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Malécange M, Sergheraert R, Teulat B, Mounier E, Lothier J, Sakr S. Biostimulant Properties of Protein Hydrolysates: Recent Advances and Future Challenges. Int J Mol Sci 2023; 24:ijms24119714. [PMID: 37298664 DOI: 10.3390/ijms24119714] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/26/2023] [Accepted: 05/28/2023] [Indexed: 06/12/2023] Open
Abstract
Over the past decade, plant biostimulants have been increasingly used in agriculture as environment-friendly tools that improve the sustainability and resilience of crop production systems under environmental stresses. Protein hydrolysates (PHs) are a main category of biostimulants produced by chemical or enzymatic hydrolysis of proteins from animal or plant sources. Mostly composed of amino acids and peptides, PHs have a beneficial effect on multiple physiological processes, including photosynthetic activity, nutrient assimilation and translocation, and also quality parameters. They also seem to have hormone-like activities. Moreover, PHs enhance tolerance to abiotic stresses, notably through the stimulation of protective processes such as cell antioxidant activity and osmotic adjustment. Knowledge on their mode of action, however, is still piecemeal. The aims of this review are as follows: (i) Giving a comprehensive overview of current findings about the hypothetical mechanisms of action of PHs; (ii) Emphasizing the knowledge gaps that deserve to be urgently addressed with a view to efficiently improve the benefits of biostimulants for different plant crops in the context of climate change.
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Affiliation(s)
- Marthe Malécange
- Institut Agro, Univ Angers, INRAE, IRHS, SFR QuaSaV, 49000 Angers, France
- BCF Life Sciences, Boisel, 56140 Pleucadeuc, France
| | | | - Béatrice Teulat
- Institut Agro, Univ Angers, INRAE, IRHS, SFR QuaSaV, 49000 Angers, France
| | | | - Jérémy Lothier
- Institut Agro, Univ Angers, INRAE, IRHS, SFR QuaSaV, 49000 Angers, France
| | - Soulaiman Sakr
- Institut Agro, Univ Angers, INRAE, IRHS, SFR QuaSaV, 49000 Angers, France
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García-Valle KM, Ruíz-Herrera LF, Ravelo-Ortega G, López-Bucio JS, Guevara-García ÁA, López-Bucio J. MITOGEN-ACTIVATED PROTEIN KINASE PHOSPHATASE 1 mediates root sensing of serotonin through jasmonic acid signaling and modulating reactive oxygen species. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 323:111396. [PMID: 35878696 DOI: 10.1016/j.plantsci.2022.111396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/19/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Serotonin (5-hydroxytryptamine) acts as a neurotransmitter in mammals and is widely distributed in the plant kingdom, where it influences root growth and defense. Mitogen-Activated Protein Kinases (MAPKs) and MAPK phosphatases (MKPs) play critical functions in decoding hormonal signalling, but their possible roles in mediating serotonin responses await investigation. In this report, we unveiled positive roles for the MITOGEN-ACTIVATED PROTEIN KINASE PHOSPHATASE1 (MKP1) in the inhibition of the primary root growth, cell division, meristem structure, and differentiation events in Arabidopsis seedlings. mkp1 mutants were less sensitive to jasmonic acid applications that halted primary root growth in wild-type (WT) plants, and consistently, the neurotransmitter activated the expression of the JASMONATE ZIM-domain (JAZ) proteins JAZ1 and JAZ10, two critical proteins orchestrating jasmonic acid signalling. This effect correlated with exacerbated production of endogenous reactive oxygen species (ROS) in the WT, a process constitutively manifested in mkp1 mutants. These data help to clarify the relationship between serotonin and growth/defense trade-offs, and reveal the importance of the MAPK pathway in root development through ROS production.
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Affiliation(s)
- Karen Monserrat García-Valle
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
| | - León Francisco Ruíz-Herrera
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
| | - Gustavo Ravelo-Ortega
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
| | - Jesús Salvador López-Bucio
- Investigador de Cátedras CONACYT, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, Morelia, Michoacán, Mexico.
| | - Ángel Arturo Guevara-García
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apartado Postal 510-3, 62250 Cuernavaca, Morelos, Mexico.
