|
1
|
Née G, Wang F, Châtel-Innocenti G, Mhamdi A, Juranville E, Vanacker H, Noctor G, Issakidis-Bourguet E. Thioredoxins m regulate plastid glucose-6-phosphate dehydrogenase activity in Arabidopsis roots under salt stress. FRONTIERS IN PLANT SCIENCE 2023; 14:1179112. [PMID: 37332692 PMCID: PMC10274509 DOI: 10.3389/fpls.2023.1179112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/05/2023] [Indexed: 06/20/2023]
Abstract
Plants contain several NADPH-producing enzymes including glucose-6-phosphate dehydrogenases (G6PDH) with different sub-cellular localizations. The activity of plastidial G6PDHs is redox-regulated by thioredoxins (TRX). Although specific TRXs are known to regulate chloroplastic isoforms of G6PDH, little information is available for plastidic isoforms found in heterotrophic organs or tissues. Here, we investigated TRX regulation of the two G6PDH plastidic isoforms of Arabidopsis roots during exposure to a mild salt stress. We report that in vitro m-type TRXs are the most efficient regulators of the G6PDH2 and G6PDH3 mainly found in Arabidopsis roots. While expression of the corresponding G6PD and plastidic TRX genes was marginally affected by salt, it impaired root growth of several of the corresponding mutant lines. Using an in situ assay for G6PDH, G6PDH2 was found to be the major contributor to salt-induced increases in activity, while data from ROS assays further provide in vivo evidence that TRX m acts in redox regulation during salt stress. Taken together, our data suggest that regulation of plastid G6PDH activity by TRX m may be an important player regulating NADPH production in Arabidopsis roots undergoing salt stress.
Collapse
Affiliation(s)
- Guillaume Née
- *Correspondence: Guillaume Née, ; Emmanuelle Issakidis-Bourguet,
| | | | | | | | | | | | | | | |
Collapse
|
|
2
|
Li X, Cai Q, Yu T, Li S, Li S, Li Y, Sun Y, Ren H, Zhang J, Zhao Y, Zhang J, Zuo Y. ZmG6PDH1 in glucose-6-phosphate dehydrogenase family enhances cold stress tolerance in maize. FRONTIERS IN PLANT SCIENCE 2023; 14:1116237. [PMID: 36968417 PMCID: PMC10034328 DOI: 10.3389/fpls.2023.1116237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Glucose-6-phosphate dehydrogenase (G6PDH) is a key enzyme in the pentose phosphate pathway responsible for the generation of nicotinamide adenine dinucleotide phosphate (NADPH), thereby playing a central role in facilitating cellular responses to stress and maintaining redox homeostasis. This study aimed to characterize five G6PDH gene family members in maize. The classification of these ZmG6PDHs into plastidic and cytosolic isoforms was enabled by phylogenetic and transit peptide predictive analyses and confirmed by subcellular localization imaging analyses using maize mesophyll protoplasts. These ZmG6PDH genes exhibited distinctive expression patterns across tissues and developmental stages. Exposure to stressors, including cold, osmotic stress, salinity, and alkaline conditions, also significantly affected the expression and activity of the ZmG6PDHs, with particularly high expression of a cytosolic isoform (ZmG6PDH1) in response to cold stress and closely correlated with G6PDH enzymatic activity, suggesting that it may play a central role in shaping responses to cold conditions. CRISPR/Cas9-mediated knockout of ZmG6PDH1 on the B73 background led to enhanced cold stress sensitivity. Significant changes in the redox status of the NADPH, ascorbic acid (ASA), and glutathione (GSH) pools were observed after exposure of the zmg6pdh1 mutants to cold stress, with this disrupted redox balance contributing to increased production of reactive oxygen species and resultant cellular damage and death. Overall, these results highlight the importance of cytosolic ZmG6PDH1 in supporting maize resistance to cold stress, at least in part by producing NADPH that can be used by the ASA-GSH cycle to mitigate cold-induced oxidative damage.
Collapse
Affiliation(s)
- Xin Li
- National Coarse Cereals Engineering Research Center, Heilongjiang Provincial Key Laboratory of Crop-Pest Interaction Biology and Ecological Control, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Quan Cai
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Tao Yu
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Shujun Li
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Sinan Li
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Yunlong Li
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Yan Sun
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Honglei Ren
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Jiajia Zhang
- College of Agriculture, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Ying Zhao
- College of Agriculture, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Jianguo Zhang
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Yuhu Zuo
- National Coarse Cereals Engineering Research Center, Heilongjiang Provincial Key Laboratory of Crop-Pest Interaction Biology and Ecological Control, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
| |
Collapse
|
|
3
|
Lei D, Lin Y, Luo M, Zhao B, Tang H, Zhou X, Yao W, Zhang Y, Wang Y, Li M, Chen Q, Luo Y, Wang X, Tang H, Zhang Y. Genome-Wide Investigation of G6PDH Gene in Strawberry: Evolution and Expression Analysis during Development and Stress. Int J Mol Sci 2022; 23:4728. [PMID: 35563120 PMCID: PMC9104510 DOI: 10.3390/ijms23094728] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/16/2022] [Accepted: 04/20/2022] [Indexed: 02/01/2023] Open
Abstract
As one of the key enzymes in the pentose phosphate pathway (PPP), glucose-6-phosphate dehydrogenase (G6PDH) provides NADPH and plays an important role in plant development and stress responses. However, little information was available about the G6PDH genes in strawberry (Fragaria × ananassa). The recent release of the whole-genome sequence of strawberry allowed us to perform a genome-wide investigation into the organization and expression profiling of strawberry G6PDH genes. In the present study, 19 strawberry G6PDH genes (FaG6PDHs) were identified from the strawberry genome database. They were designated as FaG6PDH1 to FaG6PDH19, respectively, according to the conserved domain of each subfamily and multiple sequence alignment with Arabidopsis. According to their structural and phylogenetic features, the 19 FaG6PDHs were further classified into five types: Cy, P1, P1.1, P2 and PO. The number and location of exons and introns are similar, suggesting that genes of the same type are very similar and are alleles. A cis-element analysis inferred that FaG6PDHs possessed at least one stress-responsive cis-acting element. Expression profiles derived from transcriptome data analysis exhibited distinct expression patterns of FaG6PDHs genes in different developmental stages. Real-time quantitative PCR was used to detect the expression level of five types FaG6PDHs genes and demonstrated that the genes were expressed and responded to multiple abiotic stress and hormonal treatments.
