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Jiang B, Fang X, Fu D, Wu W, Han Y, Chen H, Liu R, Gao H. Exogenous salicylic acid regulates organic acids metabolism in postharvest blueberry fruit. FRONTIERS IN PLANT SCIENCE 2022; 13:1024909. [PMID: 36388486 PMCID: PMC9665327 DOI: 10.3389/fpls.2022.1024909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Fruit acidity is an essential factor affecting blueberry organoleptic quality. The organic acid content in blueberry fruit mainly contributes to fruit acidity. This study aims to evaluate the effect of exogenous salicylic acid (SA), the principal metabolite of aspirin, on the organoleptic quality and organic acid metabolism in rabbiteye blueberry (Vaccinium virgatum Ait, 'Powderblue') during cold storage (4 °C). Results showed that SA-treated fruit reduced fruit decay and weight loss delayed fruit softening, and decline of total soluble solids (TSS). TA and total organic acid amounts stayed the same during the late storage period in SA-treated fruit. Four kinds of organic acid components, malic acid, quinic acid, citric acid, and succinic acid, were at higher levels in fruit treated by SA as compared to control. SA enhanced the activities of PEPC, NAD-MDH, and CS to promote the synthesis of malic acid and citric acid. Meanwhile, the activities of NADP-ME, ACL, and ACO, which participated in the degradation of malic acid and citric acid, were inhibited by SA. qPCR results also showed that the expression of VcPEPC, VcNAD-MDH, and VcCS genes were upregulated. In contrast, SA downregulated the expression of VcNADP-ME, VcACL, and VcACO genes. In conclusion, SA could regulate the key genes and enzymes that participated in organic acids metabolism to maintain the freshness of blueberry during cold storage, therefore minimizing the economic loss.
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Affiliation(s)
- Bo Jiang
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, China
- Food Science Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture and Rural Affairs, Hangzhou, China
- Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang Province, Hangzhou, China
- Key Laboratory of Postharvest Preservation and Processing of Fruits and Vegetables, China National Light Industry, Hangzhou, China
| | - Xiangjun Fang
- Food Science Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture and Rural Affairs, Hangzhou, China
- Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang Province, Hangzhou, China
- Key Laboratory of Postharvest Preservation and Processing of Fruits and Vegetables, China National Light Industry, Hangzhou, China
| | - Daqi Fu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Weijie Wu
- Food Science Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture and Rural Affairs, Hangzhou, China
- Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang Province, Hangzhou, China
- Key Laboratory of Postharvest Preservation and Processing of Fruits and Vegetables, China National Light Industry, Hangzhou, China
| | - Yanchao Han
- Food Science Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture and Rural Affairs, Hangzhou, China
- Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang Province, Hangzhou, China
- Key Laboratory of Postharvest Preservation and Processing of Fruits and Vegetables, China National Light Industry, Hangzhou, China
| | - Hangjun Chen
- Food Science Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture and Rural Affairs, Hangzhou, China
- Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang Province, Hangzhou, China
- Key Laboratory of Postharvest Preservation and Processing of Fruits and Vegetables, China National Light Industry, Hangzhou, China
| | - Ruiling Liu
- Food Science Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture and Rural Affairs, Hangzhou, China
- Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang Province, Hangzhou, China
- Key Laboratory of Postharvest Preservation and Processing of Fruits and Vegetables, China National Light Industry, Hangzhou, China
| | - Haiyan Gao
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, China
- Food Science Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture and Rural Affairs, Hangzhou, China
- Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang Province, Hangzhou, China
- Key Laboratory of Postharvest Preservation and Processing of Fruits and Vegetables, China National Light Industry, Hangzhou, China
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Wei QJ, Ma QL, Zhou GF, Liu X, Ma ZZ, Gu QQ. Identification of genes associated with soluble sugar and organic acid accumulation in 'Huapi' kumquat (Fortunella crassifolia Swingle) via transcriptome analysis. