0) accession revealed only minor phenotypes, but an acx3acx4 double mutant from Wassileskija (Ws) is embryo lethal. In this study, we show that acx3acx4(Col) and acx1acx3acx4(Col) mutants are viable and that enzyme activity in these mutants is significantly reduced on a range of substrates compared to wild type. However, the triple mutant displays only minor defects in seed-storage mobilization, seedling development, and adult growth. Although the triple mutant is defective in the three most active and highly-expressed ACX proteins, increases in ACX2 expression may support partial β-oxidation activity. Comparison of acx mutant alleles in the Col-0 and Ws accessions reveals independent phenotypes; the Ws acx4 mutant uniquely shows increased sensitivity to propionate, whereas the Col-0 acx4 allele has sucrose-dependent growth in the light. To dissect the issues between Col-0 and Ws, we generated mixed background mutants. Although alleles with the Col-0 acx4 mutant were viable, we were unable to isolate an acx3acx4 line using the Ws acx4 allele. Reducing ACX4 expression in several Arabidopsis backgrounds showed a split response, suggesting that the ACX4 gene and/or protein functions differently in Arabidopsis accessions.
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Affiliation(s)
- Bibi Rafeiza Khan
- Department of Biology, University of Missouri, St. Louis, St. Louis, MO 63121, USA
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Bernhardt K, Wilkinson S, Weber APM, Linka N. A peroxisomal carrier delivers NAD⁺ and contributes to optimal fatty acid degradation during storage oil mobilization. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 69:1-13. [PMID: 21895810 DOI: 10.1111/j.1365-313x.2011.04775.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The existence of a transport protein that imports cytosolic NAD(+) into peroxisomes has been controversially discussed for decades. Nevertheless, the biosynthesis of NAD(+) in the cytosol necessitates the import of NAD(+) into peroxisomes for numerous reduction/oxidation (redox) reactions. However, a gene encoding such a transport system has not yet been identified in any eukaryotic organism. Here, we describe the peroxisomal NAD(+) carrier in Arabidopsis. Our candidate gene At2g39970 encodes for a member of the mitochondrial carrier family. We confirmed its peroxisomal localization using fluorescence microscopy. For a long time At2g39970 was assumed to represent the peroxisomal ATP transporter. In this study, we could show that the recombinant protein mediated the transport of NAD(+) . Hence, At2g39970 was named PXN for peroxisomal NAD(+) carrier. The loss of PXN in Arabidopsis causes defects in NAD(+) -dependent β-oxidation during seedling establishment. The breakdown of fatty acid released from storage oil was delayed, which led to the retention of oil bodies in pxn mutant seedlings. Based on our results, we propose that PXN delivers NAD(+) for optimal fatty acid degradation during storage oil mobilization.
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Affiliation(s)
- Kristin Bernhardt
- Institut für Biochemie der Pflanzen, Heinrich-Heine Universität Düsseldorf, 40225 Düsseldorf, Germany
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Mano S, Nakamori C, Fukao Y, Araki M, Matsuda A, Kondo M, Nishimura M. A defect of peroxisomal membrane protein 38 causes enlargement of peroxisomes. PLANT & CELL PHYSIOLOGY 2011; 52:2157-72. [PMID: 22034551 DOI: 10.1093/pcp/pcr147] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Peroxisome proliferation occurs through enlargement, elongation and division of pre-existing peroxisomes. In the Arabidopsis apem mutant, apem3, peroxisomes are dramatically enlarged and reduced in number, revealing a defect in peroxisome proliferation. The APEM3 gene was found to encode peroxisomal membrane protein 38 (PMP38). To examine the relative role of PMP38 during proliferation, a double mutant was constructed consisting of apem3 and the peroxisome division mutant, apem1, in which a defect in dynamin-related protein 3A (DRP3A) results in elongation of peroxisomes. In the double mutant, almost all peroxisomes were predominantly enlarged but not elongated. DRP3A is still able to localize at the peroxisomal membrane on enlarged peroxisomes in the apem3 mutants. PMP38 is revealed to be capable of interacting with itself, but not with DRP3A. These results indicate that PMP38 has a role at a different step that requires APEM1/DRP3A. PMP38 is expressed in various tissues throughout the plant, indicating that PMP38 may participate in multiple unidentified functions in these tissues. PMP38 belongs to a mitochondrial carrier family (MCF) protein. However, unlike Arabidopsis nucleotide carrier protein 1 (AtPNC1) and AtPNC2, two other peroxisome-resident MCF proteins that function as adenine nucleotide transporters, PMP38 has no ATP or ADP transport activity. In addition, unlike AtPNC1 and AtPNC2 knock-down plants, apem3 mutants do not exhibit any gross morphological abnormalities. These results demonstrate that APEM3/PMP38 plays a role distinct from that of AtPNC1 and AtPNC2. We discuss possible mechanism of enlargement of peroxisomes in the apem3 mutants.
