Jean-Bernard Pouvreau

• Dr, Maitre de conférences
• Professor (Assistant) at Nantes Université

Branched broomrape (Phelipanche ramosa (L.) Pomel), an obligate parasitic weed with a wide host range, is known for its devasting effects on many crops worldwide. Soil fungi, notably Fusarium sp., are described as pathogenic to broomrape, while the hypothesis of the phytotoxicity of fusaric acid produced by F. verticillioides for parasitic weeds of...

In Western France, rapeseed ( Brassica napus) cultivation faces substantial yield losses due to the root holoparasitic plant Phelipanche ramosa. However, recent observations have shown a reduction in parasitism within previously heavily infested fields. This study investigates two neighboring rapeseed soils with distinct levels of parasitic infesta...

Background In western France, rapeseed farmers face significant yield losses due to root parasitism caused by Phelipanche ramosa, a holoparasite plant of the Orobanchaceae family. Recently, a reduction of parasitic plant development has been observed in fields with history of severe infestation. In a same given pedoclimatic environment, this so-cal...

Purpose The root holoparasitic plant Phelipanche ramosa has become a major constraint for rapeseed cultivation in western France for the last decades and its control remains challenging. To date, few studies have considered soil microbiota as a third partner of the parasitic plant-plant interaction. Therefore, we here addressed the question of how...

Orobanche cumana Wall., sunflower broomrape, is one of the major pests for the sunflower crop. Breeding for resistant varieties in sunflower has been the most efficient method to control this parasitic weed. However, more virulent broomrape populations continuously emerge by overcoming genetic resistance. It is thus essential to identify new broomr...

Strigolactones (SLs) are plant hormones exuded in the rhizosphere with a signaling role for the development of arbuscular mycorrhizal (AM) fungi and as stimulants of seed germination of the parasitic weeds Orobanche, Phelipanche, and Striga, the most threatening weeds of major crops worldwide. Phelipanche ramosa is present mainly on rape, hemp, and...

Strigolactones (SLs) are plant hormones exuded in the rhizosphere with a signaling role for the development of arbuscular mycorrhizal (AM) fungi and as stimulants of seed germination of the parasitic weeds Orobanche, Phelipanche and Striga, the most threatening weeds of major crops worldwide. Phelipanche ramosa is present mainly on rape, hemp and t...

The timing of leaf emergence at the shoot apical meristem, or plastochron, is highly regulated in plants. Among the genes known to regulate the plastochron in Arabidopsis (Arabidopsis thaliana), KLUH (KLU), orthologous to the rice (Oryza sativa) PLASTOCHRON1, encodes the cytochrome P450 CYP78A5, and is thought to act through generation of a still u...

In angiosperms, the α/β hydrolase DWARF14 (D14), along with the F-box protein MORE AXILLARY GROWTH2 (MAX2), perceives strigolactones (SL) to regulate developmental processes. The key SL biosynthetic enzyme CAROTENOID CLEAVAGE DIOXYGENASE8 (CCD8) is present in the moss Physcomitrium patens, and PpCCD8-derived compounds regulate moss extension. The P...

Strigolactones are a class of plant hormones involved in shoot branching, growth of symbiotic arbuscular mycorrhizal fungi, and germination of parasitic plant seeds. Assaying new molecules or compound exhibiting strigolactone-like activities is therefore important but unfortunately time-consuming and hard to implement because of the extremely low c...

Marennine has long been known as the unique peculiar pigment responsible for the natural greening of oysters. It is specifically produced by the marine diatom Haslea ostrearia and it is a natural blue molecule indeed promising for food industry because of the rarity of such non-toxic, blue-colored pigments. In the search for its still not defined m...

Phelipanche ramosa is an obligate root-parasitic weed threatening major crops in central Europe. For its germination, it has to perceive various structurally diverging host-exuded signals, including isothiocyanates (ITCs) and strigolactones (SLs). However, the receptors involved are still uncharacterized. Here, we identified five putative SL recept...

In flowering plants, the α/β hydrolase DWARF14 (D14) perceives strigolactone (SL) hormones and interacts with the F-box protein MORE AXILLARY GROWTH2 (MAX2) to regulate developmental processes. The key SL biosynthetic enzyme, CAROTENOID CLEAVAGE DEOXYGENASE8 (CCD8), is present in the moss Physcomitrium (Physcomitrella) patens , and PpCCD8-derived c...

Seeds of the parasitic weed Phelipanche ramosa are well adapted to their hosts because they germinate and form haustorial structures to connect to roots in response to diverse host-derived molecular signals. P. ramosa presents different genetic groups that are preferentially adapted to certain hosts. Since there are indications that microbes play a...

