Evidence that a common arbuscular mycorrhizal network alleviates phosphate shortage in interconnected walnut sapling and maize plants

Under agroforestry practices, inter-specific facilitation between tree rows and cultivated alleys occurs when plants increase the growth of their neighbors especially under nutrient limitation. Owing to a coarse root architecture limiting soil inorganic phosphate (Pi) uptake, walnut trees (Juglans spp.) exhibit dependency on soil-borne symbiotic arbuscular mycorrhizal fungi that extend extra-radical hyphae beyond the root Pi depletion zone. To investigate the benefits of mycorrhizal walnuts in alley cropping, we experimentally simulated an agroforestry system in which walnut rootstocks RX1 (J. regia x J. microcarpa) were connected or not by a common mycelial network (CMN) to maize plants grown under two contrasting Pi levels. Mycorrhizal colonization parameters showed that the inoculum reservoir formed by inoculated walnut donor saplings allowed the mycorrhization of maize recipient roots. Relative to non-mycorrhizal plants and whatever the Pi supply, CMN enabled walnut saplings to access maize Pi fertilization residues according to significant increases in biomass, stem diameter, and expression of JrPHT1;1 and JrPHT1;2, two mycorrhiza-inducible phosphate transporter candidates here identified by phylogenic inference of orthologs. In the lowest Pi supply, stem height, leaf Pi concentration, and biomass of RX1 were significantly higher than in non-mycorrhizal controls, showing that mycorrhizal connections between walnut and maize roots alleviated Pi deficiency in the mycorrhizal RX1 donor plant. Under Pi limitation, maize recipient plants also benefited from mycorrhization relative to controls, as inferred from larger stem diameter and height, biomass, leaf number, N content, and Pi concentration. Mycorrhization-induced Pi uptake generated a higher carbon cost for donor walnut plants than for maize plants by increasing walnut plant photosynthesis to provide the AM fungus with carbon assimilate. Here, we show that CMN alleviates Pi deficiency in co-cultivated walnut and maize plants, and may therefore contribute to limit the use of chemical P fertilizers in agroforestry systems

Multicentric Carpotarsal Osteolysis Is Caused by Mutations Clustering in the Amino-Terminal Transcriptional Activation Domain of MAFB

(The American Journal of Human Genetics, 90, 494–501; March 9, 2012)\ud In the published version of this article, the amino acid alteration caused by c.161C>T should have been notated as\ud p.Ser54Leu and not p.Pro54Leu. The wild-type amino acid is incorrectly notated in the main text, in Table 2, and in\ud Figure 4. The authors regret this error. Additionally, The Journal regrets that this erratum, originally requested in 2012,\ud was not published in a timely fashion

Abrupt warming and salinification of intermediate waters interplays with decline of deep convection in the Northwestern Mediterranean Sea

The Mediterranean Sea is a hotspot for climate change, and recent studies have reported its intense warming and salinification. In this study, we use an outstanding dataset relying mostly on glider endurance lines but also on other platforms to track these trends in the northwestern Mediterranean where deep convection occurs. Thanks to a high spatial coverage and a high temporal resolution over the period 2007–2017, we observed the warming (+0.06 ∘C year−1) and salinification (+0.012 year−1) of Levantine Intermediate Water (LIW) in the Ligurian Sea. These rates are similar to those reported closer to its formation area in the Eastern Mediterranean Sea. Further downstream, in the Gulf of Lion, the intermediate heat and salt content were exported to the deep layers from 2009 to 2013 thanks to deep convection processes. In 2014, a LIW step of +0.3 ∘C and +0.08 in salinity could be observed concomitant with a weak winter convection. Warmer and more saline LIW subsequently accumulated in the northwestern basin in the absence of intense deep convective winters until 2018. Deep stratification below the LIW thus increased, which, together with the air–sea heat fluxes intensity, constrained the depth of convection. A key prognostic indicator of the intensity of deep convective events appears to be the convection depth of the previous year

Genotype-Phenotype Correlation in NF1: Evidence for a More Severe Phenotype Associated with Missense Mutations Affecting NF1 Codons 844–848