Collapse
Affiliation(s)
- Diya Lei
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| | - Yuanxiu Lin
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
- Institute of Pomology & Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Mengwen Luo
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| | - Bing Zhao
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| | - Honglan Tang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| | - Xuan Zhou
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| | - Wantian Yao
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| | - Yunting Zhang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
- Institute of Pomology & Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Yan Wang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
- Institute of Pomology & Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Mengyao Li
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| | - Qing Chen
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| | - Ya Luo
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| | - Xiaorong Wang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
- Institute of Pomology & Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Haoru Tang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
- Institute of Pomology & Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Yong Zhang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China; (D.L.); (Y.L.); (M.L.); (B.Z.); (H.T.); (X.Z.); (W.Y.); (Y.Z.); (Y.W.); (M.L.); (Q.C.); (Y.L.); (X.W.); (H.T.)
| |
Collapse
|
|
4
|
Tian Y, Peng K, Bao Y, Zhang D, Meng J, Wang D, Wang X, Cang J. Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase genes of winter wheat enhance the cold tolerance of transgenic Arabidopsis. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 161:86-97. [PMID: 33581622 DOI: 10.1016/j.plaphy.2021.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
In this study, winter wheat G6PDH (TaG6PDH) and 6PGDH (Ta6PGDH) were investigated. Both their expression and their activity were upregulated under cold stress, suggesting that TaG6PDH and Ta6PGDH positively respond to cold stress in winter wheat. Exogenous abscisic acid (ABA) treatment markedly increased the expression and activity levels of TaG6PDH and Ta6PGDH in winter wheat under cold stress. Subsequently, TaG6PDH-and Ta6PGDH were overexpressed in Arabidopsis, and showed stronger reactive oxygen species (ROS)-scavenging ability and higher survival rate compared with wild-type (WT) plants under cold stress. In addition, we found that TaG6PDH and Ta6PGDH overexpression can promote the oxidative pentose phosphate pathway (OPPP) in the cytoplasm and peroxisomes of Arabidopsis. In summary, Arabidopsis overexpressing TaG6PDH and Ta6PGDH showed improved cold tolerance.
Collapse
Affiliation(s)
- Yu Tian
- College of Life Science, Northeast Agricultural University, Harbin, 150030, PR China
| | - Kankan Peng
- College of Life Science, Northeast Agricultural University, Harbin, 150030, PR China
| | - Yuzhuo Bao
- College of Life Science, Northeast Agricultural University, Harbin, 150030, PR China
| | - Da Zhang
- College of Life Science, Northeast Agricultural University, Harbin, 150030, PR China
| | - Jing Meng
- College of Life Science, Northeast Agricultural University, Harbin, 150030, PR China
| | - Duojia Wang
- College of Life Science, Northeast Agricultural University, Harbin, 150030, PR China
| | - Xiaonan Wang
- College of Agriculture, Northeast Agricultural University, Harbin, 150030, PR China
| | - Jing Cang
- College of Life Science, Northeast Agricultural University, Harbin, 150030, PR China.
| |
Collapse
|
|
5
|
Identification, Characterization, and Stress Responsiveness of Glucose-6-phosphate Dehydrogenase Genes in Highland Barley. PLANTS 2020; 9:plants9121800. [PMID: 33353078 PMCID: PMC7766724 DOI: 10.3390/plants9121800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/08/2020] [Accepted: 12/13/2020] [Indexed: 01/22/2023]
Abstract
G6PDH provides intermediate metabolites and reducing power (nicotinamide adenine dinucleotide phosphate, NADPH) for plant metabolism, and plays a pivotal role in the cellular redox homeostasis. In this study, we cloned five G6PDH genes (HvG6PDH1 to HvG6PDH5) from highland barley and characterized their encoded proteins. Functional analysis of HvG6PDHs in E. coli showed that HvG6PDH1 to HvG6PDH5 encode the functional G6PDH proteins. Subcellular localization and phylogenetic analysis indicated that HvG6PDH2 and HvG6PDH5 are localized in the cytoplasm, while HvG6PDH1, HvG6PDH3, and HvG6PDH4 are plastidic isoforms. Analysis of enzymatic activities and gene expression showed that HvG6PDH1 to HvG6PDH4 are involved in responses to salt and drought stresses. The cytosolic HvG6PDH2 is the major isoform against oxidative stress. HvG6PDH5 may be a house-keeping gene. In addition, HvG6PDH1 to HvG6PDH4 and their encoded enzymes responded to jasmonic acid (JA) and abscisic acid (ABA) treatments, implying that JA and ABA are probably critical regulators of HvG6PDHs (except for HvG6PDH5). Reactive oxygen species analysis showed that inhibition of cytosolic and plastidic G6PDH activities leads to increased H2O2 and O2− contents in highland barley under salt and drought stresses. These results suggest that G6PDH can maintain cellular redox homeostasis and that cytosolic HvG6PDH2 is an irreplaceable isoform against oxidative stress in highland barley.
