Myriam Charpentier

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Myriam Charpentier
Alma materLudwig Maximillians University
Scientific career
FieldsMolecular Biology
InstitutionsJohn Innes Centre

Myriam Charpentier is a molecular biologist, who specialises in cell and developmental biology at the John Innes Centre, Norwich. Charpentier studies the environmental and biological stimulus of nuclear calcium signalling in plants.

She obtained her PhD in Plant Molecular Biology from Ludwig Maximillians University of Munich. Following this, Charpentier joined the John Innes Centre in 2009, and became a David Philips fellow [1] and group leader in 2017.

Charpentier investigates what produces calcium oscillations and how calcium channels affect plant development and has published extensively on this topic. [2] [3] Nuclear calcium machinery is common to all land plants, her laboratory is exploring how this has evolved and functions across different species. Dr Charpentier has also published on topics including the dynamic organisation of the nucleus, [4] and on legume symbiosis [5] and nitrogen fixation. [6]

Charpentier's work with Giles Oldroyd led to the discovery of cyclic nucleotide–gated ion channel 15s (CNGS15s). [7] [8] These proteins are key in the process to move calcium into the nucleus, an important part of the signal to the plant that nitrogen-fixing bacteria are in the soil nearby. [9]

More recently, in 2019, Charpentier's group discovered that nuclear calcium signalling plays another important role in plant roots, besides symbiosis. Her team showed that calcium can be released by the nucleus of root apical meristem – the region of the growing root. Using genetic approaches, the team could modulate nuclear calcium signatures to obtain longer or shorter roots in the model organism Arabidopsis thaliana . [10]

Related Research Articles

Nitrogen fixation is a chemical process by which molecular nitrogen (N
2
), with a strong triple covalent bond, in the air is converted into ammonia (NH
3
) or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. Atmospheric nitrogen is molecular dinitrogen, a relatively nonreactive molecule that is metabolically useless to all but a few microorganisms. Biological nitrogen fixation or diazotrophy is an important microbially mediated process that converts dinitrogen (N2) gas to ammonia (NH3) using the nitrogenase protein complex (Nif).

Mycorrhiza Symbiotic association between a fungus and the roots of a vascular plant

A mycorrhiza is a mutual symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, its root system. Mycorrhizae play important roles in plant nutrition, soil biology, and soil chemistry.

Rhizobia

Rhizobia are diazotrophic bacteria that fix nitrogen after becoming established inside the root nodules of legumes (Fabaceae). To express genes for nitrogen fixation, rhizobia require a plant host; they cannot independently fix nitrogen. In general, they are gram negative, motile, non-sporulating rods.

Dale Sanders, FRS is a director of the John Innes Centre, an internationally leading institute for research in plant sciences and microbiology in Norwich, England.

<i>Ensifer meliloti</i> Species of bacterium

Ensifer meliloti are an aerobic, Gram-negative, and diazotrophic species of bacteria. S. meliloti are motile and possess a cluster of peritrichous flagella. S. meliloti fix atmospheric nitrogen into ammonia for their legume symbionts, such as alfalfa. S. meliloti forms a symbiotic relationship with legumes from the genera Medicago, Melilotus and Trigonella, including the model legume Medicago truncatula. This symbiosis promotes the development of a plant organ, termed a root nodule. Because soil often contains a limited amount of nitrogen for plant use, the symbiotic relationship between S. meliloti and their legume hosts has agricultural applications. These techniques reduce the need for inorganic nitrogenous fertilizers.

Root nodule Plant part

Root nodules are found on the roots of plants, primarily legumes, that form a symbiosis with nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known as rhizobia. This process has evolved multiple times within the legumes, as well as in other species found within the Rosid clade. Legume crops include beans, peas, and soybeans.

Nod factor Signaling molecule

Nod factors, are signaling molecules produced by soil bacteria known as rhizobia in response to flavonoid exudation from plants under nitrogen limited conditions. Nod factors initiate the establishment of a symbiotic relationship between legumes and rhizobia by inducing nodulation. Nod factors produce the differentiation of plant tissue in root hairs into nodules where the bacteria reside and are able to fix nitrogen from the atmosphere for the plant in exchange for photosynthates and the appropriate environment for nitrogen fixation. One of the most important features provided by the plant in this symbiosis is the production of leghemoglobin, which maintains the oxygen concentration low and prevents the inhibition of nitrogenase activity.

Arbuscular mycorrhiza Symbiotic penetrative association between a fungus and the roots of a vascular plant

An arbuscular mycorrhiza (AM) is a type of mycorrhiza in which the symbiont fungus penetrates the cortical cells of the roots of a vascular plant forming arbuscules.