Phelipanche ramosa is an obligate root-parasitic weed threatening major crops in central Europe. For its germination, it has to perceive various structurally diverging host-exuded signals, including isothiocyanates (ITCs) and strigolactones (SLs). However, the receptors involved are still uncharacterized. Here, we identified five putative SL recept...

Strigolactone (SL) plant hormones control plant architecture and are key players in both symbiotic and parasitic interactions. GR24, a synthetic SL analog, is the worldwide reference compound used in all bioassays for investigating the role of SLs in plant development and in rhizospheric interactions. In 2012, the first characterization of the SL r...

Phelipanche ramosa, a.k.a. broomrape, is a parasitic plant of the Orobanchaceae family that infests numerous hosts in Europe and Mediterranean basin. It causes huge yield losses on various crops and especially on oilseed rape which cultivation is threatened in western France. One the special features of broomrape is its seed germination. Indeed, br...

This chapter presents new insights into “blue” diatom species and marennine-like pigments in particular, concerning the biodiversity of these microalgae, their pigments, their interactions with bivalves, and their potential use in biotechnology, in particular as natural blue pigments. Historically, the term “blue diatom” refers to the marine diatom...

In grafted plants, rootstocks assure the mineral nutrition of the scion and modify its development. In this work, we show that two grapevine rootstock genotypes present different shoot branching architectures when cultivated as cuttings and that this trait is transmitted to the scion when grafted. Shoot branching plasticity in response to nitrogen...

The heterotrophic lifestyle of parasitic plants relies on the development of the haustorium, a specific infectious organ required for attachment to host roots. While haustorium development is initiated upon chemodetection of host-derived molecules in hemiparasitic plants, the induction of haustorium formation remains largely unknown in holoparasiti...

Parasitic plants are usually considered as botanical curiosities because of their shapes and colours. However, in some cases, they are proving to be terrible bioagressors in man-made ecosystems. Parasitic plants have indeed the capacity to connect intimately with other plants to exploit their resources (water, nutrients, growth regulators…) for the...

Seed dormancy release of the obligate root parasitic plant, Phelipanche ramosa, requires a minimum 4-day conditioning period followed by stimulation by host-derived germination stimulants, such as strigolactones. Germination is then mediated by germination stimulant-dependent activation of PrCYP707A1, an abscisic acid catabolic gene. The molecular...

Seed dormancy release of the obligate root parasitic plant, Phelipanche ramosa, requires a minimum 4-day conditioning period followed by stimulation by host-derived germination stimulants, such as strigolactones. Germination is then mediated by germination stimulant-dependent activation of PrCYP707A1, an abscisic acid catabolic gene. The molecular...

In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, pr...

In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, pr...

An AccQ•Tag ultra performance liquid chromatographyphotodiode array-electrospray ionization-mass spectrometry (AccQ•Tag UPLC-PDA-ESI-MS) method is presented here for the fast, robust, and sensitive quantification of 15N isotopologue enrichment of amino acids in biological samples, as for example in the special biotic interaction between the cultiva...

Strigolactones (SLs) are not only known as plant hormones but also as rhizosphere signals for establishing symbiotic and parasitic interactions. The design of new specific SL analogues is a challenging goal in understanding the basic plant biology and is also useful to control plant architectures without favoring the development of parasitic plants...

Some root-parasitic plants belonging to the Orobanche, Phelipanche or Striga genus represent one of the most destructive and intractable weed problems to agricultural production in both developed and developing countries. Compared with most of the other weeds, parasitic weeds are difficult to control by conventional methods because of their life st...

After a conditioning period, seed dormancy in obligate root parasitic plants is released by a chemical stimulus secreted by the roots of host plants. Using Phelipanche ramosa as the model, experiments conducted in this study showed that seeds require a conditioning period of at least 4 d to be receptive to the synthetic germination stimulant GR24....

The study of the blue diatoms from the genus Haslea is an arcane topic, due to investigations being restricted to the only species Haslea ostrearia (Gaillon/ Bory) Simonsen. This diatom, first observed in the early 19th century, has the peculiar ability to produce a non‐photosynthetic blue pigment, the so‐called marennine. This pigment’s name refer...

Initially known for their role in the rhizosphere in stimulating the seed germination of parasitic weeds such as the Striga and Orobanche species, and later as host recognition signals for arbuscular mycorrhizal fungi, strigolactones (SLs) were recently rediscovered as a new class of plant hormones involved in the control of shoot branching in plan...

Marennine, the blue pigment produced by the diatom Haslea ostrearia, exists in two different forms, the intra- and extracellular forms. We investigated the antibacterial, antiviral, and antiproliferative properties of both of these forms. Both forms of marennine inhibited the development of marine bacteria, in particular the pathogenic organism Vib...

