Publications by authors named "Romain Larbat"

Specialized metabolites are molecules involved in plants' interaction with their environment. Elucidating their biosynthetic pathways is a challenging but rewarding task, leading to societal applications and ecological insights. Furanocoumarins emerged multiple times in Angiosperms, raising the question of how different enzymes evolved into catalyzing identical reactions.

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Phenolamides are specialized metabolites widely distributed in the plant kingdom. Their structure is composed by the association of hydroxycinnamic acid derivatives to mono-/poly-amine through an amination catalyzed by N-hydroxycinnamoyltransferases enzymes. Tomato plants accumulate putrescine-derived phenolamides in their vegetative parts.

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Article Synopsis
  • Resistance to standard treatments highlights the need for new therapeutic molecules, particularly from plant specialized metabolites like phenolamides found in tomatoes.
  • The study focused on three major phenolamides, including one specially synthesized for research, to assess their antimicrobial, cytotoxic, and anti-inflammatory effects.
  • Results indicated that while the phenolamides had low to moderate antibacterial activity, they effectively reduced inflammation in macrophages, suggesting their potential as natural alternatives to traditional drugs.
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Article Synopsis
  • Tomato plants face significant threats from herbivore pests like the leafminer, impacting global production.
  • Understanding how tomatoes defend against these pests can help identify resistance traits and improve pest management strategies.
  • The study used metabolomic and transcriptomic analyses to reveal local and systemic responses in tomato plants, indicating strong accumulation of phenolamides and the activation of specific biosynthesis pathways during herbivory.
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During its development, the leaf undergoes profound metabolic changes to ensure, among other things, its growth. The subcellular metabolome of tomato leaves was studied at four stages of leaf development, with a particular emphasis on the composition of the vacuole, a major actor of cell growth. For this, leaves were collected at different positions of the plant, corresponding to different developmental stages.

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Furanocoumarins are phytoalexins often cited as an example to illustrate the arms race between plants and herbivorous insects. They are distributed in a limited number of phylogenetically distant plant lineages, but synthesized through a similar pathway, which raised the question of a unique or multiple emergence in higher plants. The furanocoumarin pathway was investigated in the fig tree (Ficus carica, Moraceae).

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subsp. is a wild species widespread in Algeria which is utilized for medicinal purposes as analgesic and anticholesterolemic. However, information is still scarce regarding its phytochemical content.

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Phenolamides represent a family of specialized metabolites, consisting of the association of hydroxycinnamic acid derivatives with aliphatic or aromatic amines. Since the discovery of the first phenolamide in the late 1940s, decades of phytochemical analyses have revealed a high structural diversity for this family and a wide distribution in the plant kingdom. The occurrence of structurally diverse phenolamides in almost all plant organs has led to early hypotheses on their involvement in floral initiation and fertility, as well as plant defense against biotic and abiotic stress.

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Phenolamides constitute a family of metabolites, widely represented in the plant kingdom, that can be found in all plant organs with a predominance in flowers and pollen grains. They represent a large and structurally diverse family, resulting from the association of phenolic acids with aliphatic or aromatic amines. Initially revealed as active compounds in several medicinal plant extracts, phenolamides have been extensively studied for their health-promoting and pharmacological properties.

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Stresses such as wounding or atmospheric pollutant exposure have a significant impact on plant fitness. Since it has been widely described that the metabolome directly reflects plant physiological status, a way to assess this impact is to perform a global metabolomic analysis. In this study, we investigated the effect of two abiotic stresses (mechanical wounding and ozone exposure) on parsnip metabolic balance using a liquid chromatography-mass spectrometry-based untargeted metabolomic approach.

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Ficus species have adapted to diverse environments and pests by developing physical or chemical protection strategies. Physical defences are based on the accumulation of minerals such as calcium oxalate crystals, amorphous calcium carbonates and silica that lead to tougher plants. Additional cellular structures such as non-glandular trichomes or laticifer cells make the leaves rougher or sticky upon injury.

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Foliar pathogens face heterogeneous environments depending on the maturity of leaves they interact with. In particular, nutrient availability as well as defense levels may vary significantly, with opposing effects on the success of infection. The present study tested which of these factors have a dominant effect on the pathogen's development.

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The leafminer Tuta absoluta (Meyrick) is a major pest of the tomato crop and its development rate is known to decline when nitrogen availability for crop growth is limited. Because N limitation reduces plant primary metabolism but enhances secondary metabolism, one can infer that the slow larval development arises from lower leaf nutritive value and/or higher plant defence. As an attempt to study the first alternative, we examined the tomato-T.