Collapse
|
|
6
|
Zhao Y, Cui Y, Huang S, Yu J, Wang X, Xin D, Li X, Liu Y, Dai Y, Qi Z, Chen Q. Genome-Wide Analysis of the Glucose-6-Phosphate Dehydrogenase Family in Soybean and Functional Identification of GmG6PDH2 Involvement in Salt Stress. FRONTIERS IN PLANT SCIENCE 2020; 11:214. [PMID: 32174950 PMCID: PMC7054389 DOI: 10.3389/fpls.2020.00214] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/12/2020] [Indexed: 05/31/2023]
Abstract
Glucose-6-phosphate dehydrogenase (G6PDH) is known as a critical enzyme responsible for nicotinamide adenine dinucleotide phosphate (NADPH) generation in the pentose phosphate pathway (PPP), and has an essential function in modulating redox homeostasis and stress responsiveness. In the present work, we characterized the nine members of the G6PDH gene family in soybean. Phylogenic analysis and transit peptide prediction showed that these soybean G6PDHs are divided into plastidic (P) and cytosolic (Cy) isoforms. The subcellular locations of five GmG6PDHs were further verified by confocal microscopy in Arabidopsis mesophyll protoplasts. The respective GmG6PDH genes had distinct expression patterns in various soybean tissues and at different times during seed development. Among them, the Cy-G6PDHs were strongly expressed in roots, developing seeds and nodules, while the transcripts of P-G6PDHs were mainly detected in green tissues. In addition, the activities and transcripts of GmG6PDHs were dramatically stimulated by different stress treatments, including salt, osmotic and alkali. Notably, the expression levels of a cytosolic isoform (GmG6PDH2) were extraordinarily high under salt stress and correlated well with the G6PDH enzyme activities, possibly implying a crucial factor for soybean responses to salinity. Enzymatic assay of recombinant GmG6PDH2 proteins expressed in Escherichia coli showed that the enzyme encoded by GmG6PDH2 had functional NADP+-dependent G6PDH activity. Further analysis indicated overexpression of GmG6PDH2 gene could significantly enhance the resistance of transgenic soybean to salt stress by coordinating with the redox states of ascorbic acid and glutathione pool to suppress reactive oxygen species generation. Together, these results indicate that GmG6PDH2 might be the major isoform for NADPH production in PPP, which is involved in the modulation of cellular AsA-GSH cycle to prevent the oxidative damage induced by high salinity.
Collapse
Affiliation(s)
- Ying Zhao
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Yifan Cui
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Shiyu Huang
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Jingyao Yu
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Xinyu Wang
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Dawei Xin
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Xin Li
- Key Lab of Maize Genetics and Breeding, Heilongjiang Academy of Agricultural Sciences, Harbin, China
| | - Yonghui Liu
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Yuxin Dai
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Zhaoming Qi
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Qingshan Chen
- College of Agriculture, Northeast Agricultural University, Harbin, China
| |
Collapse
|
|
7
|
TranNgoc K, Pham N, Lee C, Jang SH. Cloning, Expression, and Characterization of a Psychrophilic Glucose 6-Phosphate Dehydrogenase from Sphingomonas sp. PAMC 26621. Int J Mol Sci 2019; 20:E1362. [PMID: 30889888 PMCID: PMC6471386 DOI: 10.3390/ijms20061362] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/12/2019] [Accepted: 03/14/2019] [Indexed: 11/16/2022] Open
Abstract
Glucose 6-phosphate dehydrogenase (G6PD) (EC 1.1.1.363) is a crucial regulatory enzyme in the oxidative pentose phosphate pathway that provides reductive potential in the form of NADPH, as well as carbon skeletons for the synthesis of macromolecules. In this study, we report the cloning, expression, and characterization of G6PD (SpG6PD1) from a lichen-associated psychrophilic bacterium Sphingomonas sp. PAMC 26621. SpG6PD1 was expressed in Escherichia coli as a soluble protein, having optimum activity at pH 7.5⁻8.5 and 30 °C for NADP⁺ and 20 °C for NAD⁺. SpG6PD1 utilized both NADP⁺ and NAD⁺, with the preferential utilization of NADP⁺. A high Km value for glucose 6-phosphate and low activation enthalpy (ΔH‡) compared with the values of mesophilic counterparts indicate the psychrophilic nature of SpG6PD1. Despite the secondary structure of SpG6PD1 being maintained between 4⁻40 °C, its activity and tertiary structure were better preserved between 4⁻20 °C. The results of this study indicate that the SpG6PD1 that has a flexible structure is most suited to a psychrophilic bacterium that is adapted to a permanently cold habitat.
