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Zhang H, Zeng N, Feng Q, Xu S, Cheng J, Wang J, Zhan X. New mechanistic insights into PAHs transport across wheat root cell membrane: Evidence for ABC transporter mediation. Sci Total Environ 2023; 859:160251. [PMID: 36402320 DOI: 10.1016/j.scitotenv.2022.160251] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/13/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are a class of highly carcinogenic organic pollutants. Our previous results revealed that the active uptake of PAHs by plant roots is performed through H+/PAHs co-transport. However, the proteins and mechanisms of co-transport of PAHs remain unknown. We hypothesized that ABC transporters are involved in PAHs co-transport via the roots. We found a total of 47 ABC transporters with alkalinity and hydrophobicity which were up-regulated or newly expressed in the wheat roots after phenanthrene exposure. And the concentration of ABC transporters rose. There was a positive relationship between the concentration of phenanthrene and ABC transporter expression in the wheat roots. Additionally, the trend observed in the ABC transporters expression was also found in the gene expression. With energies below -6 kcal mol-1, a stable docking conformation formed between ABC transporters and PAHs. π-π stacking and van der Waals force bound PAHs to ABCB or ABCG. The binding strength of ABCB subfamily proteins with homodimers is stronger than that of ABCG subfamily proteins with single molecules. ABC transporters may transport PAHs by forming a dimer-shaped pocket, translocating it into cells, then opening it within the cells, to release the bound PAHs. These results contributed to our understanding of how ABC transporters aid plant root uptake of PAHs.
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Affiliation(s)
- Huihui Zhang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China
| | - Nengde Zeng
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China
| | - Qiurun Feng
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China
| | - Shuangyuan Xu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China
| | - Jian Cheng
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China
| | - Jiawei Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China
| | - Xinhua Zhan
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China.
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Ma Y, Wang D, Guo X, Zhu YG, Delgado-Baquerizo M, Chu H. Root stoichiometry explains wheat endophytes and their link with crop production after four decades of fertilization. Sci Total Environ 2022; 846:157407. [PMID: 35850352 DOI: 10.1016/j.scitotenv.2022.157407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 06/24/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Fertilization can impact root endophytic microbiomes and food production. However, the impacts of decades of continued fertilization on root microbiomes, and their link with ongoing crop production, remain poorly understood. Here, we used a four decade-long fertilization experiment, including contrasting types of organic and inorganic fertilization, to investigate the effects of long-term fertilization on multi-kingdom root endophytic microbiomes, including keystone species (modules within microbial networks), and their indirect associations with the production of wheat, which is one of the most important crops worldwide. We found that long-term inorganic (nitrogen, phosphorus, potassium (NPK)) and organic (NPK with straw (NPKS) and NPK with cow manure (NPKM)) fertilization had significant impacts on the community composition of endophytic arbuscular mycorrhizal fungi (AMF), bacteria, and non-mycorrhizal fungi. In addition, compared with NPK fertilization, NPKS and NPKM amendments significantly decreased the microbial network complexity, which was associated with changes in the root iron content. Finally, we identified an important subset of keystone root endophyte species within the microbial network (Module #2), which was positively correlated with wheat yield, and affected by changes in root carbon to phosphorus ratio. This study provides evidence that long-term fertilization can affect keystone root endophytic species in the root microbiome, with implications for food security in an over-fertilized world.
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Affiliation(s)
- Yuying Ma
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China
| | - Daozhong Wang
- Institute of Soil and Fertilizer Research, Anhui Academy of Agricultural Sciences, South Nongke Road 40, Hefei 230031, China
| | - Xisheng Guo
- Institute of Soil and Fertilizer Research, Anhui Academy of Agricultural Sciences, South Nongke Road 40, Hefei 230031, China
| | - Yong-Guan Zhu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Manuel Delgado-Baquerizo
- Laboratorio de Biodiversidad y Funcionamiento Ecosistemico, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Av. Reina Mercedes 10, E-41012 Sevilla, Spain; Unidad Asociada CSIC-UPO (BioFun), Universidad Pablo de Olavide, 41013 Sevilla, Spain.
