The essential role of NGATHA genes in style and stigma specification is widely conserved across eudicots

[EN] Carpel development and evolution are central issues for plant biology. The conservation of genetic functions conferring carpel identity has been widely studied in higher plants. However, although genetic networks directing the development of characteristic features of angiosperm carpels such as stigma and style are increasingly known in Arabidopsis thaliana, little information is available on the conservation and diversification of these networks in other species. Here, we have studied the functional conservation of NGATHA transcription factors in widely divergent species within the eudicots. We determined by in situ hybridization the expression patterns of NGATHA orthologs in Eschscholzia californica and Nicotiana benthamiana. Virus-induced gene silencing (VIGS)-mediated inactivation of NGATHA genes in both species was performed and different microscopy techniques were used for phenotypic characterization. We found the expression patterns of EcNGA and NbNGA genes during flower development to be highly similar to each other, as well as to those reported for Arabidopsis NGATHA genes. Inactivation of EcNGA and NbNGA also caused severe defects in style and stigma development in both species. These results demonstrate the widely conserved essential role of NGATHA genes in style and stigma specification and suggest that the angiosperm-specific NGATHA genes were likely recruited to direct a carpel-specific developmental program.This work was supported by the Spanish Ministerio de Ciencia e Innovacion (grant no. BIO2009-09920 to C. F.), the Spanish Ministerio de Economia y Competitividad (grant no. BIO2012-32902 to C. F.) and the Generalitat Valenciana (grant no. ACOMP/2012/099 and BEST/2009/054 to C. F.), We thank David Parejo and Victoria Palau (IBMCP) for glasshouse support, Marisol Gascon (IBMCP) for technical advice in microscopy, Amy Litt and Natalia Pabon-Mora (New York Botanical Gardens, Bronx, NY, USA) for providing VIGS plasmids and technical advice, and Barbara Ambrose (NYBG) for critical reading of the manuscript. E. californica germplasm used in this study was obtained from the National Genetic Resources Program (USA).Fourquin, C.; Ferrandiz Maestre, C. (2014). The essential role of NGATHA genes in style and stigma specification is widely conserved across eudicots. New Phytologist. 202(3):1001-1013. https://doi.org/10.1111/nph.12703S10011013202

The Role of SHI/STY/SRS Genes in Organ Growth and Carpel Development Is Conserved in the Distant Eudicot Species Arabidopsis thaliana and Nicotiana benthamiana

[EN] Carpels are a distinctive feature of angiosperms, the ovule-bearing female reproductive organs that endow them with multiple selective advantages likely linked to the evolutionary success of flowering plants. Gene regulatory networks directing the development of carpel specialized tissues and patterning have been proposed based on genetic and molecular studies carried out in Arabidopsis thaliana. However, studies on the conservation/diversification of the elements and the topology of this network are still scarce. In this work, we have studied the functional conservation of transcription factors belonging to the SHI/STY/SRS family in two distant species within the eudicots, Eschscholzia californica and Nicotiana benthamiana. We have found that the expression patterns of EcSRS-L and NbSRS-L genes during flower development are similar to each other and to those reported for Arabidopsis SHI/STY/SRS genes. We have also characterized the phenotypic effects of NbSRS-L gene inactivation and overexpression in Nicotiana. Our results support the widely conserved role of SHI/STY/SRS genes at the top of the regulatory network directing style and stigma development, specialized tissues specific to the angiosperm carpels, at least within core eudicots, providing new insights on the possible evolutionary origin of the carpels.This work was supported by the Spanish MINECO/FEDER grants no BIO2012-32902 and BIO2015-64531-R to CFe. AG-F was supported by a predoctoral contract of the Generalitat Valenciana (ACIF/2013/044). We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Gomariz, A.; Sánchez-Gerschon, V.; Fourquin, C.; Ferrandiz Maestre, C. (2017). The Role of SHI/STY/SRS Genes in Organ Growth and Carpel Development Is Conserved in the Distant Eudicot Species Arabidopsis thaliana and Nicotiana benthamiana. Frontiers in Plant Science. 8:1-17. https://doi.org/10.3389/fpls.2017.00814S1178Alvarez, J. P., Goldshmidt, A., Efroni, I., Bowman, J. L., & Eshed, Y. (2009). The NGATHA Distal Organ Development Genes Are Essential for Style Specification in Arabidopsis. The Plant Cell, 21(5), 1373-1393. doi:10.1105/tpc.109.065482ALVAREZBUYLLA, E., BENITEZ, M., DAVILA, E., CHAOS, A., ESPINOSASOTO, C., & PADILLALONGORIA, P. (2007). Gene regulatory network models for plant development. Current Opinion in Plant Biology, 10(1), 83-91. doi:10.1016/j.pbi.2006.11.008Ballester, P., & Ferrándiz, C. (2017). Shattering fruits: variations on a dehiscent theme. Current Opinion in Plant Biology, 35, 68-75. doi:10.1016/j.pbi.2016.11.008Bombarely, A., Rosli, H. G., Vrebalov, J., Moffett, P., Mueller, L. A., & Martin, G. B. (2012). 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The CRC orthologue from Pisum sativum shows conserved functions in carpel morphogenesis and vascular development