Collapse
Affiliation(s)
- Kiet TranNgoc
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan 38453, Korea.
| | - Nhung Pham
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan 38453, Korea.
| | - ChangWoo Lee
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan 38453, Korea.
| | - Sei-Heon Jang
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan 38453, Korea.
| |
Collapse
|
|
8
|
Naliwajski MR, Skłodowska M. The relationship between carbon and nitrogen metabolism in cucumber leaves acclimated to salt stress. PeerJ 2018; 6:e6043. [PMID: 30581664 PMCID: PMC6292378 DOI: 10.7717/peerj.6043] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 10/30/2018] [Indexed: 11/20/2022] Open
Abstract
The study examines the effect of acclimation on carbon and nitrogen metabolism in cucumber leaves subjected to moderate and severe NaCl stress. The levels of glucose, sucrose, NADH/NAD+-GDH, AspAT, AlaAT, NADP+-ICDH, G6PDH and 6GPDH activity were determined after 24 and 72 hour periods of salt stress in acclimated and non-acclimated plants. Although both groups of plants showed high Glc and Suc accumulation, they differed with regard to the range and time of accumulation. Acclimation to salinity decreased the activities of NADP+-ICDH and deaminating NAD+-GDH compared to controls; however, these enzymes, together with the other examined parameters, showed elevated values in the stressed plants. The acclimated plants showed higher G6PDH activity than the non-acclimated plants, whereas both groups demonstrated similar 6PGDH activity. The high activities of NADH-GDH, AlaAT and AspAT observed in the examined plants could be attributed to a high demand for glutamate. The observed changes may be required for the maintenance of correct TCA cycle activity, and acclimation appeared to positively influence these adaptive processes.
Collapse
Affiliation(s)
- Marcin Robert Naliwajski
- Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Maria Skłodowska
- Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| |
Collapse
|
|
9
|
De Lillo A, Cardi M, Landi S, Esposito S. Mechanism(s) of action of heavy metals to investigate the regulation of plastidic glucose-6-phosphate dehydrogenase. Sci Rep 2018; 8:13481. [PMID: 30194387 PMCID: PMC6128849 DOI: 10.1038/s41598-018-31348-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 08/07/2018] [Indexed: 12/26/2022] Open
Abstract
The regulation of recombinant plastidic glucose-6P dehydrogenase from Populus trichocarpa (PtP2-G6PDH - EC 1.1.1.49) was investigated by exposing wild type and mutagenized isoforms to heavy metals. Nickel and Cadmium caused a marked decrease in PtP2-G6PDH WT activity, suggesting their poisoning effect on plant enzymes; Lead (Pb++) was substantially ineffective. Copper (Cu++) and Zinc (Zn++) exposition resulted in strongest decrease in enzyme activity, thus suggesting a physiological competition with Magnesium, a well-known activator of G6PDH activity. Kinetic analyses confirmed a competitive inhibition by Copper, and a mixed inhibition by (Cd++). Mutagenized enzymes were differently affected by HMs: the reduction of disulfide (C175–C183) exposed the NADP+ binding sites to metals; C145 participates to NADP+ cofactor binding; C194 and C242 are proposed to play a role in the regulation of NADP+/NADPH binding. Copper (and possibly Zinc) is able to occupy competitively Magnesium (Mg++) sites and/or bind to NADP+, resulting in a reduced access of NADP+ sites on the enzyme. Hence, heavy metals could be used to describe specific roles of cysteine residues present in the primary protein sequence; these results are discussed to define the biochemical mechanism(s) of inhibition of plant plastidic G6PDH.
Collapse
Affiliation(s)
- Alessia De Lillo
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
| | - Manuela Cardi
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
| | - Simone Landi
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
| | - Sergio Esposito
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy.
| |
Collapse
|
|
10
|
Esposito S, Loppi S, Monaci F, Paoli L, Vannini A, Sorbo S, Maresca V, Fusaro L, Asadi Karam E, Lentini M, De Lillo A, Conte B, Cianciullo P, Basile A. In-field and in-vitro study of the moss Leptodictyum riparium as bioindicator of toxic metal pollution in the aquatic environment: Ultrastructural damage, oxidative stress and HSP70 induction. PLoS One 2018; 13:e0195717. [PMID: 29649272 PMCID: PMC5896978 DOI: 10.1371/journal.pone.0195717] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 03/28/2018] [Indexed: 01/30/2023] Open
Abstract
This study evaluates the effects of toxic metal pollution in the highly contaminated Sarno River (South Italy), by using the aquatic moss Leptodictyum riparium in bags at 3 representative sites of the river. Biological effects were assessed by metal bioaccumulation, ultrastructural changes, oxidative stress, as Reactive Oxygen Species (ROS) production and Glutathione S-transferase (GST) activity, as well as Heat Shock Proteins 70 (HSP70s) induction. The results showed that L. riparium is a valuable bioindicator for toxic metal pollution of water ecosystem, accumulating different amounts of toxic metals from the aquatic environment. Toxic metal pollution caused severe ultrastructural damage, as well as increased ROS production and induction of GST and HSP70s, in the samples exposed at the polluted sites. To assess the role and the effect of toxic metals on L. riparium, were also cultured in vitro with Cd, Cr, Cu, Fe, Ni, Pb, Zn at the same concentrations as measured at the 3 sites. Ultrastructure, ROS, GST, and HSP70s resulted severely affected by toxic metals. Based on our findings, we confirm L. riparium as a model organism in freshwater biomonitoring surveys, and GST and HSP70s as promising biomarkers of metal toxicity.