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2021; 101:4321-4331. [PMID: 33417244 DOI: 10.1002/jsfa.11072] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/23/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND The levels and ratios of sugar and acid are important contributors to fruit taste. Kumquat is one of the most economically important citrus crops, but information on the soluble sugar and organic acid metabolism in kumquat is limited. Here, two kumquat varieties - 'Rongan' (RA) and its mutant 'Huapi' (HP) - were used to assess soluble sugar and organic acid accumulation and the related genes. RESULTS Soluble sugars include sucrose, glucose and fructose, while malate, quinic acid and citrate are the dominant organic acids in the fruits of both kumquat varieties. HP accumulated more sugars but fewer organic acids than did RA. Transcriptome analysis revealed 63 and 40 differentially expressed genes involved in soluble sugar and organic acid accumulation, respectively. The genes associated with sugar synthesis and transport, including SUS, SPS, TST, STP and ERD6L, were up-regulated, whereas INVs, FRK and HXK genes related to sugar degradation were down-regulated in HP kumquat. For organic acids, the up-regulation of PEPC and NAD-MDH could accelerate malate accumulation. In contrast, high expression of NAD-IDH and GS resulted in citric acid degradation during HP fruit development. Additionally, the PK, PDH, PEPCK and FBPase genes responsible for the interconversion of soluble sugars and organic acids were also significantly altered in the early development stages in HP. CONCLUSION The high sugar accumulation in HP fruit was associated with up-regulation of SUS, SPS, TST, STP and ERD6L genes. The PEPCK, PEPC, NAD-MDH, NADP-IDH, GS and FBPase genes played important roles in acid synthesis and degradation in HP kumquat. These findings provide further insight into understanding the mechanisms underlying metabolism of sugars and organic acids in citrus. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Qing-Jiang Wei
- College of Agronomy, Jiangxi Agricultural University, Nanchang, China
| | - Qiao-Li Ma
- College of Agronomy, Jiangxi Agricultural University, Nanchang, China
| | - Gao-Feng Zhou
- National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Xiao Liu
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
| | - Zhang-Zheng Ma
- College of Agronomy, Jiangxi Agricultural University, Nanchang, China
| | - Qing-Qing Gu
- College of Agronomy, Jiangxi Agricultural University, Nanchang, China
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Zhang X, Wei X, Ali MM, Rizwan HM, Li B, Li H, Jia K, Yang X, Ma S, Li S, Chen F. Changes in the Content of Organic Acids and Expression Analysis of Citric Acid Accumulation-Related Genes during Fruit Development of Yellow ( Passiflora edulis f. flavicarpa) and Purple ( Passiflora edulis f. edulis) Passion Fruits. Int J Mol Sci 2021; 22:ijms22115765. [PMID: 34071242 PMCID: PMC8198880 DOI: 10.3390/ijms22115765] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 02/07/2023] Open
Abstract
Organic acids are key components that determine the taste and flavor of fruits and play a vital role in maintaining fruit quality and nutritive value. In this study, the fruits of two cultivars of passion fruit Yellow (Passiflora edulis f. flavicarpa) and purple (Passiflora edulis f. edulis) were harvested at five different developmental stages (i.e., fruitlet, green, veraison, near-mature and mature stage) from an orchard located in subtropical region of Fujian Province, China. The contents of six organic acids were quantified using ultra-performance liquid chromatography (UPLC), activities of citric acid related enzymes were determined, and expression levels of genes involved in citric acid metabolism were measured by quantitative real-time PCR (qRT-PCR). The results revealed that citric acid was the predominant organic acid in both cultivars during fruit development. The highest citric acid contents were observed in both cultivars at green stage, which were reduced with fruit maturity. Correlation analysis showed that citrate synthase (CS), cytosolic aconitase (Cyt-ACO) and cytosolic isocitrate dehydrogenase (Cyt-IDH) may be involved in regulating citric acid biosynthesis. Meanwhile, the PeCS2, PeACO4, PeACO5 and PeIDH1 genes may play an important role in regulating the accumulation of citric acid. This study provides new insights for future elucidation of key mechanisms regulating organic acid biosynthesis in passion fruit.
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Affiliation(s)
- Xiaoxue Zhang
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.Z.); (M.M.A.); (H.M.R.); (B.L.); (H.L.); (K.J.); (X.Y.); (S.M.)
| | - Xiaoxia Wei
- Fruit Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350002, China;
| | - Muhammad Moaaz Ali
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.Z.); (M.M.A.); (H.M.R.); (B.L.); (H.L.); (K.J.); (X.Y.); (S.M.)
| | - Hafiz Muhammad Rizwan
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.Z.); (M.M.A.); (H.M.R.); (B.L.); (H.L.); (K.J.); (X.Y.); (S.M.)
| | - Binqi Li
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.Z.); (M.M.A.); (H.M.R.); (B.L.); (H.L.); (K.J.); (X.Y.); (S.M.)
| | - Han Li
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.Z.); (M.M.A.); (H.M.R.); (B.L.); (H.L.); (K.J.); (X.Y.); (S.M.)
| | - Kaijie Jia
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.Z.); (M.M.A.); (H.M.R.); (B.L.); (H.L.); (K.J.); (X.Y.); (S.M.)
| | - Xuelian Yang
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.Z.); (M.M.A.); (H.M.R.); (B.L.); (H.L.); (K.J.); (X.Y.); (S.M.)
| | - Songfeng Ma
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.Z.); (M.M.A.); (H.M.R.); (B.L.); (H.L.); (K.J.); (X.Y.); (S.M.)
| | - Shaojia Li
- College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
- Correspondence: (S.L.); (F.C.)
| | - Faxing Chen
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.Z.); (M.M.A.); (H.M.R.); (B.L.); (H.L.); (K.J.); (X.Y.); (S.M.)