Neurofibromatosis type 1 (NF1), a common genetic disorder with a birth incidence of 1:2,000–3,000, is characterized by a highly variable clinical presentation. To date, only two clinically relevant intragenic genotype-phenotype correlations have been reported for NF1 missense mutations affecting p.Arg1809 and a single amino acid deletion p.Met922del. Both variants predispose to a distinct mild NF1 phenotype with neither externally visible cutaneous/plexiform neurofibromas nor other tumors. Here, we report 162 individuals (129 unrelated probands and 33 affected relatives) heterozygous for a constitutional missense mutation affecting one of five neighboring NF1 codons—Leu844, Cys845, Ala846, Leu847, and Gly848—located in the cysteine-serine-rich domain (CSRD). Collectively, these recurrent missense mutations affect ∼0.8% of unrelated NF1 mutation-positive probands in the University of Alabama at Birmingham (UAB) cohort. Major superficial plexiform neurofibromas and symptomatic spinal neurofibromas were more prevalent in these individuals compared with classic NF1-affected cohorts (both p < 0.0001). Nearly half of the individuals had symptomatic or asymptomatic optic pathway gliomas and/or skeletal abnormalities. Additionally, variants in this region seem to confer a high predisposition to develop malignancies compared with the general NF1-affected population (p = 0.0061). Our results demonstrate that these NF1 missense mutations, although located outside the GAP-related domain, may be an important risk factor for a severe presentation. A genotype-phenotype correlation at the NF1 region 844–848 exists and will be valuable in the management and genetic counseling of a significant number of individuals

The First Near-infrared Transmission Spectrum of HIP 41378 f, A Low-mass Temperate Jovian World in a Multiplanet System

Abstract: We present a near-infrared transmission spectrum of the long-period (P = 542 days), temperate (T eq = 294 K) giant planet HIP 41378 f obtained with the Wide-Field Camera 3 instrument aboard the Hubble Space Telescope (HST). With a measured mass of 12 ± 3 M ⊕ and a radius of 9.2 ± 0.1 R ⊕, HIP 41378 f has an extremely low bulk density (0.09 ± 0.02 g cm−3). We measure the transit depth with a median precision of 84 ppm in 30 spectrophotometric channels with uniformly sized widths of 0.018 μm. Within this level of precision, the spectrum shows no evidence of absorption from gaseous molecular features between 1.1 and 1.7 μm. Comparing the observed transmission spectrum to a suite of 1D radiative-convective-thermochemical-equilibrium forward models, we rule out clear, low-metallicity atmospheres and find that the data prefer high-metallicity atmospheres or models with an additional opacity source, such as high-altitude hazes and/or circumplanetary rings. We explore the ringed scenario for HIP 41378 f further by jointly fitting the K2 and HST light curves to constrain the properties of putative rings. We also assess the possibility of distinguishing between hazy, ringed, and high-metallicity scenarios at longer wavelengths with the James Webb Space Telescope. HIP 41378 f provides a rare opportunity to probe the atmospheric composition of a cool giant planet spanning the gap in temperature, orbital separation, and stellar irradiation between the solar system giants, directly imaged planets, and the highly irradiated hot Jupiters traditionally studied via transit spectroscopy

Stability and detectability of exomoons orbiting HIP 41378 f, a temperate Jovian planet with an anomalously low apparent density

Moons orbiting exoplanets (“exomoons”) may hold clues about planet formation, migration, and habitability. In this work, we investigate the plausibility of exomoons orbiting the temperate (T eq = 294 K) giant (R = 9.2 R ⊕) planet HIP 41378 f, which has been shown to have a low apparent bulk density of 0.09 g cm−3 and a flat near-infrared transmission spectrum, hinting that it may possess circumplanetary rings. Given this planet’s long orbital period (P ≈ 1.5 yr), it has been suggested that it may also host a large exomoon. Here, we analyze the orbital stability of a hypothetical exomoon with a satellite-to-planet mass ratio of 0.0123 orbiting HIP 41378 f. Combining a new software package, astroQTpy, with REBOUND and EqTide, we conduct a series of N-body and tidal migration simulations, demonstrating that satellites up to this size are largely stable against dynamical escape and collisions. We simulate the expected transit signal from this hypothetical exomoon and show that current transit observations likely cannot constrain the presence of exomoons orbiting HIP 41378 f, though future observations may be capable of detecting exomoons in other systems. Finally, we model the combined transmission spectrum of HIP 41378 f and a hypothetical moon with a low-metallicity atmosphere and show that the total effective spectrum would be contaminated at the ∼10 ppm level. Our work not only demonstrates the feasibility of exomoons orbiting HIP 41378 f but also shows that large exomoons may be a source of uncertainty in future high-precision measurements of exoplanet systems