| | - José López-Bucio
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
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Song W, Hu L, Ma Z, Yang L, Li J. Importance of Tyrosine Phosphorylation in Hormone-Regulated Plant Growth and Development. Int J Mol Sci 2022; 23:ijms23126603. [PMID: 35743047 PMCID: PMC9224382 DOI: 10.3390/ijms23126603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/07/2022] [Accepted: 06/11/2022] [Indexed: 02/01/2023] Open
Abstract
Protein phosphorylation is the most frequent post-translational modification (PTM) that plays important regulatory roles in a wide range of biological processes. Phosphorylation mainly occurs on serine (Ser), threonine (Thr), and tyrosine (Tyr) residues, with the phosphorylated Tyr sites accounting for ~1–2% of all phosphorylated residues. Tyr phosphorylation was initially believed to be less common in plants compared to animals; however, recent investigation indicates otherwise. Although they lack typical protein Tyr kinases, plants possess many dual-specificity protein kinases that were implicated in diverse cellular processes by phosphorylating Ser, Thr, and Tyr residues. Analyses of sequenced plant genomes also identified protein Tyr phosphatases and dual-specificity protein phosphatases. Recent studies have revealed important regulatory roles of Tyr phosphorylation in many different aspects of plant growth and development and plant interactions with the environment. This short review summarizes studies that implicated the Tyr phosphorylation in biosynthesis and signaling of plant hormones.
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Affiliation(s)
- Weimeng Song
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (W.S.); (L.H.); (Z.M.); (L.Y.)
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China
| | - Li Hu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (W.S.); (L.H.); (Z.M.); (L.Y.)
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China
| | - Zhihui Ma
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (W.S.); (L.H.); (Z.M.); (L.Y.)
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China
| | - Lei Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (W.S.); (L.H.); (Z.M.); (L.Y.)
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China
| | - Jianming Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (W.S.); (L.H.); (Z.M.); (L.Y.)
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
- Correspondence:
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Liao HS, Chung YH, Hsieh MH. Glutamate: A multifunctional amino acid in plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 318:111238. [PMID: 35351313 DOI: 10.1016/j.plantsci.2022.111238] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/15/2022] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
Glutamate (Glu) is a versatile metabolite and a signaling molecule in plants. Glu biosynthesis is associated with the primary nitrogen assimilation pathway. The conversion between Glu and 2-oxoglutarate connects Glu metabolism to the tricarboxylic acid cycle, carbon metabolism, and energy production. Glu is the predominant amino donor for transamination reactions in the cell. In addition to protein synthesis, Glu is a building block for tetrapyrroles, glutathione, and folate. Glu is the precursor of γ-aminobutyric acid that plays an important role in balancing carbon/nitrogen metabolism and various cellular processes. Glu can conjugate to the major auxin indole 3-acetic acid (IAA), and IAA-Glu is destined for oxidative degradation. Glu also conjugates with isochorismate for the production of salicylic acid. Accumulating evidence indicates that Glu functions as a signaling molecule to regulate plant growth, development, and defense responses. The ligand-gated Glu receptor-like proteins (GLRs) mediate some of these responses. However, many of the Glu signaling events are GLR-independent. The receptor perceiving extracellular Glu as a danger signal is still unknown. In addition to GLRs, Glu may act on receptor-like kinases or receptor-like proteins to trigger immune responses. Glu metabolism and Glu signaling may entwine to regulate growth, development, and defense responses in plants.
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Affiliation(s)
- Hong-Sheng Liao
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Hsin Chung
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Ming-Hsiun Hsieh
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; Department of Life Sciences, National Central University, Taoyuan 32001, Taiwan.
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Zhang L, Takahashi Y, Schroeder JI. Protein kinase sensors: an overview of new designs for visualizing kinase dynamics in single plant cells. PLANT PHYSIOLOGY 2021; 187:527-536. [PMID: 35142856 PMCID: PMC8491035 DOI: 10.1093/plphys/kiab277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 05/16/2021] [Indexed: 05/15/2023]
Abstract
Protein kinase dynamics play key roles in regulation of cell differentiation, growth, development and in diverse cell signaling networks. Protein kinase sensors enable visualization of protein kinase activity in living cells and tissues in time and space. These sensors have therefore become important and powerful molecular tools for investigation of diverse kinase activities and can resolve long-standing and challenging biological questions. In the present Update, we review new advanced approaches for genetically encoded protein kinase biosensor designs developed in animal systems together with the basis of each biosensor's working principle and components. In addition, we review recent first examples of real time plant protein kinase activity biosensor development and application. We discuss how these sensors have helped to resolve how stomatal signal transduction in response to elevated CO2 merges with abscisic acid signaling downstream of a resolved basal SnRK2 kinase activity in guard cells. Furthermore, recent advances, combined with the new strategies described in this Update, can help deepen the understanding of how signaling networks regulate unique functions and responses in distinct plant cell types and tissues and how different stimuli and signaling pathways can interact.