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Affiliation(s)
- Shoji Mano
- Department of Cell Biology, National Institute for Basic Biology, Okazaki, 444-8585 Japan.
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Kim EY, Seo YS, Kim WT. AtDSEL, an Arabidopsis cytosolic DAD1-like acylhydrolase, is involved in negative regulation of storage oil mobilization during seedling establishment. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:1705-9. [PMID: 21477884 DOI: 10.1016/j.jplph.2011.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 03/03/2011] [Accepted: 03/03/2011] [Indexed: 05/12/2023]
Abstract
Mobilization of seed storage reserves is essential for seed germination and seedling establishment. Here, we report that AtDSEL, an Arabidopsis thalianaDAD1-like Seedling Establishment-related Lipase, is involved in the mobilization of storage oils for early seedling establishment. AtDSEL is a cytosolic member of the DAD1-like acylhydrolase family encoded by At4g18550. Bacterially expressed AtDSEL preferentially hydrolyzed 1,3-diacylglycerol and 1-monoacylglycerol, suggesting that AtDSEL is an sn-1-specific lipase. AtDSEL-overexpressing transgenic Arabidopsis plants (35S:AtDSEL) were defective in post-germinative seedling growth in medium without an exogenous carbon source. This phenotype was rescued by the addition of sucrose to the growth medium. In contrast, loss-of-function mutant plants (atdsel-1 and atdsel-2) had a mildly fast-growing phenotype regardless of the presence of an exogenous carbon source. Electron microscopy revealed that 5-day-old 35S:AtDSEL cotyledons retained numerous peroxisomes and oil bodies, which were exhausted in wild-type and mutant cotyledons. The impaired seedling establishment of 35S:AtDSEL was not rescued by the addition of an exogenous fatty acid source, and 35S:AtDSEL seedling growth was insensitive to 2,4-dichlorophenoxybutyric acid, indicating that β-oxidation was blocked in AtDSEL-overexpressers. These results suggest that AtDSEL is involved in the negative regulation of seedling establishment by inhibiting the breakdown of storage oils.
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Affiliation(s)
- Eun Yu Kim
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
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Monroe-Augustus M, Ramón NM, Ratzel SE, Lingard MJ, Christensen SE, Murali C, Bartel B. Matrix proteins are inefficiently imported into Arabidopsis peroxisomes lacking the receptor-docking peroxin PEX14. PLANT MOLECULAR BIOLOGY 2011; 77:1-15. [PMID: 21553312 PMCID: PMC3529590 DOI: 10.1007/s11103-011-9782-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 04/24/2011] [Indexed: 05/24/2023]
Abstract
Mutations in peroxisome biogenesis proteins (peroxins) can lead to developmental deficiencies in various eukaryotes. PEX14 and PEX13 are peroxins involved in docking cargo-receptor complexes at the peroxisomal membrane, thus aiding in the transport of the cargo into the peroxisomal matrix. Genetic screens have revealed numerous Arabidopsis thaliana peroxins acting in peroxisomal matrix protein import; the viable alleles isolated through these screens are generally partial loss-of-function alleles, whereas null mutations that disrupt delivery of matrix proteins to peroxisomes can confer embryonic lethality. In this study, we used forward and reverse genetics in Arabidopsis to isolate four pex14 alleles. We found that all four alleles conferred reduced PEX14 mRNA levels and displayed physiological and molecular defects suggesting reduced but not abolished peroxisomal matrix protein import. The least severe pex14 allele, pex14-3, accumulated low levels of a C-terminally truncated PEX14 product that retained partial function. Surprisingly, even the severe pex14-2 allele, which lacked detectable PEX14 mRNA and PEX14 protein, was viable, fertile, and displayed residual peroxisome matrix protein import. As pex14 plants matured, import improved. Together, our data indicate that PEX14 facilitates, but is not essential for peroxisomal matrix protein import in plants.
