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Khan AL, Waqas M, Hussain J, Al-Harrasi A, Hamayun M, Lee IJ. Phytohormones enabled endophytic fungal symbiosis improve aluminum phytoextraction in tolerant Solanum lycopersicum: An examples of Penicillium janthinellum LK5 and comparison with exogenous GA3. JOURNAL OF HAZARDOUS MATERIALS 2015; 295:70-78. [PMID: 25885165 DOI: 10.1016/j.jhazmat.2015.04.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/30/2015] [Accepted: 04/03/2015] [Indexed: 06/04/2023]
Abstract
This work investigates the potentials of fungal-endophyte Penicillium janthinellum LK5 (PjLK5) and its inherent gibberellic acid (GA3) as reference to enhance aluminum (Al) induced toxicity in tolerant tomato (Solanum lycopersicum) plants. Initial screening showed significantly higher uptake of Al by PjLK5. Aluminum stress (100 μM) significantly retarted plant growth in control plants. Conversely PjLK5 and GA3 application significantly increased morphological attributes of Al-tolerant tomato plants with or without Al-stress. PjLK5 inoculation with and without Al-stress maintained the plant growth whilst extracting and translocating higher Al in shoot (∼ 1 92 mg/kg) and root (∼ 296 mg/kg). This was almost similar in GA3 treatments as well. In addition, PjLK5 inoculation extended protective effects to tomato plants by maintaining reduced cellular superoxide anions in Al stress. Al-induced oxidative stress was further reduced due to significantly higher activity of metal-responsive reduced glutathione. The functional membrane was less damaged in PjLK5 and GA3 treatments because the plants synthesized reduced levels of malondialdhyde, lenolenic and linoleic acids. Defense-related endogenous phytohormone salicylic acid was significantly up-regulated to counteract the adverse effects of Al-stress. In conclusion, the PjLK5 possess a similar bio-prospective potential as of GA3. Application of such biochemically active endophyte could increase metal phytoextraction whilst maintaining crop physiological homeostasis.
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Affiliation(s)
- Abdul Latif Khan
- UoN Chair of Oman's Medicinal Plants and Marine Natural Products, University of Nizwa, Nizwa-616, Oman; Department of Biological Sciences and Chemistry, College of Arts and Sciences, University of Nizwa, Birkat Al-Mouz, Nizwa 616, Oman
| | - Muhammad Waqas
- School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea(d) Department of Botany, Abdul Wali Khan University, Mardan Pakistan
| | - Javid Hussain
- Department of Biological Sciences and Chemistry, College of Arts and Sciences, University of Nizwa, Birkat Al-Mouz, Nizwa 616, Oman
| | - Ahmed Al-Harrasi
- UoN Chair of Oman's Medicinal Plants and Marine Natural Products, University of Nizwa, Nizwa-616, Oman; Department of Biological Sciences and Chemistry, College of Arts and Sciences, University of Nizwa, Birkat Al-Mouz, Nizwa 616, Oman.
| | - Muhammad Hamayun
- Department of Botany, Abdul Wali Khan University, Mardan, Pakistan
| | - In-Jung Lee
- School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea(d) Department of Botany, Abdul Wali Khan University, Mardan Pakistan.
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102
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Bai Y, Dougherty L, Cheng L, Zhong GY, Xu K. Uncovering co-expression gene network modules regulating fruit acidity in diverse apples. BMC Genomics 2015; 16:612. [PMID: 26276125 PMCID: PMC4537561 DOI: 10.1186/s12864-015-1816-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 08/05/2015] [Indexed: 11/10/2022] Open
Abstract
Background Acidity is a major contributor to fruit quality. Several organic acids are present in apple fruit, but malic acid is predominant and determines fruit acidity. The trait is largely controlled by the Malic acid (Ma) locus, underpinning which Ma1 that putatively encodes a vacuolar aluminum-activated malate transporter1 (ALMT1)-like protein is a strong candidate gene. We hypothesize that fruit acidity is governed by a gene network in which Ma1 is key member. The goal of this study is to identify the gene network and the potential mechanisms through which the network operates. Results Guided by Ma1, we analyzed the transcriptomes of mature fruit of contrasting acidity from six apple accessions of genotype Ma_ (MaMa or Mama) and four of mama using RNA-seq and identified 1301 fruit acidity associated genes, among which 18 were most significant acidity genes (MSAGs). Network inferring using weighted gene co-expression network analysis (WGCNA) revealed five co-expression gene network modules of significant (P < 0.001) correlation with malate. Of these, the Ma1 containing module (Turquoise) of 336 genes showed the highest correlation (0.79). We also identified 12 intramodular hub genes from each of the five modules and 18 enriched gene ontology (GO) terms and MapMan sub-bines, including two GO terms (GO:0015979 and GO:0009765) and two MapMap sub-bins (1.3.4 and 1.1.1.1) related to photosynthesis in module Turquoise. Using Lemon-Tree algorithms, we identified 12 regulator genes of probabilistic scores 35.5–81.0, including MDP0000525602 (a LLR receptor kinase), MDP0000319170 (an IQD2-like CaM binding protein) and MDP0000190273 (an EIN3-like transcription factor) of greater interest for being one of the 18 MSAGs or one of the 12 intramodular hub genes in Turquoise, and/or a regulator to the cluster containing Ma1. Conclusions The most relevant finding of this study is the identification of the MSAGs, intramodular hub genes, enriched photosynthesis related processes, and regulator genes in a WGCNA module Turquoise that not only encompasses Ma1 but also shows the highest modular correlation with acidity. Overall, this study provides important insight into the Ma1-mediated gene network controlling acidity in mature apple fruit of diverse genetic background. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1816-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yang Bai
- Horticulture Section, School of Integrative Plant Science, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA.