| | - Haiyan Chu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Dong G, Lu HL, Pan XY, He X, Jiang J, Li JY, Xu RK. Application of measuring electrochemical characteristics on plant root surfaces in screening Al-tolerant wheat. Environ Pollut 2021; 281:116993. [PMID: 33799210 DOI: 10.1016/j.envpol.2021.116993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/13/2021] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
To explore the relationship between Al phytotoxicity and the electrochemical characteristics of wheat root surfaces, a new chemical mechanism for tolerance of wheat to Al toxicity was initially proposed by conducting acute root elongation experiment, adsorption/desorption experiment, streaming potential determination, and infrared spectroscopy (ATR-FTIR) analysis respectively to classify the grade of Al tolerance of 92 wheat cultivars and quantitatively characterize the electrochemical properties of their root surfaces. Then a pot experiment was conducted with the screened wheat cultivars with different Al resistance grown on acid soils to verify their tolerance to Al toxicity. Results show that zeta potentials of the roots of 67 wheat cultivars at pH4.46 were significantly negatively correlated with Al(Ⅲ) adsorbed on the roots and their relative root elongation (P < 0.05), indicating that wheat roots with less negative charges is more tolerant to Al toxicity. Based on the mechanism, 14 Al-tolerant, 23 medium Al-tolerant and 30 Al-sensitive wheat cultivars were classified. The pot experiment reveals that the relative dry weight of Al-tolerant wheat cultivars was generally greater than that of medium Al-tolerant and Al-sensitive wheat cultivars and Al-tolerant wheat cultivars accumulate less Al in their shoots, which further verifies the relationship among charge characteristics, tolerance of wheat to Al toxicity, and Al uptake by wheat. The negative charges derived from organic functional groups on root surfaces could influence the exchangeable and complexed Al(Ⅲ) adsorbed on wheat roots and thereby affect Al tolerance of wheat cultivars. This finding not only provides a new perspective to screen Al-tolerant wheat cultivars and explain the mechanism of tolerance of wheat to Al toxicity, but is also useful for the prediction of differences in the uptake of Al in the shoots between Al-tolerant and Al-sensitive wheat cultivars, and finally contributes to the prevention of food security risk caused by Al in acid soils.
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Affiliation(s)
- Ge Dong
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hai-Long Lu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Xiao-Ying Pan
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Xian He
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jun Jiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Jiu-Yu Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Ren-Kou Xu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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Jian M, Zhang D, Wang X, Wei S, Zhao Y, Ding Q, Han Y, Ma L. Differential expression pattern of the proteome in response to cadmium stress based on proteomics analysis of wheat roots. BMC Genomics 2020; 21:343. [PMID: 32380942 PMCID: PMC7203821 DOI: 10.1186/s12864-020-6716-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 04/05/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Heavy metal cadmium (Cd) is a common environmental pollutant in soils, which has an negative impacts on crop growth and development. At present, cadmium has become a major soil and water heavy metal pollutant, which not only causes permanent and irreversible health problems for humans, but also causes a significant reduction in crop yields. RESULTS This study examined the chemical forms of Cd in the roots of two wheat varieties (M1019 and Xinong20) by continuous extraction and analyzed differences in distribution characteristics of Cd in the root cell wall, cytoplasm, and organelles by elemental content determination and subcellular separation. Furthermore, we conducted proteomics analysis of the roots of the two varieties under Cd pollution using mass spectrometry quantitative proteomics techniques. A total of 11,651 proteins were identified, of which 10,532 proteins contained quantitative information. In addition, the differentially expressed proteins in the two varieties were related to DNA replication and repair, protein metabolism, and the glutathione metabolism pathway. CONCLUSION The results of this study improve our understanding of the mechanism of plant responses to Cd stress.
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Affiliation(s)
- Mingyang Jian
- College of Agronomy, Northwest A&F University, Yangling, 712100, China
| | - Dazhong Zhang
- College of Agronomy, Northwest A&F University, Yangling, 712100, China
| | - Xiaoying Wang
- College of Agronomy, Northwest A&F University, Yangling, 712100, China
| | - Shuwei Wei
- College of Agronomy, Northwest A&F University, Yangling, 712100, China
| | - Yue Zhao
- College of Agronomy, Northwest A&F University, Yangling, 712100, China
| | - Qin Ding
- College of Horticulture, Northwest A&F University, Yangling, 712100, China.
| | - Yucui Han
- College of Agronomy, Northwest A&F University, Yangling, 712100, China.
| | - Lingjian Ma
- College of Agronomy, Northwest A&F University, Yangling, 712100, China.