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Affiliation(s)
- Melanie Monroe-Augustus
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Naxhiely Martínez Ramón
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Sarah E. Ratzel
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Matthew J. Lingard
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA. 700 Chesterfield Parkway, Chesterfield, MO 63017, USA
| | - Sarah E. Christensen
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Chaya Murali
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Bonnie Bartel
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
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45
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Modelling the peroxisomal carbon leak during lipid mobilization in Arabidopsis. Biochem Soc Trans 2011; 38:1230-3. [PMID: 20863290 DOI: 10.1042/bst0381230] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mutation of the ACN1 (acetate non-utilizing 1) locus of Arabidopsis results in altered acetate assimilation into gluconeogenic sugars and anapleurotic amino acids and leads to an overall depression in primary metabolite levels by approx. 50% during seedling development. Levels of acetyl-CoA were higher in acn1 compared with wild-type, which is counterintuitive to the activity of ACN1 as a peroxisomal acetyl-CoA synthetase. We hypothesize that ACN1 recycles free acetate to acetyl-CoA within peroxisomes in order that carbon remains fed into the glyoxylate cycle. When ACN1 is not present, carbon in the form of acetate can leak out of peroxisomes and is reactivated to acetyl-CoA within the cytosol. Kinetic models incorporating estimates of carbon input and pathway dynamics from a variety of literature sources have proven useful in explaining how ACN1 may prevent the carbon leak and even contribute to the control of peroxisomal carbon metabolism.
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46
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Kaur N, Hu J. Defining the plant peroxisomal proteome: from Arabidopsis to rice. FRONTIERS IN PLANT SCIENCE 2011; 2:103. [PMID: 22645559 PMCID: PMC3355810 DOI: 10.3389/fpls.2011.00103] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 12/08/2011] [Indexed: 05/08/2023]
Abstract
Peroxisomes are small subcellular organelles mediating a multitude of processes in plants. Proteomics studies over the last several years have yielded much needed information on the composition of plant peroxisomes. In this review, the status of peroxisome proteomics studies in Arabidopsis and other plant species and the cumulative advances made through these studies are summarized. A reference Arabidopsis peroxisome proteome is generated, and some unique aspects of Arabidopsis peroxisomes that were uncovered through proteomics studies and hint at unanticipated peroxisomal functions are also highlighted. Knowledge gained from Arabidopsis was utilized to compile a tentative list of peroxisome proteins for the model monocot plant, rice. Differences in the peroxisomal proteome between these two model plants were drawn, and novel facets in rice were expounded upon. Finally, we discuss about the current limitations of experimental proteomics in decoding the complete and dynamic makeup of peroxisomes, and complementary and integrated approaches that would be beneficial to defining the peroxisomal metabolic and regulatory roadmaps. The synteny of genomes in the grass family makes rice an ideal model to study peroxisomes in cereal crops, in which these organelles have received much less attention, with the ultimate goal to improve crop yield.
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Affiliation(s)
- Navneet Kaur
- MSU-DOE Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
| | - Jianping Hu
- MSU-DOE Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
- Plant Biology Department, Michigan State UniversityEast Lansing, MI, USA
- *Correspondence: Jianping Hu, MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA. e-mail:
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47
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Arent S, Christensen CE, Pye VE, Nørgaard A, Henriksen A. The multifunctional protein in peroxisomal beta-oxidation: structure and substrate specificity of the Arabidopsis thaliana protein MFP2. J Biol Chem 2010; 285:24066-77. [PMID: 20463021 PMCID: PMC2911295 DOI: 10.1074/jbc.m110.106005] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 04/12/2010] [Indexed: 11/06/2022] Open
Abstract
Plant fatty acids can be completely degraded within the peroxisomes. Fatty acid degradation plays a role in several plant processes including plant hormone synthesis and seed germination. Two multifunctional peroxisomal isozymes, MFP2 and AIM1, both with 2-trans-enoyl-CoA hydratase and l-3-hydroxyacyl-CoA dehydrogenase activities, function in mouse ear cress (Arabidopsis thaliana) peroxisomal beta-oxidation, where fatty acids are degraded by the sequential removal of two carbon units. A deficiency in either of the two isozymes gives rise to a different phenotype; the biochemical and molecular background for these differences is not known. Structure determination of Arabidopsis MFP2 revealed that plant peroxisomal MFPs can be grouped into two families, as defined by a specific pattern of amino acid residues in the flexible loop of the acyl-binding pocket of the 2-trans-enoyl-CoA hydratase domain. This could explain the differences in substrate preferences and specific biological functions of the two isozymes. The in vitro substrate preference profiles illustrate that the Arabidopsis AIM1 hydratase has a preference for short chain acyl-CoAs compared with the Arabidopsis MFP2 hydratase. Remarkably, neither of the two was able to catabolize enoyl-CoA substrates longer than 14 carbon atoms efficiently, suggesting the existence of an uncharacterized long chain enoyl-CoA hydratase in Arabidopsis peroxisomes.