Collapse
Affiliation(s)
- Sergio Esposito
- Dipartimento di Biologia, University of Naples Federico II, Complesso Univ. Monte Sant'Angelo, Napoli, Italy
| | - Stefano Loppi
- Dipartimento di Scienze della Vita, University of Siena, Siena, Italy
| | - Fabrizio Monaci
- Dipartimento di Scienze della Vita, University of Siena, Siena, Italy
| | - Luca Paoli
- Dipartimento di Scienze della Vita, University of Siena, Siena, Italy
| | - Andrea Vannini
- Dipartimento di Scienze della Vita, University of Siena, Siena, Italy
| | - Sergio Sorbo
- Ce.S.M.A, Section of Microscopy, University of Naples Federico II, Complesso Univ. Monte Sant'Angelo, Napoli, Italy
| | - Viviana Maresca
- Dipartimento di Biologia, University of Naples Federico II, Complesso Univ. Monte Sant'Angelo, Napoli, Italy
| | - Lina Fusaro
- Dipartimento di Biologia Ambientale, Università Sapienza, Roma, Italy
| | - Elham Asadi Karam
- Biology Department, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Marco Lentini
- Dipartimento di Biologia, University of Naples Federico II, Complesso Univ. Monte Sant'Angelo, Napoli, Italy
| | - Alessia De Lillo
- Dipartimento di Biologia, University of Naples Federico II, Complesso Univ. Monte Sant'Angelo, Napoli, Italy
| | - Barbara Conte
- Dipartimento di Biologia, University of Naples Federico II, Complesso Univ. Monte Sant'Angelo, Napoli, Italy
| | | | - Adriana Basile
- Dipartimento di Biologia, University of Naples Federico II, Complesso Univ. Monte Sant'Angelo, Napoli, Italy
| |
Collapse
|
|
11
|
Basile A, Sorbo S, Lentini M, Conte B, Esposito S. Water pollution causes ultrastructural and functional damages in Pellia neesiana (Gottsche) Limpr. J Trace Elem Med Biol 2017; 43:80-86. [PMID: 27908578 DOI: 10.1016/j.jtemb.2016.11.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/04/2016] [Accepted: 11/23/2016] [Indexed: 11/30/2022]
Abstract
The aim of this work is to evaluate the effects of freshwater pollution in the heavily contaminated Sarno River (Campania, South Italy), using Pellia neesiana (Pelliaceae Metzgeriales) in order to propose this liverwort as a potential bioindicator, able to record the effects of water pollution, particularly the one related to metal (loid) contamination. Samples of P. neesiana in nylon bags were disposed floating for one week on the waters of Sarno River in three sites characterised by an increasing pollution. As control, some specimens were cultured in vitro in Cd- and Pb-added media, at the same pollutants' levels as measured in the most polluted site. P. neesiana cell ultrastructure was modified and severe alterations were observed in chloroplasts from samples exposed in the most polluted site, and Cd- and Pb-cultured samples. Concurrently, a strong increase in the occurrence of Heat shock proteins 70 (HSP70) was detected in gametophytes following the pollution gradient. In conclusion, ultrastructural damages can be directly related to HSP 70 occurrence in liverwort tissues, and proportional to the degree of pollution present in the river; thus our study suggests P. neesiana as an affordable bioindicator of freshwaters pollution.
Collapse
Affiliation(s)
- Adriana Basile
- Dipartimento di Biologia, Università di Napoli "Federico II" - Complesso Universitario Monte Sant'Angelo, Via Cinthia 4, I-80126 Napoli, Italy
| | - Sergio Sorbo
- Ce.S.M.A, Università di Napoli "Federico II" - Complesso Universitario Monte Sant'Angelo, Via Cinthia 4, I-80126 Napoli, Italy
| | - Marco Lentini
- Dipartimento di Biologia, Università di Napoli "Federico II" - Complesso Universitario Monte Sant'Angelo, Via Cinthia 4, I-80126 Napoli, Italy
| | - Barbara Conte
- Dipartimento di Biologia, Università di Napoli "Federico II" - Complesso Universitario Monte Sant'Angelo, Via Cinthia 4, I-80126 Napoli, Italy; Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, Viale del Turismo 8, 74100 Taranto, Italy
| | - Sergio Esposito
- Dipartimento di Biologia, Università di Napoli "Federico II" - Complesso Universitario Monte Sant'Angelo, Via Cinthia 4, I-80126 Napoli, Italy.
| |
Collapse
|
|
12
|
Cardi M, Zaffagnini M, De Lillo A, Castiglia D, Chibani K, Gualberto JM, Rouhier N, Jacquot JP, Esposito S. Plastidic P2 glucose-6P dehydrogenase from poplar is modulated by thioredoxin m-type: Distinct roles of cysteine residues in redox regulation and NADPH inhibition. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 252:257-266. [PMID: 27717462 DOI: 10.1016/j.plantsci.2016.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/01/2016] [Accepted: 08/07/2016] [Indexed: 05/03/2023]
Abstract
A cDNA coding for a plastidic P2-type G6PDH isoform from poplar (Populus tremula x tremuloides) has been used to express and purify to homogeneity the mature recombinant protein with a N-terminus His-tag. The study of the kinetic properties of the recombinant enzyme showed an in vitro redox sensing modulation exerted by reduced DTT. The interaction with thioredoxins (TRXs) was then investigated. Five cysteine to serine variants (C145S - C175S - C183S - C195S - C242S) and a variant with a double substitution for Cys175 and Cys183 (C175S/C183S) have been generated, purified and biochemically characterized in order to investigate the specific role(s) of cysteines in terms of redox regulation and NADPH-dependent inhibition. Three cysteine residues (C145, C194, C242) are suggested to have a role in controlling the NADP+ access to the active site, and in stabilizing the NADPH regulatory binding site. Our results also indicate that the regulatory disulfide involves residues Cys175 and Cys183 in a position similar to those of chloroplastic P1-G6PDHs, but the modulation is exerted primarily by TRX m-type, in contrast to P1-G6PDH, which is regulated by TRX f. This unexpected specificity indicates differences in the mechanism of regulation, and redox sensing of plastidic P2-G6PDH compared to chloroplastic P1-G6PDH in higher plants.