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Li J, Shen Y, Zhu J, Liu S, Zeng N, Zhan X. miR398 is involved in the relief of phenanthrene-induced oxidative toxicity in wheat roots. Environ Pollut 2020; 258:113701. [PMID: 31818619 DOI: 10.1016/j.envpol.2019.113701] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/30/2019] [Accepted: 11/29/2019] [Indexed: 05/28/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants and could produce oxidative toxicity to plants. Our previous study has shown that miR398 is involved in response to phenanthrene treatment by targeting CSD1 and CSD2. However, it is not clear which is essential for CSD1 and CSD2 and how miR398 changes. In this study, we performed discontinuous PAGE to separate superoxide dismutase (SOD) isozymes and found that two bands of the cytosolic Cu/Zn-SOD are induced by phenanthrene at day 5 and 7. Low expression of pri-miR398 and high expression of pre-miR398 indicate that the conversion process from pri-miR398 to pre-miR398 is impeded, which causes decrease in mature miR398. The relative expression of CSD1 is entirely up-regulated, further confirming the important role of CSD1 in response to phenanthrene exposure. Besides, the overexpression of WRKY implies its potential function in answering the call from phenanthrene stress. Therefore, it is concluded that the gene silencing of CSD1 recedes due to the biosynthesis inhibition of miR398, causing the increase of SOD activity in response to phenanthrene exposure in wheat roots. Our results are useful not only for better understanding miRNAs regulation in detoxication of reactive oxygen species, but also for alleviating the toxicity to crops caused by PAHs.
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Affiliation(s)
- Jinfeng Li
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China
| | - Yu Shen
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China
| | - Jiahui Zhu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China
| | - Shiqi Liu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China
| | - Nengde Zeng
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China
| | - Xinhua Zhan
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China.
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Jia LY, Bai JY, Sun K, Wang RF, Feng HQ. Extracellular ATP released by copper stress could act as diffusible signal in alleviating the copper stress-induced cell death. Protoplasma 2019; 256:491-501. [PMID: 30251212 DOI: 10.1007/s00709-018-1309-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/10/2018] [Indexed: 06/08/2023]
Abstract
In the present work, by using tobacco cell suspension and wheat seedlings, we studied that eATP (extracellular ATP) released by copper (Cu) stress could act as diffusible signal in alleviating the Cu stress-induced cell death. A semipermeable membrane was fixed in the middle of a plastic box to divide the box into two equal compartments (A and B, respectively). This semipermeable membrane can prevent direct cell-to-cell (or seedling-to-seedling) contact and the diffusion of the macromolecules [such as ATPase (adenosine 5'-triphosphatase)] between these two compartments. The cell suspension directly stressed with CuCl2 was placed in compartment A and was incubated with the untreated cell suspension in compartment B. Such treatment significantly increased the levels of cell death and eATP content of the cell suspension in these two compartments. In contrast, addition of ATPase into the cell suspension directly stressed with CuCl2 decreased the eATP level in these two compartments but further increased the level of cell death in compartment B, compared to no addition of ATPase. Similar results were obtained when tobacco cell suspension was replaced by wheat seedlings. These observations indicate that when Cu stress from compartment A induced the plant cell death in compartment B, ATP transferred from compartment A could play a role in alleviating this cell death. Thus, it is suggested that eATP released by copper stress could act as diffusible signal in alleviating the Cu stress-induced cell death.
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Affiliation(s)
- Ling-Yun Jia
- College of Life Science, Northwest Normal University, Lanzhou, 730070, China
| | - Jing-Yue Bai
- College of Life Science, Northwest Normal University, Lanzhou, 730070, China
| | - Kun Sun
- College of Life Science, Northwest Normal University, Lanzhou, 730070, China
| | - Rong-Fang Wang
- Institute of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China
| | - Han-Qing Feng
- College of Life Science, Northwest Normal University, Lanzhou, 730070, China.
