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Palberg D, Kaszecki E, Dhanjal C, Kisiała A, Morrison EN, Stock N, Emery RJN. Impact of glyphosate and glyphosate-based herbicides on phyllospheric Methylobacterium. BMC Plant Biol 2024; 24:119. [PMID: 38369476 PMCID: PMC10875822 DOI: 10.1186/s12870-024-04818-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Accepted: 02/12/2024] [Indexed: 02/20/2024]
Abstract
Symbiotic Methylobacterium comprise a significant portion of the phyllospheric microbiome, and are known to benefit host plant growth, development, and confer tolerance to stress factors. The near ubiquitous use of the broad-spectrum herbicide, glyphosate, in farming operations globally has necessitated a more expansive evaluation of the impacts of the agent itself and formulations containing glyphosate on important components of the plant phyllosphere, including Methylobacterium.This study provides an investigation of the sensitivity of 18 strains of Methylobacterium to glyphosate and two commercially available glyphosate-based herbicides (GBH). Nearly all strains of Methylobacterium showed signs of sensitivity to the popular GBH formulations WeatherMax® and Transorb® in a modified Kirby Bauer experiment. However, exposure to pure forms of glyphosate did not show a significant effect on growth for any strain in both the Kirby Bauer test and in liquid broth, until polysorbate-20 (Tween20) was added as a surfactant. Artificially increasing membrane permeability through the introduction of polysorbate-20 caused a 78-84% reduction in bacterial cell biomass relative to controls containing glyphosate or high levels of surfactant only (0-9% and 6-37% reduction respectively). Concentrations of glyphosate as low as 0.05% w/v (500 µg/L) from both commercial formulations tested, inhibited the culturability of Methylobacterium on fresh nutrient-rich medium.To better understand the compatibility of important phyllospheric bacteria with commercial glyphosate-based herbicides, this study endeavours to characterize sensitivity in multiple strains of Methylobacterium, and explore possible mechanisms by which toxicity may be induced.
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Affiliation(s)
- Daniel Palberg
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Emma Kaszecki
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Chetan Dhanjal
- Department of Biological Sciences, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Anna Kisiała
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Erin N Morrison
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Naomi Stock
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
- Water Quality Centre, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - R J Neil Emery
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada.
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada.
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Kaszecki E, Palberg D, Grant M, Griffin S, Dhanjal C, Capperauld M, Emery RJN, Saville BJ. Euglena mutabilis exists in a FAB consortium with microbes that enhance cadmium tolerance. Int Microbiol 2024:10.1007/s10123-023-00474-7. [PMID: 38167969 DOI: 10.1007/s10123-023-00474-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/29/2023] [Accepted: 12/15/2023] [Indexed: 01/05/2024]
Abstract
BACKGROUND Synthetic algal-fungal and algal-bacterial cultures have been investigated as a means to enhance the technological applications of the algae. This inclusion of other microbes has enhanced growth and improved stress tolerance of the algal culture. The goal of the current study was to investigate natural microbial consortia to gain an understanding of the occurrence and benefits of these associations in nature. The photosynthetic protist Euglena mutabilis is often found in association with other microbes in acidic environments with high heavy metal (HM) concentrations. This may suggest that microbial interactions are essential for the protist's ability to tolerate these extreme environments. Our study assessed the Cd tolerance of a natural fungal-algal-bacterial (FAB) association whereby the algae is E. mutabilis. RESULTS This study provides the first assessment of antibiotic and antimycotic agents on an E. mutabilis culture. The results indicate that antibiotic and antimycotic applications significantly decreased the viability of E. mutabilis cells when they were also exposed to Cd. Similar antibiotic treatments of E. gracilis cultures had variable or non-significant impacts on Cd tolerance. E. gracilis also recovered better after pre-treatment with antibiotics and Cd than did E. mutabilis. The recoveries were assessed by heterotrophic growth without antibiotics or Cd. In contrast, both Euglena species displayed increased chlorophyll production upon Cd exposure. PacBio full-length amplicon sequencing and targeted Sanger sequencing identified the microbial species present in the E. mutabilis culture to be the fungus Talaromyces sp. and the bacterium Acidiphilium acidophilum. CONCLUSION This study uncovers a possible fungal, algal, and bacterial relationship, what we refer to as a FAB consortium. The members of this consortium interact to enhance the response to Cd exposure. This results in a E. mutabilis culture that has a higher tolerance to Cd than the axenic E. gracilis. The description of this interaction provides a basis for explore the benefits of natural interactions. This will provide knowledge and direction for use when creating or maintaining FAB interactions for biotechnological purposes, including bioremediation.
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Affiliation(s)
- Emma Kaszecki
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada
| | - Daniel Palberg
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada
| | - Mikaella Grant
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada
| | - Sarah Griffin
- Forensic Science Department, Trent University, Peterborough, ON, Canada
| | - Chetan Dhanjal
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | | | - R J Neil Emery
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - Barry J Saville
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada.
- Forensic Science Department, Trent University, Peterborough, ON, Canada.
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Dang DH, Kernaghan A, Emery RJN, Thompson KA, Kisiala A, Wang W. The mixed blessings of rare earth element supplements for tomatoes and ferns. Sci Total Environ 2024; 906:167822. [PMID: 37838051 DOI: 10.1016/j.scitotenv.2023.167822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 10/09/2023] [Accepted: 10/11/2023] [Indexed: 10/16/2023]
Abstract
Rare earth elements (REEs) constitute a key group of critical minerals that are strategic for the global low-carbon economy and several United Nations Sustainable Development Goals. Their expected escalating emissions into the environment from emerging anthropogenic sources can negatively affect natural ecosystems. However, their hormetic effects make these elements effective fertilizers to promote crop production. Here, we investigate the response of tomatoes and ferns to REE exposure (La, Gd, Yb). While ferns were unresponsive to REEs, these elements promote evident benefits in tomatoes, e.g., elevating nutrient uptake, higher photosynthetic capacity and phytohormone enhancement to allocate energy to green tissue and root development. Nevertheless, the non-selective cation uptake incurs risks of accumulating non-essential elements in edible tissues. These evident benefits of REEs on crops support applications in agricultural production systems, create added value to the global distribution and promote better material flow management of REEs as strategic and critical resources.
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Affiliation(s)
- Duc Huy Dang
- School of the Environment, Trent University, Peterborough, Canada; Department of Chemistry, Trent University, Peterborough, Canada.
| | - Ashlyn Kernaghan
- School of the Environment, Trent University, Peterborough, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, Canada
| | - Karen A Thompson
- School of the Environment, Trent University, Peterborough, Canada
| | - Anna Kisiala
- Department of Biology, Trent University, Peterborough, Canada
| | - Wei Wang
- School of the Environment, Trent University, Peterborough, Canada
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Aoki MM, Kisiala AB, Mathavarajah S, Schincaglia A, Treverton J, Habib E, Dellaire G, Emery RJN, Brunetti CR, Huber RJ. From biosynthesis and beyond-Loss or overexpression of the cytokinin synthesis gene, iptA, alters cytokinesis and mitochondrial and amino acid metabolism in Dictyostelium discoideum. FASEB J 2024; 38:e23366. [PMID: 38102957 DOI: 10.1096/fj.202301936rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/22/2023] [Accepted: 11/27/2023] [Indexed: 12/17/2023]
Abstract
Cytokinins (CKs) are a class of growth-promoting signaling molecules that affect multiple cellular and developmental processes. These phytohormones are well studied in plants, but their presence continues to be uncovered in organisms spanning all kingdoms, which poses new questions about their roles and functions outside of plant systems. Cytokinin production can be initiated by one of two different biosynthetic enzymes, adenylate isopentenyltransfases (IPTs) or tRNA isopentenyltransferases (tRNA-IPTs). In this study, the social amoeba, Dictyostelium discoideum, was used to study the role of CKs by generating deletion and overexpression strains of its single adenylate-IPT gene, iptA. The life cycle of D. discoideum is unique and possesses both single- and multicellular stages. Vegetative amoebae grow and divide while food resources are plentiful, and multicellular development is initiated upon starvation, which includes distinct life cycle stages. CKs are produced in D. discoideum throughout its life cycle and their functions have been well studied during the later stages of multicellular development of D. discoideum. To investigate potential expanded roles of CKs, this study focused on vegetative growth and early developmental stages. We found that iptA-deficiency results in cytokinesis defects, and both iptA-deficiency and overexpression results in dysregulated tricarboxylic acid (TCA) cycle and amino acid metabolism, as well as increased levels of adenosine monophosphate (AMP). Collectively, these findings extend our understanding of CK function in amoebae, indicating that iptA loss and overexpression alter biological processes during vegetative growth that are distinct from those reported during later development.
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Affiliation(s)
- Megan M Aoki
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - Anna B Kisiala
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | | | | | - Jared Treverton
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - Elias Habib
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Graham Dellaire
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - Craig R Brunetti
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - Robert J Huber
- Department of Biology, Trent University, Peterborough, Ontario, Canada
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5
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Tobin SW, Seneviratne D, Phan L, Seegobin M, Rico AL, Westby B, Kisiala A, Martic S, Brunetti CR, Emery RJN. Profiling of adenine-derived signaling molecules, cytokinins, in myotubes reveals fluctuations in response to lipopolysaccharide-induced cell stress. Physiol Rep 2023; 11:e15870. [PMID: 38040455 PMCID: PMC10691934 DOI: 10.14814/phy2.15870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/03/2023] [Accepted: 11/05/2023] [Indexed: 12/03/2023] Open
Abstract
Cytokinins (CTKs) are a diverse collection of evolutionarily conserved adenine-derived signaling molecules classically studied as phytohormones; however, their roles and production have been less studied in mammalian systems. Skeletal muscles are sensitive to cellular cues such as inflammation and in response, alter their secretome to regulate the muscle stem cell and myofiber niche. Using cultured C2C12 muscle cells, we profiled CTK levels to understand (1) whether CTKs are part of the muscle secretome and (2) whether CTKs are responsive to cellular stress. To induce cellular stress, C2C12 myotubes were treated with lipopolysaccharides (LPS) for 24 h and then media and cell fractions were collected for ultra high-performance liquid chromatography tandem mass spectrometry with electrospray ionization (UHPLC-(ESI+)-HRMS/MS) for metabolomics and CTK profiling. Across LPS-treated and control cells, 11 CTKs were detected in the extracellular space while 6 were detected intracellularly. We found that muscle cells are enriched in isopentenyladenine (iP) species (from free base, riboside to nucleotide forms), and that extracellular levels are increased after LPS treatment. Our study establishes that muscle cells express various forms of CTKs, and that CTK levels are responsive to LPS-induced cell stress, suggesting a role for CTKs in intra- and extracellular signaling of mammalian cells.
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Affiliation(s)
- Stephanie W. Tobin
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
| | - Dev Seneviratne
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
- Department of Forensic ScienceTrent UniversityPeterboroughCanada
| | - Lorna Phan
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
| | - Mark Seegobin
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
| | | | - Beth Westby
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
| | - Anna Kisiala
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
| | - Sanela Martic
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
- Department of Forensic ScienceTrent UniversityPeterboroughCanada
| | - Craig R. Brunetti
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
| | - R. J. Neil Emery
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
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Smith E, Lewis A, Narine SS, Emery RJN. Unlocking Potentially Therapeutic Phytochemicals in Capadulla ( Doliocarpus dentatus) from Guyana Using Untargeted Mass Spectrometry-Based Metabolomics. Metabolites 2023; 13:1050. [PMID: 37887375 PMCID: PMC10608729 DOI: 10.3390/metabo13101050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/22/2023] [Accepted: 09/28/2023] [Indexed: 10/28/2023] Open
Abstract
Doliocarpus dentatus is thought to have a wide variety of therapeutic phytochemicals that allegedly improve libido and cure impotence. Although a few biomarkers have been identified with potential antinociceptive and cytotoxic properties, an untargeted mass spectrometry-based metabolomics approach has never been undertaken to identify therapeutic biofingerprints for conditions, such as erectile dysfunction, in men. This study executes a preliminary phytochemical screening of the woody vine of two ecotypes of D. dentatus with renowned differences in therapeutic potential for erectile dysfunction. Liquid chromatography-mass spectrometry-based metabolomics was used to screen for flavonoids, terpenoids, and other chemical classes found to contrast between red and white ecotypes. Among the metabolite chemodiversity found in the ecotype screens, using a combination of GNPS, MS-DIAL, and SIRIUS, approximately 847 compounds were annotated at levels 2 to 4, with the majority of compounds falling under lipid and lipid-like molecules, benzenoids and phenylpropanoids, and polyketides, indicative of the contributions of the flavonoid, shikimic acid, and terpenoid biosynthesis pathways. Despite the extensive annotation, we report on 138 tentative compound identifications of potentially therapeutic compounds, with 55 selected compounds at a level-2 annotation, and 22 statistically significant therapeutic biomarkers, the majority of which were polyphenols. Epicatechin methyl gallate, catechin gallate, and proanthocyanidin A2 had the greatest significant differences and were also relatively abundant among the red and white ecotypes. These putatively identified compounds reportedly act as antioxidants, neutralizing damaging free radicals, and lowering cell oxidative stress, thus aiding in potentially preventing cellular damage and promoting overall well-being, especially for treating erectile dysfunction (ED).