| | - Laura Dougherty
- Horticulture Section, School of Integrative Plant Science, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA.
| | - Lailiang Cheng
- Horticulture Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA.
| | - Gan-Yuan Zhong
- USDA-ARS, Plant Genetic resource and Grape Genetic Research Units, Geneva, NY, 14456, USA.
| | - Kenong Xu
- Horticulture Section, School of Integrative Plant Science, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA.
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103
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Sun C, Liu L, Yu Y, Liu W, Lu L, Jin C, Lin X. Nitric oxide alleviates aluminum-induced oxidative damage through regulating the ascorbate-glutathione cycle in roots of wheat. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:550-61. [PMID: 25319364 DOI: 10.1111/jipb.12298] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Accepted: 10/12/2014] [Indexed: 05/21/2023]
Abstract
The possible association with nitric oxide (NO) and ascorbate-glutathione (AsA-GSH) cycle in regulating aluminum (Al) tolerance of wheat (Triticum aestivum L.) was investigated using two genotypes with different Al resistance. Exposure to Al inhibited root elongation, and triggered lipid peroxidation and oxidation of AsA to dehydroascorbate and GSH to glutathione disulfide in wheat roots. Exogenous NO significantly increased endogenous NO levels, and subsequently alleviated Al-induced inhibition of root elongation and oxidation of AsA and GSH to maintain the redox molecules in the reduced form in both wheat genotypes. Under Al stress, significantly increased activities and gene transcriptional levels of ascorbate peroxidase, glutathione reductase, and dehydroascorbate reductase, were observed in the root tips of the Al-tolerant genotype Jian-864. Nitric oxide application enhanced the activity and gene transcriptional level of these enzymes in both wheat genotypes. γ-Glutamylcysteine synthetase was not significantly affected by Al or NO, but NO treatments increased the activity of glutathione peroxidase and glutathione S-transferase to a greater extent than the Al-treated wheat seedlings. Proline was significantly decreased by Al, while it was not affected by NO. These results clearly suggest that NO protects wheat root against Al-induced oxidative stress, possibly through its regulation of the AsA-GSH cycle.
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Affiliation(s)
- Chengliang Sun
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Lijuan Liu
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yan Yu
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Wenjing Liu
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Lingli Lu
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Subtropical Soil Science and Plant Nutrition of Zhejiang Province, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Chongwei Jin
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Subtropical Soil Science and Plant Nutrition of Zhejiang Province, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Xianyong Lin
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Subtropical Soil Science and Plant Nutrition of Zhejiang Province, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
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Lynch JP, Wojciechowski T. Opportunities and challenges in the subsoil: pathways to deeper rooted crops. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2199-210. [PMID: 25582451 PMCID: PMC4986715 DOI: 10.1093/jxb/eru508] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 11/04/2014] [Accepted: 11/28/2014] [Indexed: 05/18/2023]
Abstract
Greater exploitation of subsoil resources by annual crops would afford multiple benefits, including greater water and N acquisition in most agroecosystems, and greater sequestration of atmospheric C. Constraints to root growth in the subsoil include soil acidity (an edaphic stress complex consisting of toxic levels of Al, inadequate levels of P and Ca, and often toxic levels of Mn), soil compaction, hypoxia, and suboptimal temperature. Multiple root phenes under genetic control are associated with adaptation to these constraints, opening up the possibility of breeding annual crops with root traits improving subsoil exploration. Adaptation to Al toxicity, hypoxia, and P deficiency are intensively researched, adaptation to soil hardness and suboptimal temperature less so, and adaptations to Ca deficiency and Mn toxicity are poorly understood. The utility of specific phene states may vary among soil taxa and management scenarios, interactions which in general are poorly understood. These traits and issues merit research because of their potential value in developing more productive, sustainable, benign, and resilient agricultural systems.