Impact de la fertilisation phosphatée et de la mycorhization arbusculaire sur le développement de porte-greffes de noyers fruitiers micropropagés.

The English walnut (Juglans regia L.) is the main species cultivated for the production of edible nuts. Owing to a sparse canopy and a deep rooting system, walnut is an ideal species for alley cropping, an agroforestry practice able to enhance productivity through interplant facilitative mechanisms. Walnut agroforestry requires the large scale production of seedling rootstocks selected to provide the best anchorage, vigour, and tolerance of pathogens. Due to the heterozygosity of walnut, the characteristics of agronomical interest of the chosen cultivar are not inherited via seed propagation. In vitro plant tissue culture thus plays a key role in mass propagation of high-quality walnut rootstocks. Micropropagation of walnut explants needs an ex vitro acclimatization phase to repair the in vitro induced abnormalities, and further requires a post-acclimatization growth in greenhouse conditions when plantlets become photoautotrophic. However, poor survival and slow growth rates are common difficulties encountered in nurseries when establishing micropropagated walnut saplings. As many other fruit and nut bearing trees, walnut exhibits a high dependency on symbiotic soil-borne arbuscular mycorrhizal (AM) fungi for development due to a coarse root architecture that limits soil inorganic phosphate (Pi) uptake. In the context of rootstock production, the aim of this thesis was to investigate at different development stages the establishment of seven walnut rootstocks of economic interest, upon inoculation or not with an AM fungus and two contrasting Pi fertilization regimes. We demonstrated that biotization with the AM fungus Rhizophagus irregularis improves the development of micropropagated walnut rootstocks at two decisive stages, namely ex vitro and post-vitro acclimatization. Under low-Pi conditions, biotization increases seedling performance attributes including biomass, leaf number, stem height, photosynthesis efficiency and leaf nutrition (carbon, nitrogen, and Pi). We concluded that the AM fungus improves walnut Pi nutrition, which in turn leads to increased photosynthetic rates and improved plant growth. We also showed that these benefits are rootstock-dependent, indicating that walnut mycorrhizal dependency for Pi nutrition varies between cultivars, and that the symbiotic phosphate uptake pathway may be differentially recruited depending on the chosen rootstock. We then sought to identify in Juglans spp. the phosphate transporters inducible by AM colonization. Detection of putative orthologues of the AM-specific phosphate transporter MtPT4 of the model legume Medicago truncatula was performed with Orthofinder using the BLAST all-vs-all algorithm, which identified three putative orthologues in J. regia and J. microcarpa. We validated these candidates through their expression analysis upon inoculation or not with the AM fungus R. irregularis in Pi-deficient and Pi-replete conditions. To address the benefits of mycorrhizal walnuts in alley cropping, we experimentally simulated using compartmentalized microcoms a walnut agroforestry system in which young walnut hybrid roostocks RX1 (J. regia x J. microcarpa) were connected or not by a common mycelial network (CMN) to maize (Zea maize L.) plants grown under contrasting Pi supply levels. Within a few weeks, the inoculum reservoir formed by walnut saplings allowed the mycorrhization of maize roots, thereby giving access to the maize nutrient pool. We showed that hyphal connections under P deficient condition result for both plants in growth and nutritional benefits comparable to P sufficient condition without a CMN. We concluded that a CMN is able to alleviate Pi deficiency in co-cultivated walnut and maize plants, and may therefore contribute to limit the use of chemical fertilizers in agroforestry systems.Le noyer anglais (Juglans regia L.) est la