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Li J, Yue L, Shen Y, Sheng Y, Zhan X, Xu G, Xing B. Phenanthrene-responsive microRNAs and their targets in wheat roots. Chemosphere 2017; 186:588-598. [PMID: 28818587 DOI: 10.1016/j.chemosphere.2017.08.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 07/14/2017] [Accepted: 08/06/2017] [Indexed: 05/07/2023]
Abstract
MicroRNAs (miRNAs) play key roles in plant growth, development and responses to abiotic stress. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants. However, it is yet unknown how miRNAs work during PAH uptake by plant roots. Thus, in this study we ascertain phenanthrene (a model PAH)-responsive miRNAs using small RNA high-throughput deep sequencing and their target genes in wheat roots. We identified 108 conserved and non-conserved miRNA members belonging to 82 miRNA families and found 11 differentially expressed miRNAs, among which four miRNAs (miR156, miR164, miR171a and miR9678-3p) were up-regulated and the other seven miRNAs (miR398, miR531, miR1121, miR5048-5p, miR9653b, miR9773 and miR9778) were down-regulated. ABC-transporter-related Gene CA704421 and CA697226 did not respond to phenanthrene exposure. miR156 and miR164 might regulate directly the growth and development of wheat roots by targeting SPL and NAC, respectively. miR398 and miR1121 could regulate oxidative reactions to respond to phenanthrene stress. Additionally, miR9773 might involve phenanthrene metabolism through acting on CYP450. Therefore, it is concluded that phenanthrene triggers variation in miRNA expression, which is associated with uptake of and response to phenanthrene. These findings are of significance for further understanding miRNA regulation mechanisms on PAH uptake, and providing guidance for screening of resistant cultivars in crop production and phytoremediation of PAH-contaminated soils or water at genetic level.
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Affiliation(s)
- Jinfeng Li
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China
| | - Le Yue
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China; Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, United States
| | - Yu Shen
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China; Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, United States
| | - Yu Sheng
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China
| | - Xinhua Zhan
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China.
| | - Guohua Xu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, United States.
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Hodgkinson L, Dodd I, Binley A, Ashton R, White R, Watts C, Whalley W. Root growth in field-grown winter wheat: Some effects of soil conditions, season and genotype. Eur J Agron 2017; 91:74-83. [PMID: 29129966 PMCID: PMC5669304 DOI: 10.1016/j.eja.2017.09.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 09/25/2017] [Accepted: 09/27/2017] [Indexed: 05/03/2023]
Abstract
This work compared root length distributions of different winter wheat genotypes with soil physical measurements, in attempting to explain the relationship between root length density and soil depth. Field experiments were set up to compare the growth of various wheat lines, including near isogenic lines (Rht-B1a Tall NIL and Rht-B1c Dwarf NIL) and wheat lines grown commercially (cv. Battalion, Hystar Hybrid, Istabraq, and Robigus). Experiments occurred in two successive years under rain fed conditions. Soil water content, temperature and penetrometer resistance profiles were measured, and soil cores taken to estimate vertical profiles of pore distribution, and root number with the core-break method and by root washing. Root length distributions differed substantially between years. Wetter soil in 2014/2015 was associated with shallower roots. Although there was no genotypic effect in 2014/2015, in 2013/2014 the dwarf wheat had the most roots at depth. In the shallower layers, some wheat lines, especially Battalion, seemed better at penetrating non-structured soil. The increase in penetrometer resistance with depth was a putative explanation for the rapid decrease in root length density with depth. Differences between the two years in root profiles were greater than those due to genotype, suggesting that comparisons of different genotypic effects need to take account of different soil conditions and seasonal differences. We also demonstrate that high yields are not necessarily linked to resource acquisition, which did not seem to be limiting in the low yielding dwarf NIL.