[EN] CRABS CLAW (CRC) is a member of the YABBY family of transcription factors involved in carpel morphogenesis, floral determinacy and nectary specification in arabidopsis. CRC orthologues have been functionally characterized across angiosperms, revealing additional roles in leaf vascular development and carpel identity specification in Poaceae. These studies support an ancestral role of CRC orthologues in carpel development, while roles in vascular development and nectary specification appear to be derived. This study aimed to expand research on CRC functional conservation to the legume family in order to better understand the evolutionary history of CRC orthologues in angiosperms. CRC orthologues from Pisum sativum and Medicago truncatula were identified. RNA in situ hybridization experiments determined the corresponding expression patterns throughout flower development. The phenotypic effects of reduced CRC activity were investigated in P. sativum using virus-induced gene silencing. CRC orthologues from P. sativum and M. truncatula showed similar expression patterns, mainly restricted to carpels and nectaries. However, these expression patterns differed from those of other core eudicots, most importantly in a lack of abaxial expression in the carpel and in atypical expression associated with the medial vein of the ovary. CRC downregulation in pea caused defects in carpel fusion and style/stigma development, both typically associated with CRC function in eudicots, but also affected vascular development in the carpel. The data support the conserved roles of CRC orthologues in carpel fusion, style/stigma development and nectary development. In addition, an intriguing new aspect of CRC function in legumes was the unexpected role in vascular development, which could be shared by other species from widely diverged clades within the angiosperms, suggesting that this role could be ancestral rather than derived, as so far generally accepted.We thank Rafael Martinez-Pardo (IBMCP) for greenhouse support, Alejandro Terrones (IBMCP) for technical assistance and Elisabeth Johansen (University of Aarhus, Denmark) for providing VIGS plasmids and technical advice. This work was supported by the Spanish Ministerio de Ciencia e Innovacion (BIO2009-09920), the Spanish Ministerio de Economia y Competitividad (BIO2012-32902) and the Generalitat Valenciana (ACOMP/2012/099).Fourquin ., C.; Primo-Capella, A.; Martinez-Fernandez, I.; Huet-Trujillo, E.; Ferrandiz Maestre, C. (2014). The CRC orthologue from Pisum sativum shows conserved functions in carpel morphogenesis and vascular development. Annals of Botany. 114(7):1535-1544. https://doi.org/10.1093/aob/mcu129S15351544114

A change in SHATTERPROOF protein lies at the origin of a fruit morphological novelty and a new strategy for seed dispersal in Medicago genus

[EN] Angiosperms are the most diverse and numerous group of plants, and it is generally accepted that this evolutionary success owes in part to the diversity found in fruits, key for protecting the developing seeds and ensuring seed dispersal. Although studies on the molecular basis of morphological innovations are few, they all illustrate the central role played by transcription factors acting as developmental regulators. Here, we show that a small change in the protein sequence of a MADS-box transcription factor correlates with the origin of a highly modified fruit morphology and the change in seed dispersal strategies that occurred in Medicago, a genus belonging to the large legume family. This protein sequence modification alters the functional properties of the protein, affecting the affinities for other protein partners involved in high-order complexes. Our work illustrates that variation in coding regions can generate evolutionary novelties not based on gene duplication/subfunctionalization but by interactions in complex networks, contributing also to the current debate on the relative importance of changes in regulatory or coding regions of master regulators in generating morphological novelties.This work was supported by the Spanish Ministerio de Ciencia e Innovacion (grant no. BIO2009-09920 to C.Fe.), the European Union (grant no. FP7-PEOPLE-PIRSES-2009-247589 to C.Fe. and A.C.d.O.), and a Fellowship for Foreign Young Postdocs from the Spanish Ministerio de Ciencia e Innovacion (to C.Fo.).Fourquin, C.; Del Cerro Fernández, C.; Victoria, FC.; Vialette-Guiraud, A.; De Oliveira, AC.; Ferrandiz Maestre, C. (2013). A change in SHATTERPROOF protein lies at the origin of a fruit morphological novelty and a new strategy for seed dispersal in Medicago genus. Plant Physiology. 162(2):907-917. https://doi.org/10.1104/pp.113.217570S907917162