Rhizosphere

The rhizosphere is the narrow region of soil or substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome. The rhizosphere involving the soil pores contains many bacteria and other microorganisms that feed on sloughed-off plant cells, termed rhizodeposition, and the proteins and sugars released by roots, termed root exudates. This symbiosis leads to more complex interactions, influencing plant growth and competition for resources. Much of the nutrient cycling and disease suppression by antibiotics required by plants, occurs immediately adjacent to roots due to root exudates and metabolic products of symbiotic and pathogenic communities of microorganisms. The rhizosphere also provides space to produce allelochemicals to control neighbours and relatives.

Actinorhizal plants are a group of angiosperms characterized by their ability to form a symbiosis with the nitrogen fixing actinomycetota Frankia. This association leads to the formation of nitrogen-fixing root nodules.

Microbial inoculants also known as soil inoculants or bioinoculants are agricultural amendments that use beneficial rhizosphericic or endophytic microbes to promote plant health. Many of the microbes involved form symbiotic relationships with the target crops where both parties benefit (mutualism). While microbial inoculants are applied to improve plant nutrition, they can also be used to promote plant growth by stimulating plant hormone production.

Ectomycorrhiza Non-penetrative symbiotic association between a fungus and the roots of a vascular plant

An ectomycorrhiza is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobiont, and the roots of various plant species. The mycobiont is often from the phyla Basidiomycota and Ascomycota, and more rarely from the Zygomycota. Ectomycorrhizas form on the roots of around 2% of plant species, usually woody plants, including species from the birch, dipterocarp, myrtle, beech, willow, pine and rose families. Research on ectomycorrhizas is increasingly important in areas such as ecosystem management and restoration, forestry and agriculture.

Root microbiome

The root microbiome is the dynamic community of microorganisms associated with plant roots. Because they are rich in a variety of carbon compounds, plant roots provide unique environments for a diverse assemblage of soil microorganisms, including bacteria, fungi and archaea. The microbial communities inside the root and in the rhizosphere are distinct from each other, and from the microbial communities of bulk soil, although there is some overlap in species composition.

Giles Edward Dixon Oldroyd is a Professor at the University of Cambridge, working on beneficial Legume symbioses in Medicago truncatula. He has been a Royal Society Wolfson Research Merit Award winner and the Society of Biology (SEB) President's Medal winner. From 2014 Giles has been in the top 1% of highly cited plant scientists across the world.

Nuclear calcium

The concentration of calcium in the cell nucleus can increase in response to signals from the environment. Nuclear calcium is an evolutionary conserved potent regulator of gene expression that allows cells to undergo long-lasting adaptive responses. The 'Nuclear Calcium Hypothesis’ by Hilmar Bading describes nuclear calcium in neurons as an important signaling end-point in synapse-to-nucleus communication that activates gene expression programs needed for persistent adaptations. In the nervous system, nuclear calcium is required for long-term memory formation, acquired neuroprotection, and the development of chronic inflammatory pain. In the heart, nuclear calcium is important for the development of cardiac hypertrophy. In the immune system, nuclear calcium is required for human T cell activation. Plants use nuclear calcium to control symbiosis signaling.

Martin Parniske is a German biologist with a specialisation in genetics, microbiology and biochemistry. He is university professor and head of the Institute of Genetics at the Faculty of Biology of the Ludwig Maximilian University of Munich. Parniske's scientific focus is on the molecular interaction between plants and symbiotic and pathogenic organisms including bacteria, fungi, oomycetes and insects.

Plants can be exposed to many stress factors such as disease, temperature changes, herbivory, injury and more. Therefore, in order to respond or be ready for any kind of physiological state, they need to develop some sort of system for their survival in the moment and/or for the future. Plant communication encompasses communication using volatile organic compounds, electrical signaling, and common mycorrhizal networks between plants and a host of other organisms such as soil microbes, other plants, animals, insects, and fungi. Plants communicate through a host of volatile organic compounds (VOCs) that can be separated into four broad categories, each the product of distinct chemical pathways: fatty acid derivatives, phenylpropanoids/benzenoids, amino acid derivatives, and terpenoids. Due to the physical/chemical constraints most VOCs are of low molecular mass, are hydrophobic, and have high vapor pressures. The responses of organisms to plant emitted VOCs varies from attracting the predator of a specific herbivore to reduce mechanical damage inflicted on the plant to the induction of chemical defenses of a neighboring plant before it is being attacked. In addition, the host of VOCs emitted varies from plant to plant, where for example, the Venus Fly Trap can emit VOCs to specifically target and attract starved prey. While these VOCs typically lead to increased resistance to herbivory in neighboring plants, there is no clear benefit to the emitting plant in helping nearby plants. As such, whether neighboring plants have evolved the capability to "eavesdrop" or whether there is an unknown tradeoff occurring is subject to much scientific debate. As related to the aspect of meaning-making, the field is also identified as phytosemiotics.