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Affiliation(s)
- Jonathan P Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, PA 16802, USA IBG2, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, Jülich D-52445, Germany
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105
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Mickelbart MV, Hasegawa PM, Bailey-Serres J. Genetic mechanisms of abiotic stress tolerance that translate to crop yield stability. Nat Rev Genet 2015; 16:237-51. [PMID: 25752530 DOI: 10.1038/nrg3901] [Citation(s) in RCA: 405] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Crop yield reduction as a consequence of increasingly severe climatic events threatens global food security. Genetic loci that ensure productivity in challenging environments exist within the germplasm of crops, their wild relatives and species that are adapted to extreme environments. Selective breeding for the combination of beneficial loci in germplasm has improved yields in diverse environments throughout the history of agriculture. An effective new paradigm is the targeted identification of specific genetic determinants of stress adaptation that have evolved in nature and their precise introgression into elite varieties. These loci are often associated with distinct regulation or function, duplication and/or neofunctionalization of genes that maintain plant homeostasis.
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Affiliation(s)
- Michael V Mickelbart
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Paul M Hasegawa
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907, USA
| | - Julia Bailey-Serres
- 1] Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California Riverside, California 92521, USA. [2] Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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106
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Tokizawa M, Kobayashi Y, Saito T, Kobayashi M, Iuchi S, Nomoto M, Tada Y, Yamamoto YY, Koyama H. SENSITIVE TO PROTON RHIZOTOXICITY1, CALMODULIN BINDING TRANSCRIPTION ACTIVATOR2, and other transcription factors are involved in ALUMINUM-ACTIVATED MALATE TRANSPORTER1 expression. PLANT PHYSIOLOGY 2015; 167:991-1003. [PMID: 25627216 PMCID: PMC4348791 DOI: 10.1104/pp.114.256552] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 01/22/2015] [Indexed: 05/18/2023]
Abstract
In Arabidopsis (Arabidopsis thaliana) the root apex is protected from aluminum (Al) rhizotoxicity by excretion of malate, an Al chelator, by ALUMINUM-ACTIVATED MALATE TRANSPORTER1 (AtALMT1). AtALMT1 expression is fundamentally regulated by the SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1) zinc finger protein, but other transcription factors have roles that enable Al-inducible expression with a broad dynamic range. In this study, we characterized multiple cis-elements in the AtALMT1 promoter that interact with transcription factors. In planta complementation assays of AtALMT1 driven by 5' truncated promoters of different lengths showed that the promoter region between -540 and 0 (the first ATG) restored the Al-sensitive phenotype of atalm1 and thus contains cis-elements essential for AtALMT1 expression for Al tolerance. Computation of overrepresented octamers showed that eight regions in this promoter region contained potential cis-elements involved in Al induction and STOP1 regulation. Mutation in a position around -297 from the first ATG completely inactivated AtALMT1 expression and Al response. In vitro binding assays showed that this region contained the STOP1 binding site, which accounted for the recognition by four zinc finger domains of the protein. Other positions were characterized as cis-elements that regulated expression by repressors and activators and a transcription factor that determines root tip expression of AtALMT1. From the consensus of known cis-elements, we identified CALMODULIN-BINDING TRANSCRIPTION ACTIVATOR2 to be an activator of AtALMT1 expression. Al-inducible expression of AtALMT1 changed transcription starting sites, which increased the abundance of transcripts with a shortened 5' untranslated region. The present analyses identified multiple mechanisms that regulate AtALMT1 expression.