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Affiliation(s)
- Ewart Smith
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9J 0G2, Canada
| | - Ainsely Lewis
- Department of Biology, Trent University, Peterborough, ON K9J 0G2, Canada
| | - Suresh S. Narine
- Trent Centre for Biomaterials Research, Trent University, Peterborough, ON K9J 0G2, Canada
- Departments of Physics & Astronomy and Chemistry, Trent University, Peterborough, ON K9J 0G2, Canada
| | - R. J. Neil Emery
- Department of Biology, Trent University, Peterborough, ON K9J 0G2, Canada
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7
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Logan SR, Seegobin M, Emery RJN, Brunetti CR. Components of the Nucleotide Salvage Pathway Increase Frog Virus 3 (FV3) Replication. Viruses 2023; 15:1716. [PMID: 37632058 PMCID: PMC10460048 DOI: 10.3390/v15081716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/02/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
Viruses are obligate intracellular parasites that alter host metabolic machinery to obtain energy and macromolecules that are pivotal for replication. Ranavirus, including the type species of the genus frog virus 3 (FV3), represent an ecologically important group of viruses that infect fish, amphibians, and reptiles. It was established that fatty acid synthesis, glucose, and glutamine metabolism exert roles during iridovirus infections; however, no information exists regarding the role of purine metabolism. In this study, we assessed the impact of exogenously applied purines adenine, adenosine, adenosine 5'-monophosphate (AMP), inosine 5'-monophosphate (IMP), inosine, S-adenosyl-L-homocysteine (SAH), and S-adenosyl-L-methionine (SAM) on FV3 replication. We found that all compounds except for SAH increased FV3 replication in a dose-dependent manner. Of the purines investigated, adenine and adenosine produced the most robust response, increasing FV3 replication by 58% and 51%, respectively. While all compounds except SAH increased FV3 replication, only adenine increased plaque area. This suggests that the stimulatory effect of adenine on FV3 replication is mediated by a mechanism that is at least in part independent from the other compounds investigated. Our results are the first to report a response to exogenously applied purines and may provide insight into the importance of purine metabolism during iridoviral infection.
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Affiliation(s)
| | | | | | - Craig R. Brunetti
- Department of Biology, Trent University, 1600 West Bank Dr., Peterborough, ON K9J 7B8, Canada; (S.R.L.); (R.J.N.E.)
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8
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Seng S, Ponce GE, Andreas P, Kisiala A, De Clerck-Floate R, Miller DG, Chen MS, Price PW, Tooker JF, Emery RJN, Connor EF. Abscisic Acid: A Potential Secreted Effector Synthesized by Phytophagous Insects for Host-Plant Manipulation. Insects 2023; 14:489. [PMID: 37367305 DOI: 10.3390/insects14060489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/18/2023] [Accepted: 05/18/2023] [Indexed: 06/28/2023]
Abstract
Abscisic acid (ABA) is an isoprenoid-derived plant signaling molecule involved in a wide variety of plant processes, including facets of growth and development as well as responses to abiotic and biotic stress. ABA had previously been reported in a wide variety of animals, including insects and humans. We used high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-(ESI)-MS/MS) to examine concentrations of ABA in 17 species of phytophagous insects, including gall- and non-gall-inducing species from all insect orders with species known to induce plant galls: Thysanoptera, Hemiptera, Lepidoptera, Coleoptera, Diptera, and Hymenoptera. We found ABA in insect species in all six orders, in both gall-inducing and non-gall-inducing species, with no tendency for gall-inducing insects to have higher concentrations. The concentrations of ABA in insects often markedly exceeded those typically found in plants, suggesting it is highly improbable that insects obtain all their ABA from their host plant via consumption and sequestration. As a follow-up, we used immunohistochemistry to determine that ABA localizes to the salivary glands in the larvae of the gall-inducing Eurosta solidaginis (Diptera: Tephritidae). The high concentrations of ABA, combined with its localization to salivary glands, suggest that insects are synthesizing and secreting ABA to manipulate their host plants. The pervasiveness of ABA among both gall- and non-gall-inducing insects and our current knowledge of the role of ABA in plant processes suggest that insects are using ABA to manipulate source-sink mechanisms of nutrient allocation or to suppress host-plant defenses. ABA joins the triumvirate of phytohormones, along with cytokinins (CKs) and indole-3-acetic acid (IAA), that are abundant, widespread, and localized to glandular organs in insects and used to manipulate host plants.
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Affiliation(s)
- Stephannie Seng
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - Gabriela E Ponce
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Peter Andreas
- Department of Biology, Trent University, Peterborough, ON K9J 7B8, Canada
| | - Anna Kisiala
- Department of Biology, Trent University, Peterborough, ON K9J 7B8, Canada
| | | | - Donald G Miller
- Department of Biological Sciences, California State University, Chico, CA 95929, USA
| | - Ming-Shun Chen
- USDA-ARS and Department of Entomology, Kansas State University, Manhattan, KS 66506, USA
| | - Peter W Price
- Department of Ecology and Evolutionary Biology, Northern Arizona University, Flagstaff, AZ 86001, USA
| | - John F Tooker
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, ON K9J 7B8, Canada
| | - Edward F Connor
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
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Nguyen NH, Nguyen QT, Dang DH, Emery RJN. Phytohormones enhance heavy metal responses in Euglena gracilis: Evidence from uptake of Ni, Pb and Cd and linkages to hormonomic and metabolomic dynamics. Environ Pollut 2023; 320:121094. [PMID: 36682616 DOI: 10.1016/j.envpol.2023.121094] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/28/2022] [Accepted: 01/14/2023] [Indexed: 06/17/2023]
Abstract
Over the last decade, significant effort has been made to understand phytohormonal functions (e.g., cytokinins (CKs) and abscisic acid (ABA)) in metal stress responses of higher plants and algae. Despite the potential for these phytohormones to improve industrial remediation by Euglena gracilis (Euglenophyceae), no such roles have been elucidated for this highly adaptive species and its response to heavy metals. This study demonstrates that toxic metals (nickel, lead, cadmium) modify hormonal activity profiles (i.e., CK forms and their concentrations) in E. gracilis. Furthermore, exogenous ABA or CK (tZ) enabled higher metal uptake efficiency (i.e., 9.35% in lead and 9.2% in cadmium uptake with CK) and alleviated metal toxicity through the regulation of endogenous CKs (i.e., total CK, isoprenoid CK) and gibberellin (GAs, GA1 and GA3) levels. These responses suggest that E. gracilis regulates multiple phytohormone signals during metal stress acclimation. A deeper approach, using untargeted metabolomic analyses, gave more detailed insight into phytohormone-controlled pathways and associated modified metabolites, which were frequently related to metal accumulation and the physiological acclimation to metal presence. Significant changes in the levels of cellular metabolites, especially those involved in acclimation to metal stress, were under the influence of phytohormones in algal cells. When grown under metal stress conditions, the presence of exogenous ABA or CKs, caused changes in cellular metabolites which included those from: lipid pathways, riboflavin metabolism, the biosynthesis of cofactors/vitamins, and carbohydrate metabolism. Also, bioactive secondary metabolites (e.g., terpenoids, alkaloids, flavonoids, carotenoids) were modified in algal cells treated with phytohormones. Thus, the study gives a detailed view on the regulatory functions of ABA and CKs in algal metal bioremediation strategies, which are attributed to enhanced metal uptake and in the fine-tuning of plant hormone levels during metal stress response. The results can guide efforts to develop efficient, low-cost and environmentally friendly methods for bioremediation.
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Affiliation(s)
- Ngoc Hai Nguyen
- Trent University, Department of Biology, Peterborough, Canada.
| | | | - Duc Huy Dang
- Trent University, School of the Environment and Chemistry Department, Peterborough, Canada
| | - R J Neil Emery
- Trent University, Department of Biology, Peterborough, Canada
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10
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Sarkar A, Kisiala A, Adhikary D, Basu U, Emery RJN, Rahman H, Kav NNV. Silicon ameliorates clubroot responses in canola (Brassica napus): A "multi-omics"-based investigation into possible mechanisms. Physiol Plant 2023; 175:e13900. [PMID: 36992551 DOI: 10.1111/ppl.13900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/23/2023] [Accepted: 03/27/2023] [Indexed: 06/19/2023]
Abstract
Clubroot disease, caused by Plasmodiophora brassicae Woronin, results in severe yield losses in Brassica crops, including canola. Silicon (Si) mitigates several stresses and enhances plant resistance to phytopathogens. We investigated the effects of Si on clubroot disease symptoms in canola at two concentrations of Si, Si: soil in 1: 100 w/w (Si1.0) and Si: soil in 1:200 w/w (Si0.5) under greenhouse conditions. In addition, the effects of Si on P. brassicae-induced gene expression, endogenous levels of phytohormones and metabolites were studied using "omics" approaches. Si application reduced clubroot symptoms and improved plant growth parameters. Gene expression analysis revealed increased transcript-level responses in Si1.0 compared to Si0.5 plants at 7-, 14-, and 21-days post-inoculation (dpi). Pathogen-induced transcript-level changes were affected by Si treatment, with genes related to antioxidant activity (e.g., POD, CAT), phytohormone biosynthesis and signalling (e.g., PDF1.2, NPR1, JAZ, IPT, TAA), nitrogen metabolism (e.g., NRT, AAT), and secondary metabolism (e.g., PAL, BCAT4) exhibiting differential expression. Endogenous levels of phytohormones (e.g., auxin, cytokinin), a majority of the amino acids and secondary metabolites (e.g., glucosinolates) were increased at 7 dpi, followed by a decrease at 14- and 21-dpi due to Si-treatment. Stress hormones such as abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA) also decreased at the later time points in Si0.5, and Si1.0 treated plants. Si appears to improve clubroot symptoms while enhancing plant growth and associated metabolic processes, including nitrogen metabolism and secondary metabolite biosynthesis.
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Affiliation(s)
- Ananya Sarkar
- Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Anna Kisiala
- Biology Department, Trent University, Peterborough, Ontario, Canada
| | - Dinesh Adhikary
- Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Urmila Basu
- Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - R J Neil Emery
- Biology Department, Trent University, Peterborough, Ontario, Canada
| | - Habibur Rahman
- Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Nat N V Kav
- Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
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11
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Palberg D, Kisiała A, Jorge GL, Emery RJN. A survey of Methylobacterium species and strains reveals widespread production and varying profiles of cytokinin phytohormones. BMC Microbiol 2022; 22:49. [PMID: 35135483 PMCID: PMC8822675 DOI: 10.1186/s12866-022-02454-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 01/21/2022] [Indexed: 12/02/2022] Open
Abstract
Background Symbiotic Methylobacterium strains comprise a significant part of plant microbiomes. Their presence enhances plant productivity and stress resistance, prompting classification of these strains as plant growth-promoting bacteria (PGPB). Methylobacteria can synthesize unusually high levels of plant hormones, called cytokinins (CKs), including the most active form, trans-Zeatin (tZ). Results This study provides a comprehensive inventory of 46 representatives of Methylobacterium genus with respect to phytohormone production in vitro, including 16 CK forms, abscisic acid (ABA) and indole-3-acetic acid (IAA). High performance-liquid chromatography—tandem mass spectrometry (HPLC–MS/MS) analyses revealed varying abilities of Methylobacterium strains to secrete phytohormones that ranged from 5.09 to 191.47 pmol mL−1 for total CKs, and 0.46 to 82.16 pmol mL−1 for tZ. Results indicate that reduced methanol availability, the sole carbon source for bacteria in the medium, stimulates CK secretion by Methylobacterium. Additionally, select strains were able to transform L-tryptophan into IAA while no ABA production was detected. Conclusions To better understand features of CKs in plants, this study uncovers CK profiles of Methylobacterium that are instrumental in microbe selection for effective biofertilizer formulations. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02454-9.
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Affiliation(s)
- Daniel Palberg
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Anna Kisiała
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada.
| | - Gabriel Lemes Jorge
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada.,Department of Technology, Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil
| | - R J Neil Emery
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
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12
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Uprety BK, Morrison EN, Emery RJN, Farrow SC. Customizing lipids from oleaginous microbes: leveraging exogenous and endogenous approaches. Trends Biotechnol 2021; 40:482-508. [PMID: 34625276 DOI: 10.1016/j.tibtech.2021.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/08/2021] [Accepted: 09/10/2021] [Indexed: 12/22/2022]
Abstract
To meet the growing demands of the oleochemical industry, tailored lipid sources are expanding to oleaginous microbes. To control the fatty acid composition of microbial lipids, ground-breaking exogenous and endogenous approaches are being developed. Exogenous approaches employ extracellular tools such as product-specific feedstocks, process optimization, elicitors, and magnetic and mechanical energy, whereas endogenous approaches leverage biology through the use of product-specific microbes, adaptive laboratory evolution (ALE), and the creation of custom strains via random and targeted cellular engineering. We consolidate recent advances from both fields into a review that will serve as a resource for those striving to fulfill the vision of microbial cell factories for tailored lipid production.