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Affiliation(s)
- Li Zhang
- Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, California 92093, USA
- Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
| | - Yohei Takahashi
- Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, California 92093, USA
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Verma D, Bhagat PK, Sinha AK. A dual-specificity phosphatase, MAP kinase phosphatase 1, positively regulates blue light-mediated seedling development in Arabidopsis. PLANTA 2021; 253:131. [PMID: 34057637 DOI: 10.1007/s00425-021-03649-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/24/2021] [Indexed: 06/12/2023]
Abstract
A dual-specificity phosphatase MKP1 negatively regulates the activity of MPK6 by dephosphorylating it and acts as a positive regulator of blue light (BL)-mediated photomorphogenic development in Arabidopsis. Reversible phosphorylation of proteins is one of the major post-translational modifications in nearly all signaling pathways in plants. MAP kinase phosphatases are very crucial in the regulation of MAPKs as they dephosphorylate both threonine (Thr) and tyrosine (Tyr) residues within the T-X-Y motif of active MAPKs. Therefore, to gain insight of involvement of MAP kinase phosphatases in the regulation of light signaling, we searched for the potential phosphatase which may regulate the function of MPK6, a negative regulator of blue light (BL)-mediated photomorphogenic development. We report here the identification of a dual-specificity phosphatase, MAP kinase phosphatase 1 (MKP1) as a positive regulator of BL-mediated seedling development. Overexpression of MKP1 enhances the BL-induced inhibition of hypocotyl elongation and displays more opened cotyledons. We also show that MKP1OE accumulates more pigments and positively affects the expression of downstream light-related genes in response to BL. In vitro and in vivo evidences also demonstrate that MKP1 not only interacts with but also dephosphorylates MPK6 in BL. In addition, MKP1 regulates stability as well as activity of MPK6 upon BL. Taken together our study highlights the important role of phosphatases in the regulation of a signaling pathway and identifies the role of MKP1 in the negative regulation of MPK6 activity leading to a change in BL-induced photomorphogenic responses.
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Affiliation(s)
- Deepanjali Verma
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Prakash Kumar Bhagat
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Alok Krishna Sinha
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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Ravelo-Ortega G, López-Bucio JS, Ruiz-Herrera LF, Pelagio-Flores R, Ayala-Rodríguez JÁ, de la Cruz HR, Guevara-García ÁA, López-Bucio J. The growth of Arabidopsis primary root is repressed by several and diverse amino acids through auxin-dependent and independent mechanisms and MPK6 kinase activity. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 302:110717. [PMID: 33288023 DOI: 10.1016/j.plantsci.2020.110717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/08/2020] [Accepted: 10/11/2020] [Indexed: 05/14/2023]
Abstract
Amino acids serve as structural monomers for protein synthesis and are considered important biostimulants for plants. In this report, the effects of all 20-L amino acids in Arabidopsis primary root growth were evaluated. 15 amino acids inhibited growth, being l-leucine (l-Leu), l-lysine (l-Lys), l-tryptophan (l-Trp), and l-glutamate (l-Glu) the most active, which repressed both cell division and elongation in primary roots. Comparisons of DR5:GFP expression and growth of WT Arabidopsis seedlings and several auxin response mutants including slr, axr1 and axr2 single mutants, arf7/arf19 double mutant and tir1/afb2/afb3 triple mutant, treated with inhibitory concentrations of l-Glu, l-Leu, l-Lys and l-Trp revealed gene-dependent, specific changes in auxin response. In addition, l- isomers of Glu, Leu and Lys, but not l-Trp diminished the GFP fluorescence of pPIN1::PIN1:GFP, pPIN2::PIN2:GFP, pPIN3::PIN3:GFP and pPIN7::PIN7:GFP constructs in root tips. MPK6 activity in roots was enhanced by amino acid treatment, being greater in response to l-Trp while mpk6 mutants supported cell division and elongation at high doses of l-Glu, l-Leu, l-Lys and l-Trp. We conclude that independently of their auxin modulating properties, amino acids signals converge in MPK6 to alter the Arabidopsis primary root growth.
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Affiliation(s)
- Gustavo Ravelo-Ortega
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
| | - Jesús Salvador López-Bucio
- CONACYT‑Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
| | - León Francisco Ruiz-Herrera
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
| | - Ramón Pelagio-Flores
- Facultad de Químico Farmacobiología, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
| | - Juan Ángel Ayala-Rodríguez
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
| | - Homero Reyes de la Cruz
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
| | | | - José López-Bucio
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030 Morelia, Michoacán, Mexico.
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López-Bucio JS, Salmerón-Barrera GJ, Ravelo-Ortega G, Raya-González J, León P, de la Cruz HR, Campos-García J, López-Bucio J, Guevara-García ÁA. Mitogen-activated protein kinase 6 integrates phosphate and iron responses for indeterminate root growth in Arabidopsis thaliana. PLANTA 2019; 250:1177-1189. [PMID: 31190117 DOI: 10.1007/s00425-019-03212-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/06/2019] [Indexed: 05/21/2023]
Abstract
A MAPK module, of which MPK6 kinase is an important component, is involved in the coordination of the responses to Pi and Fe in the primary root meristem of Arabidopsis thaliana. Phosphate (Pi) deficiency induces determinate primary root growth in Arabidopsis through cessation of cell division in the meristem, which is linked to an increased iron (Fe) accumulation. Here, we show that Mitogen-Activated Protein Kinase6 (MPK6) has a role in Arabidopsis primary root growth under low Pi stress. MPK6 activity is induced in roots in response to low Pi, and such induction is enhanced by Fe supplementation, suggesting an MPK6 role in coordinating Pi/Fe balance in mediating root growth. The differentiation of the root meristem induced by low Pi levels correlates with altered expression of auxin-inducible genes and auxin transporter levels via MPK6. Our results indicate a critical role of the MPK6 kinase in coordinating meristem cell activity to Pi and Fe availability for proper primary root growth.
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Affiliation(s)
- Jesús Salvador López-Bucio
- CONACYT-Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030, Morelia, Michoacán, Mexico.
| | | | - Gustavo Ravelo-Ortega
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030, Morelia, Michoacán, Mexico
| | - Javier Raya-González
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030, Morelia, Michoacán, Mexico
| | - Patricia León
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, CP 62250, Cuernavaca, Morelos, Mexico
| | - Homero Reyes de la Cruz
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030, Morelia, Michoacán, Mexico
| | - Jesús Campos-García
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030, Morelia, Michoacán, Mexico
| | - José López-Bucio
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, CP 58030, Morelia, Michoacán, Mexico
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Zhang W, Song J, Yue S, Duan K, Yang H. MhMAPK4 from Malus hupehensis Rehd. decreases cell death in tobacco roots by controlling Cd 2+ uptake. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 168:230-240. [PMID: 30388541 DOI: 10.1016/j.ecoenv.2018.09.126] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 09/13/2018] [Accepted: 09/29/2018] [Indexed: 05/23/2023]
Abstract
Cadmium (Cd) induces cell death in plant roots. Mitogen-activated protein kinase (MAPK) plays a role in the regulation of cell death induced by Cd in plant roots. In this study, MhMAPK4 was isolated from the roots of Malus hupehensis. Subcellular localization showed that the MhMAPK4 protein was located in the cell membrane and cytoplasm and is a transmembrane protein that is characterized by hydrophily. The expression of MhMAPK4 in the roots of M. hupehensis was up-regulated by Cd sulfate and Cd chloride. Phenotypic comparison under Cd stress showed that the growth of wild-type (WT) tobacco was lower than the transgenic lines overexpressing MhMAPK4. The fresh weight and the root length of WT also was lower than that of the transgenic tobacco. The net Cd2+ influx in the tobacco roots was decreased by the overexpression of MhMAPK4, as was root Cd accumulation. The recovery time of the Cd2+ influx to stable state in the transgenic tobacco was also shorter than the WT. The expression of iron-regulated transporter 1 (NtIRT1) and natural resistance associated macrophage protein 5 (NtNRAMP5) was relatively low in the transgenic lines under Cd stress. Cell death and apoptosis in the tobacco roots was reduced following the overexpression of MhMAPK4. The activity of vacuolar processing enzyme (VPE) and the transcript level of VPE in the transgenic tobacco was lower than that of WT under Cd stress. In addition, the electrolyte leakage and malondialdehyde and hydrogen peroxide contents in the transgenic tobacco were lower than those of WT, whereas the antioxidant enzyme activity and expression were higher. These results suggest that MhMAPK4 regulates Cd accumulation by mediating Cd2+ uptake by the roots, and controls Cd-caused cell death by adjusting VPE activity.
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Affiliation(s)
- Weiwei Zhang
- College of Horticulture Science and Engineering, Shandong Agricultural University, State Key Laboratory of Crop Biology, 61 Daizong street, Tai'an, Shandong 271018, PR China.
| | - Jianfei Song
- College of Horticulture Science and Engineering, Shandong Agricultural University, State Key Laboratory of Crop Biology, 61 Daizong street, Tai'an, Shandong 271018, PR China.
| | - Songqing Yue
- College of Horticulture Science and Engineering, Shandong Agricultural University, State Key Laboratory of Crop Biology, 61 Daizong street, Tai'an, Shandong 271018, PR China.
| | - Kaixuan Duan
- College of Horticulture Science and Engineering, Shandong Agricultural University, State Key Laboratory of Crop Biology, 61 Daizong street, Tai'an, Shandong 271018, PR China.
| | - Hongqiang Yang
- College of Horticulture Science and Engineering, Shandong Agricultural University, State Key Laboratory of Crop Biology, 61 Daizong street, Tai'an, Shandong 271018, PR China.
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