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Affiliation(s)
- Mutsutomo Tokizawa
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan (M.T., Y.K., T.S., Y.Y.Y., H.K.);RIKEN BioResource Center, Ibaraki 305-0074, Japan (M.K., S.I.); andDivision of Biological Science, Graduate School of Science (M.N.), and The Center for Gene Research, Division of Biological Science (Y.T.), Nagoya University, Aichi 464-8602, Japan
| | - Yuriko Kobayashi
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan (M.T., Y.K., T.S., Y.Y.Y., H.K.);RIKEN BioResource Center, Ibaraki 305-0074, Japan (M.K., S.I.); andDivision of Biological Science, Graduate School of Science (M.N.), and The Center for Gene Research, Division of Biological Science (Y.T.), Nagoya University, Aichi 464-8602, Japan
| | - Tatsunori Saito
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan (M.T., Y.K., T.S., Y.Y.Y., H.K.);RIKEN BioResource Center, Ibaraki 305-0074, Japan (M.K., S.I.); andDivision of Biological Science, Graduate School of Science (M.N.), and The Center for Gene Research, Division of Biological Science (Y.T.), Nagoya University, Aichi 464-8602, Japan
| | - Masatomo Kobayashi
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan (M.T., Y.K., T.S., Y.Y.Y., H.K.);RIKEN BioResource Center, Ibaraki 305-0074, Japan (M.K., S.I.); andDivision of Biological Science, Graduate School of Science (M.N.), and The Center for Gene Research, Division of Biological Science (Y.T.), Nagoya University, Aichi 464-8602, Japan
| | - Satoshi Iuchi
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan (M.T., Y.K., T.S., Y.Y.Y., H.K.);RIKEN BioResource Center, Ibaraki 305-0074, Japan (M.K., S.I.); andDivision of Biological Science, Graduate School of Science (M.N.), and The Center for Gene Research, Division of Biological Science (Y.T.), Nagoya University, Aichi 464-8602, Japan
| | - Mika Nomoto
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan (M.T., Y.K., T.S., Y.Y.Y., H.K.);RIKEN BioResource Center, Ibaraki 305-0074, Japan (M.K., S.I.); andDivision of Biological Science, Graduate School of Science (M.N.), and The Center for Gene Research, Division of Biological Science (Y.T.), Nagoya University, Aichi 464-8602, Japan
| | - Yasuomi Tada
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan (M.T., Y.K., T.S., Y.Y.Y., H.K.);RIKEN BioResource Center, Ibaraki 305-0074, Japan (M.K., S.I.); andDivision of Biological Science, Graduate School of Science (M.N.), and The Center for Gene Research, Division of Biological Science (Y.T.), Nagoya University, Aichi 464-8602, Japan
| | - Yoshiharu Y Yamamoto
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan (M.T., Y.K., T.S., Y.Y.Y., H.K.);RIKEN BioResource Center, Ibaraki 305-0074, Japan (M.K., S.I.); andDivision of Biological Science, Graduate School of Science (M.N.), and The Center for Gene Research, Division of Biological Science (Y.T.), Nagoya University, Aichi 464-8602, Japan
| | - Hiroyuki Koyama
- Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan (M.T., Y.K., T.S., Y.Y.Y., H.K.);RIKEN BioResource Center, Ibaraki 305-0074, Japan (M.K., S.I.); andDivision of Biological Science, Graduate School of Science (M.N.), and The Center for Gene Research, Division of Biological Science (Y.T.), Nagoya University, Aichi 464-8602, Japan
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107
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Emamverdian A, Ding Y, Mokhberdoran F, Xie Y. Heavy metal stress and some mechanisms of plant defense response. ScientificWorldJournal 2015; 2015:756120. [PMID: 25688377 PMCID: PMC4321847 DOI: 10.1155/2015/756120] [Citation(s) in RCA: 343] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 01/02/2015] [Accepted: 01/05/2015] [Indexed: 11/18/2022] Open
Abstract
Unprecedented bioaccumulation and biomagnification of heavy metals (HMs) in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS). This would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM) toxicity. The key elements of these are chelating metals by forming phytochelatins (PCs) or metallothioneins (MTs) metal complex at the intra- and intercellular level, which is followed by the removal of HM ions from sensitive sites or vacuolar sequestration of ligand-metal complex. Nonenzymatically synthesized compounds such as proline (Pro) are able to strengthen metal-detoxification capacity of intracellular antioxidant enzymes. Another important additive component of plant defense system is symbiotic association with arbuscular mycorrhizal (AM) fungi. AM can effectively immobilize HMs and reduce their uptake by host plants via binding metal ions to hyphal cell wall and excreting several extracellular biomolecules. Additionally, AM fungi can enhance activities of antioxidant defense machinery of plants.