Orchid mycorrhizae are symbiotic relationships between the roots of plants of the family Orchidaceae and a variety of fungi. Nearly all orchids are myco-heterotrophic at some point in their life cycle. Orchid mycorrhizae are critically important during orchid germination, as an orchid seed has virtually no energy reserve and obtains its carbon from the fungal symbiont.

Mycorrhiza helper bacteria Group of organisms

Mycorrhiza helper bacteria (MHB) are a group of organisms that form symbiotic associations with both ectomycorrhiza and arbuscular mycorrhiza. MHBs are diverse and belong to a wide variety of bacterial phyla including both Gram-negative and Gram-positive bacteria. Some of the most common MHBs observed in studies belong to the phylas Pseudomonas and Streptomyces. MHBs have been seen to have extremely specific interactions with their fungal hosts at times, but this specificity is lost with plants. MHBs enhance mycorrhizal function, growth, nutrient uptake to the fungus and plant, improve soil conductance, aid against certain pathogens, and help promote defense mechanisms. These bacteria are naturally present in the soil, and form these complex interactions with fungi as plant root development starts to take shape. The mechanisms through which these interactions take shape are not well-understood and needs further study.

Plant nucleus movement is the movement of the cell nucleus in plants by the cytoskeleton.

References

  1. "David Phillips fellows". United Kingdom Research and Innovation . Retrieved 31 March 2020.
  2. Charpentier, Myriam (30 July 2018). "Calcium signals in the plant nucleus: origin and function". Journal of Experimental Botany . 69 (17): 4165–4173. doi: 10.1093/jxb/ery160 . ISSN   0022-0957. PMID   29718301.
  3. Kelner, Audrey; Leitão, Nuno; Chabaud, Mireille; Charpentier, Myriam; de Carvalho-Niebel, Fernanda (27 February 2018). "Dual Color Sensors for Simultaneous Analysis of Calcium Signal Dynamics in the Nuclear and Cytoplasmic Compartments of Plant Cells". Frontiers in Plant Science . 9: 245. doi: 10.3389/fpls.2018.00245 . ISSN   1664-462X. PMC   5835324 . PMID   29535753.
  4. Thorpe, Stephen D.; Charpentier, Myriam (2 January 2017). "Highlight on the dynamic organization of the nucleus". Nucleus. 8 (1): 2–10. doi:10.1080/19491034.2016.1243634. ISSN   1949-1034. PMC   5287096 . PMID   27715428.
  5. Murray, Jeremy D.; Muni, RajaSekhara Reddy Duvvuru; Torres-Jerez, Ivone; Tang, Yuhong; Allen, Stacy; Andriankaja, Megan; Li, Guangming; Laxmi, Ashverya; Cheng, Xiaofei; Wen, Jiangqi; Vaughan, David (January 2011). "Vapyrin, a gene essential for intracellular progression of arbuscular mycorrhizal symbiosis, is also essential for infection by rhizobia in the nodule symbiosis of Medicago truncatula: VAPYRIN is required for rhizobial and mycorrhizal symbioses". The Plant Journal . 65 (2): 244–252. doi:10.1111/j.1365-313X.2010.04415.x. PMID   21223389.
  6. Charpentier, Myriam; Oldroyd, Giles (October 2010). "How close are we to nitrogen-fixing cereals?". Current Opinion in Plant Biology . 13 (5): 556–564. doi:10.1016/j.pbi.2010.08.003. PMID   20817544.
  7. "Scientists discover missing link in plant nitrogen fixation process". phys.org. Retrieved 8 March 2019.
  8. "Missing link in plant nitrogen fixation process discovered". ScienceDaily. Retrieved 8 March 2019.
  9. Oldroyd, Giles E. D.; Morris, Richard J.; Sanders, Dale; Véry, Anne-Aliénor; Thouin, Julien; Soumpourou, Eleni; Findlay, Kim; Radhakrishnan, Guru V.; Martins, Teresa Vaz (27 May 2016). "Nuclear-localized cyclic nucleotide–gated channels mediate symbiotic calcium oscillations". Science . 352 (6289): 1102–1105. Bibcode:2016Sci...352.1102C. doi:10.1126/science.aae0109. ISSN   0036-8075. PMID   27230377. S2CID   206646218.
  10. Leitão, Nuno; Dangeville, Pierre; Carter, Ross; Charpentier, Myriam (25 October 2019). "Nuclear calcium signatures are associated with root development". Nature Communications . 10 (1): 4865. Bibcode:2019NatCo..10.4865L. doi:10.1038/s41467-019-12845-8. ISSN   2041-1723. PMC   6814746 . PMID   31653864.