Role of the FUL-SHP network in the evolution of fruit morphology and function

Arabidopsis research in the last decade has started to unravel the genetic networks directing gynoecium and fruit patterning in this model species. Only recently, the work from several groups has also started to address the conservation of these networks in a wide number of species with very different fruit morphologies, and we are now beginning to understand how they might have evolved. This review summarizes recent advances in this field, focusing mainly on MADS-box genes with a well-known role in dehiscence zone development, while also discussing how these studies may contribute to expand our views on fruit evolution.The work in the laboratory of Ferrándiz is supported by the Spanish Ministerio de Economia y Competitividad (grant no. BIO2012-32902 to CF) and the EU (FP7-PEOPLE-PIRSES-2009–247589).Ferrandiz Maestre, C.; Fourquin, C. (2014). Role of the FUL-SHP network in the evolution of fruit morphology and function. Journal of Experimental Botany. 65(16):4505-4513. https://doi.org/10.1093/jxb/ert479S45054513651

Quelles connaissances du Plan S et de la stratégie de non-cession des droits ??

Cette enquête intitulée « Quelle·s connaissance·s du Plan S et de la stratégie de rétention [non-cession] des droits ? » a été menée à la fin de l’année 2022 par le groupe juridique du groupe de travail science ouverte du Consortium Couperin (GTSO). Diffusée sous forme d’un questionnaire en ligne, elle s’adressait aux professionnels de l’information scientifique et technique (IST) et personnels des services d’appui à la recherche, travaillant dans des universités, organismes de recherche et grandes écoles. L’objectif de cette enquête était de mesurer le niveau de connaissance et d’appropriation du Plan S de ces professionnels, leurs besoins éventuels d’accompagnement, alors qu’il n’existe pas à ce jour de cadre d’application global du Plan S dans les établissements et structures de recherche françaises

Transcriptional networks orchestrating programmed cell death during plant development

Transcriptional gene regulation is a fundamental biological principle in the development of eukaryotes. It does control not only cell proliferation, specification, and differentiation, but also cell death processes as an integral feature of an organism's developmental program. As in animals, developmentally regulated cell death in plants occurs in numerous contexts and is of vital importance for plant vegetative and reproductive development. In comparison with the information available on the molecular regulation of programmed cell death (PCD) in animals, however, our knowledge on plant PCD still remains scarce. Here, we discuss the functions of different classes of transcription factors that have been implicated in the control of developmentally regulated cell death. Though doubtlessly representing but a first layer of PCD regulation, information on PCD-regulating transcription factors and their targets represents a promising strategy to understand the complex machinery that ensures the precise and failsafe execution of PCD processes in plant development

The effect of NGATHA altered activity on auxin signaling pathways within the Arabidopsis gynoecium

[EN] The four NGATHA genes (NGA) form a small subfamily within the large family of B3-domain transcription factors of Arabidopsis thaliana. NGA genes act redundantly to direct the development of the apical tissues of the gynoecium, the style, and the stigma. Previous studies indicate that NGA genes could exert this function at least partially by directing the synthesis of auxin at the distal end of the developing gynoecium through the upregulation of two different YUCCA genes, which encode flavin monooxygenases involved in auxin biosynthesis. We have compared three developing pistil transcriptome data sets from wildtype, nga quadruple mutants, and a 35S::NGA3 line. The differentially expressed genes showed a significant enrichment for auxin-related genes, supporting the idea of NGA genes as major regulators of auxin accumulation and distribution within the developing gynoecium. We have introduced reporter lines for several of these differentially expressed genes involved in synthesis, transport and response to auxin in NGA gain- and loss-of-function backgrounds. We present here a detailed map of the response of these reporters to NGA misregulation that could help to clarify the role of NGA in auxin-mediated gynoecium morphogenesis. Our data point to a very reduced auxin synthesis in the developing apical gynoecium of nga mutants, likely responsible for the lack of DR5rev::GFP reporter activity observed in these mutants. In addition, NGA altered activity affects the expression of protein kinases that regulate the cellular localization of auxin efflux regulators, and thus likely impact auxin transport. Finally, protein accumulation in pistils of several ARFs was differentially affected by nga mutations or NGA overexpression, suggesting that these accumulation patterns depend not only on auxin distribution but could be also regulated by transcriptional networks involving NGA factors.This work was supported by the Spanish Ministerio de Ciencia e Innovacion (grant no. BIO2009–09920 to Cristina Ferrándiz), the Fondazione Cariplo (grant “Fruitalia” to Lucia Colombo and Cristina Ferrándiz), and the European Union (grant no. FP7–PEOPLE–PIRSES–2009–247589 to Lucia Colombo, Cristina Ferrándiz, Antonio C. Oliveira).Martínez Fernández, I.; