201
|
Ding W, Tong H, Zheng W, Ye J, Pan Z, Zhang B, Zhu S. Isolation, Characterization and Transcriptome Analysis of a Cytokinin Receptor Mutant Osckt1 in Rice. FRONTIERS IN PLANT SCIENCE 2017; 8:88. [PMID: 28197164 PMCID: PMC5281565 DOI: 10.3389/fpls.2017.00088] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 01/16/2017] [Indexed: 05/04/2023]
Abstract
Cytokinins play important roles in regulating plant development, including shoot and root meristems, leaf longevity, and grain yield. However, the in planta functions of rice cytokinin receptors have not been genetically characterized yet. Here we isolated a rice mutant, Osckt1, with enhanced tolerance to cytokinin treatment. Further analysis showed that Osckt1 was insensitive to aromatic cytokinins but responded normally to isoprenoid and phenylurea-type cytokinins. Map-based cloning revealed that the mutation occurred in a putative cytokinin receptor gene, histidine kinase 6 (OsHK6). OsCKT1 was found to be expressed in various tissues throughout the plant and the protein was located in the endoplasmic reticulum. In addition, whole-genome gene expression profiling analysis showed that OsCKT1 was involved in cytokinin regulation of a number of biological processes, including secondary metabolism, sucrose and starch metabolism, chlorophyll synthesis, and photosynthesis. Our results demonstrate that OsCKT1 plays important roles in cytokinin perception and control of root development in rice.
Collapse
Affiliation(s)
- Wona Ding
- College of Science and Technology, Ningbo UniversityNingbo, China
| | - Huishan Tong
- School of Marine Sciences, Ningbo UniversityNingbo, China
| | - Wenjuan Zheng
- College of Science and Technology, Ningbo UniversityNingbo, China
| | - Jing Ye
- College of Science and Technology, Ningbo UniversityNingbo, China
| | - Zhichong Pan
- College of Science and Technology, Ningbo UniversityNingbo, China
| | - Botao Zhang
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of SciencesNingbo, China
- *Correspondence: Botao Zhang, Shihua Zhu,
| | - Shihua Zhu
- College of Science and Technology, Ningbo UniversityNingbo, China
- *Correspondence: Botao Zhang, Shihua Zhu,
| |
Collapse
|
202
|
Guan P. Dancing with Hormones: A Current Perspective of Nitrate Signaling and Regulation in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2017; 8:1697. [PMID: 29033968 PMCID: PMC5625010 DOI: 10.3389/fpls.2017.01697] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/15/2017] [Indexed: 05/18/2023]
Abstract
In nature and agriculture, nitrate availability is a main environmental cue for plant growth, development and stress responses. Nitrate signaling and regulation are hence at the center of communications between plant intrinsic programs and the environment. It is also well known that endogenous phytohormones play numerous critical roles in integrating extrinsic cues and intrinsic responses, regulating and refining almost all aspects of plant growth, development and stress responses. Therefore, interaction between nitrate and phytohormones, such as auxins, cytokinins, abscisic acid, gibberellins, and ethylene, is prevalent. The growing evidence indicates that biosynthesis, de-conjugation, transport, and signaling of hormones are partly controlled by nitrate signaling. Recent advances with nitrate signaling and transcriptional regulation in Arabidopsis give rise to new paradigms. Given the comprehensive nitrate transport, sensing, signaling and regulations at the level of the cell and organism, nitrate itself is a local and long-distance signal molecule, conveying N status at the whole-plant level. A direct molecular link between nitrate signaling and cell cycle progression was revealed with TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR1-20 (TCP20) - NIN-LIKE PROTEIN 6/7 (NLP6/7) regulatory nexus. NLPs are key regulators of nitrogen responses in plants. TCPs function as the main regulators of plant morphology and architecture, with the emerging role as integrators of plant developmental responses to the environment. By analogy with auxin being proposed as a plant morphogen, nitrate may be an environmental morphogen. The morphogen-gradient-dependent and cell-autonomous mechanisms of nitrate signaling and regulation are an integral part of cell growth and cell identification. This is especially true in root meristem growth that is regulated by intertwined nitrate, phytohormones, and glucose-TOR signaling pathways. Furthermore, the nitrate transcriptional hierarchy is emerging. Nitrate regulators in primary nitrate signaling can individually and combinatorially control downstream transcriptional networks and hormonal pathways for signal propagation and amplification. Under the new paradigms, nitrate-induced hormone metabolism and signaling deserve fresh examination. The close interplay and convergent regulation of nitrate and hormonal signaling at morphological, physiological, and molecular levels have significant effects on important agronomic traits, especially nutrient-dependent adaptive root system growth and architecture.
Collapse
|
203
|
Raines T, Blakley IC, Tsai YC, Worthen JM, Franco-Zorrilla JM, Solano R, Schaller GE, Loraine AE, Kieber JJ. Characterization of the cytokinin-responsive transcriptome in rice. BMC PLANT BIOLOGY 2016; 16:260. [PMID: 27931185 PMCID: PMC5146874 DOI: 10.1186/s12870-016-0932-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 10/25/2016] [Indexed: 05/18/2023]
Abstract
BACKGROUND Cytokinin activates transcriptional cascades important for development and the responses to biotic and abiotic stresses. Most of what is known regarding cytokinin-regulated gene expression comes from studies of the dicotyledonous plant Arabidopsis thaliana. To expand the understanding of the cytokinin-regulated transcriptome, we employed RNA-Seq to analyze gene expression in response to cytokinin in roots and shoots of the monocotyledonous plant rice. RESULTS We identified over 4,600 and approximately 2,400 genes differentially expressed in response to cytokinin in roots and shoots respectively. There were some similarities in the sets of cytokinin-regulated genes identified in rice and Arabidopsis, including an up-regulation of genes that act to reduce cytokinin function. Consistent with this, we found that the preferred DNA-binding motif of a rice type-B response regulator is similar to those from Arabidopsis. Analysis of the genes regulated by cytokinin in rice revealed a large number of transcription factors, receptor-like kinases, and genes involved in protein degradation, as well as genes involved in development and the response to biotic stress. Consistent with the over-representation of genes involved in biotic stress, there is a substantial overlap in the genes regulated by cytokinin and those differentially expressed in response to pathogen infection, suggesting that cytokinin plays an integral role in the transcriptional response to pathogens in rice, including the induction of a large number of WRKY transcription factors. CONCLUSIONS These results begin to unravel the complex gene regulation after cytokinin perception in a crop of agricultural importance and provide insight into the processes and responses modulated by cytokinin in monocots.
Collapse
Affiliation(s)
- Tracy Raines
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280 USA
- Present address: AgBiome, Inc., 104 TW Alexander Drive, Bldg 18, Research Triangle Park, NC 27713 USA
| | - Ivory C. Blakley
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, North Carolina Research Campus, Kannapolis, NC 28081 USA
| | - Yu-Chang Tsai
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280 USA
- Present address: Department of Agronomy, National Taiwan University, Taipei, 10617 Taiwan
| | | | - José Manuel Franco-Zorrilla
- Genomics Unit, Centro Nacional de Biotecnología (CNB)-Consejo Superior de Investigaciones Científicas (CSIC), Darwin 3, 28049 Madrid, Spain
| | - Roberto Solano
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología (CNB)-Consejo Superior de Investigaciones Científicas (CSIC), Darwin 3, 28049 Madrid, Spain
| | - G. Eric Schaller
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755 USA
| | - Ann E. Loraine
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, North Carolina Research Campus, Kannapolis, NC 28081 USA
| | - Joseph J. Kieber
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280 USA
| |
Collapse
|
204
|
Merewitz E, Xu Y, Huang B. Differentially Expressed Genes Associated with Improved Drought Tolerance in Creeping Bentgrass Overexpressing a Gene for Cytokinin Biosynthesis. PLoS One 2016; 11:e0166676. [PMID: 27855226 PMCID: PMC5113972 DOI: 10.1371/journal.pone.0166676] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 11/02/2016] [Indexed: 12/03/2022] Open
Abstract
Transformation with an isopentenyl transferase (ipt) gene controlling cytokinin (CK) synthesis has been shown to enhance plant drought tolerance. The objective of this study was to identify differentially-expressed genes (DEGs) in creeping bentgrass (Agrostis stolonifera) overexpressing ipt compared to non-transgenic plants. The ipt transgene was controlled by a senescence-activated promoter (SAG12). Both a null transformed line (NT) and SAG12-ipt plants were exposed to drought stress in an environmentally-controlled growth chamber until the soil water content declined to approximately 5% and leaf relative water content declined to 47%, which were both significantly below the well-watered controls. RNA was extracted from leaf samples of both well-watered and drought-stressed plants. Eight sets of subtractive hybridizations were performed for detection of up-regulated and down-regulated genes due to the presence of the transgene and due to drought stress in both NT and transgenic plants. Sequencing analysis revealed the identity of 252 DEGs due to either the transgene and drought stress. Sequencing analysis of 170 DEGs identified genes encoding for proteins that were related to energy production, metabolism, stress defense, signaling, protein synthesis and transport, and membrane transport could play major roles in the improved drought tolerance by overexpressing ipt in creeping bentgrass.
Collapse
Affiliation(s)
- Emily Merewitz
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, 48824, United States of America
| | - Yi Xu
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901, United States of America
| | - Bingru Huang
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901, United States of America
- * E-mail:
| |
Collapse
|
205
|
Ciaglia E, Abate M, Laezza C, Pisanti S, Vitale M, Seneca V, Torelli G, Franceschelli S, Catapano G, Gazzerro P, Bifulco M. Antiglioma effects of N6-isopentenyladenosine, an endogenous isoprenoid end product, through the downregulation of epidermal growth factor receptor. Int J Cancer 2016; 140:959-972. [PMID: 27813087 DOI: 10.1002/ijc.30505] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 10/25/2016] [Indexed: 12/15/2022]
Abstract
Malignant gliomas are highly dependent on the isoprenoid pathway for the synthesis of lipid moieties critical for cell proliferation. The isoprenoid derivative N6-isopentenyladenosine (iPA) displays pleiotropic biological effects, including a direct anti-tumor activity in several tumor models. The antiglioma effects of iPA was then explored in U87MG cells both in vitro and grafted in mice and the related molecular mechanism confirmed in primary derived patients' glioma cells. iPA powerfully inhibited tumor cell growth and induced caspase-dependent apoptosis through a mechanism involving a marked accumulation of the pro-apoptotic BIM protein and inhibition of EGFR. Indeed, activating AMPK following conversion into its iPAMP active form, iPA stimulated EGFR phosphorylation and ubiquitination along a proteasome-mediated pathway which was responsible for receptor degradation and its downstream signaling pathways inhibition, including the STAT3, ERK and AKT cascade. The inhibition of AMPK by compound C prevented iPA-mediated phosphorylation of EGFR, known to precede receptor loss. As expected the block of EGFR degradation, by exposure to the proteasome inhibitor MG132, significantly reduced iPA-induced cell death. Given the importance of receptor degradation in iPA-mediated cytotoxicity, we also documented that the EGFR expression levels in a panel of primary glioma cells confers them a high sensitivity to iPA treatment. In conclusion our study provides the first evidence of iPA antiglioma effect. Indeed, as glioma is driven by aberrant signaling of growth factor receptors, particularly the EGFR, iPA, alone or in association with EGFR targeted therapies, might be a promising therapeutic tool to achieve a potent anti-tumoral effect.
Collapse
Affiliation(s)
- Elena Ciaglia
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| | - Mario Abate
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| | - Chiara Laezza
- Institute of Endocrinology and Experimental Oncology, IEOS CNR, Naples, Italy.,Department of Biology and Cellular and Molecular Pathology, University of Naples Federico II, Naples, Italy
| | - Simona Pisanti
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| | - Mario Vitale
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| | - Vincenzo Seneca
- Department of Neurosurgery, "G.Rummo" Medical Hospital, Benevento, Italy
| | - Giovanni Torelli
- Department of Neurosurgery, "San Giovanni di Dio e Ruggi d'Aragona University Hospital", Salerno's School of Medicine, Salerno, Italy
| | | | - Giuseppe Catapano
- Department of Neurosurgery, "G.Rummo" Medical Hospital, Benevento, Italy
| | | | - Maurizio Bifulco
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| |
Collapse
|
206
|
Simm S, Scharf KD, Jegadeesan S, Chiusano ML, Firon N, Schleiff E. Survey of Genes Involved in Biosynthesis, Transport, and Signaling of Phytohormones with Focus on Solanum lycopersicum. Bioinform Biol Insights 2016; 10:185-207. [PMID: 27695302 PMCID: PMC5038615 DOI: 10.4137/bbi.s38425] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 08/15/2016] [Accepted: 08/16/2016] [Indexed: 12/19/2022] Open
Abstract
Phytohormones control the development and growth of plants, as well as their response to biotic and abiotic stress. The seven most well-studied phytohormone classes defined today are as follows: auxins, ethylene, cytokinin, abscisic acid, jasmonic acid, gibberellins, and brassinosteroids. The basic principle of hormone regulation is conserved in all plants, but recent results suggest adaptations of synthesis, transport, or signaling pathways to the architecture and growth environment of different plant species. Thus, we aimed to define the extent to which information from the model plant Arabidopsis thaliana is transferable to other plants such as Solanum lycopersicum. We extracted the co-orthologues of genes coding for major pathway enzymes in A. thaliana from the translated genomes of 12 species from the clade Viridiplantae. Based on predicted domain architecture and localization of the identified proteins from all 13 species, we inspected the conservation of phytohormone pathways. The comparison was complemented by expression analysis of (co-) orthologous genes in S. lycopersicum. Altogether, this information allowed the assignment of putative functional equivalents between A. thaliana and S. lycopersicum but also pointed to some variations between the pathways in eudicots, monocots, mosses, and green algae. These results provide first insights into the conservation of the various phytohormone pathways between the model system A. thaliana and crop plants such as tomato. We conclude that orthologue prediction in combination with analysis of functional domain architecture and intracellular localization and expression studies are sufficient tools to transfer information from model plants to other plant species. Our results support the notion that hormone synthesis, transport, and response for most part of the pathways are conserved, and species-specific variations can be found.
Collapse
Affiliation(s)
- Stefan Simm
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.; Cluster of Excellence Macromolecular Complexes, Institute for Molecular Cell Biology of Plants, Frankfurt am Main, Germany
| | - Klaus-Dieter Scharf
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.; Cluster of Excellence Macromolecular Complexes, Institute for Molecular Cell Biology of Plants, Frankfurt am Main, Germany
| | - Sridharan Jegadeesan
- Department of Vegetable Research, Institute for Plant Sciences, Agricultural Research Organization, Volcani Centre, Bet Dagan, Israel.; The Robert H. Smith Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Maria Luisa Chiusano
- Department of Soil, Plants Environmental and Animal Production Sciences, Laboratory of Computer Aided Biosciences, University of Studies of Naples Federico II, Portici, Naples, Italy
| | - Nurit Firon
- Department of Vegetable Research, Institute for Plant Sciences, Agricultural Research Organization, Volcani Centre, Bet Dagan, Israel
| | - Enrico Schleiff
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.; Cluster of Excellence Macromolecular Complexes, Institute for Molecular Cell Biology of Plants, Frankfurt am Main, Germany
| |
Collapse
|
207
|
Worakan P, Karaket N, Maneejantra N, Supaibulwatana K. A Phenylurea Cytokinin, CPPU, Elevated Reducing Sugar and Correlated to Andrographolide Contents in Leaves of Andrographis paniculata (Burm. F.) Wall. Ex Nees. Appl Biochem Biotechnol 2016; 181:638-649. [PMID: 27613615 DOI: 10.1007/s12010-016-2238-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 09/02/2016] [Indexed: 12/20/2022]
Abstract
Cytokinins are phytohormones that play multiple roles to control plant growth and development. In this study, leaf biomass and the production of andrographolide compounds in a medicinal plant Andrographis paniculata were significantly increased after exogenously treating with the synthetic cytokinin cytokinin-1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU) at 0 (water), 5, or 10 mg L-1 and observed the results for 24 h, 48 h, and 7 days of treatment. It was found that CPPU could significantly enhance new axillary bud formation and further promote branching 4.6-5.6-fold higher, resulting in higher fresh weight (FW) and dry weight (DW) than the control. Application of CPPU at 5 mg L-1 significantly promoted the highest contents of total reducing sugar at 2.5-fold in leaves and at 1.5-fold in roots. Although treatments of CPPU significantly affected the increasing contents of chlorophyll and carotenoid (1.2-1.6-fold), CPPU at 10 mg L-1 slightly caused leaf stress and chlorophyll reduction. Interestingly, 5 mg L-1 CPPU could enhance andrographolide content, an active anti-infectious compound in Andrographis paniculata (2.2-fold higher than the control) that reached the highest content at 24 h after treatment. This study suggested that CPPU should be suitable for field application to promote leaf yields and induce the production of useful pharmaceutical compounds in Andrographis paniculata.
Collapse
Affiliation(s)
- Phapawee Worakan
- Department of Biotechnology, Faculty of Science, Mahidol University, 272 Rama VI Rd., Ratchathewi, Bangkok, 10400, Thailand
| | - Netiya Karaket
- School of Interdisciplinary Studies, Mahidol University, Kanchanaburi Campus, Kanchanaburi, Thailand
| | - Nuchada Maneejantra
- Department of Biotechnology, Faculty of Science, Mahidol University, 272 Rama VI Rd., Ratchathewi, Bangkok, 10400, Thailand
| | - Kanyaratt Supaibulwatana
- Department of Biotechnology, Faculty of Science, Mahidol University, 272 Rama VI Rd., Ratchathewi, Bangkok, 10400, Thailand.
| |
Collapse
|
208
|
Nisler J, Kopečný D, Končitíková R, Zatloukal M, Bazgier V, Berka K, Zalabák D, Briozzo P, Strnad M, Spíchal L. Novel thidiazuron-derived inhibitors of cytokinin oxidase/dehydrogenase. PLANT MOLECULAR BIOLOGY 2016; 92:235-48. [PMID: 27422623 DOI: 10.1007/s11103-016-0509-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/29/2016] [Indexed: 05/11/2023]
Abstract
Two new TDZ derivatives (HETDZ and 3FMTDZ) are very potent inhibitors of CKX and are promising candidates for in vivo studies. Cytokinin hormones regulate a wide range of essential processes in plants. Thidiazuron (N-phenyl-N'-1,2,3-thiadiazol-5-yl urea, TDZ), formerly registered as a cotton defoliant, is a well known inhibitor of cytokinin oxidase/dehydrogenase (CKX), an enzyme catalyzing the degradation of cytokinins. TDZ thus increases the lifetime of cytokinins and their effects in plants. We used in silico modeling to design, synthesize and characterize twenty new TDZ derivatives with improved inhibitory properties. Two compounds, namely 1-[1,2,3]thiadiazol-5-yl-3-(3-trifluoromethoxy-phenyl)urea (3FMTDZ) and 1-[2-(2-hydroxyethyl)phenyl]-3-(1,2,3-thiadiazol-5-yl)urea (HETDZ), displayed up to 15-fold lower IC 50 values compared with TDZ for AtCKX2 from Arabidopsis thaliana and ZmCKX1 and ZmCKX4a from Zea mays. Binding modes of 3FMTDZ and HETDZ were analyzed by X-ray crystallography. Crystal structure complexes, solved at 2.0 Å resolution, revealed that HETDZ and 3FMTDZ bound differently in the active site of ZmCKX4a: the thiadiazolyl ring of 3FMTDZ was positioned over the isoalloxazine ring of FAD, whereas that of HETDZ had the opposite orientation, pointing toward the entrance of the active site. The compounds were further tested for cytokinin activity in several cytokinin bioassays. We suggest that the combination of simple synthesis, lowered cytokinin activity, and enhanced inhibitory effects on CKX isoforms, makes 3FMTDZ and HETDZ suitable candidates for in vivo studies.
Collapse
Affiliation(s)
- Jaroslav Nisler
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany AS CR, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic.
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic.
- Department of Chemistry of Natural Compounds, Faculty of Food and Biochemical Technology, University of Chemistry and Technology in Prague, Technická 5, 166 28, Prague, Czech Republic.
| | - David Kopečný
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic.
| | - Radka Končitíková
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Marek Zatloukal
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany AS CR, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Václav Bazgier
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany AS CR, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
- Department of Physical Chemistry, Faculty of Science, Palacký University, 17. listopadu 1192/12, 771 46, Olomouc, Czech Republic
| | - Karel Berka
- Department of Physical Chemistry, Faculty of Science, Palacký University, 17. listopadu 1192/12, 771 46, Olomouc, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, 17. listopadu 1192/12, 771 46, Olomouc, Czech Republic
| | - David Zalabák
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Pierre Briozzo
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, Université Paris-Saclay, 78026, Versailles, France
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany AS CR, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Lukáš Spíchal
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany AS CR, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| |
Collapse
|
209
|
Šmehilová M, Dobrůšková J, Novák O, Takáč T, Galuszka P. Cytokinin-Specific Glycosyltransferases Possess Different Roles in Cytokinin Homeostasis Maintenance. FRONTIERS IN PLANT SCIENCE 2016; 7:1264. [PMID: 27602043 PMCID: PMC4993776 DOI: 10.3389/fpls.2016.01264] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/08/2016] [Indexed: 05/18/2023]
Abstract
Plant hormones cytokinins (CKs) are one of the major mediators of physiological responses throughout plant life span. Therefore, a proper homeostasis is maintained by regulation of their active levels. Besides degradation, CKs are deactivated by uridine diphosphate glycosyltransferases (UGTs). Physiologically, CKs active levels decline in senescing organs, providing a signal to nutrients that a shift to reproductive tissues has begun. In this work, we show CK glucosides distribution in Arabidopsis leaves during major developmental transition phases. Besides continuous accumulation of N-glucosides we detected sharp maximum of the glucosides in senescence. This is caused prevalently by N7-glucosides followed by N9-glucosides and specifically also by trans-zeatin-O-glucoside (tZOG). Interestingly, we observed a similar trend in response to exogenously applied CK. In Arabidopsis, only three UGTs deactivate CKs in vivo: UGT76C1, UGT76C2 and UGT85A1. We thereby show that UGT85A1 is specifically expressed in senescent leaves whereas UGT76C2 is activated rapidly in response to exogenously applied CK. To shed more light on the UGTs physiological roles, we performed a comparative study on UGTs loss-of-function mutants, characterizing a true ugt85a1-1 loss-of-function mutant for the first time. Although no altered phenotype was detected under standard condition we observed reduced chlorophyll degradation with increased anthocyanin accumulation in our experiment on detached leaves accompanied by senescence and stress related genes modulated expression. Among the mutants, ugt76c2 possessed extremely diminished CK N-glucosides levels whereas ugt76c1 showed some specificity toward cis-zeatin (cZ). Besides tZOG, a broader range of CK glucosides was decreased in ugt85a1-1. Performing CK metabolism gene expression profiling, we revealed that activation of CK degradation pathway serves as a general regulatory mechanism of disturbed CK homeostasis followed by decreased CK signaling in all UGT mutants. In contrast, a specific regulation of CKX7, CKX1 and CKX2 was observed for each individual UGT mutant isoform after exogenous CK uptake. Employing an in silico prediction we proposed cytosolic localization of UGT76C1 and UGT76C2, that we further confirmed by GFP tagging of UGT76C2. Integrating all the results, we therefore hypothesize that UGTs possess different physiological roles in Arabidopsis and serve as a fine-tuning mechanism of active CK levels in cytosol.
Collapse
Affiliation(s)
- Mária Šmehilová
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in OlomoucOlomouc, Czech Republic
| | - Jana Dobrůšková
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in OlomoucOlomouc, Czech Republic
| | - Ondřej Novák
- Laboratory of Growth Regulators and Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc and Institute of Experimental Botany ASCROlomouc, Czech Republic
| | - Tomáš Takáč
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in OlomoucOlomouc, Czech Republic
| | - Petr Galuszka
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in OlomoucOlomouc, Czech Republic
| |
Collapse
|
210
|
Seo H, Kim S, Sagong HY, Son HF, Jin KS, Kim IK, Kim KJ. Structural basis for cytokinin production by LOG from Corynebacterium glutamicum. Sci Rep 2016; 6:31390. [PMID: 27507425 PMCID: PMC4979012 DOI: 10.1038/srep31390] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/19/2016] [Indexed: 01/22/2023] Open
Abstract
"Lonely guy" (LOG) has been identified as a cytokinin-producing enzyme in plants and plant-interacting fungi. The gene product of Cg2612 from the soil-dwelling bacterium Corynebacterium glutamicum was annotated as an LDC. However, the facts that C. glutamicum lacks an LDC and Cg2612 has high amino acid similarity with LOG proteins suggest that Cg2612 is possibly an LOG protein. To investigate the function of Cg2612, we determined its crystal structure at a resolution of 2.3 Å. Cg2612 functions as a dimer and shows an overall structure similar to other known LOGs, such as LOGs from Arabidopsis thaliana (AtLOG), Claviceps purpurea (CpLOG), and Mycobacterium marinum (MmLOG). Cg2612 also contains a "PGGXGTXXE" motif that contributes to the formation of an active site similar to other LOGs. Moreover, biochemical studies on Cg2612 revealed that the protein has phosphoribohydrolase activity but not LDC activity. Based on these structural and biochemical studies, we propose that Cg2612 is not an LDC family enzyme, but instead belongs to the LOG family. In addition, the prenyl-binding site of Cg2612 (CgLOG) comprised residues identical to those seen in AtLOG and CpLOG, albeit dissimilar to those in MmLOG. The work provides structural and functional implications for LOG-like proteins from other microorganisms.
Collapse
Affiliation(s)
- Hogyun Seo
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Sangwoo Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
- School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798, Republic of Korea
| | - Hye-Young Sagong
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Hyeoncheol Francis Son
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Kyeong Sik Jin
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Jigok-ro 80, Pohang, Kyungbuk 790-784, Korea
| | - Il-Kwon Kim
- Biopoecess Research Depart. R&D Center, DAESANG Corp., Icheon-si, Gyeonggi-do, 467-810, Republic of Korea
| | - Kyung-Jin Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
| |
Collapse
|
211
|
Shang XL, Xie RR, Tian H, Wang QL, Guo FQ. Putative zeatin O-glucosyltransferase OscZOG1 regulates root and shoot development and formation of agronomic traits in rice. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:627-41. [PMID: 26507364 DOI: 10.1111/jipb.12444] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 10/27/2015] [Indexed: 05/18/2023]
Abstract
As a ubiquitous reaction, glucosylation controls the bioactivity of cytokinins in plant growth and development. Here we show that genetic manipulation of zeatin-O-glucosylation regulates the formation of important agronomic traits in rice by manipulating the expression of OscZOG1 gene, encoding a putative zeatin O-glucosyltransferase. We found that OscZOG1 was preferentially expressed in shoot and root meristematic tissues and nascent organs. The growth of lateral roots was stimulated in the overexpression lines, but inhibited in RNA interference lines. In shoots, knockdown of OscZOG1 expression by RNA interference significantly improved tillering, panicle branching, grain number per panicle and seed size, which are important agronomic traits for grain yield. In contrast, constitutive expression of OscZOG1 leads to negative effects on the formation of the grain-yielding traits with a marked increase in the accumulation levels of cis-zeatin O-glucoside (cZOG) in the transgenic rice plants. In this study, our findings demonstrate the feasibility of improving the critical yield-determinant agronomic traits, including tiller number, panicle branches, total grain number per panicle and grain weight by downregulating the expression level of OscZOG1. Our results suggest that modulating the levels of cytokinin glucosylation can function as a fine-tuning switch in regulating the formation of agronomic traits in rice.
Collapse
Affiliation(s)
- Xiao-Ling Shang
- The National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research (Shanghai), Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Rong-Rong Xie
- The National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research (Shanghai), Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Hua Tian
- The National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research (Shanghai), Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Qing-Long Wang
- The National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research (Shanghai), Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Fang-Qing Guo
- The National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research (Shanghai), Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| |
Collapse
|
212
|
Abstract
Cytokinin is an essential plant hormone that is involved in a wide range of plant growth and developmental processes which are controlled through its signalling pathway. Cytokinins are a class of molecules that are N(6)-substituted adenine derivatives, such as isopentenyl adenine, and trans- and cis-zeatin, which are common in most plants. The ability to perceive and respond to cytokinin occurs through a modified bacterial two-component pathway that functions via a multi-step phosphorelay. This cytokinin signalling process is a crucial part of almost all stages of plant life, from embryo patterning to apical meristem regulation, organ development and eventually senescence. The cytokinin signalling pathway involves the co-ordination of three types of proteins: histidine kinase receptors to perceive the signal, histidine phosphotransfer proteins to relay the signal, and response regulators to provide signal output. This pathway contains both positive and negative elements that function in a complex co-ordinated manner to control cytokinin-regulated plant responses. Although much is known about how this cytokinin signal is perceived and initially regulated, there are still many avenues that need to be explored before the role of cytokinin in the control of plant processes is fully understood.
Collapse
|
213
|
Nemchinov LG, Boutanaev AM, Postnikova OA. Virus-induced gene silencing of the RPC5-like subunit of RNA polymerase III caused pleiotropic effects in Nicotiana benthamiana. Sci Rep 2016; 6:27785. [PMID: 27282827 PMCID: PMC4901293 DOI: 10.1038/srep27785] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 05/24/2016] [Indexed: 12/30/2022] Open
Abstract
In eukaryotic cells, RNA polymerase III is highly conserved and transcribes housekeeping genes such as ribosomal 5S rRNA, tRNA and other small RNAs. The RPC5-like subunit is one of the 17 subunits forming RNAPIII and its exact functional roles in the transcription are poorly understood. In this work, we report that virus-induced gene silencing of transcripts encoding a putative RPC5-like subunit of the RNA Polymerase III in a model species Nicotiana benthamiana had pleiotropic effects, including but not limited to severe dwarfing appearance, chlorosis, nearly complete reduction of internodes and abnormal leaf shape. Using transcriptomic analysis, we identified genes and pathways affected by RPC5 silencing and thus presumably related to the cellular roles of the subunit as well as to the downstream cascade of reactions in response to partial loss of RNA Polymerase III function. Our results suggest that silencing of the RPC5L in N. benthamiana disrupted not only functions commonly associated with the core RNA Polymerase III transcripts, but also more diverse cellular processes, including responses to stress. We believe this is the first demonstration that activity of the RPC5 subunit is critical for proper functionality of RNA Polymerase III and normal plant development.
Collapse
Affiliation(s)
- Lev G. Nemchinov
- USDA/ARS, Beltsville Agricultural Research Center, Molecular Plant Pathology Laboratory, Beltsville MD 20705, USA
| | - Alexander M. Boutanaev
- Institute of Basic Biological Problems, Russian Academy of Sciences, 2 Institute Street, Pushchino, Moscow Region, 142292, Russia
| | - Olga A. Postnikova
- USDA/ARS, Beltsville Agricultural Research Center, Molecular Plant Pathology Laboratory, Beltsville MD 20705, USA
| |
Collapse
|
214
|
Phytohormones of microalgae: biological role and involvement in the regulation of physiological processes. Pt II. Cytokinins and gibberellins. ACTA ACUST UNITED AC 2016. [DOI: 10.15407/alg26.02.203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
215
|
Zheng C, Zhu Y, Wang C, Guo T. Wheat Grain Yield Increase in Response to Pre-Anthesis Foliar Application of 6-Benzylaminopurine Is Dependent on Floret Development. PLoS One 2016; 11:e0156627. [PMID: 27258059 PMCID: PMC4892633 DOI: 10.1371/journal.pone.0156627] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 05/17/2016] [Indexed: 12/02/2022] Open
Abstract
Wheat yield is largely determined during the period prior to flowering, when the final numbers of fertile florets and grains per spike are established. The aim of this study was to assess the dynamics of floret primordia development in winter wheat in response to pre-anthesis application of a synthetic cytokinin, 6-benzylaminopurine (6-BA). We conducted an experiment in which two foliar spray treatments were applied (water or 6-BA) to Chinese winter wheat at 25 days after jointing during two growing seasons (2012–2013 and 2013–2014). Both the final grain number per spike and grain yield at maturity exhibited remarkable increases in response to the 6-BA treatment. Application of 6-BA increased the number of fertile florets in basal spikelets and, to a greater extent, in central spikelets. The mechanism by which 6-BA application affected the final number of fertile florets primarily involved suppression of the floret abortion rates. Application of 6-BA considerably reduced the abortion rates of basal, central and apical spikelet florets (by as much as 77% compared with the control), as well as the degeneration rates of basal and central spikelet florets, albeit to a lesser degree. The effect of 6-BA application on the likelihood of proximal florets being set was limited to the distal florets in the whole spike, whereas obvious increases in the likelihood of grain set under 6-BA treatment were observed in distal florets, primarily in central spikelet positions. The results of this study provide important evidence that 6-BA application to florets (final fertile floret production) results in an increased grain yield.
Collapse
Affiliation(s)
- Chunfeng Zheng
- The College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- The Collaborative Innovation Centre of Henan Food Crops, Henan Agricultural University, Zhengzhou, 450002, China
- The National Engineering Research Centre for Wheat, Henan Agricultural University, Zhengzhou, 450002, China
| | - Yunji Zhu
- The College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- The Collaborative Innovation Centre of Henan Food Crops, Henan Agricultural University, Zhengzhou, 450002, China
- The National Engineering Research Centre for Wheat, Henan Agricultural University, Zhengzhou, 450002, China
- * E-mail:
| | - Chenyang Wang
- The College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- The Collaborative Innovation Centre of Henan Food Crops, Henan Agricultural University, Zhengzhou, 450002, China
- The National Engineering Research Centre for Wheat, Henan Agricultural University, Zhengzhou, 450002, China
| | - Tiancai Guo
- The College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- The Collaborative Innovation Centre of Henan Food Crops, Henan Agricultural University, Zhengzhou, 450002, China
- The National Engineering Research Centre for Wheat, Henan Agricultural University, Zhengzhou, 450002, China
| |
Collapse
|
216
|
Liu C, Pedersen C, Schultz-Larsen T, Aguilar GB, Madriz-Ordeñana K, Hovmøller MS, Thordal-Christensen H. The stripe rust fungal effector PEC6 suppresses pattern-triggered immunity in a host species-independent manner and interacts with adenosine kinases. THE NEW PHYTOLOGIST 2016. [PMID: 27252028 DOI: 10.1111/nph.14034] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/25/2016] [Indexed: 05/20/2023]
Abstract
We identified a wheat stripe rust (Puccinia striiformis) effector candidate (PEC6) with pattern-triggered immunity (PTI) suppression function and its corresponding host target. PEC6 compromised PTI host species-independently. In Nicotiana benthamiana, it hampers reactive oxygen species (ROS) accumulation and callose deposition induced by Pseudomonas fluorescens. In Arabidopsis, plants expressing PEC6 were more susceptible to Pseudomonas syringae pv. tomato (Pto) DC3000 ΔAvrPto/ΔAvrPtoB. In wheat, PEC6-suppression of P. fluorescens-elicited PTI was revealed by the fact that it allowed activation of effector-triggered immunity by Pto DC3000. Knocking down of PEC6 expression by virus-mediated host-induced gene silencing decreased the number of rust pustules, uncovering PEC6 as an important pathogenicity factor. PEC6, overexpressed in plant cells without its signal peptide, was localized to the nucleus and cytoplasm. A yeast two-hybrid assay showed that PEC6 interacts with both wheat and Arabidopsis adenosine kinases (ADKs). Knocking down wheat ADK expression by virus-induced gene silencing reduced leaf growth and enhanced the number of rust pustules, indicating that ADK is important in plant development and defence. ADK plays essential roles in regulating metabolism, cytokinin interconversion and methyl transfer reactions, and our data propose a model where PEC6 may affect one of these processes by targeting ADK to favour fungal growth.
Collapse
Affiliation(s)
- Changhai Liu
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Carsten Pedersen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Torsten Schultz-Larsen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Geziel B Aguilar
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Kenneth Madriz-Ordeñana
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Mogens S Hovmøller
- Department of Agroecology, Aarhus University, Forsøgsvej 1, Slagelse, DK-4200, Denmark
| | - Hans Thordal-Christensen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| |
Collapse
|
217
|
Nguyen QT, Kisiala A, Andreas P, Neil Emery R, Narine S. Soybean Seed Development: Fatty Acid and Phytohormone Metabolism and Their Interactions. Curr Genomics 2016; 17:241-60. [PMID: 27252591 PMCID: PMC4869011 DOI: 10.2174/1389202917666160202220238] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 07/27/2015] [Accepted: 08/04/2015] [Indexed: 12/20/2022] Open
Abstract
Vegetable oil utilization is determined by its fatty acid composition. In soybean and other grain crops, during the seed development oil accumulation is important trait for value in food or industrial applications. Seed development is relatively short and sensitive to unfavorable abiotic conditions. These stresses can lead to a numerous undesirable qualitative as well as quantitative changes in fatty acid production. Fatty acid manipulation which targets a higher content of a specific single fatty acid for food or industrial application has gained more attention. Despite several successes in modifying the ratio of endogenous fatty acids in most domesticated oilseed crops, numerous obstacles in FA manipulation of seed maturation are yet to be overcome. Remarkably, connections with plant hormones have not been well studied despite their critical roles in the regulation and promotion of a plethora of processes in plant growth and development. While activities of phytohormones during the reproductive phase have been partially clarified in seed physiology, the biological role of plant hormones in oil accumulation during seed development has not been investigated. In this review seed development and numerous effects of abiotic stresses are discussed. After describing fatty acid and phytohormone metabolism and their interactions, we postulate that the endogenous plant hormones play important roles in fatty acid production in soybean seeds.
Collapse
Affiliation(s)
- Quoc Thien. Nguyen
- Environmental & Life Sciences Graduate Program, Trent University, Peterborough, Ontario,Canada
| | - Anna Kisiala
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - Peter Andreas
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - R.J. Neil Emery
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - Suresh Narine
- Trent Centre for Biomaterials Research, Departments of Physics & Astronomy and Chemistry, Trent University, Peterborough,Ontario, Canada
| |
Collapse
|
218
|
Zürcher E, Müller B. Cytokinin Synthesis, Signaling, and Function--Advances and New Insights. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 324:1-38. [PMID: 27017005 DOI: 10.1016/bs.ircmb.2016.01.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The plant hormones referred to as cytokinins are chemical signals that control numerous developmental processes throughout the plant life cycle, including gametogenesis, root meristem specification, vascular development, shoot and root growth, meristem homeostasis, senescence, and more. In addition, they mediate responses to environmental cues such as light, stress, and nutrient conditions. The core mechanistics of cytokinin metabolism and signaling have been elucidated, but more layers of regulation, additional functions, and interactions with other signals are continuously discovered and described. In this chapter, we recapitulate the highlights of over 100 years of cytokinin research covering its isolation, the elucidation of phosphorelay signaling, and how cytokinin functions in various developmental contexts including its interaction with other pathways. Additionally, given cytokinin's paracrine signaling mechanism, we postulate that cellular exporters for cytokinins exist.
Collapse
Affiliation(s)
- E Zürcher
- Department of Plant and Microbial Biology, Zurich-Basel Plant Science Center, University of Zurich Zurich, Switzerland
| | - B Müller
- Department of Plant and Microbial Biology, Zurich-Basel Plant Science Center, University of Zurich Zurich, Switzerland.
| |
Collapse
|
219
|
Roy A, Sahoo D, Tripathy BC. Light-hormone interaction in the red-light-induced suppression of photomorphogenesis in rice seedlings. PROTOPLASMA 2016; 253:393-402. [PMID: 25902895 DOI: 10.1007/s00709-015-0818-1] [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: 11/30/2014] [Accepted: 04/07/2015] [Indexed: 06/04/2023]
Abstract
Red light perceived by the shoot bottom suppresses photomorphogenesis in rice seedlings mediated by phytochrome A. Shoots of these seedlings grown in red light having their shoot bottom exposed were deficient in chlorophyll and accumulated high concentration of trans-zeatin riboside. However, reduced presence of isopentynyl adenosine, dihydrozeatin riboside was observed in shoots of red-light-grown non-green seedlings in comparison to green seedling. The message abundance of cytokinin receptor (OsHK5), transporters (OsENT1, OsENT2), and response regulators (OsRR4, OsRR10) was downregulated in these red-light-grown non-green seedlings. Attenuation of greening process was reversed by application of exogenous cytokinin analogue, benzyladenine, or supplementing red light with blue light. In the same vein, the suppression of gene expression of cytokinin receptor, transporters, and type-A response regulators was reversed in red-light-grown seedlings treated with benzyladenine suggesting that the disarrayed cytokinin (CK) signaling cascade is responsible for non-greening of seedlings grown in red light. The reversal of red-light-induced suppression of photomorphogenesis by blue light and benzyladenine demonstrates the interaction of light and cytokinin signaling cascades in the regulation of photomorphogenesis. Partial reversal of greening process by exogenous application of benzyladenine suggests, apart from CKs perception, transportation and responsiveness, other factors are also involved in modulation of suppression of photomorphogenesis by red light.
Collapse
Affiliation(s)
- Ansuman Roy
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | | | - Baishnab C Tripathy
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
| |
Collapse
|
220
|
Agarwal P, Dabi M, More P, Patel K, Jana K, Agarwal PK. Improved Shoot Regeneration, Salinity Tolerance and Reduced Fungal Susceptibility in Transgenic Tobacco Constitutively Expressing PR-10a Gene. FRONTIERS IN PLANT SCIENCE 2016; 7:217. [PMID: 26973666 PMCID: PMC4770195 DOI: 10.3389/fpls.2016.00217] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 02/08/2016] [Indexed: 05/06/2023]
Abstract
Plants in ecosystems are simultaneously exposed to abiotic and biotic stresses, which restrict plant growth and development. The complex responses to these stresses are largely regulated by plant hormones, which in turn, orchestrate the different biochemical and molecular pathways to maneuver stress tolerance. The PR-10 protein family is reported to be involved in defense regulation, stress response and plant growth and development. The JcPR-10a overexpression resulted in increased number of shoot buds in tobacco (Nicotiana tabacum), which could be due to high cytokinin to auxin ratio in the transgenics. The docking analysis shows the binding of three BAP molecules at the active sites of JcPR-10a protein. JcPR-10a transgenics showed enhanced salt tolerance, as was evident by increased germination rate, shoot and root length, relative water content, proline, soluble sugar and amino acid content under salinity. Interestingly, the transgenics also showed enhanced endogenous cytokinin level as compared to WT, which, further increased with salinity. Exposure of gradual salinity resulted in increased stomatal conductance, water use efficiency, photosynthesis rate and reduced transpiration rate. Furthermore, the transgenics also showed enhanced resistance against Macrophomina fungus. Thus, JcPR-10a might be working in co-ordination with cytokinin signaling in mitigating the stress induced damage by regulating different stress signaling pathways, leading to enhanced stress tolerance.
Collapse
Affiliation(s)
- Parinita Agarwal
- Division of Wasteland Research, CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific & Industrial ResearchBhavnagar, India
| | - Mitali Dabi
- Division of Wasteland Research, CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific & Industrial ResearchBhavnagar, India
- Academy of Scientific and Innovative Research, CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial ResearchBhavnagar, India
| | - Prashant More
- Division of Wasteland Research, CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific & Industrial ResearchBhavnagar, India
- Academy of Scientific and Innovative Research, CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial ResearchBhavnagar, India
| | - Khantika Patel
- Division of Wasteland Research, CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific & Industrial ResearchBhavnagar, India
| | - Kalyanashis Jana
- Academy of Scientific and Innovative Research, CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial ResearchBhavnagar, India
| | - Pradeep K. Agarwal
- Division of Wasteland Research, CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific & Industrial ResearchBhavnagar, India
- Academy of Scientific and Innovative Research, CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial ResearchBhavnagar, India
| |
Collapse
|
221
|
Hart DS, Keightley A, Sappington D, Nguyen PTM, Chritton C, Seckinger GR, Torres KC. Stability of adenine-based cytokinins in aqueous solution. IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY. PLANT : JOURNAL OF THE TISSUE CULTURE ASSOCIATION 2016; 52:1-9. [PMID: 26937154 PMCID: PMC4759223 DOI: 10.1007/s11627-015-9734-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 11/19/2015] [Indexed: 06/05/2023]
Abstract
Since the isolation of the first cytokinin almost 60 yr ago, cytokinins have become critically important for ornamental and agricultural crops in plant tissue culture. Despite the extensive research on this class of compounds, little information is available on the chemical stability of cytokinins in solution or following an autoclave cycle with Murashige and Skoog (MS) basal medium. This work describes the stability in aqueous solutions of five widely used adenine-based cytokinins: trans-zeatin (tZ), 6-(γ,γ-dimethylallylamino) purine (2iP), kinetin, benzyladenine (BA), and m-topolin. High pressure liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (ESI-MS) were used to quantify and identify their degradation. BA, kinetin, 2iP, and m-topolin were stable at 1.0 mg mL-1 in 0.05 N KOH, with no statistically significant concentration changes (p > 0.05) after 90 d of storage at temperatures of -20°C, 2-6°C, or 25°C. The cytokinin tZ was used as a model compound to evaluate stability under alkaline and acid conditions as well as after repeated freeze-thaw cycles. Trans-zeatin retained >90% of the initial concentration of 1.0 mg mL-1 when dissolved in 0.01 N KOH and stored at -20°C and 2-6°C for 90 d, with only the 2-6°C temperature treatment showing a statistical significant concentration change (p = 0.03). The 1.0 mg mL-1 tZ solution in 0.01 N KOH was stable through six repeated freeze-thaw cycles over 90 d without any significant change in concentration compared to the initial freeze-thaw. Yet, tZ showed highly significant concentration changes when dissolved at 50 mg mL-1 and 0.5 N KOH. All of these adenine-based cytokinins showed exceptional stability following an autoclave cycle at 121°C, 110 kPa for 30 min when in solutions of 1.0 mg mL-1 in 0.05 N KOH, with no significant degradation detected. Trans-zeatin was also found to be stable after one autoclave cycle with 1× MS-basal salts.
Collapse
Affiliation(s)
- David S. Hart
- />PhytoTechnology Laboratories, 9245 Flint Street, Overland Park, KS 66214 USA
| | - Andrew Keightley
- />Biological Mass Spectrometry and Proteomics Facility, University of Missouri at Kansas City, Kansas, MO 64110 USA
| | - Daryl Sappington
- />PhytoTechnology Laboratories, 9245 Flint Street, Overland Park, KS 66214 USA
| | - Phuong T. M. Nguyen
- />PhytoTechnology Laboratories, 9245 Flint Street, Overland Park, KS 66214 USA
| | - Charleen Chritton
- />PhytoTechnology Laboratories, 9245 Flint Street, Overland Park, KS 66214 USA
| | - Gary R. Seckinger
- />PhytoTechnology Laboratories, 9245 Flint Street, Overland Park, KS 66214 USA
| | - Kenneth C. Torres
- />PhytoTechnology Laboratories, 9245 Flint Street, Overland Park, KS 66214 USA
| |
Collapse
|
222
|
Décima Oneto C, Otegui ME, Baroli I, Beznec A, Faccio P, Bossio E, Blumwald E, Lewi D. Water deficit stress tolerance in maize conferred by expression of an isopentenyltransferase (IPT) gene driven by a stress- and maturation-induced promoter. J Biotechnol 2016; 220:66-77. [DOI: 10.1016/j.jbiotec.2016.01.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 10/22/2022]
|
223
|
von Schwartzenberg K, Lindner AC, Gruhn N, Šimura J, Novák O, Strnad M, Gonneau M, Nogué F, Heyl A. CHASE domain-containing receptors play an essential role in the cytokinin response of the moss Physcomitrella patens. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:667-79. [PMID: 26596764 PMCID: PMC4737067 DOI: 10.1093/jxb/erv479] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
While the molecular basis for cytokinin action is quite well understood in flowering plants, little is known about the cytokinin signal transduction in early diverging land plants. The genome of the bryophyte Physcomitrella patens (Hedw.) B.S. encodes three classical cytokinin receptors, the CHASE domain-containing histidine kinases, CHK1, CHK2, and CHK3. In a complementation assay with protoplasts of receptor-deficient Arabidopsis thaliana as well as in cytokinin binding assays, we found evidence that CHK1 and CHK2 receptors can function in cytokinin perception. Using gene targeting, we generated a collection of CHK knockout mutants comprising single (Δchk1, Δchk2, Δchk3), double (Δchk1,2, Δchk1,3, Δchk2,3), and triple (Δchk1,2,3) mutants. Mutants were characterized for their cytokinin response and differentiation capacities. While the wild type did not grow on high doses of cytokinin (1 µM benzyladenine), the Δchk1,2,3 mutant exhibited normal protonema growth. Bud induction assays showed that all three cytokinin receptors contribute to the triggering of budding, albeit to different extents. Furthermore, while the triple mutant showed no response in this bioassay, the remaining mutants displayed budding responses in a diverse manner to different types and concentrations of cytokinins. Determination of cytokinin levels in mutants showed no drastic changes for any of the cytokinins; thus, in contrast to Arabidopsis, revealing only small impacts of cytokinin signaling on homeostasis. In summary, our study provides a first insight into the molecular action of cytokinin in an early diverging land plant and demonstrates that CHK receptors play an essential role in bud induction and gametophore development.
Collapse
Affiliation(s)
| | - Ann-Cathrin Lindner
- Biozentrum Klein Flottbek, Universität Hamburg, Ohnhorststr. 18, D-22609 Hamburg, Germany
| | - Njuscha Gruhn
- Institute for Biology/ Applied Genetics, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Albrecht-Thaer-Weg 6, D-14195 Berlin, Germany
| | - Jan Šimura
- Laboratory of Growth Regulators & Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic
| | - Ondřej Novák
- Laboratory of Growth Regulators & Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic
| | - Miroslav Strnad
- Laboratory of Growth Regulators & Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic
| | - Martine Gonneau
- Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, INRA Centre de Versailles-Grignon, Route de St-Cyr, 78026 Versailles Cedex, France
| | - Fabien Nogué
- Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, INRA Centre de Versailles-Grignon, Route de St-Cyr, 78026 Versailles Cedex, France
| | - Alexander Heyl
- Institute for Biology/ Applied Genetics, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Albrecht-Thaer-Weg 6, D-14195 Berlin, Germany Biology Department, Adelphi University, Science 116, 1 South Avenue, PO Box 701, Garden City, NY 11530-070, USA
| |
Collapse
|
224
|
Vylíčilová H, Husičková A, Spíchal L, Srovnal J, Doležal K, Plíhal O, Plíhalová L. C2-substituted aromatic cytokinin sugar conjugates delay the onset of senescence by maintaining the activity of the photosynthetic apparatus. PHYTOCHEMISTRY 2016; 122:22-33. [PMID: 26706318 DOI: 10.1016/j.phytochem.2015.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/29/2015] [Accepted: 12/02/2015] [Indexed: 05/04/2023]
Abstract
Cytokinins are plant hormones with biological functions ranging from coordination of plant growth and development to the regulation of senescence. A series of 2-chloro-N(6)-(halogenobenzylamino)purine ribosides was prepared and tested for cytokinin activity in detached wheat leaf senescence, tobacco callus and Amaranthus bioassays. The synthetic compounds showed significant activity, especially in delaying senescence in detached wheat leaves. They were also tested in bacterial receptor bioassays using both monocot and dicot members of the cytokinin receptor family. Most of the derivatives did not trigger cytokinin signaling via the AHK3 and AHK4 receptors from Arabidopsis thaliana in the bacterial assay, but some of them specifically activated the ZmHK1 receptor from Zea mays and were also more active than the aromatic cytokinin BAP in an ARR5::GUS cytokinin bioassay using transgenic Arabidopsis plants. Whole transcript expression analysis was performed using an Arabidopsis model to gather information about the reprogramming of gene transcription when senescent leaves were treated with selected C2-substituted aromatic cytokinin ribosides. Genome-wide expression profiling revealed that the synthetic halogenated derivatives induced the expression of genes related to cytokinin signaling and metabolism. They also prompted both up- and down-regulation of a unique combination of genes coding for components of the photosystem II (PSII) reaction center, light-harvesting complex II (LHCII), and the oxygen-evolving complex, as well as several stress factors responsible for regulating photosynthesis and chlorophyll degradation. Chlorophyll content and fluorescence analyses demonstrated that treatment with the halogenated derivatives increased the efficiency of PSII photochemistry and the abundance of LHCII relative to DMSO- and BAP-treated controls. These findings demonstrate that it is possible to manipulate and fine-tune leaf longevity using synthetic aromatic cytokinin analogs.
Collapse
Affiliation(s)
- Hana Vylíčilová
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Chemical Biology and Genetics, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| | - Alexandra Husičková
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Biophysics, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| | - Lukáš Spíchal
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Chemical Biology and Genetics, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| | - Josef Srovnal
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University and University Hospital in Olomouc, Hněvotínská 5, CZ-77900 Olomouc, Czech Republic
| | - Karel Doležal
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Chemical Biology and Genetics, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| | - Ondřej Plíhal
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Molecular Biology, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic.
| | - Lucie Plíhalová
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Chemical Biology and Genetics, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| |
Collapse
|
225
|
Jiskrová E, Novák O, Pospíšilová H, Holubová K, Karády M, Galuszka P, Robert S, Frébort I. Extra- and intracellular distribution of cytokinins in the leaves of monocots and dicots. N Biotechnol 2016; 33:735-742. [PMID: 26777983 DOI: 10.1016/j.nbt.2015.12.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/13/2015] [Accepted: 12/16/2015] [Indexed: 10/22/2022]
Abstract
The plant hormones cytokinins are a convenient target of genetic manipulations that bring benefits in biotechnological applications. The present work demonstrates the importance of the subcellular compartmentalization of cytokinins on the model dicot plant Arabidopsis thaliana and monocot crop Hordeum vulgare. The method of protoplast and vacuole isolation combined with precise cytokinin analysis and recovery assay of a vacuolar marker protein were used to quantify the contents of individual cytokinin forms in the leaf extracellular space, cell interior and vacuole. The data obtained for wild type plants and in each case a specific mutant line allow comparing the effect of genetic manipulations on the hormone distribution and homeostatic balance of cytokinins in the modified plants.
Collapse
Affiliation(s)
- Eva Jiskrová
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| | - Ondřej Novák
- Department of Metabolomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| | - Hana Pospíšilová
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| | - Katarína Holubová
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| | - Michal Karády
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic; Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå SE-90183, Sweden
| | - Petr Galuszka
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic
| | - Stéphanie Robert
- Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå SE-90183, Sweden
| | - Ivo Frébort
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc CZ-78371, Czech Republic.
| |
Collapse
|
226
|
Pospíšilová H, Jiskrová E, Vojta P, Mrízová K, Kokáš F, Čudejková MM, Bergougnoux V, Plíhal O, Klimešová J, Novák O, Dzurová L, Frébort I, Galuszka P. Transgenic barley overexpressing a cytokinin dehydrogenase gene shows greater tolerance to drought stress. N Biotechnol 2016; 33:692-705. [PMID: 26773738 DOI: 10.1016/j.nbt.2015.12.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/07/2015] [Accepted: 12/08/2015] [Indexed: 01/10/2023]
Abstract
Together with auxins, cytokinins are the main plant hormones involved in many different physiological processes. Given this knowledge, cytokinin levels can be manipulated by genetic modification in order to improve agronomic parameters of cereals in relation to, for example, morphology, yield, and tolerance to various stresses. The barley (Hordeum vulgare) cultivar Golden Promise was transformed using the cytokinin dehydrogenase 1 gene from Arabidopsis thaliana (AtCKX1) under the control of mild root-specific β-glucosidase promoter from maize. Increased cytokinin degradation activity was observed positively to affect the number and length of lateral roots. The impact on morphology depended upon the recombinant protein's subcellular compartmentation. While assumed cytosolic and vacuolar targeting of AtCKX1 had negligible effect on shoot growth, secretion of AtCKX1 protein to the apoplast had a negative effect on development of the aerial part and yield. Upon the application of severe drought stress, all transgenic genotypes maintained higher water content and showed better growth and yield parameters during revitalization. Higher tolerance to drought stress was most caused by altered root morphology resulting in better dehydration avoidance.
Collapse
Affiliation(s)
- Hana Pospíšilová
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Eva Jiskrová
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Petr Vojta
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic; Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hněvotínská 1333/5, 779 00 Olomouc, Czech Republic
| | - Katarína Mrízová
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Filip Kokáš
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Mária Majeská Čudejková
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Veronique Bergougnoux
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Ondřej Plíhal
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Jana Klimešová
- Department of Crop Science, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic
| | - Ondřej Novák
- Department of Metabolomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Lenka Dzurová
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Ivo Frébort
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Petr Galuszka
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
| |
Collapse
|
227
|
Shanks CM, Rice JH, Zubo Y, Schaller GE, Hewezi T, Kieber JJ. The Role of Cytokinin During Infection of Arabidopsis thaliana by the Cyst Nematode Heterodera schachtii. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:57-68. [PMID: 26479273 DOI: 10.1094/mpmi-07-15-0156-r] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Plant-parasitic cyst nematodes induce the formation of hypermetabolic feeding sites, termed syncytia, as their sole source of nutrients. The formation of the syncytium is orchestrated by the nematode, in part, by modulation of phytohormone responses, including cytokinin. In response to infection by the nematode Heterodera schachtii, cytokinin signaling is transiently induced at the site of infection and in the developing syncytium. Arabidopsis lines with reduced cytokinin sensitivity show reduced susceptibility to nematode infection, indicating that cytokinin signaling is required for optimal nematode development. Furthermore, lines with increased cytokinin sensitivity also exhibit reduced nematode susceptibility. To ascertain why cytokinin hypersensitivity reduces nematode parasitism, we examined the transcriptomes in wild type and a cytokinin-hypersensitive type-A arr Arabidopsis mutant in response to H. schachtii infection. Genes involved in the response to biotic stress and defense response were elevated in the type-A arr mutant in the absence of nematodes and were hyperinduced following H. schachtii infection, which suggests that the Arabidopsis type-A arr mutants impede nematode development because they are primed to respond to pathogen infection. These results suggest that cytokinin signaling is required for optimal H. schachtii parasitism of Arabidopsis but that elevated cytokinin signaling triggers a heightened immune response to nematode infection.
Collapse
Affiliation(s)
- Carly M Shanks
- 1 Department of Biology, University of North Carolina, Chapel Hill, NC 27599, U.S.A
| | - J Hollis Rice
- 2 Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996, U.S.A
| | - Yan Zubo
- 3 Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, U.S.A
| | - G Eric Schaller
- 3 Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, U.S.A
| | - Tarek Hewezi
- 2 Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996, U.S.A
| | - Joseph J Kieber
- 1 Department of Biology, University of North Carolina, Chapel Hill, NC 27599, U.S.A
| |
Collapse
|
228
|
Shahzad A, Siddiqui S, Bano A. Rhizoremediation of petroleum hydrocarbon, prospects and future. RSC Adv 2016. [DOI: 10.1039/c6ra12458e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Oil refineries generate several tones of oily waste which is dumped in an open pit within the vicinity of oil field.
Collapse
Affiliation(s)
- Asim Shahzad
- Mohi-Ud-Din Islamic University
- Pakistan
- Department of Bio Sciences
- University of Wah
- Wah Cannt
| | - Samina Siddiqui
- National Center for Excellence in Geology
- University of Peshawar
- Pakistan
| | - Asghari Bano
- Department of Bio Sciences
- University of Wah
- Wah Cannt
- Pakistan
| |
Collapse
|
229
|
Shull TE, Kurepa J, Smalle JA. Cytokinin signaling promotes differential stability of type-B ARRs. PLANT SIGNALING & BEHAVIOR 2016; 11:e1169354. [PMID: 27031369 PMCID: PMC4883968 DOI: 10.1080/15592324.2016.1169354] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 03/14/2016] [Accepted: 03/16/2016] [Indexed: 06/05/2023]
Abstract
Cytokinins control key aspects of plant growth, including shoot and root meristem development and the timing of senescence of leaves and stems. Cytokinin perception triggers a 2-component signaling mechanism that ultimately leads to phosphorylation-dependent activation of a class of transcriptional regulators called type-B ARRs (RRBs). We have recently shown that the stability of the RRB family member ARR1 is increased in response to elevated cytokinin concentrations. In contrast, cytokinin decreases the stability of the closely related RRB member ARR2. The molecular mechanism governing the differential stability regulation of these 2 closely related RRBs remains unknown.
Collapse
Affiliation(s)
- Timothy E. Shull
- University of Kentucky, College of Agriculture, Food and Environment, Department of Plant and Soil Science, Lexington, KY, USA
| | - Jasmina Kurepa
- University of Kentucky, College of Agriculture, Food and Environment, Department of Plant and Soil Science, Lexington, KY, USA
| | - Jan A. Smalle
- University of Kentucky, College of Agriculture, Food and Environment, Department of Plant and Soil Science, Lexington, KY, USA
| |
Collapse
|
230
|
Paul S, Wildhagen H, Janz D, Teichmann T, Hänsch R, Polle A. Tissue- and Cell-Specific Cytokinin Activity in Populus × canescens Monitored by ARR5::GUS Reporter Lines in Summer and Winter. FRONTIERS IN PLANT SCIENCE 2016; 7:652. [PMID: 27242853 PMCID: PMC4865519 DOI: 10.3389/fpls.2016.00652] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/28/2016] [Indexed: 05/20/2023]
Abstract
Cytokinins play an important role in vascular development. But knowledge on the cellular localization of this growth hormone in the stem and other organs of woody plants is lacking. The main focus of this study was to investigate the occurrence and cellular localization of active cytokinins in leaves, roots, and along the stem of Populus × canescens and to find out how the pattern is changed between summer and winter. An ARR5::GUS reporter construct was used to monitor distribution of active cytokinins in different tissues of transgenic poplar lines. Three transgenic lines tested under outdoor conditions showed no influence of ARR5::GUS reporter construct on the growth performance compared with the wild-type, but one line lost the reporter activity. ARR5::GUS activity indicated changes in the tissue- and cell type-specific pattern of cytokinin activity during dormancy compared with the growth phase. ARR5::GUS activity, which was present in the root tips in the growing season, disappeared in winter. In the stem apex ground tissue, ARR5::GUS activity was higher in winter than in summer. Immature leaves from tissue-culture grown plants showed inducible ARR5::GUS activity. Leaf primordia in summer showed ARR5::GUS activity, but not the expanded leaves of outdoor plants or leaf primordia in winter. In stem cross sections, the most prominent ARR5::GUS activity was detected in the cortex region and in the rays of bark in summer and in winter. In the cambial zone the ARR5::GUS activity was more pronounced in the dormant than in growth phase. The pith and the ray cells adjacent to the vessels also displayed ARR5::GUS activity. In silico analyses of the tissue-specific expression patterns of the whole PtRR type-A family of poplar showed that PtRR10, the closest ortholog to the Arabidopsis ARR5 gene, was usually the most highly expressed gene in all tissues. In conclusion, gene expression and tissue-localization indicate high activity of cytokinins not only in summer, but also in winter. The presence of the signal in meristematic tissues supports their role in meristem maintenance. The reporter lines will be useful to study the involvement of cytokinins in acclimation of poplar growth to stress.
Collapse
Affiliation(s)
- Shanty Paul
- Department of Forest Botany and Tree Physiology, Georg-August-Universität GöttingenGöttingen, Germany
| | - Henning Wildhagen
- Department of Forest Botany and Tree Physiology, Georg-August-Universität GöttingenGöttingen, Germany
| | - Dennis Janz
- Department of Forest Botany and Tree Physiology, Georg-August-Universität GöttingenGöttingen, Germany
| | - Thomas Teichmann
- Department of Forest Botany and Tree Physiology, Georg-August-Universität GöttingenGöttingen, Germany
| | - Robert Hänsch
- Department of Molecular and Cell Biology of Plants, Institute for Plant Biology, University of TechnologyBraunschweig, Germany
| | - Andrea Polle
- Department of Forest Botany and Tree Physiology, Georg-August-Universität GöttingenGöttingen, Germany
- *Correspondence: Andrea Polle,
| |
Collapse
|
231
|
Brizzolari A, Marinello C, Carini M, Santaniello E, Biondi PA. Evaluation of the antioxidant activity and capacity of some natural N6-substituted adenine derivatives (cytokinins) by fluorimetric and spectrophotometric assays. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 1019:164-8. [PMID: 26753810 DOI: 10.1016/j.jchromb.2015.12.047] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 11/25/2022]
Abstract
Four natural N(6)-substituted adenine derivatives (cytokinins) were evaluated for the first time in vitro for they antioxidant capacity by using fluorimetric and spectrophotometric assays, i.e., the oxygen radical absorbance capacity (ORAC), trolox equivalence antioxidant capacity (TEAC) and the 2-deoxyribose degradation (2-DRA) assays. The results from the TEAC assay show that only N(6)-(4-hydroxybenzyl)adenine (p-topolin) shows an electron transfer capacity due to the presence of a phenolic moiety in the N(6)-position. The results from the ORAC test show that the antioxidant activity of N(6)-furfuryladenine (kinetin, K) is the highest up to a concentration of 1 μM, whereas at concentrations higher than 1 μM p-topolin is the most efficient antioxidant. Analysis of the kinetic data suggests that, compared to the other cytokinins, more sites of the molecular structure of p-topolin are available for the quenching of peroxyl radicals. The hydroxyl radical scavenger ability, as measured by the 2-DRA assay, showed that all tested cytokinins react in this test and that N(6)-(Δ(2)-isopentenyl)adenine is slightly more potent, probably because of the allylic methylene group present in the N(6)-isopentenyl moiety. Our data suggest that a part of the biological activity of the evaluated cytokinins is likely to be related to an intrinsic antioxidant capacity.
Collapse
Affiliation(s)
- Andrea Brizzolari
- Department of Health Sciences, Università degli Studi di Milano, Via Di Rudinì 8, 20142 Milan, Italy
| | - Cristina Marinello
- Department of Pharmaceutical Sciences, Università degli Studi di Milano, Via Mangiagalli 25, 20133 Milano, Italy
| | - Marina Carini
- Department of Pharmaceutical Sciences, Università degli Studi di Milano, Via Mangiagalli 25, 20133 Milano, Italy
| | - Enzo Santaniello
- Department of Health Sciences, Università degli Studi di Milano, Via Di Rudinì 8, 20142 Milan, Italy
| | - Pier Antonio Biondi
- Department of Veterinary Science and Public Health, Università degli Studi di Milano, Via Celoria 10, 20133 Milan, Italy.
| |
Collapse
|
232
|
Fan X, Wu J, Chen T, Tie W, Chen H, Zhou F, Lin Y. Loss-of-function mutation of rice SLAC7 decreases chloroplast stability and induces a photoprotection mechanism in rice. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:1063-77. [PMID: 25739330 PMCID: PMC5029597 DOI: 10.1111/jipb.12350] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 02/25/2015] [Indexed: 05/11/2023]
Abstract
Plants absorb sunlight to power the photochemical reactions of photosynthesis, which can potentially damage the photosynthetic machinery. However, the mechanism that protects chloroplasts from the damage remains unclear. In this work, we demonstrated that rice (Oryza sativa L.) SLAC7 is a generally expressed membrane protein. Loss-of-function of SLAC7 caused continuous damage to the chloroplasts of mutant leaves under normal light conditions. Ion leakage indicators related to leaf damage such as H2 O2 and abscisic acid levels were significantly higher in slac7-1 than in the wild type. Consistently, the photosynthesis efficiency and Fv/Fm ratio of slac7-1 were significantly decreased (similar to photoinhibition). In response to chloroplast damage, slac7-1 altered its leaf morphology (curled or fused leaf) by the synergy between plant hormones and transcriptional factors to decrease the absorption of light, suggesting that a photoprotection mechanism for chloroplast damage was activated in slac7-1. When grown in dark conditions, slac7-1 displayed a normal phenotype. SLAC7 under the control of the AtSLAC1 promoter could partially complement the phenotypes of Arabidopsis slac1 mutants, indicating a partial conservation of SLAC protein functions. These results suggest that SLAC7 is essential for maintaining the chloroplast stability in rice.
Collapse
Affiliation(s)
- Xiaolei Fan
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jiemin Wu
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
| | - Taiyu Chen
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
| | - Weiwei Tie
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
| | - Hao Chen
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
| | - Fei Zhou
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yongjun Lin
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
| |
Collapse
|
233
|
Xu J, Zhang L, Yang DL, Li Q, He Z. Thymidine kinases share a conserved function for nucleotide salvage and play an essential role in Arabidopsis thaliana growth and development. THE NEW PHYTOLOGIST 2015; 208:1089-1103. [PMID: 26139575 DOI: 10.1111/nph.13530] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 05/23/2015] [Indexed: 06/04/2023]
Abstract
Thymidine kinases (TKs) are important components in the nucleotide salvage pathway. However, knowledge about plant TKs is quite limited. In this study, the molecular function of TKs in Arabidopsis thaliana was investigated. Two TKs were identified and named AtTK1 and AtTK2. Expression of both genes was ubiquitous, but AtTK1 was strongly expressed in high-proliferation tissues. AtTK1 was localized to the cytosol, whereas AtTK2 was localized to the mitochondria. Mutant analysis indicated that the two genes function coordinately to sustain normal plant development. Enzymatic assays showed that the two TK proteins shared similar catalytic specificity for pyrimidine nucleosides. They were able to complement an Escherichia coli strain lacking TK activity. 5'-Fluorodeoxyuridine (FdU) resistance and 5-ethynyl 2'-deoxyuridine (EdU) incorporation assays confirmed their activity in vivo. Furthermore, the tk mutant phenotype could be alleviated by nucleotide feeding, establishing that the biosynthesis of pyrimidine nucleotides was disrupted by the TK deficiency. Finally, both human and rice (Oryza sativa) TKs were able to rescue the tk mutants, demonstrating the functional conservation of TKs across organisms. Taken together, our findings clarify the specialized function of two TKs in A. thaliana and establish that the salvage pathway mediated by the kinases is essential for plant growth and development.
Collapse
Affiliation(s)
- Jing Xu
- National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Lin Zhang
- National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Dong-Lei Yang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qun Li
- National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Zuhua He
- National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| |
Collapse
|
234
|
Kopečný D, Končitíková R, Popelka H, Briozzo P, Vigouroux A, Kopečná M, Zalabák D, Šebela M, Skopalová J, Frébort I, Moréra S. Kinetic and structural investigation of the cytokinin oxidase/dehydrogenase active site. FEBS J 2015; 283:361-77. [PMID: 26519657 DOI: 10.1111/febs.13581] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/26/2015] [Accepted: 10/28/2015] [Indexed: 12/24/2022]
Abstract
Cytokinins are hormones that regulate plant development and their environmental responses. Their levels are mainly controlled by the cytokinin oxidase/dehydrogenase (CKO), which oxidatively cleaves cytokinins using redox-active electron acceptors. CKO belongs to the group of flavoproteins with an 8α-N1-histidyl FAD covalent linkage. Here, we investigated the role of seven active site residues, H105, D169, E288, V378, E381, P427 and L492, in substrate binding and catalysis of the CKO1 from maize (Zea mays, ZmCKO1) combining site-directed mutagenesis with kinetics and X-ray crystallography. We identify E381 as a key residue for enzyme specificity that restricts substrate binding as well as quinone electron acceptor binding. We show that D169 is important for catalysis and that H105 covalently linked to FAD maintains the enzyme's structural integrity, stability and high rates with electron acceptors. The L492A mutation significantly modulates the cleavage of aromatic cytokinins and zeatin isomers. The high resolution X-ray structures of ZmCKO1 and the E381S variant in complex with N6-(2-isopentenyl)adenosine reveal the binding mode of cytokinin ribosides. Those of ZmCKO2 and ZmCKO4a contain a mobile domain, which might contribute to binding of the N9 substituted cytokinins.
Collapse
Affiliation(s)
- David Kopečný
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Radka Končitíková
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Hana Popelka
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Pierre Briozzo
- Institut Jean-Pierre Bourgin, UMR1318 INRA, AgroParisTech, Versailles, France
| | - Armelle Vigouroux
- Institute for Integrative Biology of the Cell (I2BC), CNRS-CEA-Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Martina Kopečná
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - David Zalabák
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Marek Šebela
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Jana Skopalová
- Department of Analytical Chemistry, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Ivo Frébort
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Solange Moréra
- Institute for Integrative Biology of the Cell (I2BC), CNRS-CEA-Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| |
Collapse
|
235
|
Jégu T, Domenichini S, Blein T, Ariel F, Christ A, Kim SK, Crespi M, Boutet-Mercey S, Mouille G, Bourge M, Hirt H, Bergounioux C, Raynaud C, Benhamed M. A SWI/SNF Chromatin Remodelling Protein Controls Cytokinin Production through the Regulation of Chromatin Architecture. PLoS One 2015; 10:e0138276. [PMID: 26457678 PMCID: PMC4601769 DOI: 10.1371/journal.pone.0138276] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/26/2015] [Indexed: 02/07/2023] Open
Abstract
Chromatin architecture determines transcriptional accessibility to DNA and consequently gene expression levels in response to developmental and environmental stimuli. Recently, chromatin remodelers such as SWI/SNF complexes have been recognized as key regulators of chromatin architecture. To gain insight into the function of these complexes during root development, we have analyzed Arabidopsis knock-down lines for one sub-unit of SWI/SNF complexes: BAF60. Here, we show that BAF60 is a positive regulator of root development and cell cycle progression in the root meristem via its ability to down-regulate cytokinin production. By opposing both the deposition of active histone marks and the formation of a chromatin regulatory loop, BAF60 negatively regulates two crucial target genes for cytokinin biosynthesis (IPT3 and IPT7) and one cell cycle inhibitor (KRP7). Our results demonstrate that SWI/SNF complexes containing BAF60 are key factors governing the equilibrium between formation and dissociation of a chromatin loop controlling phytohormone production and cell cycle progression.
Collapse
Affiliation(s)
- Teddy Jégu
- Institut de Biologie des Plantes, UMR8618 CNRS-Université Paris-Sud XI, Saclay Plant Sciences, Orsay, France
| | - Séverine Domenichini
- Institut de Biologie des Plantes, UMR8618 CNRS-Université Paris-Sud XI, Saclay Plant Sciences, Orsay, France
| | - Thomas Blein
- Institut des Sciences du Végétal, UPR2355 CNRS, Saclay Plant Sciences, Gif-sur-Yvette, France
| | - Federico Ariel
- Institut des Sciences du Végétal, UPR2355 CNRS, Saclay Plant Sciences, Gif-sur-Yvette, France
| | - Aurélie Christ
- Institut des Sciences du Végétal, UPR2355 CNRS, Saclay Plant Sciences, Gif-sur-Yvette, France
| | - Soon-Kap Kim
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology KAUST, Thuwal, Saudi Arabia
| | - Martin Crespi
- Institut des Sciences du Végétal, UPR2355 CNRS, Saclay Plant Sciences, Gif-sur-Yvette, France
| | | | - Grégory Mouille
- Institut Jean-Pierre Bourgin, UMR1318 INRA/AgroParisTech, Versailles, France
| | - Mickaël Bourge
- Pôle de Biologie Cellulaire, Imagif, Centre de Recherche de Gif, CNRS, IFR87, Gif-sur-Yvette, France
| | - Heribert Hirt
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology KAUST, Thuwal, Saudi Arabia
| | - Catherine Bergounioux
- Institut de Biologie des Plantes, UMR8618 CNRS-Université Paris-Sud XI, Saclay Plant Sciences, Orsay, France
| | - Cécile Raynaud
- Institut de Biologie des Plantes, UMR8618 CNRS-Université Paris-Sud XI, Saclay Plant Sciences, Orsay, France
| | - Moussa Benhamed
- Institut de Biologie des Plantes, UMR8618 CNRS-Université Paris-Sud XI, Saclay Plant Sciences, Orsay, France
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology KAUST, Thuwal, Saudi Arabia
- * E-mail:
| |
Collapse
|
236
|
Böttcher C, Burbidge CA, Boss PK, Davies C. Changes in transcription of cytokinin metabolism and signalling genes in grape (Vitis vinifera L.) berries are associated with the ripening-related increase in isopentenyladenine. BMC PLANT BIOLOGY 2015; 15:223. [PMID: 26377914 PMCID: PMC4573921 DOI: 10.1186/s12870-015-0611-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/10/2015] [Indexed: 05/02/2023]
Abstract
BACKGROUND Cytokinins are known to play an important role in fruit set and early fruit growth, but their involvement in later stages of fruit development is less well understood. Recent reports of greatly increased cytokinin concentrations in the flesh of ripening kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang & A.R. Ferguson) and grapes (Vitis vinifera L.) have suggested that these hormones are implicated in the control of ripening-related processes. RESULTS A similar pattern of isopentenyladenine (iP) accumulation was observed in the ripening fruit of several grapevine cultivars, strawberry (Fragaria ananassa Duch.) and tomato (Solanum lycopersicum Mill.), suggesting a common, ripening-related role for this cytokinin. Significant differences in maximal iP concentrations between grapevine cultivars and between fruit species might reflect varying degrees of relevance or functional adaptations of this hormone in the ripening process. Grapevine orthologues of five Arabidopsis (Arabidopsis thaliana L.) gene families involved in cytokinin metabolism and signalling were identified and analysed for their expression in developing grape berries and a range of other grapevine tissues. Members of each gene family were characterised by distinct expression profiles during berry development and in different grapevine organs, suggesting a complex regulation of cellular cytokinin activities throughout the plant. The post-veraison-specific expression of a set of biosynthesis, activation, perception and signalling genes together with a lack of expression of degradation-related genes during the ripening phase were indicative of a local control of berry iP concentrations leading to the observed accumulation of iP in ripening grapes. CONCLUSIONS The transcriptional analysis of grapevine genes involved in cytokinin production, degradation and response has provided a possible explanation for the ripening-associated accumulation of iP in grapes and other fruit. The pre- and post-veraison-specific expression of different members from each of five gene families suggests a highly complex and finely-tuned regulation of cytokinin concentrations and response to different cytokinin species at particular stages of fruit development. The same complexity and specialisation is also reflected in the distinct expression profiles of cytokinin-related genes in other grapevine organs.