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Comparative phylogenetic analyses of the R2R3-MYB transcription factor family revealed that five subgroups were preferentially found in woody species and were totally absent from Brassicaceae and monocots (Soler et al., 2015). Here, we analyzed one of these subgroups (WPS-I) for which no gene had been yet characterized.

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Article Synopsis
  • Wood is made up of special cells that get thicker and stronger through a process that involves a substance called lignin.
  • Researchers found out that a protein called EgMYB1 helps control how much lignin these cells make by working with another protein named EgH1.3.
  • This partnership between EgMYB1 and EgH1.3 helps ensure that wood cells develop properly and don’t make too much lignin too early or in the wrong way.
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In plants, the partitioning of carbon resources between growth and defense is detrimental for their development. From a metabolic viewpoint, growth is mainly related to primary metabolism including protein, amino acid and lipid synthesis, whereas defense is based notably on the biosynthesis of a myriad of secondary metabolites. Environmental factors, such as nitrate fertilization, impact the partitioning of carbon resources between growth and defense.

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Induced chemical defence is a cost-efficient protective strategy, whereby plants induce the biosynthesis of defence-related compounds only in the case of pest attack. Plant responses that are pathogen specific lower the cost of defence, compared to constitutive defence. As nitrogen availability (N) in the root zone is one of the levers mediating the concentration of defence-related compounds in plants, we investigated its influence on response traits of tomato to two pathogenic bacteria, growing plants hydroponically at low or high N supply.

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This study falls within the framework of the industrial exploitation of by-products of the prickly pear (Opuntia ficus-indica). The study aims to evaluate the use of hydro-ethanolic extract of prickly pear peels as a substitute of vitamin E used as antioxidant in margarine preservation. The extract was rich in total phenolics (1512.

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Comparative genomics analysis unravels lineage-specific bursts of gene duplications related to the emergence of specialized pathways. The CYP76C subfamily of cytochrome P450 enzymes is specific to Brassicaceae. Two of its members were recently associated with monoterpenol metabolism.

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Phenolics are implicated in the defence strategies of many plant species rendering their concentration increase of putative practical interest in the field of crop protection. Little attention has been given to the nature, concentration and distribution of phenolics within vegetative organs of tomato (Solanum lycopersicum. L) as compared to fruits.

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The seed composition of four varieties of Opuntia ficus-indica growing in Algeria was investigated. Seeds ground into a fine powder were first, subjected to oil extraction and fatty acids analysis. The phenolic compounds were then extracted from the defatted powder of seeds in order to be quantified and characterised by liquid chromatography coupled to mass spectrometry (LC-MS(n)) and to nuclear magnetic resonance (LC-NMR) approaches.

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Plant growth and defence are both fuelled by compounds synthesized from a common pool of carbon and nitrogen, implying the existence of a competition for carbon and nitrogen allocation to both metabolisms. The ratio of carbon to nitrogen (C:N) of an organ is often regarded as a convenient indicator of growth and quality. The purpose of this work was to assess whether or not it is possible to extend its use to characterize the trade-off between growth and defence processes.

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High concentrations of phenolics have been shown to play a role in plant resistance to pathogens. One way to obtain increased phenolic concentrations in plant tissues is to limit mineral nitrogen (N) availability; however, over long periods, this treatment will have a negative effect on plant growth. The aim of our study was to determine the effect of repeated short-term N limitations on plant growth and phenolic metabolism in leaves.

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Coumarins are important compounds that contribute to the adaptation of plants to biotic or abiotic stresses. Among coumarins, umbelliferone occupies a pivotal position in the plant phenylpropanoid network. Previous studies indicated that umbelliferone is derived from the ortho-hydroxylation of p-coumaric acid by an unknown biochemical step to yield 2,4-dihydroxycinnamic acid, which then undergoes spontaneous lactonization.

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Background: Understanding the regulation of the flavonoid pathway is important for maximising the nutritional value of crop plants and possibly enhancing their resistance towards pathogens. The flavonoid 3'5'-hydroxylase (F3'5'H) enzyme functions at an important branch point between flavonol and anthocyanin synthesis, as is evident from studies in petunia (Petunia hybrida), and potato (Solanum tuberosum). The present work involves the identification and characterisation of a F3'5'H gene from tomato (Solanum lycopersicum), and the examination of its putative role in flavonoid metabolism.

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