principale espèce cultivée pour la production de noix comestibles. Sa canopée peu dense et son système d'enracinement profond font du noyer une espèce idéale pour la culture en allées, une pratique agroforestière pouvant améliorer la productivité en favorisant les mécanismes de facilitation inter-plantes. L'agroforesterie du noyer fruitier nécessite la production à grande échelle de porte-greffes (PG) sélectionnés pour offrir le meilleur ancrage, la meilleure vigueur et la meilleure tolérance aux agents pathogènes. En raison de l'hétérozygotie du noyer qui ne reproduit pas à l'identique ces caractéristiques, la multiplication végétative in vitro joue un rôle clé dans la propagation des PG de noyer fruitier de qualité. La micropropagation des explants végétaux nécessite une phase d'acclimatation ex vitro pour réparer les anomalies induites in vitro, puis une post-acclimatation en serre lorsque les plantules deviennent photoautotrophes. Cependant, une faible survie et des taux de croissance lents sont des difficultés courantes rencontrées dans les pépinières lors de l'établissement de vitroplants. Comme beaucoup d'arbres fruitiers et à noix, le noyer présente une forte dépendance à l'égard des champignons mycorhiziens à arbuscules (MA) symbiotiques du sol pour sa nutrition phosphatée et son développement en raison de racines peu ramifiées qui limitent l'absorption du phosphate inorganique du sol (Pi). Dans le contexte de la production de PG de noyer fruitier, cette thèse a consisté à analyser, à différents stades de développement, l'établissement de sept PG présentant un intérêt économique, après inoculation ou non par un champignon MA dans des conditions contrastées de disponibilité en Pi. Nous avons démontré que la biotisation par le champignon MA Rhizophagus irregularis améliore le développement des PG lors de l'acclimatation ex vitro et post-vitro. Lors d'une carence en Pi, la biotisation augmente comparativement aux témoins les caractéristiques de performance des vitroplants, notamment la biomasse, le nombre de feuilles, la hauteur des tiges, l'efficacité photosynthétique et la nutrition foliaire (carbone, azote, Pi). Toutefois, ces avantages dépendent du PG, suggérant un recrutement différentiel de la voie d'absorption symbiotique du Pi selon le cultivar étudié. Ceci nous a conduit à identifier chez les Juglans spp. les transporteurs de Pi inductibles par la mycorhization. La détection des orthologues putatifs du transporteur de phosphate MtPT4 spécifique de la symbiose MA chez la légumineuse modèle Medicago truncatula, réalisée avec Orthofinder à l'aide de l'algorithme BLAST all-vs-all, a permis d'identifier trois orthologues putatifs chez J. regia et chez J. microcarpa. Nous avons validé ces candidats par l'étude comparative de leur expression après inoculation ou non par R. irregularis dans des conditions contrastées de disponibilité en Pi. Afin d'étudier les avantages de la mycorhization du noyer en culture en allées, nous avons simulé à l'aide de microcosmes compartimentés un système agroforestier dans lequel le PG RX1 (J. regia x J. microcarpa) est relié ou non par un réseau mycélien commun (RMC) à des racines de maïs (Zea maize L.), cultivé dans des conditions contrastées de disponibilité en Pi. En huit semaines, le réservoir de propagules fongiques formé par les racines de noyer a permis la mycorhization du maïs, autorisant ainsi un accès aux résidus de fertilisation. Nous avons montré que le RMC développé lors d'une carence en Pi conduit chez les deux plantes en co-culture à des bénéfices en termes de croissance et de nutrition, comparables à ceux observés sans mycorhization et sans carence. Cette étude démontre qu'un RMC peut pallier une carence phosphatée chez le maïs et le noyer élevés en co-culture, et donc contribuer à limiter l'apport d'intrants chimiques en systèmes agroforestiers

Impact de la fertilisation phosphatée et de la mycorhization arbusculaire sur le développement de porte-greffes de noyer fruitier micropropagés