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Affiliation(s)
- Abolghassem Emamverdian
- Center of Modern Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
- College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Yulong Ding
- Center of Modern Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
- Bamboo Research Institute, Nanjing Forestry University, Nanjing 210037, China
| | - Farzad Mokhberdoran
- Department of Agronomy and Plant Breeding, Faculty of Agriculture, Islamic Azad University, Mashhad Branch, Mashhad 9187147578, Iran
| | - Yinfeng Xie
- Center of Modern Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
- College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
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108
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Matsumoto H, Riechers DE, Lygin AV, Baluška F, Sivaguru M. Aluminum Signaling and Potential Links with Safener-Induced Detoxification in Plants. ALUMINUM STRESS ADAPTATION IN PLANTS 2015. [DOI: 10.1007/978-3-319-19968-9_1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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109
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Rengel Z, Bose J, Chen Q, Tripathi BN. Magnesium alleviates plant toxicity of aluminium and heavy metals. CROP AND PASTURE SCIENCE 2015; 66:1298. [PMID: 0 DOI: 10.1071/cp15284] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Magnesium (Mg) is an essential nutrient that can alleviate soilborne toxicity of many ions. This review paper critically assesses the literature on interactions and mechanisms influencing Mg alleviation of aluminium (Al) and heavy metal toxicity. Hydrated radii of Mg2+ and Al3+ are similar; therefore, these two ions compete for binding to ion transporters and other important biological molecules. In monocotyledonous species such as rice and wheat, millimolar concentrations of Mg alleviate Al toxicity, mainly by decreasing Al saturation and activity at cell wall and plasma membrane binding sites. In dicotyledonous legume species such as soybean (Glycine max), rice bean (Vigna umbellata) and broad bean (Vicia faba), micromolar concentrations of Mg may enhance biosynthesis of organic ligands and thus underpin alleviation of Al toxicity. Resistance to Al may be enhanced by increased expression of the genes coding for Mg transporters, as well as by upregulation of activity of Mg-transport proteins; intracellular Mg2+ activity may thus be increased under Al stress, which may increase the activity of H+-ATPases. In Vicia faba, Mg-related enhancement in the activity of plasma membrane H+-ATPase under Al stress was found to be due to post-translational modification (increased phosphorylation of the penultimate threonine as well as association with regulatory 14-3-3 proteins), resulting in increased resistance to Al stress. Magnesium can alleviate heavy metal stress by decreasing negative electrical potential and thus metal ion activities at the plasma membrane surface (physico-chemical competition), by enhancing activities of enzymes involved in biosynthesis of organic ligands, and by increasing vacuolar sequestration of heavy metals via increasing H+-pumping activity at the tonoplast. Future work should concentrate on characterising the role of intracellular Mg2+ homeostasis and Mg transporters in alleviating metal stress as well as in transcriptional, translational and post-translational regulation of H+-pumps and enzymes involved in biosynthesis and exudation of organic ligands.
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110
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Poschenrieder C, Tolrà R, Hajiboland R, Arroyave C, Barceló J. Mechanisms of Hyper-resistance and Hyper-tolerance to Aluminum in Plants. ALUMINUM STRESS ADAPTATION IN PLANTS 2015. [DOI: 10.1007/978-3-319-19968-9_5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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111
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Aluminum-Induced Inhibition of Root Growth: Roles of Cell Wall Assembly, Structure, and Function. ALUMINUM STRESS ADAPTATION IN PLANTS 2015. [DOI: 10.1007/978-3-319-19968-9_13] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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112
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Ding H, Lu H, Lavoie M, Xie J, Li Y, Lv X, Fu Z, Qian H. Unraveling the toxicity mechanisms of the herbicide diclofop-methyl in rice: modulation of the activity of key enzymes involved in citrate metabolism and induction of cell membrane anion channels. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:10654-10660. [PMID: 25307187 DOI: 10.1021/jf503974t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Residual soil concentrations of the herbicide diclofop-methyl (DM) can be toxic to other nontarget plant species, but the toxicity mechanisms at play are not fully understood. In the present study, we analyzed the toxic effect of DM on root growth and metabolism in the rice species Oryza sativa. The results show that a 48-h exposure to a trace level (5 μg/L) of DM inhibits rice root growth by almost 70%. A 48-h exposure to 5 μg/L DM also leads to an ≈2.5-fold increase in citrate synthase (CS) activity (and CS gene transcription) and an ≈2-fold decrease in the citrate lyase gene transcripts, which lead to an increase in the intracellular concentration of citrate and in citrate exudation rate. Addition of a specific inhibitor of cell membrane anion channel, anthracene-9-carboxylic acid, decreased citrate release in the culture, suggesting that DM-induced citrate loss from the cells is mediated by a specific membrane-bound channel protein. This study brings new insights into the key biochemical mechanisms leading to DM toxicity in rice.
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Affiliation(s)
- Haiyan Ding
- College of Biological and Environmental Engineering and ∥Department of Food Science and Technology, Zhejiang University of Technology , Hangzhou 310032, P. R. China
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Surapu V, Ediga A, Meriga B. Salicylic Acid Alleviates Aluminum Toxicity in Tomato Seedlings (Lycopersicum esculentum Mill.) through Activation of Antioxidant Defense System and Proline Biosynthesis. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/abb.2014.59091] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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