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Affiliation(s)
- Bijaya K Uprety
- Discovery Biology, Noblegen Inc., Peterborough, ON K9L 1Z8, Canada; Biology Department, Trent University, Peterborough, ON K9L 0G2, Canada
| | - Erin N Morrison
- Discovery Biology, Noblegen Inc., Peterborough, ON K9L 1Z8, Canada; Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9L 0G2, Canada
| | - R J Neil Emery
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9L 0G2, Canada; Biology Department, Trent University, Peterborough, ON K9L 0G2, Canada
| | - Scott C Farrow
- Discovery Biology, Noblegen Inc., Peterborough, ON K9L 1Z8, Canada; Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9L 0G2, Canada.
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13
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Nguyen HN, Nguyen TQ, Kisiala AB, Emery RJN. Beyond transport: cytokinin ribosides are translocated and active in regulating the development and environmental responses of plants. Planta 2021; 254:45. [PMID: 34365553 DOI: 10.1007/s00425-021-03693-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 08/01/2021] [Indexed: 06/13/2023]
Abstract
Riboside type cytokinins are key components in cytokinin metabolism, transport, and sensitivity, making them important functional signals in plant growth and development and environmental stress responses. Cytokinin (CKs) are phytohormones that regulate multiple processes in plants and are critical for agronomy, as they are involved in seed filling and plant responses to biotic and abiotic stress. Among the over 30 identified CKs, there is uncertainty about the roles of many of the individual CK structural forms. Cytokinin free bases (CKFBs), have been studied in great detail, but, by comparison, roles of riboside-type CKs (CKRs) in CK metabolism and associated signaling pathways and their distal impacts on plant physiology remain largely unknown. Here, recent findings on CKR abundance, transport and localization, are summarized, and their importance in planta is discussed. The history of CKR analyses is reviewed, in the context of the determination of CK metabolic pathways, and research on CKR affinity for CK receptors, all of which yield essential insights into their functions. Recent studies suggest that CKR forms are a lot more than a group of transport CKs and, beyond this, they play important roles in plant development and responses to environmental stress. In this context, this review discusses the involvement of CKRs in plant development, and highlight the less anticipated functions of CKRs in abiotic stress tolerance. Based on this, possible mechanisms for CKR modes of action are proposed and experimental approaches to further uncover their roles and future biotechnological applications are suggested.
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Affiliation(s)
- Hai Ngoc Nguyen
- Department of Biology, Trent University, Peterborough, ON, K9L 0G2, Canada.
| | - Thien Quoc Nguyen
- Department of Biology, Trent University, Peterborough, ON, K9L 0G2, Canada
| | - Anna B Kisiala
- Department of Biology, Trent University, Peterborough, ON, K9L 0G2, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, ON, K9L 0G2, Canada
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14
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Nguyen HN, Lai N, Kisiala AB, Emery RJN. Isopentenyltransferases as master regulators of crop performance: their function, manipulation, and genetic potential for stress adaptation and yield improvement. Plant Biotechnol J 2021; 19:1297-1313. [PMID: 33934489 PMCID: PMC8313133 DOI: 10.1111/pbi.13603] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 03/23/2021] [Accepted: 04/11/2021] [Indexed: 05/27/2023]
Abstract
Isopentenyltransferase (IPT) in plants regulates a rate-limiting step of cytokinin (CTK) biosynthesis. IPTs are recognized as key regulators of CTK homeostasis and phytohormone crosstalk in both biotic and abiotic stress responses. Recent research has revealed the regulatory function of IPTs in gene expression and metabolite profiles including source-sink modifications, energy metabolism, nutrient allocation and storage, stress defence and signalling pathways, protein synthesis and transport, and membrane transport. This suggests that IPTs play a crucial role in plant growth and adaptation. In planta studies of IPT-driven modifications indicate that, at a physiological level, IPTs improve stay-green characteristics, delay senescence, reduce stress-induced oxidative damage and protect photosynthetic machinery. Subsequently, these improvements often manifest as enhanced or stabilized crop yields and this is especially apparent under environmental stress. These mechanisms merit consideration of the IPTs as 'master regulators' of core cellular metabolic pathways, thus adjusting plant homeostasis/adaptive responses to altered environmental stresses, to maximize yield potential. If their expression can be adequately controlled, both spatially and temporally, IPTs can be a key driver for seed yield. In this review, we give a comprehensive overview of recent findings on how IPTs influence plant stress physiology and yield, and we highlight areas for future research.
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Affiliation(s)
| | - Nhan Lai
- School of BiotechnologyVietnam National UniversityHo Chi Minh CityVietnam
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15
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Aoki MM, Kisiala AB, Rahman T, Morrison EN, Emery RJN. Cytokinins are pervasive among common in vitro culture media: An analysis of their forms, concentrations and potential sources. J Biotechnol 2021; 334:43-46. [PMID: 34029612 DOI: 10.1016/j.jbiotec.2021.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/08/2021] [Accepted: 05/18/2021] [Indexed: 01/15/2023]
Abstract
The number of organisms that are known to produce cytokinins (CKs) continues to increase. In fact, species from all life kingdoms have now been shown to either produce CKs or at least have the genetic components to make it possible. In vitro growth of microorganisms, plant/animal cells, and tissue cultures often requires nutrient-rich media composed of ingredients with organic origins including: yeast extract, peptone, tryptone, or various plant or animal extracts. These compounds, derived from microbial, plant and animal materials, can be the source of significant levels of exogenous CKs in the culture medium. As CK investigative work continues to expand rapidly, it is of critical importance to draw attention to this complexity; the presence of CKs in growth medium affects CK metabolism of the cultured organism and interferes with the readings of analytical instrumentation used to profile CKs in tested microorganisms or cell cultures.
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Affiliation(s)
- Megan M Aoki
- Department of Biology, Trent University, Peterborough, Ontario, K9L 0G2, Canada.
| | - Anna B Kisiala
- Department of Biology, Trent University, Peterborough, Ontario, K9L 0G2, Canada
| | - Tamzida Rahman
- Department of Biology, Trent University, Peterborough, Ontario, K9L 0G2, Canada
| | - Erin N Morrison
- Department of Biology, Trent University, Peterborough, Ontario, K9L 0G2, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, Ontario, K9L 0G2, Canada
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16
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Nguyen TQ, Sesin V, Kisiala A, Emery RJN. Phytohormonal Roles in Plant Responses to Heavy Metal Stress: Implications for Using Macrophytes in Phytoremediation of Aquatic Ecosystems. Environ Toxicol Chem 2021; 40:7-22. [PMID: 33074580 DOI: 10.1002/etc.4909] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 05/25/2020] [Accepted: 10/15/2020] [Indexed: 05/20/2023]
Abstract
Heavy metals can represent a threat to the health of aquatic ecosystems. Unlike organic chemicals, heavy metals cannot be eliminated by natural processes such as their degradation into less toxic compounds, and this creates unique challenges for their remediation from soil, water, and air. Phytoremediation, defined as the use of plants for the removal of environmental contaminants, has many benefits compared to other pollution-reducing methods. Phytoremediation is simple, efficient, cost-effective, and environmentally friendly because it can be carried out at the polluted site, which simplifies logistics and minimizes exposure to humans and wildlife. Macrophytes represent a unique tool to remediate diverse environmental media because they can accumulate heavy metals from contaminated sediment via roots, from water via submerged leaves, and from air via emergent shoots. In this review, a synopsis is presented about how plants, especially macrophytes, respond to heavy metal stress; and we propose potential roles that phytohormones can play in the alleviation of metal toxicity in the aquatic environment. We focus on the uptake, translocation, and accumulation mechanisms of heavy metals in organs of macrophytes and give examples of how phytohormones interact with plant defense systems under heavy metal exposure. We advocate for a more in-depth understanding of these processes to inform more effective metal remediation techniques from metal-polluted water bodies. Environ Toxicol Chem 2021;40:7-22. © 2020 SETAC.
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Affiliation(s)
- Thien Q Nguyen
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - Verena Sesin
- Environmental and Life Sciences, Trent University, Peterborough, Ontario, Canada
| | - Anna Kisiala
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, Ontario, Canada
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17
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Gibb M, Kisiala AB, Morrison EN, Emery RJN. The Origins and Roles of Methylthiolated Cytokinins: Evidence From Among Life Kingdoms. Front Cell Dev Biol 2020; 8:605672. [PMID: 33240900 PMCID: PMC7680852 DOI: 10.3389/fcell.2020.605672] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 10/19/2020] [Indexed: 12/24/2022] Open
Abstract
Cytokinins (CKs) are a group of adenine-derived, small signaling molecules of crucial importance for growth and multiple developmental processes in plants. Biological roles of classical CKs: isopentenyladenine (iP), trans and cis isomers of zeatin (tZ, cZ), and dihydrozeatin, have been studied extensively and their functions are well defined in many aspects of plant physiology. In parallel, extensive knowledge exists for genes involved in tRNA modifications that lead to the production of tRNA-bound methylthiolated CKs, especially in bacterial and mammalian systems. However, not much is known about the origins, fates, and possible functions of the unbound methylthiolated CKs (2MeS-CKs) in biological systems. 2MeS-CKs are the free base or riboside derivatives of iP or Z-type CKs, modified by the addition of a thiol group (–SH) at position 2 of the adenine ring that is subsequently methylated. Based on the evidence to date, these distinctive CK conjugates are derived exclusively via the tRNA degradation pathway. This review summarizes the knowledge on the probable steps involved in the biosynthesis of unbound 2MeS-CKs across diverse kingdoms of life. Furthermore, it provides examples of CK profiles of organisms from which the presence of 2MeS-CKs have been detected and confirms a close association and balance between the production of classical CKs and 2MeS-CKs. Finally, it discusses available reports regarding the possible physiological functions of 2MeS-CKs in different biological systems.
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Affiliation(s)
- Maya Gibb
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - Anna B Kisiala
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - Erin N Morrison
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, ON, Canada
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18
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Nguyen TQ, Sesin V, Kisiala A, Emery RJN. The Role of Phytohormones in Enhancing Metal Remediation Capacity of Algae. Bull Environ Contam Toxicol 2020; 105:671-678. [PMID: 32435845 DOI: 10.1007/s00128-020-02880-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/08/2020] [Indexed: 05/28/2023]
Abstract
Heavy metal (HM) contamination of the environment is a major issue worldwide, creating an ever-increasing demand for remediation techniques. Remediation with algae offers an ecologically safe, cost-effective, and efficient option for HM removal. Similar to plants, growth and development of algae are controlled by the hormonal system, where phytohormones are involved in HM tolerance and thus can regulate remediation ability; however, the underlying mechanisms of phytohormone function remain elusive. This review aims to draw a comprehensive model of phytohormone contributions to algal performance under HM stress. We focus on the mechanisms of HM biosorption, uptake and intracellular storage, and on how phytohormones interact with algal defence systems under HM exposure. We provide examples of successful utilization of algae in remediation, and of post-processing of algal materials. Finally, we discuss the advantages and risks of using algae for remediation. An in-depth understanding of these processes can inform effective HM remediation techniques.
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Affiliation(s)
- Thien Q Nguyen
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Verena Sesin
- Environmental and Life Sciences, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada.
| | - Anna Kisiala
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
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19
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Nguyen HN, Perry L, Kisiala A, Olechowski H, Emery RJN. Cytokinin activity during early kernel development corresponds positively with yield potential and later stage ABA accumulation in field-grown wheat (Triticum aestivum L.). Planta 2020; 252:76. [PMID: 33030628 DOI: 10.1007/s00425-020-03483-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/28/2020] [Indexed: 05/08/2023]
Abstract
Early cytokinin activity and late abscisic acid dynamics during wheat kernel development correspond to cultivars with higher yield potential. Cytokinins represent prime targets for marker development for wheat breeding programs. Two major phytohormone groups, abscisic acid (ABA) and cytokinins (CKs), are of crucial importance for seed development. Wheat (Triticum aestivum L.) yield is, to a high degree, determined during the milk and dough stages of kernel development. Therefore, understanding the hormonal regulation of these early growth stages is fundamental for crop-improvement programs of this important cereal. Here, we profiled ABA and 25 CK metabolites (including active forms, precursors and inactive conjugates) during kernel development in five field-grown wheat cultivars. The levels of ABA and profiles of CK forms varied greatly among the tested cultivars and kernel stages suggesting that several types of CK metabolites are involved in spatiotemporal regulation of kernel development. The seed yield potential was associated with the elevated levels of active CK levels (tZ, cZ). Interestingly, the increased kernel cZ levels were followed by higher ABA production, suggesting there is an interaction between these two phytohormones. Furthermore, we analyzed the expression patterns of representatives of the four main CK metabolic gene families. The unique transcriptional patterns of the IPT (biosynthesis) and ZOG (reversible inactivation) gene family members (GFMs) in the high and low yield cultivars additionally indicate that there is a significant association between CK metabolism and yield potential in wheat. Based on these results, we suggest that both CK metabolites and their associated genes, can serve as important, early markers of yield performance in modern wheat breeding programs.
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Affiliation(s)
- Hai Ngoc Nguyen
- Biology Department, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada.
| | - Laura Perry
- Biology Department, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Anna Kisiala
- Biology Department, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Henry Olechowski
- Dow Chemical Canada ULC, Suite 2400-215 2nd Street S.W., Calgary, AB, T2P 1M4, Canada
| | - R J Neil Emery
- Biology Department, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
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20
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Emery RJN, Kisiala A. The Roles of Cytokinins in Plants and Their Response to Environmental Stimuli. Plants (Basel) 2020; 9:plants9091158. [PMID: 32911673 PMCID: PMC7570256 DOI: 10.3390/plants9091158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 09/02/2020] [Indexed: 01/08/2023]
Abstract
Cytokinins (CKs) are adenine-derived, small-molecule plant growth regulators that control aspects of almost all plant growth and development processes. Internally, CKs play significant roles in plant cell division, nutrient allocation, and photosynthetic performance, and they are also detection and signaling agents for plant responses to the environmental challenges. CK functions in plant metabolism include plant adaptations to various abiotic stresses as well as their regulatory role in plant interactions with biotic components of the environment. Interestingly, CK biosynthesis is not exclusive to plants. New genetic and chemical approaches have revealed that both beneficial (symbiotic microorganisms) and detrimental (pathogenic bacteria, fungi, or insects) non-plant biota can secrete these phytohormones to purposefully modify plant metabolism. Therefore, while many open questions remain about how CKs are actively utilized by plants and plant-interacting organisms, CK roles should be seen more broadly, as signaling molecules for which effects range from within cells to as far as interkingdom relationships. The papers in this Special Issue highlight several aspects of CK biosynthesis, metabolism, and functions within plants and among plant-associated organisms, typifying the extensive range of roles played by these signaling molecules. The collection of papers represents new examples for CK researchers to consider advancing the growing range of topics related to how CKs mediate responses to many kinds of environmental stimuli and stresses.
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21
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Aoki MM, Emery RJN, Anjard C, Brunetti CR, Huber RJ. Cytokinins in Dictyostelia - A Unique Model for Studying the Functions of Signaling Agents From Species to Kingdoms. Front Cell Dev Biol 2020; 8:511. [PMID: 32714926 PMCID: PMC7316887 DOI: 10.3389/fcell.2020.00511] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023] Open
Abstract
Cytokinins (CKs) are a diverse group of evolutionarily significant growth-regulating molecules. While the CK biosynthesis and signal transduction pathways are the most well-understood in plant systems, these molecules have been identified in all kingdoms of life. This review follows the recent discovery of an expanded CK profile in the social amoeba, Dictyostelium discoideum. A comprehensive review on the present knowledge of CK biosynthesis, signal transduction, and CK-small molecule interactions within members of Dictyostelia will be summarized. In doing so, the utility of social amoebae will be highlighted as a model system for studying the evolution of these hormone-like signaling agents, which will set the stage for future research in this area.
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Affiliation(s)
- Megan M Aoki
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - Christophe Anjard
- Institut Lumière Matière, CNRS UMR 5306, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Craig R Brunetti
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - Robert J Huber
- Department of Biology, Trent University, Peterborough, ON, Canada
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22
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Andreas P, Kisiala A, Emery RJN, De Clerck-Floate R, Tooker JF, Price PW, Miller III DG, Chen MS, Connor EF. Cytokinins Are Abundant and Widespread Among Insect Species. Plants (Basel) 2020; 9:E208. [PMID: 32041320 PMCID: PMC7076654 DOI: 10.3390/plants9020208] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/29/2020] [Accepted: 01/31/2020] [Indexed: 01/09/2023]
Abstract
Cytokinins (CKs) are a class of compounds that have long been thought to be exclusively plant growth regulators. Interestingly, some species of phytopathogenic bacteria and fungi have been shown to, and gall-inducing insects have been hypothesized to, produce CKs and use them to manipulate their host plants. We used high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-MS/MS) to examine concentrations of a wide range of CKs in 17 species of phytophagous insects, including gall- and non-gall-inducing species from all six orders of Insecta that contain species known to induce galls: Thysanoptera, Hemiptera, Lepidoptera, Coleoptera, Diptera, and Hymenoptera. We found CKs in all six orders of insects, and they were not associated exclusively with gall-inducing species. We detected 24 different CK analytes, varying in their chemical structure and biological activity. Isoprenoid precursor nucleotide and riboside forms of trans-zeatin (tZ) and isopentenyladenine (iP) were most abundant and widespread across the surveyed insect species. Notably, the observed concentrations of CKs often markedly exceeded those reported in plants suggesting that insects are synthesizing CKs rather than obtaining them from the host plant via tissue consumption, compound sequestration, and bioaccumulation. These findings support insect-derived CKs as means for gall-inducing insects to manipulate their host plant to facilitate cell proliferation, and for both gall- and non-gall-inducing insects to modify nutrient flux and plant defenses during herbivory. Furthermore, wide distribution of CKs across phytophagous insects, including non-gall-inducing species, suggests that insect-borne CKs could be involved in manipulation of source-sink mechanisms of nutrient allocation to sustain the feeding site and altering plant defensive responses, rather than solely gall induction. Given the absence of any evidence for genes in the de novo CK biosynthesis pathway in insects, we postulate that the tRNA-ipt pathway is responsible for CK production. However, the unusually high concentrations of CKs in insects, and the tendency toward dominance of their CK profiles by tZ and iP suggest that the tRNA-ipt pathway functions differently and substantially more efficiently in insects than in plants.
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Affiliation(s)
- Peter Andreas
- Department of Biology, Trent University, Peterborough, ON K9J 7B8, Canada; (P.A.); (A.K.); (R.J.N.E.)
| | - Anna Kisiala
- Department of Biology, Trent University, Peterborough, ON K9J 7B8, Canada; (P.A.); (A.K.); (R.J.N.E.)
| | - R. J. Neil Emery
- Department of Biology, Trent University, Peterborough, ON K9J 7B8, Canada; (P.A.); (A.K.); (R.J.N.E.)
| | | | - John F. Tooker
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA;
| | - Peter W. Price
- Department of Ecology and Evolutionary Biology, Northern Arizona University, Flagstaff, AZ 86001, USA;
| | - Donald G. Miller III
- Department of Biological Sciences, California State University, Chico, CA 95929, USA;
| | - Ming-Shun Chen
- USDA-ARS and Department of Entomology, Kansas State University, Manhattan, KS 66506, USA;
| | - Edward F. Connor
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
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Aoki MM, Kisiala AB, Li S, Stock NL, Brunetti CR, Huber RJ, Emery RJN. Cytokinin Detection during the Dictyostelium discoideum Life Cycle: Profiles Are Dynamic and Affect Cell Growth and Spore Germination. Biomolecules 2019; 9:E702. [PMID: 31694277 PMCID: PMC6920973 DOI: 10.3390/biom9110702] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/01/2019] [Accepted: 11/01/2019] [Indexed: 01/18/2023] Open
Abstract
Cytokinins (CKs) are a family of evolutionarily conserved growth regulating hormones. While CKs are well-characterized in plant systems, these N6-substituted adenine derivatives are found in a variety of organisms beyond plants, including bacteria, fungi, mammals, and the social amoeba, Dictyostelium discoideum. Within Dictyostelium, CKs have only been studied in the late developmental stages of the life cycle, where they promote spore encapsulation and dormancy. In this study, we used ultra high-performance liquid chromatography-positive electrospray ionization-high resolution tandem mass spectrometry (UHPLC-(ESI+)-HRMS/MS) to profile CKs during the Dictyostelium life cycle: growth, aggregation, mound, slug, fruiting body, and germination. Comprehensive profiling revealed that Dictyostelium produces 6 CK forms (cis-Zeatin (cZ), discadenine (DA), N6-isopentenyladenine (iP), N6-isopentenyladenine-9-riboside (iPR), N6-isopentenyladenine-9-riboside-5' phosphate (iPRP), and 2-methylthio-N6-isopentenyladenine (2MeSiP)) in varying abundance across the sampled life cycle stages, thus laying the foundation for the CK biosynthesis pathway to be defined in this organism. Interestingly, iP-type CKs were the most dominant CK analytes detected during growth and aggregation. Exogenous treatment of AX3 cells with various CK types revealed that iP was the only CK to promote the proliferation of cells in culture. In support of previous studies, metabolomics data revealed that DA is one of the most significantly upregulated small molecules during Dictyostelium development, and our data indicates that total CK levels are highest during germination. While much remains to be explored in Dictyostelium, this research offers new insight into the nature of CK biosynthesis, secretion, and function during Dictyostelium growth, development, and spore germination.
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Affiliation(s)
- Megan M. Aoki
- Department of Biology, Trent University, Peterborough, ON K9L 0G2 Canada; (A.B.K.); (C.R.B.); (R.J.H.); (R.J.N.E.)
| | - Anna B. Kisiala
- Department of Biology, Trent University, Peterborough, ON K9L 0G2 Canada; (A.B.K.); (C.R.B.); (R.J.H.); (R.J.N.E.)
| | - Shaojun Li
- Noblegen, Peterborough, ON K9L 0G2, Canada;
| | - Naomi L. Stock
- Water Quality Centre, Trent University, Peterborough, ON K9L 0G2, Canada;
| | - Craig R. Brunetti
- Department of Biology, Trent University, Peterborough, ON K9L 0G2 Canada; (A.B.K.); (C.R.B.); (R.J.H.); (R.J.N.E.)
| | - Robert J. Huber
- Department of Biology, Trent University, Peterborough, ON K9L 0G2 Canada; (A.B.K.); (C.R.B.); (R.J.H.); (R.J.N.E.)
| | - R. J. Neil Emery
- Department of Biology, Trent University, Peterborough, ON K9L 0G2 Canada; (A.B.K.); (C.R.B.); (R.J.H.); (R.J.N.E.)
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Kisiala A, Kambhampati S, Stock NL, Aoki M, Emery RJN. Quantification of Cytokinins Using High-Resolution Accurate-Mass Orbitrap Mass Spectrometry and Parallel Reaction Monitoring (PRM). Anal Chem 2019; 91:15049-15056. [PMID: 31660717 DOI: 10.1021/acs.analchem.9b03728] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Anna Kisiala
- Department of Biology, Trent University, 1600 West Bank Dr., Peterborough, Ontario K9L 0G2, Canada
| | - Shrikaar Kambhampati
- Donald Danforth Plant Science Center, 975 N Warson Rd., Saint Louis, Missouri 63132, United States
| | - Naomi L. Stock
- Water Quality Centre, Trent University, 1600 West Bank Dr., Peterborough, Ontario K9L 0G2, Canada
| | - Megan Aoki
- Department of Biology, Trent University, 1600 West Bank Dr., Peterborough, Ontario K9L 0G2, Canada
| | - R. J. Neil Emery
- Department of Biology, Trent University, 1600 West Bank Dr., Peterborough, Ontario K9L 0G2, Canada
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Abo Gamar MI, Kisiala A, Emery RJN, Yeung EC, Stone SL, Qaderi MM. Elevated carbon dioxide decreases the adverse effects of higher temperature and drought stress by mitigating oxidative stress and improving water status in Arabidopsis thaliana. Planta 2019; 250:1191-1214. [PMID: 31190116 DOI: 10.1007/s00425-019-03213-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 06/06/2019] [Indexed: 06/09/2023]
Abstract
This study revealed that elevated carbon dioxide increases Arabidopsis tolerance to higher temperature and drought stress by mitigating oxidative stress and improving water status of plants. Few studies have considered multiple aspects of plant responses to key components of global climate change, including higher temperature, elevated carbon dioxide (ECO2), and drought. Hence, their individual and combinatorial effects on plants need to be investigated in the context of understanding climate change impact on plant growth and development. We investigated the interactive effects of temperature, CO2, watering regime, and genotype on Arabidopsis thaliana (WT and ABA-insensitive mutant, abi1-1). Plants were grown in controlled-environment growth chambers under two temperature regimes (22/18 °C and 28/24 °C, 16 h light/8 h dark), two CO2 concentrations (400 and 700 μmol mol-1), and two watering regimes (well-watered and water-stressed) for 18 days. Plant growth, anatomical, physiological, molecular, and hormonal responses were determined. Our study provided valuable information about plant responses to the interactive effects of multiple environmental factors. We showed that drought and ECO2 had larger effects on plants than higher temperatures. ECO2 alleviated the detrimental effects of temperature and drought by mitigating oxidative stress and plant water status, and this positive effect was consistent across multiple response levels. The WT plants performed better than the abi1-1 plants; the former had higher rosette diameter, total dry mass, leaf and soil water potential, leaf moisture, proline, ethylene, trans-zeatin, isopentyladenine, and cis-zeatin riboside than the latter. The water-stressed plants of both genotypes accumulated more abscisic acid (ABA) than the well-watered plants; however, higher temperatures decreased the ability of WT plants to produce ABA in response to drought. We conclude that drought strongly, while higher temperature to a lesser extent, affects Arabidopsis seedlings, and ECO2 reduces the adverse effects of these stressors more efficiently in the WT plants than in the abi1-1 plants. Findings from this study can be extrapolated to other plant species that share similar characteristics and/or family with Arabidopsis.
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Affiliation(s)
- Mohammad I Abo Gamar
- Department of Biology, Life Science Centre, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
| | - Anna Kisiala
- Department of Biology, Trent University, 2140 East Bank Drive, Peterborough, ON, K9J 7B8, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, 2140 East Bank Drive, Peterborough, ON, K9J 7B8, Canada
| | - Edward C Yeung
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Sophia L Stone
- Department of Biology, Life Science Centre, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
| | - Mirwais M Qaderi
- Department of Biology, Life Science Centre, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada.
- Department of Biology, Mount Saint Vincent University, 166 Bedford Highway, Halifax, NS, B3M 2J6, Canada.
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Aoki MM, Seegobin M, Kisiala A, Noble A, Brunetti C, Emery RJN. Phytohormone metabolism in human cells: Cytokinins are taken up and interconverted in HeLa cell culture. FASEB Bioadv 2019; 1:320-331. [PMID: 32123835 PMCID: PMC6996375 DOI: 10.1096/fba.2018-00032] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 02/06/2019] [Accepted: 02/07/2019] [Indexed: 01/30/2023] Open
Abstract
Cytokinins (CKs) encompass a group of phytohormones, known to orchestrate many critical processes in plant development. Excluding Archaea, CKs are pervasive among all kingdoms, but much less is reported about their metabolism beyond plants. Recent evidence from mammalian tissues indicates the presence of six additional CK forms beyond the previously identified, single mammalian CK, N6-isopentenyladenosine (i6A). There is limited understanding of CK biosynthesis pathways in mammalian systems; therefore, human cervical cancer (HeLa) cells were used to further characterize CK processing by tracking the interconversion of CKs into their various structural derivatives in mammalian cells in a time-course study. Through high-performance liquid chromatography-positive electrospray ionization-tandem mass spectrometry (HPLC-(+ESI)-MS/MS), we document changes in the functional profiles of endogenous CKs in a human cell line following metabolism by HeLa cell cultures. The nucleotide CK fraction (iPRP) was found exclusively within the cell pellet (0.34 pmol/106 cells), and the active free base (FB) form (iP) and riboside fraction (iPR) were found in greater abundance extracellularly (1.67 and 0.10 nmol/L respectively). For further confirmation, we demonstrate that HeLa cells metabolize an exogenously supplied CK, N6-benzyladenosine (BAR). In the HeLa culture supernatant, a 12-fold decrease in BAR concentration was observed within the first 24 hours of incubation accompanied by a fivefold increase in the FB form, N6-benzyladenine (BA). These findings support the hypothesis that HeLa cells have the enzymatic pathways required for the metabolism of both endogenous and exogenous CKs.
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Affiliation(s)
- Megan M. Aoki
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
| | - Mark Seegobin
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
| | - Anna Kisiala
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
| | | | - Craig Brunetti
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
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Goh DM, Cosme M, Kisiala AB, Mulholland S, Said ZMF, Spíchal L, Emery RJN, Declerck S, Guinel FC. A Stimulatory Role for Cytokinin in the Arbuscular Mycorrhizal Symbiosis of Pea. Front Plant Sci 2019; 10:262. [PMID: 30915091 PMCID: PMC6423060 DOI: 10.3389/fpls.2019.00262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/19/2019] [Indexed: 05/03/2023]
Abstract
The arbuscular mycorrhizal (AM) symbiosis between terrestrial plants and AM fungi is regulated by plant hormones. For most of these, a role has been clearly assigned in this mutualistic interaction; however, there are still contradictory reports for cytokinin (CK). Here, pea plants, the wild type (WT) cv. Sparkle and its mutant E151 (Pssym15), were inoculated with the AM fungus Rhizophagus irregularis. E151 has previously been characterized as possessing high CK levels in non-mycorrhizal (myc-) roots and exhibiting high number of fungal structures in mycorrhizal (myc+) roots. Myc- and myc+ plants were treated 7, 9, and 11 days after inoculation (DAI) with synthetic compounds known to alter CK status. WT plants were treated with a synthetic CK [6-benzylaminopurine (BAP)] or the CK degradation inhibitor INCYDE, whereas E151 plants were treated with the CK receptor antagonist PI-55. At 13 DAI, plant CK content was analyzed by mass spectrometry. The effects of the synthetic compounds on AM colonization were assessed at 28 (WT) or 35 (E151) DAI via a modified magnified intersections method. The only noticeable difference seen between myc- and myc+ plants in terms of CK content was in the levels of nucleotides (NTs). Whereas WT plants responded to fungi by lowering their NT levels, E151 plants did not. Since NTs are thought to be converted into active CK forms, this result suggests that active CKs were synthesized more effectively in WT than in E151. In general, myc+ and myc- WT plants responded similarly to INCYDE by lowering significantly their NT levels and increasing slightly their active CK levels; these responses were less obvious in BAP-treated WT plants. In contrast, the response of E151 plants to PI-55 depended on the plant mycorrhizal status. Whereas treated myc- plants exhibited high NT and low active CK levels, treated myc+ plants displayed low levels of both NTs and active CKs. Moreover, treated WT plants were more colonized than treated E151 plants. We concluded that CKs have a stimulatory role in AM colonization because increased active CK levels were paralleled with increased AM colonization while decreased CK levels corresponded to reduced AM colonization.
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Affiliation(s)
- Dane M. Goh
- Biology, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Marco Cosme
- Mycology, Applied Microbiology, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | | | | | | | - Lukáš Spíchal
- Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University Olomouc, Olomouc, Czechia
| | | | - Stéphane Declerck
- Mycology, Applied Microbiology, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
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Seegobin M, Kisiala A, Noble A, Kaplan D, Brunetti C, Emery RJN. Canis familiaris tissues are characterized by different profiles of cytokinins typical of the tRNA degradation pathway. FASEB J 2018; 32:fj201800347. [PMID: 29894666 DOI: 10.1096/fj.201800347] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Cytokinins (CKs) are a group of phytohormones essential to plant growth and development. The presence of these N6-modified adenine derivatives has also been documented in other groups of organisms, including bacteria, fungi, and insects. Thus far, however, only a single CK, N6-(Δ2-isopentenyl) adenine-9-riboside (iPR), has been identified in mammals. In plants, the nucleotide form of isopentenyladenine [iPR (either mono-, di-, or tri-) phosphate (iPRP)] is the first form of CK synthesized, and it is further modified to produce other CK types. To determine if a similar biosynthesis pathway exists in mammals, we tested for the presence of 27 CKs in a wide selection of canine organs using HPLC electrospray ionization-tandem mass spectrometry. Seven forms of CK were detected in the majority of the analyzed samples, including iPR, iPRP, cis-zeatin-9-riboside, cis-zeatin-9-riboside-5' (either mono-, di-, or triphosphate), 2-methylthio-N6-isopentenyladenine, 2-methylthio-N6-isopentenyladenosine, and 2-methylthio-zeatin. Total CK concentrations ranged from 1.96 pmol/g fresh weight (adrenal glands) to 1.40 × 103 pmol/g fresh weight (thyroid). The results of this study provide evidence that mammalian cells, like plant cells, can synthesize and process a diverse set of CKs including cis- and methylthiol-type CKs.-Seegobin, M., Kisiala, A., Noble, A., Kaplan, D., Brunetti, C., Emery, R. J. N. Canis familiaris tissues are characterized by different profiles of cytokinins typical of tRNA degradation pathway.
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Affiliation(s)
- Mark Seegobin
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - Anna Kisiala
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | | | - David Kaplan
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Craig Brunetti
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, Ontario, Canada
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Zhang H, Guiguet A, Dubreuil G, Kisiala A, Andreas P, Emery RJN, Huguet E, Body M, Giron D. Dynamics and origin of cytokinins involved in plant manipulation by a leaf-mining insect. Insect Sci 2017; 24:1065-1078. [PMID: 28636152 DOI: 10.1111/1744-7917.12500] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 05/03/2017] [Accepted: 06/08/2017] [Indexed: 05/22/2023]
Abstract
Several herbivorous insects and plant-associated microorganisms control the phytohormonal balance, thus enabling them to successfully exploit the plant by inhibiting plant defenses and withdrawing plant resources for their own benefit. The leaf-mining moth Phyllonorycter blancardella modifies the cytokinin (CK) profile of mined leaf-tissues, and the insect symbiotic bacteria Wolbachia is involved in the plant manipulation to the benefit of the insect host. To gain a deeper understanding into the possible origin and dynamics of CKs, we conducted an extensive characterization of CKs in larvae and in infected apple leaves. Our results show the enhanced CK levels in mines, both on green and yellow leaves, allowing insects to control their nutritional supply under fluctuating environmental conditions. The spatial distribution of CKs within the mined leaves shows that hormone manipulation is strictly limited to the mine suggesting the absence of CK translocation from distant leaf areas toward the insect feeding site. Mass spectrometry analyses reveal that major CK types accumulating in mines and larvae are similar to what is observed for most gall-inducers, suggesting that strategies underlying the plant manipulation may be shared between herbivorous insects with distinct life histories. Results further show that CKs are detected in the highest levels in larvae, reinforcing our hypothesis that CKs accumulating in the mines originate from the insect itself. Presence of bacteria-specific methylthio-CKs is consistent with previous results suggesting that insect bacterial symbionts contribute to the observed phenotype. Our study provides key findings toward the understanding of molecular mechanisms underlying this intricate plant-insect-microbe interaction.
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Affiliation(s)
- Hui Zhang
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS/Université François-Rabelais de Tours, Tours, France
| | - Antoine Guiguet
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS/Université François-Rabelais de Tours, Tours, France
- Département de Biologie, École Normale Supérieure de Lyon, Lyon, France
- Department of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - Géraldine Dubreuil
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS/Université François-Rabelais de Tours, Tours, France
| | - Anna Kisiala
- Department of Biology, Trent University, Peterborough, Canada
| | - Peter Andreas
- Department of Biology, Trent University, Peterborough, Canada
| | - R J Neil Emery
- Department of Biology, Trent University, Peterborough, Canada
| | - Elisabeth Huguet
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS/Université François-Rabelais de Tours, Tours, France
| | - Mélanie Body
- Division of Plant Sciences, Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, USA
| | - David Giron
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS/Université François-Rabelais de Tours, Tours, France
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Fonouni-Farde C, Kisiala A, Brault M, Emery RJN, Diet A, Frugier F. DELLA1-Mediated Gibberellin Signaling Regulates Cytokinin-Dependent Symbiotic Nodulation. Plant Physiol 2017; 175:1795-1806. [PMID: 29046420 PMCID: PMC5717729 DOI: 10.1104/pp.17.00919] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 10/17/2017] [Indexed: 05/06/2023]
Abstract
In legume plants, low-nitrogen soils promote symbiotic interactions with rhizobial bacteria, leading to the formation of nitrogen-fixing root nodules. Among critical signals regulating this developmental process are bacterial Nod Factors (NFs) and several plant hormones, including cytokinins (CKs) and gibberellins (GAs). Here, we show in Medicago truncatula that GA signaling mediated by DELLA1 decreases the amount of bioactive CKs in roots and negatively impacts the Cytokinin Response1 (CRE1)-dependent NF activation of a subset of CK-signaling genes as well as of the CK-regulated Nodulation Signaling Pathway2 and Ethylene Response Factor Required for Nodulation1 early nodulation genes. Consistently, a dominant-active DELLA1 protein can partially rescue the reduced nodulation of the cre1 mutant and triggers the formation of nodule-like structures when expressed in the root cortex or in the root epidermis. This suggests a model where the DELLA1-mediated GA signaling interplays with the CRE1-dependent CK pathway to regulate early nodulation in response to both NF and CK signals critical for this symbiotic interaction.
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Affiliation(s)
- Camille Fonouni-Farde
- Institute of Plant Sciences Paris-Saclay (IPS2), Centre National de la Recherche Scientifique, Université Paris Sud, Université Paris Diderot, Institut National de la Recherche Agronomique, Université Evry, Université Paris-Saclay, 91190 Gif-sur-Yvette, France
| | - Anna Kisiala
- Biology Department, Trent University, Peterborough K9J 7B8, Canada
| | - Mathias Brault
- Institute of Plant Sciences Paris-Saclay (IPS2), Centre National de la Recherche Scientifique, Université Paris Sud, Université Paris Diderot, Institut National de la Recherche Agronomique, Université Evry, Université Paris-Saclay, 91190 Gif-sur-Yvette, France
| | - R J Neil Emery
- Biology Department, Trent University, Peterborough K9J 7B8, Canada
| | - Anouck Diet
- Institute of Plant Sciences Paris-Saclay (IPS2), Centre National de la Recherche Scientifique, Université Paris Sud, Université Paris Diderot, Institut National de la Recherche Agronomique, Université Evry, Université Paris-Saclay, 91190 Gif-sur-Yvette, France
| | - Florian Frugier
- Institute of Plant Sciences Paris-Saclay (IPS2), Centre National de la Recherche Scientifique, Université Paris Sud, Université Paris Diderot, Institut National de la Recherche Agronomique, Université Evry, Université Paris-Saclay, 91190 Gif-sur-Yvette, France
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Prudent M, Salon C, Smith DL, Emery RJN. Nod factor supply under water stress conditions modulates cytokinin biosynthesis and enhances nodule formation and N nutrition in soybean. Plant Signal Behav 2016; 11:e1212799. [PMID: 27454159 PMCID: PMC5058462 DOI: 10.1080/15592324.2016.1212799] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/04/2016] [Accepted: 07/08/2016] [Indexed: 05/29/2023]
Abstract
Nod factors (NF) are molecules produced by rhizobia which are involved in the N2-fixing symbiosis with legume plants, enabling the formation of specific organs called nodules. Under drought conditions, nitrogen acquisition by N2-fixation is depressed, resulting in low legume productivity. In this study, we evaluated the effects of NF supply on nitrogen acquisition and on cytokinin biosynthesis of soybean plants grown under drought. NF supply to water stressed soybeans increased the CK content of all organs. The profile of CK metabolites also shifted from t-Z to cis-Z and an accumulation of nucleotide and glucoside conjugates. The changes in CK coincided with enhanced nodule formation with sustained nodule specific activity, which ultimately increased the total nitrogen fixed by the plant.
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Affiliation(s)
| | | | - Donald L. Smith
- Plant Science Department, McGill University, McDonald Campus, St Anne de Bellevue, Quebec, Canada
| | - R. J. Neil Emery
- Department of Biology, Trent University, Peterborough, Ontario, Canada
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Jardinaud MF, Boivin S, Rodde N, Catrice O, Kisiala A, Lepage A, Moreau S, Roux B, Cottret L, Sallet E, Brault M, Emery RJN, Gouzy J, Frugier F, Gamas P. A Laser Dissection-RNAseq Analysis Highlights the Activation of Cytokinin Pathways by Nod Factors in the Medicago truncatula Root Epidermis. Plant Physiol 2016; 171:2256-76. [PMID: 27217496 PMCID: PMC4936592 DOI: 10.1104/pp.16.00711] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 05/18/2016] [Indexed: 05/19/2023]
Abstract
Nod factors (NFs) are lipochitooligosaccharidic signal molecules produced by rhizobia, which play a key role in the rhizobium-legume symbiotic interaction. In this study, we analyzed the gene expression reprogramming induced by purified NF (4 and 24 h of treatment) in the root epidermis of the model legume Medicago truncatula Tissue-specific transcriptome analysis was achieved by laser-capture microdissection coupled to high-depth RNA sequencing. The expression of 17,191 genes was detected in the epidermis, among which 1,070 were found to be regulated by NF addition, including previously characterized NF-induced marker genes. Many genes exhibited strong levels of transcriptional activation, sometimes only transiently at 4 h, indicating highly dynamic regulation. Expression reprogramming affected a variety of cellular processes, including perception, signaling, regulation of gene expression, as well as cell wall, cytoskeleton, transport, metabolism, and defense, with numerous NF-induced genes never identified before. Strikingly, early epidermal activation of cytokinin (CK) pathways was indicated, based on the induction of CK metabolic and signaling genes, including the CRE1 receptor essential to promote nodulation. These transcriptional activations were independently validated using promoter:β-glucuronidase fusions with the MtCRE1 CK receptor gene and a CK response reporter (TWO COMPONENT SIGNALING SENSOR NEW). A CK pretreatment reduced the NF induction of the EARLY NODULIN11 (ENOD11) symbiotic marker, while a CK-degrading enzyme (CYTOKININ OXIDASE/DEHYDROGENASE3) ectopically expressed in the root epidermis led to increased NF induction of ENOD11 and nodulation. Therefore, CK may play both positive and negative roles in M. truncatula nodulation.
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Affiliation(s)
- Marie-Françoise Jardinaud
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Stéphane Boivin
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Nathalie Rodde
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Olivier Catrice
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Anna Kisiala
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Agnes Lepage
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Sandra Moreau
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Brice Roux
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Ludovic Cottret
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Erika Sallet
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Mathias Brault
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - R J Neil Emery
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Jérôme Gouzy
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Florian Frugier
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
| | - Pascal Gamas
- LIPM, Université de Toulouse, Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, 31326 Castanet-Tolosan, France (M.-F.J., N.R., O.C., A.L., S.M., B.R., L.C., E.S., J.G., P.G.);INPT-Université de Toulouse, ENSAT, 31326 Castanet-Tolosan, France (M.-F.J.);Institute of Plant Sciences-Paris Saclay University, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique/Universités Paris-Sud/Paris-Diderot/d'Evry, 91190 Gif-sur-Yvette, France (S.B., M.B., F.F.);Biology Department, Trent University, Peterborough, Ontario, Canada K9J 7B8 (A.K., R.J.N.E.); andDepartment of Plant Genetics, Physiology, and Biotechnology, University of Technology and Life Sciences, 85-789 Bydgoszcz, Poland (A.K.)
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Kurepin LV, Pharis RP, Neil Emery RJ, Reid DM, Chinnappa CC. Phenotypic plasticity of sun and shade ecotypes of Stellaria longipes in response to light quality signaling, gibberellins and auxin. Plant Physiol Biochem 2015; 94:174-80. [PMID: 26113156 DOI: 10.1016/j.plaphy.2015.06.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/10/2015] [Accepted: 06/12/2015] [Indexed: 05/20/2023]
Abstract
Stellaria longipes plant communities (ecotypes) occur in several environmentally distinct habitats along the eastern slopes of southern Alberta's Rocky Mountains. One ecotype occurs in a prairie habitat at ∼1000 m elevation where Stellaria plants grow in an environment in which the light is filtered by taller neighbouring vegetation, i.e. sunlight with a low red to far-red (R/FR) ratio. This ecotype exhibits a high degree of phenotypic plasticity by increasing stem elongation in response to the low R/FR ratio light signal. Another Stellaria ecotype occurs nearby at ∼2400 m elevation in a much cooler alpine habitat, one where plants rarely experience low R/FR ratio shade light. Stem elongation of plants is largely regulated by gibberellins (GAs) and auxin, indole-3-acetic acid (IAA). Shoots of the prairie ecotype plants show increased IAA levels under low R/FR ratio light and they also increase their stem growth in response to applied IAA. The alpine ecotype plants show neither response. Plants from both ecotypes produce high levels of growth-active GA1 under low R/FR ratio light, though they differ appreciably in their catabolism of GA1. The alpine ecotype plants exhibit very high levels of GA8, the inactive product of GA1 metabolism, under both normal and low R/FR ratio light. Alpine origin plants may de-activate GA1 by conversion to GA8 via a constitutively high level of expression of the GA2ox gene, thereby maintaining their dwarf phenotype and exhibiting a reduced phenotypic plasticity in terms of shoot elongation. In contrast, prairie plants exhibit a high degree of phenotypic plasticity, using low R/FR ratio light-mediated changes in GA and IAA concentrations to increase shoot elongation, thereby accessing direct sunlight to optimize photosynthesis. There thus appear to be complex adaptation strategies for the two ecotypes, ones which involve modifications in the homeostasis of endogenous hormones.
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Affiliation(s)
- Leonid V Kurepin
- Department of Biology, Western University, London, Ontario, Canada.
| | - Richard P Pharis
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - R J Neil Emery
- Biology Department, Trent University, Peterborough, Ontario, Canada
| | - David M Reid
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - C C Chinnappa
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
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Jones JMC, Clairmont L, Macdonald ES, Weiner CA, Emery RJN, Guinel FC. E151 (sym15), a pleiotropic mutant of pea (Pisum sativum L.), displays low nodule number, enhanced mycorrhizae, delayed lateral root emergence, and high root cytokinin levels. J Exp Bot 2015; 66:4047-59. [PMID: 25948707 PMCID: PMC4473994 DOI: 10.1093/jxb/erv201] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In legumes, the formation of rhizobial and mycorrhizal root symbioses is a highly regulated process which requires close communication between plant and microorganism. Plant mutants that have difficulties establishing symbioses are valuable tools for unravelling the mechanisms by which these symbioses are formed and regulated. Here E151, a mutant of Pisum sativum cv. Sparkle, was examined to characterize its root growth and symbiotic defects. The symbioses in terms of colonization intensity, functionality of micro-symbionts, and organ dominance were compared between the mutant and wild type. The endogenous cytokinin (CK) and abscisic acid (ABA) levels and the effect of the exogenous application of these two hormones were determined. E151 was found to be a low and delayed nodulator, exhibiting defects in both the epidermal and cortical programmes though a few mature and functional nodules develop. Mycorrhizal colonization of E151 was intensified, although the fungal functionality was impaired. Furthermore, E151 displayed an altered lateral root (LR) phenotype compared with that of the wild type whereby LR emergence is initially delayed but eventually overcome. No differences in ABA levels were found between the mutant and the wild type, but non-inoculated E151 exhibited significantly high CK levels. It is hypothesized that CK plays an essential role in differentially mediating the entry of the two micro-symbionts into the cortex; whereas it would inhibit the entry of the rhizobia in that tissue, it would promote that of the fungus. E151 is a developmental mutant which may prove to be a useful tool in further understanding the role of hormones in the regulation of beneficial root symbioses.
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Affiliation(s)
- James M C Jones
- Biology Department, 75 University Avenue W, Wilfrid Laurier University, Waterloo, ON, Canada, N2L 3C5
| | - Lindsey Clairmont
- Biology Department, 75 University Avenue W, Wilfrid Laurier University, Waterloo, ON, Canada, N2L 3C5
| | - Emily S Macdonald
- Biology Department, 75 University Avenue W, Wilfrid Laurier University, Waterloo, ON, Canada, N2L 3C5
| | - Catherine A Weiner
- Biology Department, 75 University Avenue W, Wilfrid Laurier University, Waterloo, ON, Canada, N2L 3C5
| | - R J Neil Emery
- Biology Department, 1600 West Bank Drive, Trent University, Peterborough, ON, Canada, K9J 7B8
| | - Frédérique C Guinel
- Biology Department, 75 University Avenue W, Wilfrid Laurier University, Waterloo, ON, Canada, N2L 3C5
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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Goggin DE, Emery RJN, Kurepin LV, Powles SB. A potential role for endogenous microflora in dormancy release, cytokinin metabolism and the response to fluridone in Lolium rigidum seeds. Ann Bot 2015; 115:293-301. [PMID: 25471097 PMCID: PMC4551082 DOI: 10.1093/aob/mcu231] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/07/2014] [Accepted: 10/09/2014] [Indexed: 05/05/2023]
Abstract
BACKGROUND AND AIMS Dormancy in Lolium rigidum (annual ryegrass) seeds can be alleviated by warm stratification in the dark or by application of fluridone, an inhibitor of plant abscisic acid (ABA) biosynthesis via phytoene desaturase. However, germination and absolute ABA concentration are not particularly strongly correlated. The aim of this study was to determine if cytokinins of both plant and bacterial origin are involved in mediating dormancy status and in the response to fluridone. METHODS Seeds with normal or greatly decreased (by dry heat pre-treatment) bacterial populations were stratified in the light or dark and in the presence or absence of fluridone in order to modify their dormancy status. Germination was assessed and seed cytokinin concentration and composition were measured in embryo-containing or embryo-free seed portions. KEY RESULTS Seeds lacking bacteria were no longer able to lose dormancy in the dark unless supplied with exogenous gibberellin or fluridone. Although these seeds showed a dramatic switch from active cytokinin free bases to O-glucosylated storage forms, the concentrations of individual cytokinin species were only weakly correlated to dormancy status. However, cytokinins of apparently bacterial origin were affected by fluridone and light treatment of the seeds. CONCLUSIONS It is probable that resident microflora contribute to dormancy status in L. rigidum seeds via a complex interaction between hormones of both plant and bacterial origin. This interaction needs to be taken into account in studies on endogenous seed hormones or the response of seeds to plant growth regulators.
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Affiliation(s)
- Danica E Goggin
- School of Plant Biology, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia, Biology Department, Trent University, 1600 West Bank Drive, Peterborough K9J7B8, Canada and Department of Biology, Western University, 1151 Richmond Street, London N6A3K7, Canada
| | - R J Neil Emery
- School of Plant Biology, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia, Biology Department, Trent University, 1600 West Bank Drive, Peterborough K9J7B8, Canada and Department of Biology, Western University, 1151 Richmond Street, London N6A3K7, Canada
| | - Leonid V Kurepin
- School of Plant Biology, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia, Biology Department, Trent University, 1600 West Bank Drive, Peterborough K9J7B8, Canada and Department of Biology, Western University, 1151 Richmond Street, London N6A3K7, Canada
| | - Stephen B Powles
- School of Plant Biology, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia, Biology Department, Trent University, 1600 West Bank Drive, Peterborough K9J7B8, Canada and Department of Biology, Western University, 1151 Richmond Street, London N6A3K7, Canada
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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Kisiala A, Laffont C, Emery RJN, Frugier F. Bioactive cytokinins are selectively secreted by Sinorhizobium meliloti nodulating and nonnodulating strains. Mol Plant Microbe Interact 2013; 26:1225-31. [PMID: 24001254 DOI: 10.1094/mpmi-02-13-0054-r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Bacteria present in the rhizosphere of plants often synthesize phytohormones, and these signals can consequently affect root system development. In legumes, plants adapt to nitrogen starvation by forming lateral roots as well as a new organ, the root nodule, following a symbiotic interaction with bacteria collectively referred to as rhizobia. As cytokinin (CK) phytohormones were shown to be necessary and sufficient to induce root nodule organogenesis, the relevance of CK production by symbiotic rhizobia was questioned. In this study, we analyzed quantitatively, by liquid chromatography-tandem mass spectrometry, the production of 25 forms of CK in nine rhizobia strains belonging to four different species. All bacterial strains were able to synthesize a mix of CK, and bioactive forms of CK, such as iP, were notably found to be secreted in bacterial culture supernatants. Use of a mutant affected in extracellular polysaccharide (EPS) production revealed a negative correlation of EPS production with the ability to secrete CK. In addition, analysis of a nonnodulating Sinorhizobium meliloti strain revealed a similar pattern of CK production and secretion when compared with a related nodulating strain. This indicates that bacterially produced CK are not sufficient to induce symbiotic nodulation.
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Pilkington SM, Montefiori M, Galer AL, Neil Emery RJ, Allan AC, Jameson PE. Endogenous cytokinin in developing kiwifruit is implicated in maintaining fruit flesh chlorophyll levels. Ann Bot 2013; 112:57-68. [PMID: 23644363 PMCID: PMC3690984 DOI: 10.1093/aob/mct093] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Accepted: 03/11/2013] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Green kiwifruit (Actinidia deliciosa) retain high concentrations of chlorophyll in the fruit flesh, whereas in gold-fleshed kiwifruit (A. chinensis) chlorophyll is degraded to colourless catabolites during fruit development, leaving yellow carotenoids visible. The plant hormone group the cytokinins has been implicated in the delay of senescence, and so the aim of this work was to investigate the link between cytokinin levels in ripening fruit and chlorophyll de-greening. METHODS The expression of genes related to cytokinin metabolism and signal transduction and the concentration of cytokinin metabolites were measured. The regulation of gene expression was assayed using transient activation of the promoter of STAY-GREEN2 (SGR2) by cytokinin response regulators. KEY RESULTS While the total amount of cytokinin increased in fruit of both species during maturation and ripening, a high level of expression of two cytokinin biosynthetic gene family members, adenylate isopentenyltransferases, was only detected in green kiwifruit fruit during ripening. Additionally, high levels of O-glucosylated cytokinins were detected only in green kiwifruit, as was the expression of the gene for zeatin O-glucosyltransferase, the enzyme responsible for glucosylating cytokinin into a storage form. Season to season variation in gene expression was seen, and some de-greening of the green kiwifruit fruit occurred in the second season, suggesting environmental effects on the chlorophyll degradation pathway. Two cytokinin-related response regulators, RRA17 and RRB120, showed activity against the promoter of kiwifruit SGR2. CONCLUSIONS The results show that in kiwifruit, levels of cytokinin increase markedly during fruit ripening, and that cytokinin metabolism is differentially regulated in the fruit of the green and gold species. However, the causal factor(s) associated with the maintenance or loss of chlorophyll in kiwifruit during ripening remains obscure.
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Affiliation(s)
- Sarah M. Pilkington
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 92169, Auckland, New Zealand
- University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Mirco Montefiori
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 92169, Auckland, New Zealand
| | - Amy L. Galer
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, Ontario, K9J 7B8, Canada
| | - R. J. Neil Emery
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, Ontario, K9J 7B8, Canada
| | - Andrew C. Allan
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 92169, Auckland, New Zealand
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Paula E. Jameson
- University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
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40
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Logan BA, Reblin JS, Zonana DM, Dunlavey RF, Hricko CR, Hall AW, Schmiege SC, Butschek RA, Duran KL, Emery RJN, Kurepin LV, Lewis JD, Pharis RP, Phillips NG, Tissue DT. Impact of eastern dwarf mistletoe (Arceuthobium pusillum) on host white spruce (Picea glauca) development, growth and performance across multiple scales. Physiol Plant 2013; 147:502-13. [PMID: 22905764 DOI: 10.1111/j.1399-3054.2012.01681.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 06/13/2012] [Accepted: 06/18/2012] [Indexed: 05/12/2023]
Abstract
Infection by eastern dwarf mistletoe (Arceuthobium pusillum) modifies needle and branch morphology and hastens white spruce (Picea glauca) mortality. We examined potential causal mechanisms and assessed the impacts of infection-induced alterations to host development and performance across scales ranging from needle hormone contents to bole expansion. Needles on infected branches (IBs) possessed higher total cytokinin (CK) and lower abscisic acid contents than needles on uninfected branches (UBs). IBs exhibited greater xylem growth than same-aged UBs, which is consistent with the promotive effect of CKs on vascular differentiation and organ sink strength. Elevated CK content may also explain the dense secondary and tertiary branching observed at the site of infection, i.e. the formation of 'witches' brooms' with significantly lower light capture efficiencies. Observed hormone perturbations were consistent with higher rates of transpiration, lower water use efficiencies (WUEs) and more negative needle carbon isotope ratios observed for IBs. Observed reductions in needle size allowed IBs to compensate for reduced hydraulic conductivity. Severe infections resulted in dramatically decreased diameter growth of the bole. It seems likely that the modifications to host hormone contents by eastern dwarf mistletoe infection led white spruce trees to dedicate a disproportionate fraction of their photoassimilate and other resources to self-shaded branches with low WUE. This would have decreased the potential for fixed carbon accumulation, generating a decline in the whole-tree resource pool. As mistletoe infections grew in size and the number of IBs increased, this burden was manifested as increasingly greater reductions in bole growth.
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Affiliation(s)
- Barry A Logan
- Biology Department, Bowdoin College, Brunswick, ME 04011, USA.
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41
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Hayward AR, Coates KE, Galer AL, Hutchinson TC, Emery RJN. Chelator profiling in Deschampsia cespitosa (L.) Beauv. Reveals a Ni reaction, which is distinct from the ABA and cytokinin associated response to Cd. Plant Physiol Biochem 2013; 64:84-91. [PMID: 23399533 DOI: 10.1016/j.plaphy.2012.12.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 12/31/2012] [Indexed: 05/04/2023]
Abstract
Plant hormones, including abscisic acid (ABA) and cytokinins (CKs), fluctuate as a result of excess metal exposure. Changes in hormonal concentration regulate plant growth and may also signal activation of metal chelators. The grass Deschampsia cespitosa was dosed with either Ni or Cd or pulsed with exogenous ABA. The roots were analyzed for ABA and CKs and for multiple potential metal chelators including: amino acids, nicotianamine (NA), and phytochelatins (PCs). They were quantified after 3 h and after 7 days, using LC-ESI MS/MS. The Ni treatment caused no measurable change in ABA or CK concentration; however, an increase in NA was documented. The Cd treatment resulted in a short-term ABA increase followed by a reduction in CKs and an increase in PC concentration. An exogenous ABA pulse in non-metal challenged plants induced changes in CKs and PCs that followed those of Cd treatment. Ni and Cd stress resulted in distinctly different detoxification responses. Since the reaction of CKs and putative metal chelators to Cd stress can be mimicked by an exogenous ABA pulse, it is suggested that ABA acts as a stress signal, resulting in reduced growth by way of decreased CK concentration and reduced metal toxicity through increased PC production.
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Affiliation(s)
- Allison R Hayward
- Department of Biology, Trent University, Peterborough, Ontario, Canada K9J 7B8.
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42
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Powell AF, Paleczny AR, Olechowski H, Emery RJN. Changes in cytokinin form and concentration in developing kernels correspond with variation in yield among field-grown barley cultivars. Plant Physiol Biochem 2013; 64:33-40. [PMID: 23352907 DOI: 10.1016/j.plaphy.2012.12.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 12/04/2012] [Indexed: 05/01/2023]
Abstract
The aim of the present study was to determine if relationships between cytokinin (CK) profiles and corresponding enzymatic regulation were consistent with differences in kernel yield among commercial barley (Hordeum vulgare L.) cultivars, differing in parameters relating to productivity and grown under agronomically-relevant field conditions. Quantification of the CKs at six distinct stages of kernel development by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) revealed a significant increase in CKs, especially trans-zeatin (tZ), during the stage when grain filling occurs, with a greater CK concentration observed in the cultivar with the greatest number of kernels per spike, which was also the highest yielding cultivar. High levels of the cis-zeatin (cZ) CK form were observed at the first developmental stage, indicating a possible role in early embryo development and viability. Cytokinin oxidase (CKX; EC 1.5.99.12) activity was evaluated at each stage through a colorimetric assay, as the enzyme provides a primary mechanism for the irreversible degradation and, thus, regulation of CKs. However, no peaks in CKX activity were observed and no differences were detected at the particular stages examined. Isopentenyl transferase (IPT) gene expression was also examined and suggests that biosynthesis contributes to regulation of CK concentrations in developing barley kernels.
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Walton LJ, Kurepin LV, Yeung EC, Shah S, Emery RJN, Reid DM, Pharis RP. Ethylene involvement in silique and seed development of canola, Brassica napus L. Plant Physiol Biochem 2012; 58:142-150. [PMID: 22809685 DOI: 10.1016/j.plaphy.2012.06.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 06/19/2012] [Indexed: 06/01/2023]
Abstract
A wide range of plant hormones, including gibberellins (GAs) and auxins are known to be involved in regulating seed and fruit growth and development. Changes in ethylene biosynthesis are also associated with seed and fruit development, but ethylene's role in these processes is poorly understood, as is its possible interaction with the other plant hormones. A major complication of investigating ethylene-induced regulation of developmental processes is ethylene's biphasic mode of action. To investigate ethylene's actions and interactions we used a 1-amino-cyclopropane-1-carboxylic acid (ACC) deaminase transgenic canola line. This line evolves significantly less ethylene from its siliques and seeds, relative to plants from a wild type (WT) background. Plants of the transgenic line also had smaller siliques which were associated with reductions in both seed size and seed number. Application of ethephon, a compound that produces ethylene, to plants of the transgenic line restored the WT phenotype for both siliques and seeds. Application of the same dose of ethephon to WT plants diminished both silique and seed development, showing ethylene's biphasic effect and effectively producing the ACC deaminase transgenic phenotype. There were significant decreases in endogenous concentrations of GA(1) and GA(4) and also of indole-3-acetic acid (IAA), between WT seeds and seedless siliques and seeds and siliques from the transgenic line plants. These differences were emphasized during early stages (10-20 days after pollination) of seed and silique development. The above results strongly suggest that ethylene interacts with other endogenous plant hormones in regulating silique and seed development and growth in WT lines of canola.