This phD is part of the CASDAR MycoAgra project. The aim of the PhD is to understand mycorrhiza mechanisms in an agroforestry integrated culture system between walnut tree and corn culture; and to found out mycorrhiza impact on the global production. To identify which cultivation practices permit the best mycorrhiza fungi development, our study is organized in two axes of work: - We first want to know the impact of interculture on the common mycorrhizal network. - And the impact of nitrogen content in the soil on the common mycorrhizal network To the end, we expect to purpose to farmers crop itineraries that used as less as we can synthetic fertilizers, through alternative system.Ce sujet qui s'insère dans le projet CASDAR MycoAgra, s'inscrit dans le cadre d'une agriculture durable et plus particulièrement d'une culture intégrée du noyer dans des parcelles cultivées de maïs, et permettra à terme de mieux comprendre le fonctionnement mycorhizien des sols et son impact sur la production globale du système agroforestier. Afin de déterminer les pratiques culturales les plus favorables à la présence et au développement des champignons mycorhiziens à arbuscules communs aux deux plantes cultivées, 2 axes d'études complémentaires seront suivis : - l'étude des effets de différentes intercultures sur le réseau mycélien - l'étude de l'effet de la concentration en azote sur le réseau mycélien. À terme, cette étude débouchera sur des propositions concrètes faites aux agriculteurs sous forme d'itinéraires techniques adaptés et ancrés dans une démarche qui vise à réduire les intrants de synthèse par la mise en place de systèmes alternatifs

Impact de la fertilisation phosphatée et de la mycorhization arbusculaire sur le développement de porte-greffes de noyers fruitiers micropropagés.