Phelipanche ramosa is a major parasitic weed of Brassica napus. The first step in a host-parasitic plant interaction is stimulation of parasite seed germination by compounds released from host roots. However, germination stimulants produced by B. napus have not been identified yet. In this study, we characterized the germination stimulants that acc...

Phelipanche ramosa L. (Pomel) is a major root-parasitic weed attacking many important crops. Success in controlling this parasite is rare and a better understanding of its unique biology is needed to develop new specific control strategies. In the present study, quantitative polymerase chain reaction experiments showed that sucrose synthase encodin...

Phelipanche ramosa L. parasitizes major crops, acting as a competitive sink for host photoassimilates, especially sucrose. An understanding of the mechanisms of sucrose utilization in parasites is an important step in the development of new control methods. Therefore, in this study, we characterized the invertase gene family in P. ramosa and analys...

The dynamics of Orobanche foetida parasitizing faba bean are examined using Petri dish experiments. Rates of broomrape seed germination and seedling attachment to the host roots were quantified on three resistant genotypes (the Egyptian line Giza 429, the Spanish cultivar Baraca, and the Tunisian cultivar Najeh [XBJ90.03-16-1-1-1]) and the suscepti...

Fusarium and Alternaria spp. are phytopathogenic fungi which are known to be virulent on broomrapes and to produce sphinganine-analog mycotoxins (SAMs). AAL-toxin is a SAM produced by Alternaria alternata which causes the inhibition of sphinganine N-acyltransferase, a key enzyme in sphingolipid biosynthesis, leading to accumulation of sphingoid bas...

Colorimetric study of marennine, a blue-green pigment from the diatom Haslea ostrearia responsible for natural greening of cultured oyster. Pouvreau J-B., Morançais M., Pondaven P., Fleurence J., Guérard F., Dufossé L.. In : « Pigments in Food, For Quality and Health », Heinonen M. (Ed), © Yliopistopaino, Helsinki, Finland, ISBN 978-952-10-4846-3,...

Among microalgae, the marine diatom Haslea ostrearia has the distinctive feature of synthesizing and releasing, into the surrounding environment, a blue-green polyphenolic pigment called marennine. The oyster-breeding industry commonly makes use of this natural phenomenon for the greening of oysters grown in the ponds of the French Atlantic coast....

Among microalgae, the marine diatom Haslea ostrearia has the distinctive feature of synthesizing and releasing, into the surrounding environment, a blue-green polyphenolic pigment called marennine. The oyster-breeding industry commonly makes use of this natural phenomenon for the greening of oysters grown in the ponds of the French Atlantic coast....

Haslea ostrearia, a tychopelagic marine diatom distributed world-wide, characteristically settles in oyster-ponds. This diatom synthesizes and releases into the external medium a blue-green polyphenolic pigment called "marennine" (Mn), which is responsible for oyster greening. During the bloom of H. ostrearia in ponds, mainly occurring in autumn al...

This paper describes a new approach for quantifying marennine, a blue-green pigment synthesized by the marine diatom Haslea ostrearia, which is known to be responsible for the greening of cultured oysters in French coastal areas. The method uses gel-filtration HPLC interfaced with a photodiode-array detector (PDA). Under the chromatographic conditi...

Introduction La plante parasite Orobanche ramosa menace très sérieusement la culture de tomate (Lycopersicon esculentum Mill.) dans le bassin méditerranéen (Parker and Riches, 1993), faute de génotypes résistants disponibles. Complètement dépourvu de chlorophylle, O. ramosa dépend entièrement du saccharose prélevé chez la plante haute. La biodégrad...

Haslea ostrearia is a common marine tychopelagic diatom which has the particularity of synthesizing a blue-green hydrosoluble pigment called “marennine”. This pigment, when released into the external medium, is known to be responsible for the colour of oyster gills. Here we present results for main biophysical and biochemical characteristics of pur...

The diatom Haslea ostrearia that lives in oyster ponds has the distinctive feature of synthesizing “marennine”, a blue-green pigment of which the chemical nature still remains unknown. This pigment is responsible for the greening of oyster gills. Here, we report a new method for extraction and purification of intracellular (accumulated in the apex...

The marine diatom Haslea ostrearia has the distinctive feature of synthesizing and releasing into the external environment, a blue-green polyphenolic pigment called marennine. The oyster-breeding industry the commonly makes use of this natural phenomenon for the greening of oysters grown in the ponds of the French Atlantic coast. The complete molec...

IntheparasiticplantStrigahermonthica(Del.Benth),aspar-aginesynthesisplaysaprominentroleinthemetabolismofthehost-derivednitrogenandinthedetoxificationprocessofasteady-stateN-excess.Here,weshowthatasparaginesynthe-tase(EC6.3.5.4),theprimaryenzymeinvolvedinasparagineproductioninplants,isencodedinStrigabyasmallgenefamily,withatleasttwoASgenes,including...