Collapse
Affiliation(s)
- Christine Böttcher
- CSIRO Agriculture Flagship, Waite Campus, WIC West Building, PMB2, Glen Osmond, South Australia, 5064, Australia.
| | - Crista A Burbidge
- CSIRO Agriculture Flagship, Waite Campus, WIC West Building, PMB2, Glen Osmond, South Australia, 5064, Australia.
| | - Paul K Boss
- CSIRO Agriculture Flagship, Waite Campus, WIC West Building, PMB2, Glen Osmond, South Australia, 5064, Australia.
| | - Christopher Davies
- CSIRO Agriculture Flagship, Waite Campus, WIC West Building, PMB2, Glen Osmond, South Australia, 5064, Australia.
| |
Collapse
|
237
|
Poursarebani N, Seidensticker T, Koppolu R, Trautewig C, Gawroński P, Bini F, Govind G, Rutten T, Sakuma S, Tagiri A, Wolde GM, Youssef HM, Battal A, Ciannamea S, Fusca T, Nussbaumer T, Pozzi C, Börner A, Lundqvist U, Komatsuda T, Salvi S, Tuberosa R, Uauy C, Sreenivasulu N, Rossini L, Schnurbusch T. The Genetic Basis of Composite Spike Form in Barley and 'Miracle-Wheat'. Genetics 2015; 201:155-65. [PMID: 26156223 PMCID: PMC4566260 DOI: 10.1534/genetics.115.176628] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 06/27/2015] [Indexed: 12/21/2022] Open
Abstract
Inflorescences of the tribe Triticeae, which includes wheat (Triticum sp. L.) and barley (Hordeum vulgare L.) are characterized by sessile spikelets directly borne on the main axis, thus forming a branchless spike. 'Compositum-Barley' and tetraploid 'Miracle-Wheat' (T. turgidum convar. compositum (L.f.) Filat.) display noncanonical spike-branching in which spikelets are replaced by lateral branch-like structures resembling small-sized secondary spikes. As a result of this branch formation 'Miracle-Wheat' produces significantly more grains per spike, leading to higher spike yield. In this study, we first isolated the gene underlying spike-branching in 'Compositum-Barley,' i.e., compositum 2 (com2). Moreover, we found that COM2 is orthologous to the branched head(t) (bh(t)) locus regulating spike branching in tetraploid 'Miracle-Wheat.' Both genes possess orthologs with similar functions in maize BRANCHED SILKLESS 1 (BD1) and rice FRIZZY PANICLE/BRANCHED FLORETLESS 1 (FZP/BFL1) encoding AP2/ERF transcription factors. Sequence analysis of the bh(t) locus in a collection of mutant and wild-type tetraploid wheat accessions revealed that a single amino acid substitution in the DNA-binding domain gave rise to the domestication of 'Miracle-Wheat.' mRNA in situ hybridization, microarray experiments, and independent qRT-PCR validation analyses revealed that the branch repression pathway in barley is governed through the spike architecture gene Six-rowed spike 4 regulating COM2 expression, while HvIDS1 (barley ortholog of maize INDETERMINATE SPIKELET 1) is a putative downstream target of COM2. These findings presented here provide new insights into the genetic basis of spike architecture in Triticeae, and have disclosed new targets for genetic manipulations aiming at boosting wheat's yield potential.
Collapse
Affiliation(s)
- Naser Poursarebani
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Tina Seidensticker
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Ravi Koppolu
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Corinna Trautewig
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Piotr Gawroński
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Federica Bini
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Geetha Govind
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Twan Rutten
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Shun Sakuma
- National Institute of Agrobiological Sciences, Plant Genome Research Unit, Tsukuba 305 8602, Japan
| | - Akemi Tagiri
- National Institute of Agrobiological Sciences, Plant Genome Research Unit, Tsukuba 305 8602, Japan
| | - Gizaw M Wolde
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Helmy M Youssef
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany Faculty of Agriculture, Cairo University, 12613 Giza, Egypt
| | - Abdulhamit Battal
- John Innes Centre, Department of Crop Genetics, Colney, Norwich, NR4 7UH, United Kingdom Biological Sciences, Middle East Technical University, Cankaya, 06800, Ankara, Turkey
| | | | | | - Thomas Nussbaumer
- Plant Genome and Systems Biology, Helmholtz Center Munich, D-85764, Neuherberg, Germany
| | | | - Andreas Börner
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Udda Lundqvist
- Nordic Genetic Resource Center, SE-230 53 Alnarp, Sweden
| | - Takao Komatsuda
- National Institute of Agrobiological Sciences, Plant Genome Research Unit, Tsukuba 305 8602, Japan
| | - Silvio Salvi
- Dipartimento di Scienze Agrarie, University of Bologna, 40127 Bologna, Italy
| | - Roberto Tuberosa
- Dipartimento di Scienze Agrarie, University of Bologna, 40127 Bologna, Italy
| | - Cristobal Uauy
- John Innes Centre, Department of Crop Genetics, Colney, Norwich, NR4 7UH, United Kingdom
| | - Nese Sreenivasulu
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| | - Laura Rossini
- Parco Tecnologico Padano, 26900 Lodi, Italy Università degli Studi di Milano, DiSAA, I-20133 Milan, Italy
| | - Thorsten Schnurbusch
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, D-06466 Stadt Seeland, Germany
| |
Collapse
|
238
|
Maita S, Sotomayor C. The effect of three plant bioregulators on pollen germination, pollen tube growth and fruit set in almond [Prunus dulcis (Mill.) D.A. Webb] cvs. Non Pareil and Carmel. ELECTRON J BIOTECHN 2015. [DOI: 10.1016/j.ejbt.2015.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
|
239
|
Chen LJ, Liu J, Zhao FF, Li JY, Wang SX, Lin HH, Xi DH. Characterisation of the dark green islands of cucumber mosaic virus infected Nicotiana tabacum. PLANT CELL REPORTS 2015; 34:1225-38. [PMID: 25782691 DOI: 10.1007/s00299-015-1781-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 02/24/2015] [Accepted: 03/03/2015] [Indexed: 06/04/2023]
Abstract
KEY MESSAGE There are significant differences between the DGIs and LGTs. Additionally, most of the characteristics indicate that the DGIs are more similar to recovered tissue and can resist viral attacks. Dark green islands (DGIs) surrounded by light green tissues (LGTs) are common leaf symptoms of plants that are systemically infected by various mosaic viruses. We performed cytological, physiological and molecular biological analyses of the DGIs and LGTs in cucumber mosaic virus-infected Nicotiana tabacum leaves. Our results indicated that the DGIs contained less virus than did the LGTs. Compared to the LGTs, the DGIs contained higher levels of the metabolites involved in plant defence. The contents of reduced glutathione and ascorbic acid were increased in the DGIs to reach levels that were even higher than those of control plants. Moreover, hormone measurements and quantitative real-time PCR analysis revealed that the endogenous salicylic acid, ethylene and defence genes mediated these elevations by playing positive roles in the regulation of the DGIs responses to viral infection. The accumulation of cytokinin was also much greater in the DGIs than in the LGTs. Finally, northern blotting analysis indicated that the accumulation of viral small interfering RNAs was decreased in the DGIs compared to the LGTs. Taken together, these results suggest that DGIs might represent leaf areas that have recovered from viral infection due to locally enhanced defence responses.
Collapse
Affiliation(s)
- Li-Juan Chen
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, Chengdu, 610064, China
| | | | | | | | | | | | | |
Collapse
|
240
|
Mooi CMY, Koh SP, Long K. Simultaneous detection and quantification of zeatin and kinetin in coconut water using ultra performance liquid chromatography coupled with a simple step solid phase extraction. JOURNAL OF ANALYTICAL CHEMISTRY 2015. [DOI: 10.1134/s1061934815070114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
241
|
Li YJ, Wang B, Dong RR, Hou BK. AtUGT76C2, an Arabidopsis cytokinin glycosyltransferase is involved in drought stress adaptation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2015; 236:157-67. [PMID: 26025529 DOI: 10.1016/j.plantsci.2015.04.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/27/2015] [Accepted: 04/01/2015] [Indexed: 05/20/2023]
Abstract
The Arabidopsis uridine diphosphate (UDP)-glycosyltransferase 76C2 (UGT76C2), a member of family 1 UGTs, is described as a cytokinin glycosyltransferase. In this study, we demonstrate a novel role of UGT76C2 in response to water deficit. QRT-PCR assay identified that the expression of this gene was downregulated by drought, osmotic stress and abscisic acid (ABA). Compared with wild type (WT) plants, transgenic lines ectopically expressing UGT76C2 exhibited reduced tolerance to ABA and osmotic stress during postgermination growth, while enhanced adaptation to drought stress at mature stage. Consistently, the ugt76c2 mutant plants showed opposite responses to these conditions. To explore the possible mechanisms of UGT76C2 contributing to drought stress adaptation, six stress inducible genes including DREB2A, RD22, RD29B, LEA, COR47 and KIN1 were detected, which showed significant upregulation in UGT76C2 overexpression plants under drought stress. Besides, five cytokinin marker genes AHK2, AHK3, AHK4, ARR1 and ARR2 were also evaluated, which showed less induced in UGT76C2 overexpression plants in response to drought stress. Our results reveal that UGT76C2, as a cytokinin glycosyltransferase, is involved in the plant response to drought stress and might represent novel cues in abiotic stress adaptation.
Collapse
Affiliation(s)
- Yan-jie Li
- The Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education of China, School of Life Science, Shandong University, Jinan, Shandong 250100, PR China
| | - Bo Wang
- The Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education of China, School of Life Science, Shandong University, Jinan, Shandong 250100, PR China; Institute of Applied Chemistry and Biological Engineering, Weifang Engineering Vocational College, Weifang, Shandong 262500, PR China
| | - Rui-rui Dong
- The Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education of China, School of Life Science, Shandong University, Jinan, Shandong 250100, PR China
| | - Bing-kai Hou
- The Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education of China, School of Life Science, Shandong University, Jinan, Shandong 250100, PR China.
| |
Collapse
|
242
|
Morrison EN, Emery RJN, Saville BJ. Phytohormone Involvement in the Ustilago maydis- Zea mays Pathosystem: Relationships between Abscisic Acid and Cytokinin Levels and Strain Virulence in Infected Cob Tissue. PLoS One 2015; 10:e0130945. [PMID: 26107181 PMCID: PMC4479884 DOI: 10.1371/journal.pone.0130945] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/27/2015] [Indexed: 02/02/2023] Open
Abstract
Ustilago maydis is the causative agent of common smut of corn. Early studies noted its ability to synthesize phytohormones and, more recently these growth promoting substances were confirmed as cytokinins (CKs). Cytokinins comprise a group of phytohormones commonly associated with actively dividing tissues. Lab analyses identified variation in virulence between U. maydis dikaryon and solopathogen infections of corn cob tissue. Samples from infected cob tissue were taken at sequential time points post infection and biochemical profiling was performed using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI MS/MS). This hormone profiling revealed that there were altered levels of ABA and major CKs, with a marked reduction in CK glucosides, increases in methylthiol CKs and a particularly dramatic increase in cisZ CK forms, in U. maydis infected tissue. These changes were more pronounced in the more virulent dikaryon relative to the solopathogenic strain suggesting a role for cytokinins in moderating virulence during biotrophic infection. These findings highlight the fact that U. maydis does not simply mimic a fertilized seed but instead reprograms the host tissue. Results underscore the suitability of the Ustilago maydis- Zea mays model as a basis for investigating the control of phytohormone dynamics during biotrophic infection of plants.