- Correspondence: (S.L.); (F.C.)
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Zhao Y, Huang Y, Wang Y, Cui Y, Liu Z, Hua J. RNA interference of GhPEPC2 enhanced seed oil accumulation and salt tolerance in Upland cotton. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 271:52-61. [PMID: 29650157 DOI: 10.1016/j.plantsci.2018.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 03/02/2018] [Accepted: 03/13/2018] [Indexed: 05/14/2023]
Abstract
Phosphoenolpyruvate carboxylase (PEPCase) mainly produces oxaloacetic acid for tricarboxylic acid (TCA) cycle. Here we reported that GhPEPC2 silencing with PEPC2-RNAi vector could regulate oil and protein accumulation in cottonseeds. In GhPEPC2 transgenic plants, PEPCase activities in immature embryos were significantly reduced, and the oil content in seed kernel was increased 7.3 percentages, whereas total proteins decreased 5.65 percentages. Compared to wild type, agronomical traits of transgenic plant were obviously unaffected. Furthermore, gene expression profile of GhPEPC2 transgenic seeds were investigated using RNA-seq, most lipid synthesis related genes were up-regulated, but amino acid metabolic related genes were down-regulated. In addition, the GhPEPC2 transgenic cotton seedlings were stressed using sodium salts at seedling stage, and the salt tolerance was significantly enhanced. Our observations of GhPEPC2 in cotton would shade light on understanding the regulation of oil content, protein accumulation and salt tolerance enhancement in other plants.
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Affiliation(s)
- Yanpeng Zhao
- Laboratory of Cotton Genetics, Genomics and Breeding/Beijing Key Laboratory of Crop Genetic Improvement/Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.
| | - Yi Huang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
| | - Yumei Wang
- Research Institute of Cash Crops, Hubei Academy of Agricultural Sciences, Wuhan, 430064, Hubei, China.
| | - Yupeng Cui
- Laboratory of Cotton Genetics, Genomics and Breeding/Beijing Key Laboratory of Crop Genetic Improvement/Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.
| | - Zhengjie Liu
- Laboratory of Cotton Genetics, Genomics and Breeding/Beijing Key Laboratory of Crop Genetic Improvement/Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.
| | - Jinping Hua
- Laboratory of Cotton Genetics, Genomics and Breeding/Beijing Key Laboratory of Crop Genetic Improvement/Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.
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Ting MKY, She YM, Plaxton WC. Transcript profiling indicates a widespread role for bacterial-type phosphoenolpyruvate carboxylase in malate-accumulating sink tissues. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5857-5869. [PMID: 29240945 PMCID: PMC5854131 DOI: 10.1093/jxb/erx399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Phosphoenolpyruvate carboxylase (PEPC) is an important regulatory enzyme situated at a key branch point of central plant metabolism. Plant genomes encode several plant-type PEPC (PTPC) isozymes, along with a distantly related bacterial-type PEPC (BTPC). BTPC is expressed at high levels in developing castor oil seeds where it tightly interacts with co-expressed PTPC polypeptides to form unusual hetero-octameric Class-2 PEPC complexes that are desensitized to allosteric inhibition by L-malate. Analysis of RNA-Seq and microarray transcriptome datasets revealed two distinct patterns of tissue-specific BTPC expression in vascular plants. Species such as Arabidopsis thaliana, strawberry, rice, maize, and poplar mainly exhibited pollen- or floral-specific BTPC expression. By contrast, BTPC transcripts were relatively abundant in developing castor, cotton, and soybean seeds, cassava tubers, as well as immature tomato, cucumber, grape, and avocado fruit. Immunoreactive 118 kDa BTPC polypeptides were detected on immunoblots of cucumber and tomato fruit extracts. Co-immunoprecipitation established that as in castor, BTPCs physically interact with endogenous PTPCs to form Class-2 PEPC complexes in tomato and cucumber fruit. We hypothesize that Class-2 PEPCs simultaneously maintain rapid anaplerotic PEP carboxylation and respiratory CO2 refixation in diverse, biosynthetically active sinks that accumulate high malate levels.
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Affiliation(s)
- Michael K Y Ting
- Department of Biology, Queen’s University, Kingston, Ontario, Canada
| | - Yi-Min She
- Centre for Biologics Evaluation Biologics and Genetic Therapies Directorate, Health Canada, Ottawa, Ontario, Canada
| | - William C Plaxton
- Department of Biology, Queen’s University, Kingston, Ontario, Canada
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
- Correspondence:
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Walker RP, Paoletti A, Leegood RC, Famiani F. Phosphorylation of phosphoenolpyruvate carboxykinase (PEPCK) and phosphoenolpyruvate carboxylase (PEPC) in the flesh of fruits. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 108:323-327. [PMID: 27497301 DOI: 10.1016/j.plaphy.2016.07.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 07/03/2016] [Accepted: 07/19/2016] [Indexed: 05/22/2023]
Abstract
This study determined whether phosphoenolpyruvate carboxykinase (PEPCK) and phosphoenolpyruvate carboxylase (PEPC) are phosphorylated in the flesh of a range of fruits. This was done by incubating fruit flesh with 32P[P] (where 32P[P] = 32PO43-), then PEPCK and PEPC were immunoprecipitated from extracts using specific antisera. The incorporation of 32P[P] into these enzymes was then determined by autoradiography of SDS-PAGE gels. Both enzymes were subject to phosphorylation in vivo in the flesh of grape, tomato, cherry and plum. PEPCK was also subject to phosphorylation in vivo in developing grape seeds. Proteolytic cleavage of PEPCK showed that it was phosphorylated at a site(s) located on its N-terminal extension. Potentially phosphorylation of these enzymes could contribute to the coordinate regulation of their activities in the flesh of fruits and in developing seeds.
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Affiliation(s)
- Robert P Walker
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Italy.
| | - Andrea Paoletti
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Italy
| | - Richard C Leegood
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2 TN, UK
| | - Franco Famiani
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Italy.
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Guo LX, Shi CY, Liu X, Ning DY, Jing LF, Yang H, Liu YZ. Citrate Accumulation-Related Gene Expression and/or Enzyme Activity Analysis Combined With Metabolomics Provide a Novel Insight for an Orange Mutant. Sci Rep 2016; 6:29343. [PMID: 27385485 PMCID: PMC4935991 DOI: 10.1038/srep29343] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/17/2016] [Indexed: 01/12/2023] Open
Abstract
'Hong Anliu' (HAL, Citrus sinensis cv. Hong Anliu) is a bud mutant of 'Anliu' (AL), characterized by a comprehensive metabolite alteration, such as lower accumulation of citrate, high accumulation of lycopene and soluble sugars in fruit juice sacs. Due to carboxylic acid metabolism connects other metabolite biosynthesis and/or catabolism networks, we therefore focused analyzing citrate accumulation-related gene expression profiles and/or enzyme activities, along with metabolic fingerprinting between 'HAL' and 'AL'. Compared with 'AL', the transcript levels of citrate biosynthesis- and utilization-related genes and/or the activities of their respective enzymes such as citrate synthase, cytosol aconitase and ATP-citrate lyase were significantly higher in 'HAL'. Nevertheless, the mitochondrial aconitase activity, the gene transcript levels of proton pumps, including vacuolar H(+)-ATPase, vacuolar H(+)-PPase, and the juice sac-predominant p-type proton pump gene (CsPH8) were significantly lower in 'HAL'. These results implied that 'HAL' has higher abilities for citrate biosynthesis and utilization, but lower ability for the citrate uptake into vacuole compared with 'AL'. Combined with the metabolites-analyzing results, a model was then established and suggested that the reduction in proton pump activity is the key factor for the low citrate accumulation and the comprehensive metabolite alterations as well in 'HAL'.