The English walnut (Juglans regia L.) is the main species cultivated for the production of edible nuts. Owing to a sparse canopy and a deep rooting system, walnut is an ideal species for alley cropping, an agroforestry practice able to enhance productivity through interplant facilitative mechanisms. Walnut agroforestry requires the large scale production of seedling rootstocks selected to provide the best anchorage, vigour, and tolerance of pathogens. Due to the heterozygosity of walnut, the characteristics of agronomical interest of the chosen cultivar are not inherited via seed propagation. In vitro plant tissue culture thus plays a key role in mass propagation of high-quality walnut rootstocks. Micropropagation of walnut explants needs an ex vitro acclimatization phase to repair the in vitro induced abnormalities, and further requires a post-acclimatization growth in greenhouse conditions when plantlets become photoautotrophic. However, poor survival and slow growth rates are common difficulties encountered in nurseries when establishing micropropagated walnut saplings. As many other fruit and nut bearing trees, walnut exhibits a high dependency on symbiotic soil-borne arbuscular mycorrhizal (AM) fungi for development due to a coarse root architecture that limits soil inorganic phosphate (Pi) uptake. In the context of rootstock production, the aim of this thesis was to investigate at different development stages the establishment of seven walnut rootstocks of economic interest, upon inoculation or not with an AM fungus and two contrasting Pi fertilization regimes. We demonstrated that biotization with the AM fungus Rhizophagus irregularis improves the development of micropropagated walnut rootstocks at two decisive stages, namely ex vitro and post-vitro acclimatization. Under low-Pi conditions, biotization increases seedling performance attributes including biomass, leaf number, stem height, photosynthesis efficiency and leaf nutrition (carbon, nitrogen, and Pi). We concluded that the AM fungus improves walnut Pi nutrition, which in turn leads to increased photosynthetic rates and improved plant growth. We also showed that these benefits are rootstock-dependent, indicating that walnut mycorrhizal dependency for Pi nutrition varies between cultivars, and that the symbiotic phosphate uptake pathway may be differentially recruited depending on the chosen rootstock. We then sought to identify in Juglans spp. the phosphate transporters inducible by AM colonization. Detection of putative orthologues of the AM-specific phosphate transporter MtPT4 of the model legume Medicago truncatula was performed with Orthofinder using the BLAST all-vs-all algorithm, which identified three putative orthologues in J. regia and J. microcarpa. We validated these candidates through their expression analysis upon inoculation or not with the AM fungus R. irregularis in Pi-deficient and Pi-replete conditions. To address the benefits of mycorrhizal walnuts in alley cropping, we experimentally simulated using compartmentalized microcoms a walnut agroforestry system in which young walnut hybrid roostocks RX1 (J. regia x J. microcarpa) were connected or not by a common mycelial network (CMN) to maize (Zea maize L.) plants grown under contrasting Pi supply levels. Within a few weeks, the inoculum reservoir formed by walnut saplings allowed the mycorrhization of maize roots, thereby giving access to the maize nutrient pool. We showed that hyphal connections under P deficient condition result for both plants in growth and nutritional benefits comparable to P sufficient condition without a CMN. We concluded that a CMN is able to alleviate Pi deficiency in co-cultivated walnut and maize plants, and may therefore contribute to limit the use of chemical fertilizers in agroforestry systems.Le noyer anglais (Juglans regia L.) est la principale espèce cultivée pour la production de noix comestibles. Sa canopée peu dense et son système d'enracinement profond font du noyer une espèce idéale pour la culture en allées, une pratique agroforestière pouvant améliorer la productivité en favorisant les mécanismes de facilitation inter-plantes. L'agroforesterie du noyer fruitier nécessite la production à grande échelle de porte-greffes (PG) sélectionnés pour offrir le meilleur ancrage, la meilleure vigueur et la meilleure tolérance aux agents pathogènes. En raison de l'hétérozygotie du noyer qui ne reproduit pas à l'identique ces caractéristiques, la multiplication végétative in vitro joue un rôle clé dans la propagation des PG de noyer fruitier de qualité. La micropropagation des explants végétaux nécessite une phase d'acclimatation ex vitro pour réparer les anomalies induites in vitro, puis une post-acclimatation en serre lorsque les plantules deviennent photoautotrophes. Cependant, une faible survie et des taux de croissance lents sont des difficultés courantes rencontrées dans les pépinières lors de l'établissement de vitroplants. Comme beaucoup d'arbres fruitiers et à noix, le noyer présente une forte dépendance à l'égard des champignons mycorhiziens à arbuscules (MA) symbiotiques du sol pour sa nutrition phosphatée et son développement en raison de racines peu ramifiées qui limitent l'absorption du phosphate inorganique du sol (Pi). Dans le contexte de la production de PG de noyer fruitier, cette thèse a consisté à analyser, à différents stades de développement, l'établissement de sept PG présentant un intérêt économique, après inoculation ou non par un champignon MA dans des conditions contrastées de disponibilité en Pi. Nous avons démontré que la biotisation par le champignon MA Rhizophagus irregularis améliore le développement des PG lors de l'acclimatation ex vitro et post-vitro. Lors d'une carence en Pi, la biotisation augmente comparativement aux témoins les caractéristiques de performance des vitroplants, notamment la biomasse, le nombre de feuilles, la hauteur des tiges, l'efficacité photosynthétique et la nutrition foliaire (carbone, azote, Pi). Toutefois, ces avantages dépendent du PG, suggérant un recrutement différentiel de la voie d'absorption symbiotique du Pi selon le cultivar étudié. Ceci nous a conduit à identifier chez les Juglans spp. les transporteurs de Pi inductibles par la mycorhization. La détection des orthologues putatifs du transporteur de phosphate MtPT4 spécifique de la symbiose MA chez la légumineuse modèle Medicago truncatula, réalisée avec Orthofinder à l'aide de l'algorithme BLAST all-vs-all, a permis d'identifier trois orthologues putatifs chez J. regia et chez J. microcarpa. Nous avons validé ces candidats par l'étude comparative de leur expression après inoculation ou non par R. irregularis dans des conditions contrastées de disponibilité en Pi. Afin d'étudier les avantages de la mycorhization du noyer en culture en allées, nous avons simulé à l'aide de microcosmes compartimentés un système agroforestier dans lequel le PG RX1 (J. regia x J. microcarpa) est relié ou non par un réseau mycélien commun (RMC) à des racines de maïs (Zea maize L.), cultivé dans des conditions contrastées de disponibilité en Pi. En huit semaines, le réservoir de propagules fongiques formé par les racines de noyer a permis la mycorhization du maïs, autorisant ainsi un accès aux résidus de fertilisation. Nous avons montré que le RMC développé lors d'une carence en Pi conduit chez les deux plantes en co-culture à des bénéfices en termes de croissance et de nutrition, comparables à ceux observés sans mycorhization et sans carence. Cette étude démontre qu'un RMC peut pallier une carence phosphatée chez le maïs et le noyer élevés en co-culture, et donc contribuer à limiter l'apport d'intrants chimiques en systèmes agroforestiers