Collapse
Affiliation(s)
- Manuela Cardi
- Dipartimento di Biologia, Univ. di Napoli "Federico II", I-80126 Napoli, Italy
| | - Mirko Zaffagnini
- Dipartimento di Farmacia e Biotecnologie, Univ. di Bologna, I-40126 Bologna, Italy
| | - Alessia De Lillo
- Dipartimento di Biologia, Univ. di Napoli "Federico II", I-80126 Napoli, Italy
| | - Daniela Castiglia
- Dipartimento di Biologia, Univ. di Napoli "Federico II", I-80126 Napoli, Italy
| | - Kamel Chibani
- Université de Lorraine, UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, 54506, Vandoeuvre-lès-Nancy, France; INRA, UMR 1136 Interactions Arbres/Microorganismes, Centre INRA Nancy Lorraine, 54280, Champenoux, France
| | - José Manuel Gualberto
- Université de Strasbourg, Institut de Biologie Moléculaire Des Plantes (IBMP), CNRS-UPR 2357, 67084 Strasbourg, France
| | - Nicolas Rouhier
- Université de Lorraine, UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, 54506, Vandoeuvre-lès-Nancy, France; INRA, UMR 1136 Interactions Arbres/Microorganismes, Centre INRA Nancy Lorraine, 54280, Champenoux, France
| | - Jean-Pierre Jacquot
- Université de Lorraine, UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, 54506, Vandoeuvre-lès-Nancy, France; INRA, UMR 1136 Interactions Arbres/Microorganismes, Centre INRA Nancy Lorraine, 54280, Champenoux, France
| | - Sergio Esposito
- Dipartimento di Biologia, Univ. di Napoli "Federico II", I-80126 Napoli, Italy.
| |
Collapse
|
|
13
|
Landi S, Nurcato R, De Lillo A, Lentini M, Grillo S, Esposito S. Glucose-6-phosphate dehydrogenase plays a central role in the response of tomato (Solanum lycopersicum) plants to short and long-term drought. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 105:79-89. [PMID: 27085599 DOI: 10.1016/j.plaphy.2016.04.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 04/05/2016] [Accepted: 04/07/2016] [Indexed: 05/03/2023]
Abstract
The present study was undertaken to investigate the expression, occurrence and activity of glucose 6 phosphate dehydrogenase (G6PDH - EC 1.1.1.49), the key-enzyme of the Oxidative Pentose Phosphate Pathway (OPPP), in tomato plants (Solanum lycopersicum cv. Red Setter) exposed to short- and long-term drought stress. For the first time, drought effects have been evaluated in plants under different growth conditions: in hydroponic laboratory system, and in greenhouse pots under controlled conditions; and in open field, in order to evaluate drought response in a representative agricultural environment. Interestingly, changes observed appear strictly associated to the induction of well known stress response mechanisms, such as the increase of proline synthesis, accumulation of chaperone Hsp70, and ascorbate peroxidase. Results show significant increase in total activity of G6PDH, and specifically in expression and occurrence of cytosolic isoform (cy-G6PDH) in plants grown in any cultivation system upon drought. Intriguingly, the results clearly suggest that abscissic acid (ABA) pathway and signaling cascade (protein phosphatase 2C PP2C) could be strictly related to increased G6PDH expression, occurrence and activities. We hypothesized for G6PDH a specific role as one of the main reductants' suppliers to counteract the effects of drought stress, in the light of converging evidences given by young and adult tomato plants under stress of different duration and intensity.
Collapse
Affiliation(s)
- Simone Landi
- Università di Napoli ''Federico II", Dipartimento di Biologia, Via Cinthia, I-80126, Napoli, Italy; National Research Council of Italy, Institute of Biosciences and Bioresources, Research Division Portici, Portici, 80055, Naples, Italy
| | - Roberta Nurcato
- National Research Council of Italy, Institute of Biosciences and Bioresources, Research Division Portici, Portici, 80055, Naples, Italy
| | - Alessia De Lillo
- Università di Napoli ''Federico II", Dipartimento di Biologia, Via Cinthia, I-80126, Napoli, Italy
| | - Marco Lentini
- Università di Napoli ''Federico II", Dipartimento di Biologia, Via Cinthia, I-80126, Napoli, Italy
| | - Stefania Grillo
- National Research Council of Italy, Institute of Biosciences and Bioresources, Research Division Portici, Portici, 80055, Naples, Italy
| | - Sergio Esposito
- Università di Napoli ''Federico II", Dipartimento di Biologia, Via Cinthia, I-80126, Napoli, Italy.
| |
Collapse
|
|
14
|
Nitrogen Assimilation, Abiotic Stress and Glucose 6-Phosphate Dehydrogenase: The Full Circle of Reductants. PLANTS 2016; 5:plants5020024. [PMID: 27187489 PMCID: PMC4931404 DOI: 10.3390/plants5020024] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 04/28/2016] [Accepted: 05/03/2016] [Indexed: 02/06/2023]
Abstract
Glucose 6 phosphate dehydrogenase (G6PDH; EC 1.1.1.49) is well-known as the main regulatory enzyme of the oxidative pentose phosphate pathway (OPPP) in living organisms. Namely, in Planta, different G6PDH isoforms may occur, generally localized in cytosol and plastids/chloroplasts. These enzymes are differently regulated by distinct mechanisms, still far from being defined in detail. In the last decades, a pivotal function for plant G6PDHs during the assimilation of nitrogen, providing reductants for enzymes involved in nitrate reduction and ammonium assimilation, has been described. More recently, several studies have suggested a main role of G6PDH to counteract different stress conditions, among these salinity and drought, with the involvement of an ABA depending signal. In the last few years, this recognized vision has been greatly widened, due to studies clearly showing the non-conventional subcellular localization of the different G6PDHs, and the peculiar regulation of the different isoforms. The whole body of these considerations suggests a central question: how do the plant cells distribute the reductants coming from G6PDH and balance their equilibrium? This review explores the present knowledge about these mechanisms, in order to propose a scheme of distribution of reductants produced by G6PDH during nitrogen assimilation and stress.
Collapse
|
|
15
|
Ortiz C, Moraca F, Medeiros A, Botta M, Hamilton N, Comini MA. Binding Mode and Selectivity of Steroids towards Glucose-6-phosphate Dehydrogenase from the Pathogen Trypanosoma cruzi. Molecules 2016; 21:368. [PMID: 26999093 PMCID: PMC6273692 DOI: 10.3390/molecules21030368] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/08/2016] [Accepted: 03/11/2016] [Indexed: 11/17/2022] Open
Abstract
Glucose-6-phosphate dehydrogenase (G6PDH) plays a housekeeping role in cell metabolism by generating reducing power (NADPH) and fueling the production of nucleotide precursors (ribose-5-phosphate). Based on its indispensability for pathogenic parasites from the genus Trypanosoma, G6PDH is considered a drug target candidate. Several steroid-like scaffolds were previously reported to target the activity of G6PDH. Epiandrosterone (EA) is an uncompetitive inhibitor of trypanosomal G6PDH for which its binding site to the enzyme remains unknown. Molecular simulation studies with the structure of Trypanosoma cruzi G6PDH revealed that EA binds in a pocket close to the G6P binding-site and protrudes into the active site blocking the interaction between substrates and hence catalysis. Site directed mutagenesis revealed the important steroid-stabilizing effect of residues (L80, K83 and K84) located on helix α-1 of T. cruzi G6PDH. The higher affinity and potency of 16α-Br EA by T. cruzi G6PDH is explained by the formation of a halogen bond with the hydrogen from the terminal amide of the NADP+-nicotinamide. At variance with the human enzyme, the inclusion of a 21-hydroxypregnane-20-one moiety to a 3β-substituted steroid is detrimental for T. cruzi G6PDH inhibition. The species-specificity of certain steroid derivatives towards the parasite G6PDH and the corresponding biochemically validated binding models disclosed in this work may prove valuable for the development of selective inhibitors against the pathogen's enzyme.
Collapse
Affiliation(s)
- Cecilia Ortiz
- Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo 11400, Uruguay.
| | - Francesca Moraca
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via Aldo Moro 2, Siena 53100, Italy.
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, BioLife Science Building, Suite 333, 1900 N 12th Street, Philadelphia, PA 19122, USA.
| | - Andrea Medeiros
- Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo 11400, Uruguay.
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Av. Gral. Flores 2125, Montevideo 11800, Uruguay.
| | - Maurizio Botta
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via Aldo Moro 2, Siena 53100, Italy.
| | - Niall Hamilton
- Drug Discovery Unit, Cancer Research, UK Manchester Institute, Wilmslow Road, Manchester M204BX, UK.
| | - Marcelo A Comini
- Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo 11400, Uruguay.
| |
Collapse
|
|
16
|
Long X, He B, Fang Y, Tang C. Identification and Characterization of the Glucose-6-Phosphate Dehydrogenase Gene Family in the Para Rubber Tree, Hevea brasiliensis. FRONTIERS IN PLANT SCIENCE 2016; 7:215. [PMID: 26941770 PMCID: PMC4766392 DOI: 10.3389/fpls.2016.00215] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 02/08/2016] [Indexed: 05/30/2023]
Abstract
As a key enzyme in the pentose phosphate pathway (PPP), glucose-6-phosphate dehydrogenase (G6PDH) provides nicotinamide adenine dinucleotide phosphate (NADPH) and intermediary metabolites for rubber biosynthesis, and plays an important role in plant development and stress responses. In this study, four Hevea brasiliensis (Para rubber tree) G6PDH genes (HbG6PDH1 to 4) were identified and cloned using a genome-wide scanning approach. All four HbG6PDH genes encode functional G6PDH enzymes as shown by heterologous expression in E. coli. Phylogeny analysis and subcellular localization prediction show that HbG6PDH3 is a cytosolic isoform, while the other three genes (HbG6PDH1, 2 and 4) are plastidic isoforms. The subcellular locations of HbG6PDH3 and 4, two latex-abundant isoforms were further verified by transient expression in rice protoplasts. Enzyme activity assay and expression analysis showed HbG6PDH3 and 4 were implicated in PPP during latex regeneration, and to influence rubber production positively in rubber tree. The cytosolic HbG6PDH3 is a predominant isoform in latex, implying a principal role for this isoform in controlling carbon flow and NADPH production in the PPP during latex regeneration. The expression pattern of plastidic HbG6PDH4 correlates well with the degree of tapping panel dryness, a physiological disorder that stops the flow of latex from affected rubber trees. In addition, the four HbG6PDHs responded to temperature and drought stresses in root, bark, and leaves, implicating their roles in maintaining redox balance and defending against oxidative stress.
Collapse
|
|
17
|
Zhao C, Wang X, Wang X, Wu K, Li P, Chang N, Wang J, Wang F, Li J, Bi Y. Glucose-6-phosphate dehydrogenase and alternative oxidase are involved in the cross tolerance of highland barley to salt stress and UV-B radiation. JOURNAL OF PLANT PHYSIOLOGY 2015; 181:83-95. [PMID: 26009793 DOI: 10.1016/j.jplph.2015.03.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 05/18/2023]
Abstract
In this study, a new mechanism involving glucose-6-phosphate dehydrogenase (G6PDH) and alternative pathways (AP) in salt pretreatment-induced tolerance of highland barley to UV-B radiation was investigated. When highland barley was exposed to UV-B radiation, the G6PDH activity decreased but the AP capacity increased. In contrast, under UV-B+NaCl treatment, the G6PDH activity was restored to the control level and the maximal AP capacity and antioxidant enzyme activities were reached. Glucosamine (Glucm, an inhibitor of G6PDH) obviously inhibited the G6PDH activity in highland barley under UV-B + NaCl treatment and a similar pattern was observed in reduced glutathione (GSH) and ascorbic acid (Asc) contents. Similarly, salicylhydroxamic acid (SHAM, an inhibitor of AOX) significantly reduced the AP capacity in highland barley under UV-B + NaCl treatment. The UV-B-induced hydrogen peroxide (H2O2) accumulation was also followed. Further studies indicated that non-functioning of G6PDH or AP under UV-B+NaCl + Glucm or UV-B + NaCl + SHAM treatment also caused damages in photosynthesis and stomatal movement. Western blot analysis confirmed that the alternative oxidase (AOX) and G6PDH were dependent each other in cross tolerance to UV-B and salt. The inhibition of AP or G6PDH activity resulted in a significant accumulation or reduction of NADPH content, respectively, under UV-B+NaCl treatment in highland barley leaves. Taken together, our results indicate that AP and G6PDH mutually regulate and maintain photosynthesis and stomata movement in the cross adaptation of highland barley seedlings to UV-B and salt by modulating redox homeostasis and NADPH content.
Collapse
Affiliation(s)
- Chengzhou Zhao
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Xiaomin Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
| | - Xiaoyu Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Kunlun Wu
- Qinghai Academy of Agricultural and Forestry Sciences, People's Republic of China
| | - Ping Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Ning Chang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Jianfeng Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Feng Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Jiaolong Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Yurong Bi
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
| |
Collapse
|
|
18
|
Expression and characterization of a cytosolic glucose 6 phosphate dehydrogenase isoform from barley (Hordeum vulgare) roots. Protein Expr Purif 2015; 112:8-14. [PMID: 25888782 DOI: 10.1016/j.pep.2015.03.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/26/2015] [Accepted: 03/31/2015] [Indexed: 12/30/2022]
Abstract
In plant cells, glucose 6 phosphate dehydrogenase (G6PDH-EC 1.1.1.49) regulates the oxidative pentose phosphate pathway (OPPP), a metabolic route involved in the production of NADPH for various biosynthetic processes and stress response. In this study, we report the overexpression of a cytosolic G6PDH isoform from barley (Hordeum vulgare) roots in bacteria, and the biochemical characterization of the purified recombinant enzyme (HvCy-G6PDH). A full-length cDNA coding for a cytosolic isoform of G6PDH was isolated, and the sequence was cloned into pET3d vector; the protein was overexpressed in Escherichia coli BL21 (DE3) and purified by anion exchange and affinity chromatography. The kinetic properties were calculated: the recombinant HvCy-G6PDH showed KMs and KINADPH comparable to those observed for the enzyme purified from barley roots; moreover, the analysis of NADPH inhibition suggested a competitive mechanism. Therefore, this enzyme could be utilised for the structural and regulatory characterization of this isoform in higher plants.
Collapse
|
|
19
|
Cardi M, Castiglia D, Ferrara M, Guerriero G, Chiurazzi M, Esposito S. The effects of salt stress cause a diversion of basal metabolism in barley roots: possible different roles for glucose-6-phosphate dehydrogenase isoforms. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2015; 86:44-54. [PMID: 25461699 DOI: 10.1016/j.plaphy.2014.11.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 11/02/2014] [Indexed: 05/03/2023]
Abstract
In this study the effects of salt stress and nitrogen assimilation have been investigated in roots of hydroponically-grown barley plants exposed to 150 mM NaCl, in presence or absence of ammonium as the sole nitrogen source. Salt stress determines a diversion of root metabolism towards the synthesis of osmolytes, such as glycine betaine and proline, and increased levels of reduced glutathione. The metabolic changes triggered by salt stress result in a decrease in both activities and protein abundance of key enzymes, namely GOGAT and PEP carboxylase, and in a slight increase in HSP70. These variations would enhance the requirement for reductants supplied by the OPPP, consistently with the observed increase in total G6PDH activity. The involvement and occurrence of the different G6PDH isoforms have been investigated, and the kinetic properties of partially purified cytosolic and plastidial G6PDHs determined. Bioinformatic analyses examining co-expression profiles of G6PDHs in Arabidopsis and barley corroborate the data presented. Moreover, the gene coding for the root P2-G6PDH isoform was fully sequenced; the biochemical properties of the corresponding protein were examined experimentally. The results are discussed in the light of the possible distinct roles and regulation of the different G6PDH isoforms during salt stress in barley roots.
Collapse
Affiliation(s)
- Manuela Cardi
- Università di Napoli Federico II, Dipartimento di Biologia, Via Cinthia, 6, I-80126 Napoli, Italy
| | - Daniela Castiglia
- Università di Napoli Federico II, Dipartimento di Biologia, Via Cinthia, 6, I-80126 Napoli, Italy
| | - Myriam Ferrara
- Università di Napoli Federico II, Dipartimento di Biologia, Via Cinthia, 6, I-80126 Napoli, Italy
| | - Gea Guerriero
- Università di Napoli Federico II, Dipartimento di Biologia, Via Cinthia, 6, I-80126 Napoli, Italy
| | - Maurizio Chiurazzi
- Institute of Biosciences and BioResources - CNR, Via P. Castellino 111, I-80128 Napoli, Italy
| | - Sergio Esposito
- Università di Napoli Federico II, Dipartimento di Biologia, Via Cinthia, 6, I-80126 Napoli, Italy.
| |
Collapse
|