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Affiliation(s)
- Ling-Xia Guo
- Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China
- College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Cai-Yun Shi
- Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China
- College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Xiao Liu
- Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China
- College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Dong-Yuan Ning
- Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China
- College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Long-Fei Jing
- Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China
- College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Huan Yang
- Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China
- College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Yong-Zhong Liu
- Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China
- College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China
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Muramatsu M, Suzuki R, Yamazaki T, Miyao M. Comparison of plant-type phosphoenolpyruvate carboxylases from rice: identification of two plant-specific regulatory regions of the allosteric enzyme. PLANT & CELL PHYSIOLOGY 2015; 56:468-480. [PMID: 25505033 DOI: 10.1093/pcp/pcu189] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Phosphoenolpyruvate carboxylase (PEPC) is a key enzyme of primary metabolism in bacteria, algae and vascular plants, and it undergoes allosteric regulation by various metabolic effectors. Rice (Oryza sativa) has five plant-type PEPCs, four cytosolic and one chloroplastic. We investigated their kinetic properties using recombinant proteins and found that, like most plant-type PEPCs, rice cytosolic isozymes were activated by glucose 6-phosphate and by alkaline pH. In contrast, no such activation was observed for the chloroplastic isozyme, Osppc4. In addition, Osppc4 showed low affinity for the substrate phosphoenolpyruvate (PEP) and very low sensitivities to allosteric inhibitors aspartate and glutamate. By comparing the isozyme amino acid sequences and three-dimensional structures simulated on the basis of the reported crystal structures, we identified two regions where Osppc4 has unique features that can be expected to affect its kinetic properties. One is the N-terminal extension; replacement of the extension of Osppc2a (cytosolic) with that from Osppc4 reduced the aspartate and glutamate sensitivities to about one-tenth of the wild-type values but left the PEP affinity unaffected. The other is the N-terminal loop, in which a conserved lysine at the N-terminal end is replaced with a glutamate-alanine pair in Osppc4. Replacement of the lysine of Osppc2a with glutamate-alanine lowered the PEP affinity to a quarter of the wild-type level (down to the Osppc4 level), without affecting inhibitor sensitivity. Both the N-terminal extension and the N-terminal loop are specific to plant-type PEPCs, suggesting that plant-type isozymes acquired these regions so that their activity could be regulated properly at the sites where they function.
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Affiliation(s)
- Masayuki Muramatsu
- Functional Plant Research Unit, National Institute of Agrobiological Sciences, Kannondai, Tsukuba, 305-8602 Japan
| | - Rintaro Suzuki
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, Kannondai, Tsukuba, 305-8602 Japan
| | - Toshimasa Yamazaki
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, Kannondai, Tsukuba, 305-8602 Japan
| | - Mitsue Miyao
- Functional Plant Research Unit, National Institute of Agrobiological Sciences, Kannondai, Tsukuba, 305-8602 Japan
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Chang KS, Jeon H, Gu MB, Pack SP, Jin E. Conversion of carbon dioxide to oxaloacetate using integrated carbonic anhydrase and phosphoenolpyruvate carboxylase. Bioprocess Biosyst Eng 2013; 36:1923-8. [DOI: 10.1007/s00449-013-0968-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/03/2013] [Indexed: 11/29/2022]
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The remarkable diversity of plant PEPC (phosphoenolpyruvate carboxylase): recent insights into the physiological functions and post-translational controls of non-photosynthetic PEPCs. Biochem J 2011; 436:15-34. [DOI: 10.1042/bj20110078] [Citation(s) in RCA: 224] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PEPC [PEP (phosphoenolpyruvate) carboxylase] is a tightly controlled enzyme located at the core of plant C-metabolism that catalyses the irreversible β-carboxylation of PEP to form oxaloacetate and Pi. The critical role of PEPC in assimilating atmospheric CO2 during C4 and Crassulacean acid metabolism photosynthesis has been studied extensively. PEPC also fulfils a broad spectrum of non-photosynthetic functions, particularly the anaplerotic replenishment of tricarboxylic acid cycle intermediates consumed during biosynthesis and nitrogen assimilation. An impressive array of strategies has evolved to co-ordinate in vivo PEPC activity with cellular demands for C4–C6 carboxylic acids. To achieve its diverse roles and complex regulation, PEPC belongs to a small multigene family encoding several closely related PTPCs (plant-type PEPCs), along with a distantly related BTPC (bacterial-type PEPC). PTPC genes encode ~110-kDa polypeptides containing conserved serine-phosphorylation and lysine-mono-ubiquitination sites, and typically exist as homotetrameric Class-1 PEPCs. In contrast, BTPC genes encode larger ~117-kDa polypeptides owing to a unique intrinsically disordered domain that mediates BTPC's tight interaction with co-expressed PTPC subunits. This association results in the formation of unusual ~900-kDa Class-2 PEPC hetero-octameric complexes that are desensitized to allosteric effectors. BTPC is a catalytic and regulatory subunit of Class-2 PEPC that is subject to multi-site regulatory phosphorylation in vivo. The interaction between divergent PEPC polypeptides within Class-2 PEPCs adds another layer of complexity to the evolution, physiological functions and metabolic control of this essential CO2-fixing plant enzyme. The present review summarizes exciting developments concerning the functions, post-translational controls and subcellular location of plant PTPC and BTPC isoenzymes.
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