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Affiliation(s)
- Susan Arent
- From the Protein Chemistry Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark
| | - Caspar E. Christensen
- From the Protein Chemistry Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark
| | - Valerie E. Pye
- From the Protein Chemistry Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark
| | - Allan Nørgaard
- From the Protein Chemistry Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark
| | - Anette Henriksen
- From the Protein Chemistry Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark
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Li-Beisson Y, Shorrosh B, Beisson F, Andersson MX, Arondel V, Bates PD, Baud S, Bird D, DeBono A, Durrett TP, Franke RB, Graham IA, Katayama K, Kelly AA, Larson T, Markham JE, Miquel M, Molina I, Nishida I, Rowland O, Samuels L, Schmid KM, Wada H, Welti R, Xu C, Zallot R, Ohlrogge J. Acyl-lipid metabolism. THE ARABIDOPSIS BOOK 2010; 8:e0133. [PMID: 22303259 PMCID: PMC3244904 DOI: 10.1199/tab.0133] [Citation(s) in RCA: 236] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables.
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49
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Negrel J, Javelle F. The biosynthesis of acetovanillone in tobacco cell-suspension cultures. PHYTOCHEMISTRY 2010; 71:751-9. [PMID: 20188386 DOI: 10.1016/j.phytochem.2010.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 01/19/2010] [Accepted: 01/19/2010] [Indexed: 05/28/2023]
Abstract
A soluble enzyme, extracted from tobacco cell-suspension cultures 24h after treatment with 100 microM methyl jasmonate, has been shown to synthesize acetovanillone (apocynin) from feruloyl-CoA in the presence of NAD. The enzyme displayed Michaelis-Menten kinetics with apparent K(m) values of 5.6 microM for feruloyl-CoA and 260 microM for NAD and exhibited very high specificity for its substrates. The increase in acetovanillone synthase activity was followed by an increase in the concentration of both acetovanillone and acetosyringone in the culture medium. No intermediate could be detected when analysing the reaction medium by HPLC during the formation of acetovanillone in cell-free extracts. The apparent molecular mass estimated by gel permeation on an FPLC column was ca. 79 kDa. To our knowledge, this is the first report of an enzymic system catalysing the synthesis of an acetophenone. This work demonstrates that the biosynthesis of acetophenones in tobacco proceeds from hydroxycinnamic acids through a CoA-dependent beta-oxidation pathway. Interestingly in methyl jasmonate-treated cells, which synthesize very large amounts of hydroxycinnamoylputrescines, inhibition of the synthesis of these conjugates increased the concentration of acetovanillone and acetosyringone in the culture medium, suggesting that the two metabolic pathways can compete for their common precursors, i.e. hydroxycinnamoyl-CoA thioesters.
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50
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Ramón NM, Bartel B. Interdependence of the peroxisome-targeting receptors in Arabidopsis thaliana: PEX7 facilitates PEX5 accumulation and import of PTS1 cargo into peroxisomes. Mol Biol Cell 2010; 21:1263-71. [PMID: 20130089 PMCID: PMC2847529 DOI: 10.1091/mbc.e09-08-0672] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Peroxisomes compartmentalize certain metabolic reactions critical to plant and animal development. The import of proteins from the cytosol into the organelle matrix depends on more than a dozen peroxin (PEX) proteins, with PEX5 and PEX7 serving as receptors that shuttle proteins bearing one of two peroxisome-targeting signals (PTSs) into the organelle. PEX5 is the PTS1 receptor; PEX7 is the PTS2 receptor. In plants and mammals, PEX7 depends on PEX5 binding to deliver PTS2 cargo into the peroxisome. In this study, we characterized a pex7 missense mutation, pex7-2, that disrupts both PEX7 cargo binding and PEX7-PEX5 interactions in yeast, as well as PEX7 protein accumulation in plants. We examined localization of peroxisomally targeted green fluorescent protein derivatives in light-grown pex7 mutants and observed not only the expected defects in PTS2 protein import but also defects in PTS1 import. These PTS1 import defects were accompanied by reduced PEX5 accumulation in light-grown pex7 seedlings. Our data suggest that PEX5 and PTS1 import depend on the PTS2 receptor PEX7 in Arabidopsis and that the environment may influence this dependence. These data advance our understanding of the biogenesis of these essential organelles and provide a possible rationale for the retention of the PTS2 pathway in some organisms.
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