Collapse
Affiliation(s)
- Erin N. Morrison
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada
| | - R. J. Neil Emery
- Biology Department, Trent University, Peterborough, Ontario, Canada
| | - Barry J. Saville
- Forensic Science Program, Trent University, Peterborough, Ontario, Canada
| |
Collapse
|
243
|
Ravi BX, Varuvel GVA, kilimas R, Robert J. Apogamous sporophyte development through spore reproduction of a South Asia's critically endangered fern: Pteris tripartita Sw. ASIAN PACIFIC JOURNAL OF REPRODUCTION 2015. [DOI: 10.1016/s2305-0500(15)30010-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
244
|
Functional roles of three cutin biosynthetic acyltransferases in cytokinin responses and skotomorphogenesis. PLoS One 2015; 10:e0121943. [PMID: 25803274 PMCID: PMC4372371 DOI: 10.1371/journal.pone.0121943] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/09/2015] [Indexed: 11/24/2022] Open
Abstract
Cytokinins (CKs) regulate plant development and growth via a two-component signaling pathway. By forward genetic screening, we isolated an Arabidopsis mutant named grow fast on cytokinins 1 (gfc1), whose seedlings grew larger aerial parts on MS medium with CK. gfc1 is allelic to a previously reported cutin mutant defective in cuticular ridges (dcr). GFC1/DCR encodes a soluble BAHD acyltransferase (a name based on the first four enzymes characterized in this family: Benzylalcohol O-acetyltransferase, Anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase and Deacetylvindoline 4-O-acetyltransferase) with diacylglycerol acyltransferase (DGAT) activity in vitro and is necessary for normal cuticle formation on epidermis in vivo. Here we show that gfc1 was a CK-insensitive mutant, as revealed by its low regeneration frequency in vitro and resistance to CK in adventitious root formation and dark-grown hypocotyl inhibition assays. In addition, gfc1 had de-etiolated phenotypes in darkness and was therefore defective in skotomorphogenesis. The background expression levels of most type-A Arabidopsis Response Regulator (ARR) genes were higher in the gfc1 mutant. The gfc1-associated phenotypes were also observed in the cutin-deficient glycerol-3-phosphate acyltransferase 4/8 (gpat4/8) double mutant [defective in glycerol-3-phosphate (G3P) acyltransferase enzymes GPAT4 and GPAT8, which redundantly catalyze the acylation of G3P by hydroxyl fatty acid (OH-FA)], but not in the cutin-deficient mutant cytochrome p450, family 86, subfamily A, polypeptide 2/aberrant induction of type three 1 (cyp86A2/att1), which affects the biosynthesis of some OH-FAs. Our results indicate that some acyltransferases associated with cutin formation are involved in CK responses and skotomorphogenesis in Arabidopsis.
Collapse
|
245
|
Žižková E, Dobrev PI, Muhovski Y, Hošek P, Hoyerová K, Haisel D, Procházková D, Lutts S, Motyka V, Hichri I. Tomato (Solanum lycopersicum L.) SlIPT3 and SlIPT4 isopentenyltransferases mediate salt stress response in tomato. BMC PLANT BIOLOGY 2015; 15:85. [PMID: 25888402 PMCID: PMC4404076 DOI: 10.1186/s12870-015-0415-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 01/06/2015] [Indexed: 05/04/2023]
Abstract
BACKGROUND Cytokinins (CKs) are involved in response to various environmental cues, including salinity. It has been previously reported that enhancing CK contents improved salt stress tolerance in tomato. However, the underlying mechanisms of CK metabolism and signaling under salt stress conditions remain to be deciphered. RESULTS Two tomato isopentenyltransferases, SlIPT3 and SlIPT4, were characterized in tomato and Arabidopsis. Both proteins displayed isopentenyltransferase (IPT) activity in vitro, while their encoding genes exhibited different spatio-temporal expression patterns during tomato plant development. SlIPT3 and SlIPT4 were affected by the endogenous CK status, tightly connected with CKs feedback regulation, as revealed by hormonal treatements. In response to salt stress, SlIPT3 and SlIPT4 were strongly repressed in tomato roots, and differently affected in young and old leaves. SlIPT3 overexpression in tomato resulted in high accumulation of different CK metabolites, following modifications of CK biosynthesis-, signaling- and degradation-gene expression. In addition, 35S::SlIPT3 tomato plants displayed improved tolerance to salinity consecutive to photosynthetic pigments and K(+)/Na(+) ratio retention. Involvement of SlIPT3 and SlIPT4 in salt stress response was also observed in Arabidopsis ipt3 knock-out complemented plants, through maintenance of CK homeostasis. CONCLUSIONS SlIPT3 and SlIPT4 are functional IPTs encoded by differently expressed genes, distinctively taking part in the salinity response. The substantial participation of SlIPT3 in CK metabolism during salt stress has been determined in 35S::SlIPT3 tomato transformants, where enhancement of CKs accumulation significantly improved plant tolerance to salinity, underlining the importance of this phytohormone in stress response.
Collapse
Affiliation(s)
- Eva Žižková
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, 165 02, Czech Republic.
| | - Petre I Dobrev
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, 165 02, Czech Republic.
| | - Yordan Muhovski
- Département Sciences du vivant, Centre wallon de Recherches Agronomiques, Gembloux, B-5030, Belgium.
| | - Petr Hošek
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, 165 02, Czech Republic.
- Department of Biomedical Informatics, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, 272 01, Czech Republic.
| | - Klára Hoyerová
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, 165 02, Czech Republic.
| | - Daniel Haisel
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, 165 02, Czech Republic.
| | - Dagmar Procházková
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, 165 02, Czech Republic.
| | - Stanley Lutts
- Groupe de Recherche en Physiologie Végétale (GRPV), Earth and Life Institute - Agronomy (ELI-A), Université catholique de Louvain (UCL), Louvain-la-Neuve, 1348, Belgium.
| | - Václav Motyka
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, 165 02, Czech Republic.
| | - Imène Hichri
- Groupe de Recherche en Physiologie Végétale (GRPV), Earth and Life Institute - Agronomy (ELI-A), Université catholique de Louvain (UCL), Louvain-la-Neuve, 1348, Belgium.
- Institut National de la Recherche Agronomique, Institut Sophia Agrobiotech (ISA), UMR INRA 1355, CNRS 7254, Université de Nice-Sophia Antipolis, 400 route des Chappes, BP167, F-06903, Sophia-Antipolis Cedex, France.
| |
Collapse
|
246
|
Schäfer M, Meza-Canales ID, Navarro-Quezada A, Brütting C, Vanková R, Baldwin IT, Meldau S. Cytokinin levels and signaling respond to wounding and the perception of herbivore elicitors in Nicotiana attenuata. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:198-212. [PMID: 24924599 PMCID: PMC4286249 DOI: 10.1111/jipb.12227] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/11/2014] [Indexed: 05/21/2023]
Abstract
Nearly half a century ago insect herbivores were found to induce the formation of green islands by manipulating cytokinin (CK) levels. However, the response of the CK pathway to attack by chewing insect herbivores remains unclear. Here, we characterize the CK pathway of Nicotiana attenuata (Torr. ex S. Wats.) and its response to wounding and perception of herbivore-associated molecular patterns (HAMPs). We identified 44 genes involved in CK biosynthesis, inactivation, degradation, and signaling. Leaf wounding rapidly induced transcriptional changes in multiple genes throughout the pathway, as well as in the levels of CKs, including isopentenyladenosine and cis-zeatin riboside; perception of HAMPs present in the oral secretions (OS) of the specialist herbivore Manduca sexta amplified these responses. The jasmonate pathway, which triggers many herbivore-induced processes, was not required for these HAMP-triggered changes, but rather suppressed the CK responses. Interestingly CK pathway changes were observed also in systemic leaves in response to wounding and OS application indicating a role of CKs in mediating long distance systemic processes in response to herbivory. Since wounding and grasshopper OS elicited similar accumulations of CKs in Arabidopsis thaliana L., we propose that CKs are integral components of wounding and HAMP-triggered responses in many plant species.
Collapse
Affiliation(s)
- Martin Schäfer
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology07745, Jena, Germany
| | - Ivan D Meza-Canales
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology07745, Jena, Germany
| | - Aura Navarro-Quezada
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology07745, Jena, Germany
| | - Christoph Brütting
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology07745, Jena, Germany
| | - Radomira Vanková
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany AS CR165 02 Prague 6-Lysolaje, Czech Republic
| | - Ian T Baldwin
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology07745, Jena, Germany
| | - Stefan Meldau
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology07745, Jena, Germany
- German Centre for integrative Biodiversity Research (iDiv)04107, Leipzig, Germany
| |
Collapse
|
247
|
Morrison EN, Knowles S, Hayward A, Thorn RG, Saville BJ, Emery RJN. Detection of phytohormones in temperate forest fungi predicts consistent abscisic acid production and a common pathway for cytokinin biosynthesis. Mycologia 2015; 107:245-57. [PMID: 25572099 DOI: 10.3852/14-157] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The phytohormones, abscisic acid and cytokinin, once were thought to be present uniquely in plants, but increasing evidence suggests that these hormones are present in a wide variety of organisms. Few studies have examined fungi for the presence of these "plant" hormones or addressed whether their levels differ based on the nutrition mode of the fungus. This study examined 20 temperate forest fungi of differing nutritional modes (ectomycorrhizal, wood-rotting, saprotrophic). Abscisic acid and cytokinin were present in all fungi sampled; this indicated that the sampled fungi have the capacity to synthesize these two classes of phytohormones. Of the 27 cytokinins analyzed by HPLC-ESI MS/MS, seven were present in all fungi sampled. This suggested the existence of a common cytokinin metabolic pathway in fungi that does not vary among different nutritional modes. Predictions regarding the source of isopentenyl, cis-zeatin and methylthiol CK production stemming from the tRNA degradation pathway among fungi are discussed.
Collapse
Affiliation(s)
- Erin N Morrison
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, K9J 7B8 Canada
| | - Sarah Knowles
- Biology Department, Trent University, Peterborough, Ontario, K9J 7B8 Canada
| | - Allison Hayward
- Biology Department, Trent University, Peterborough, Ontario, K9J 7B8 Canada
| | - R Greg Thorn
- Department of Biology, Western University, London, Ontario, N6A 5B7 Canada
| | - Barry J Saville
- Forensic Science Program, Trent University, Peterborough, Ontario, K9J 7B8 Canada
| | - R J N Emery
- Biology Department, Trent University, Peterborough, Ontario, K9J 7B8 Canada
| |
Collapse
|
248
|
Zhao J, Bai W, Zeng Q, Song S, Zhang M, Li X, Hou L, Xiao Y, Luo M, Li D, Luo X, Pei Y. Moderately enhancing cytokinin level by down-regulation of GhCKX expression in cotton concurrently increases fiber and seed yield. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2015; 35:60. [PMID: 25653571 PMCID: PMC4309883 DOI: 10.1007/s11032-015-0232-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 08/29/2014] [Indexed: 05/03/2023]
Abstract
Cotton is the leading natural fiber crop in the world. Cotton seeds are also an important oil and protein source. However, enhancement of fiber abundance usually leads to a smaller seed. Thus, it has become a challenge for cotton breeding to concurrently increase fiber yield and seed yield. To improve cotton yield, we elevated the endogenous cytokinin level in transgenic cotton by constitutive suppression of cytokinin dehydrogenase (CKX), a key negative regulator controlling endogenous cytokinin in plants. The slightly and moderately suppressed transgenic cotton plants showed normal growth and development, while the severely suppressed plants exhibited a typical cytokinin-overproduction alteration. The suppression of CKX led to an enhancement of endogenous cytokinins in transgenic cotton plants. Total cytokinins in moderately suppressed lines, CR-3 and CR-6, increased by 20.4 and 55.5 % respectively, and that in the severely suppressed line (CR-13) increased by 134.2 % compared to the wild type. The moderately suppressed lines showed a delay in leaf senescence, higher photosynthesis, more fruiting branches and bolls, and bigger seed size. Field trials showed that seed yield and lint yield of the moderately suppressed CR-6 line increased by 15.4 and 20.0 %, respectively. Meanwhile, the enhanced cytokinin level in transgenic cottons did not show significant influence on fiber qualities. Our data demonstrated that CKX is a promising gene for crop yield improvement.
Collapse
Affiliation(s)
- Juan Zhao
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Wenqin Bai
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Qiwei Zeng
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Shuiqing Song
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Mi Zhang
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Xianbi Li
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Lei Hou
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Yuehua Xiao
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Ming Luo
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Demou Li
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Xiaoying Luo
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| | - Yan Pei
- Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400716 People’s Republic of China
| |
Collapse
|
249
|
The Importance of Phytohormones and Microbes in Biofertilizers. BACTERIAL METABOLITES IN SUSTAINABLE AGROECOSYSTEM 2015. [DOI: 10.1007/978-3-319-24654-3_6] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
250
|
Soil Bacteria and Phytohormones for Sustainable Crop Production. BACTERIAL METABOLITES IN SUSTAINABLE AGROECOSYSTEM 2015. [DOI: 10.1007/978-3-319-24654-3_5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|