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Affiliation(s)
- Linda J Walton
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
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Long C, Held M, Hayward A, Nisler J, Spíchal L, Neil Emery RJ, Moffatt BA, Guinel FC. Seed development, seed germination and seedling growth in the R50 (sym16) pea mutant are not directly linked to altered cytokinin homeostasis. Physiol Plant 2012; 145:341-59. [PMID: 22324805 DOI: 10.1111/j.1399-3054.2012.01594.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
R50 (sym16) is a pea nodulation mutant that accumulates cytokinin (CK) in its vegetative organs. Total CK content increases as the plant ages because of the low activity of the enzyme cytokinin oxidase/dehydrogenase (CKX) responsible for CK degradation. R50 exhibits a large seed with high relative water content, and its seedling establishes itself slowly. Whether these two traits are linked to abnormal CK levels was considered here. R50 was found to have a similar germination rate but a much slower epicotyl emergence than Sparkle, its wild-type (WT). At the onset of emergence, the starch grains in R50 cotyledons were larger than those of WT; furthermore, they did not degrade as fast as in WT because of low amylase activity. No differences between the pea lines were observed in the CK forms identified during seed embryogenesis. However, while CK content compared to that of WT was reduced early in R50 embryogenesis, it was elevated later on in its dry seeds where CKX activity was low, although CKX transcript abundance remained high. Transcripts of the two known PsCKX isoforms exhibited tissue- and development-specific profiles with no detectable PsCKX2 expression in cotyledons. There were more of both transcripts in R50 roots than in WT roots, but less of PsCKX2 than PsCKX1 in R50 shoots compared to WT shoots. Thus, although there is a definite CKX post-transcriptional defect in R50 dry seeds, an abnormal CK homeostasis is not the basis of the delay in R50 seedling establishment, which we linked to abnormal amylase activity early in development.
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Affiliation(s)
- Chengli Long
- Department of Biology, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada
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45
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Faix B, Radchuk V, Nerlich A, Hümmer C, Radchuk R, Emery RJN, Keller H, Götz KP, Weschke W, Geigenberger P, Weber H. Barley grains, deficient in cytosolic small subunit of ADP-glucose pyrophosphorylase, reveal coordinate adjustment of C:N metabolism mediated by an overlapping metabolic-hormonal control. Plant J 2012; 69:1077-1093. [PMID: 22098161 DOI: 10.1111/j.1365-313x.2011.04857.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The barley Risø16 mutation leads to inactivation of cytosolic ADP-Glc pyrophosphorylase, and results in decreased ADP-Glc and endospermal starch levels. Here we show that this mutation is accompanied by a decrease in storage protein accumulation and seed size, which indicates that alteration of a single enzymatic step can change the network of storage metabolism as a whole. We used comprehensive transcript, metabolite and hormonal profiling to compare grain metabolism and development of Risø16 and wild-type endosperm. Despite increased sugar availability in mutant endosperm, glycolytic intermediates downstream of hexose phosphates remained unchanged or decreased, while several glycolytic enzymes were downregulated at the transcriptional level. Metabolite and transcript profiling also indicated an inhibition of the tricarboxylic acid cycle at the level of mitochondrial nicotinamide adenine dinucleotide (NAD)-isocitrate dehydrogenase and an attendant decrease in alpha-ketoglutarate and amino acids levels in Risø16, compared with wild type. Decreased levels of cytokinins in Risø16 endosperm suggested co-regulation between starch synthesis, abscisic acid (ABA) deficiency and cytokinin biosynthesis. Comparative cis-element analysis in promoters of jointly downregulated genes in Risø16 revealed an overlap between metabolic and hormonal regulation, which leds to a coordinated downregulation of endosperm-specific and ABA-inducible gene expression (storage proteins) together with repression by sugars (isocitrate dehydrogenase, amylases). Such co-regulation ensured that decreased carbon fluxes into starch lead to a coordinated inhibition of glycolysis, amino acid and storage proteins biosynthesis, which is useful in the prevention of osmotic imbalances and oxidative stress due to increased accumulation of sugars.
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Affiliation(s)
- Benjamin Faix
- Department Biologie I, Ludwig-Maximilians-Universität München, Grosshaderner Str. 2-4, D-82152 Martinsried, Germany
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46
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Atkins CA, Emery RJN, Smith PMC. Consequences of transforming narrow leafed lupin (Lupinus angustifolius [L.]) with an ipt gene under control of a flower-specific promoter. Transgenic Res 2011; 20:1321-32. [PMID: 21344295 DOI: 10.1007/s11248-011-9497-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 02/10/2011] [Indexed: 11/25/2022]
Abstract
Phenotypes of five transgenic lines of narrow-leafed lupin (Lupinus angustifolius [L] cv Merrit) stably transformed with the isopentenyl pyrophosphate transferase (ipt) gene from Agrobacterium tumefaciens coupled to a flower-specific promoter (TP12) from Nicotiana tabacum [L.] are described. Expression of the transgene was detected in floral tissues and in shoot apical meristems on all orders of inflorescence. In each transgenic line there was significant axillary bud outgrowth at all nodes on the main stem with pronounced branch development from the more basal nodes in three of the lines. The lowest basal branches developed in a manner similar to the upper stem axillary branches on cv Merrit and bore fruits, which, in two lines, contained a significant yield of filled seeds at maturity. Senescence of the cotyledons was delayed in all lines with green cotyledons persisting beyond anthesis in one case. IPT expression increased cytokinin (CK) levels in flowers, meristem tissues and phloem exudates in a form specific manner, which was suggestive of localized flower and meristem production with significant long-distance re-distribution in phloem. The total number of fruits formed (pod set) on some transgenic lines was increased compared to cv Merrit. Grain size compared to cv Merrit was not significantly altered in transgenic lines.
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Affiliation(s)
- Craig A Atkins
- School of Plant Biology, The University of Western Australia, Crawley, Perth, WA 6009, Australia.
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47
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Simmons DBD, Emery RJN. Phytochelatin induction by selenate in Chlorella vulgaris, and regulation of effect by sulfate levels. Environ Toxicol Chem 2011; 30:469-476. [PMID: 21038439 DOI: 10.1002/etc.392] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Phytochelatins (PCs) are short metal detoxification peptides made from the sulfur-rich molecule glutathione. The production of PCs by algae caused by Se exposure has never been studied, although many algae accumulate Se, forming Se-rich proteins and peptides, and higher plants have demonstrated PC production when treated with Se; therefore, a goal of the current study was to examine whether Se induces PC production in algae. Furthermore, selenate is thought to compete with sulfate in the S assimilation pathway, and sulfate therefore may have a protective effect against the toxic effects of high doses of Se in algae. Hence, the interaction of selenate and sulfate was investigated with respect to the induction of PCs. Chlorella vulgaris was cultured in media with either low (31.2 µM) or high (312 µM) concentrations of sulfate. These cultures were exposed to selenate in doses of 7, 35, and 70 nM for 48 h. In a separate treatment, Cd (890 nM) was added as a positive PC-inducing control, and one no-metal negative control was used. Total Se and Se speciation were determined, and glutathione, phytochelatin-2, and phytochelatin-3 were quantified in each of cell digests, cell medium, and cell lysates. We found that PCs and their precursor glutathione were induced by selenate as well as by a Cd control. The high concentration of sulfate was able to counter selenate-induced production of PCs and glutathione. These data support two possible mechanisms: a negative feedback system in the S assimilation pathway that affects PC production when sulfate is abundant, and competition for uptake at the ion transport level between selenate and sulfate.
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Affiliation(s)
- Denina B D Simmons
- Environmental & Life Sciences, Trent University, Peterborough, Ontario, Canada
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48
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Radchuk R, Conrad U, Saalbach I, Giersberg M, Emery RJN, Küster H, Nunes-Nesi A, Fernie AR, Weschke W, Weber H. Abscisic acid deficiency of developing pea embryos achieved by immunomodulation attenuates developmental phase transition and storage metabolism. Plant J 2010; 64:715-30. [PMID: 21105920 DOI: 10.1111/j.1365-313x.2010.04376.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The transition of pea embryos from pre-storage to maturation is partially controlled by abscisic acid (ABA). Immunomodulation in pea embryos specifically reduces free ABA levels during transition stages. Such seeds are, therefore, suitable models for studying ABA deficiency by global transcript and metabolite analysis. Compared with the wild type, anti-ABA seeds are smaller, contain fewer globulins and show lower dry matter accumulation and delayed differentiation. Free sugars are decreased, indicating lower uptake and/or elevated mobilisation. Lower levels of trans-zeatins suggest that ABA reduction influences rates of cytokinin synthesis and/or its level of accumulation. Abscisic acid deficiency leads to a general downregulation of gene expression related to transcription and translation. At the transcriptional level, anti-ABA embryos reveal a wide-range repression of carbohydrate oxidation, downregulated sucrose mobilisation, glycolysis and the tricarboxylic acid cycle/Krebs cycle (TCA cycle). Genes related to starch, amino acid and storage protein biosynthesis are downregulated, indicating a general decrease in metabolic fluxes. We conclude that during embryo differentiation ABA triggers broad upregulation of gene activity and genetic reprogramming, involving regulated protein degradation via the ubiquitin/proteasome system. Abscisic acid deficiency affects gene expression associated with transport processes and stimulation of membrane energisation. Our study identified mediators and downstream signalling elements of ABA during embryo differentiation, such as the transcription factor FUSCA3, SnRK1 kinase and Ca(2+) signalling processes. This suggests that ABA interacts with SnRK1 complexes, thus connecting SnRK1, sugar and stress signalling with ABA. Certain protein kinases/phosphatases known to negatively respond to ABA are upregulated in the modulated line, whilst those which respond positively are downregulated, pointing to a highly coordinated response of the gene network to ABA levels.
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Affiliation(s)
- Ruslana Radchuk
- Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), D-06466 Gatersleben, Germany
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49
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Goggin DE, Emery RJN, Powles SB, Steadman KJ. Initial characterisation of low and high seed dormancy populations of Lolium rigidum produced by repeated selection. J Plant Physiol 2010; 167:1282-1288. [PMID: 20478642 DOI: 10.1016/j.jplph.2010.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 04/22/2010] [Accepted: 04/22/2010] [Indexed: 05/29/2023]
Abstract
The physiological and biochemical bases of seed dormancy in Lolium rigidum (annual ryegrass) are largely unknown, and study of this process is complicated by the outcrossing nature of the species and the strong influence of environment on seed dormancy. In order to identify heritable biochemical factors contributing to seed dormancy in L. rigidum, seeds from a field-collected population were used to select sub-populations with consistently low or high seed dormancy over four generations. Low-dormancy seeds showed constitutive alpha-amylase activity prior to imbibition, higher concentrations of polyphenols and cis-zeatin, and lower abscisic acid and cis-zeatin riboside concentrations than high-dormancy seeds. Selection for high dormancy was associated with a reduction in response to dark-stratification for 21d at 20 degrees C (an effective means of releasing dormancy in the original, unselected population) over successive generations, but fluridone remained effective in breaking dormancy. Crossing of low- and high-dormancy populations indicated that dormancy level was not dependent upon the maternal genotype of the seed, and that the constitutive alpha-amylase activity and high seed anthocyanin concentrations characteristic of the low-dormancy populations were not correlated to high basal germination ability.
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Affiliation(s)
- Danica E Goggin
- Western Australian Herbicide Resistance Initiative, School of Plant Biology, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia.
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50
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Riebeseel E, Häusler RE, Radchuk R, Meitzel T, Hajirezaei MR, Emery RJN, Küster H, Nunes-Nesi A, Fernie AR, Weschke W, Weber H. The 2-oxoglutarate/malate translocator mediates amino acid and storage protein biosynthesis in pea embryos. Plant J 2010. [PMID: 19845879 DOI: 10.1111/j.1365-313x.2009.04058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Heterotrophic plastids of seeds perform many biosynthetic reactions. Understanding their function in crop plants is crucial for seed production. Physiological functions depend on the uptake of precursors by a range of different metabolite translocators. The 2-oxoglutarate/malate translocator gene (PsOMT), which is highly expressed during pea (Pisum sativum) embryo maturation, has an important role during seed storage. PsOMT functions have been studied by antisense repression in maturing pea embryos, and were found to reduce mRNA levels and transport rates of 2-oxoglutarate and malate by 50-70%. Combined metabolite and transcript profiling revealed that OMT repression affects the conversion of carbohydrates from sucrose into amino acids and proteins, decreases seed weight and delays maturation. OMT-repressed pea embryos have increased levels of organic acids, ammonia, and higher ratios of Asn : Asp and Gln : Glu. Decreased levels of most other amino acids indicate the reduced usage of organic acids and ammonia for amino acid biosynthesis in plastids, possibly caused by substrate limitation of the plastidial glutamine synthetase/glutamine-2-oxoglutarate aminotransferase cycle. Expression of storage proteins is delayed, and mature seeds have reduced protein content. Downregulated gene expression of starch biosynthesis and plastidial glucose-6-phosphate transport in asOMT embryos reveals that decreased 2-oxoglutarate/malate transport capacity affects other pathways of central carbon metabolism. Gene expression analysis related to plastid physiology revealed that OMT repression delays differentiation of storage plastids, thereby maintaining gene expression associated with green chloroplasts. We conclude that OMT is important for protein-storing crop seeds, and is necessary for amino acid biosynthesis in pea seeds. In addition, carbon supply as mediated by OMT controls plastid differentiation during seed maturation.
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Affiliation(s)
- Erik Riebeseel
- Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), D-06466 Gatersleben, Germany
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