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Affiliation(s)
- L. Hodgkinson
- Lancaster Environment Centre, Lancaster University, LA1 4YQ, United Kingdom
| | - I.C. Dodd
- Lancaster Environment Centre, Lancaster University, LA1 4YQ, United Kingdom
| | - A. Binley
- Lancaster Environment Centre, Lancaster University, LA1 4YQ, United Kingdom
| | - R.W. Ashton
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
| | - R.P. White
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
| | - C.W. Watts
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
| | - W.R. Whalley
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
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Shen Y, Du J, Yue L, Zhan X. Proteomic analysis of plasma membrane proteins in wheat roots exposed to phenanthrene. Environ Sci Pollut Res Int 2016; 23:10863-10871. [PMID: 26897580 DOI: 10.1007/s11356-016-6307-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/15/2016] [Indexed: 05/28/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and toxic to humans through ingestion of contaminated food crops. PAHs can enter crop roots through proton/PAH symporters; however, to date, the symporter remains unclear. Here we reveal, for the first time, the plasma membrane proteome of Triticum aestivum seedling roots in response to phenanthrene (a model PAH) exposure. Two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF/TOF-MS and protein database search engines were employed to analyze and identify phenanthrene-responsive proteins. Over 192 protein spots are reproducibly detected in each gel, while 8 spots are differentially expressed under phenanthrene treatment. Phenanthrene induces five up-regulated proteins distinguished as 5-methyltetrahydropteroyltriglutamate-homocysteine methyltransferase 2, enolase, heat shock protein 80-2, probable mediator of RNA polymerase II transcription subunit 37e (heat shock 70-kDa protein 1), and lactoylglutathione lyase. Three proteins identified as adenosine kinase 2, 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase 1c, and glyceraldehyde-3-phosphate dehydrogenase 3 are down-regulated under exposure to phenanthrene. The up-regulated proteins are related to plant defense response, antioxidant system, and glycolysis. The down-regulated proteins involve the metabolism of high-energy compounds and plant growth. Magnesium, which is able to bind to enolase, can enhance the transport of phenanthrene into wheat roots. Therefore, it is concluded that phenanthrene can induce differential expression of proteins in relation to carbohydrate metabolism, self-defense, and plant growth on wheat root plasma membrane. This study not only provides novel insights into PAH uptake by plant roots and PAH stress responses, but is also a good starting point for further determination and analyses of their functions using genetic and other approaches.
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Affiliation(s)
- Yu Shen
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China
| | - Jiangxue Du
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China
| | - Le Yue
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China
| | - Xinhua Zhan
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China.
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Königshofer H, Löppert HG. Regulation of invertase activity in different root zones of wheat (Triticum aestivum L.) seedlings in the course of osmotic adjustment under water deficit conditions. J Plant Physiol 2015; 183:130-7. [PMID: 26125123 DOI: 10.1016/j.jplph.2015.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/10/2015] [Accepted: 06/11/2015] [Indexed: 05/05/2023]
Abstract
Osmotic adjustment of roots is an essential adaptive mechanism to sustain water uptake and root growth under water deficit. In this paper, the role of invertases (β-fructofuranosidase, EC 3.2.1.26) in osmotic adjustment was investigated in the root tips (cell division and elongation zone) and the root maturation zone of wheat (Triticum aestivum L. cv. Josef) in the course of osmotic stress imposed by 20% polyethylene glycol (PEG) 6000. The two root zones investigated differed distinctly in the response of invertases to water deprivation. In the root tips, the activity of the vacuolar and cell wall-bound invertases increased markedly under water stress resulting in the accumulation of hexoses (glucose and fructose) that contributed significantly to osmotic adjustment. A transient rise in hydrogen peroxide (H2O2) preceded the enhancement of invertases upon exposure to osmotic stress. Treatment with the NADPH oxidase inhibitor diphenylene iodonium (DPI) abolished the stress induced H2O2 production and suppressed the stimulation of the vacuolar invertase activity, whereas the activity of the cell wall-bound invertase was not influenced by DPI. As a consequence of the inhibitory effect of DPI on the vacuolar invertase, hexose levels and osmotic adjustment were also markedly decreased in the root tips under water deficit in the presence of DPI. These data suggest that H2O2 probably generated by a NADPH oxidase is required as a signalling molecule for the up-regulation of the vacuolar invertase activity in the root tips under osmotic stress, thereby enhancing the capacity for osmotic adjustment. In the root maturation zone, an early H2O2 signal could not be detected in response to PEG application. Only an increase in the glucose level that was not paralleled by fructose and a slight stimulation of the activity of the vacuolar invertase occurred in the maturation zone after water deprivation. The stress induced accumulation of glucose in the maturation zone was not affected by DPI and thus seems to be not regulated by NADPH oxidase-derived H2O2. Altogether, osmotic adjustment was considerably smaller in the maturation zone than in the root tips.
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Affiliation(s)
- Helga Königshofer
- Institute of Botany, Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna, Gregor Mendel Straße 33, 1180 Vienna, Austria
| | - Hans-Georg Löppert
- Institute of Botany, Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna, Gregor Mendel Straße 33, 1180 Vienna, Austria.
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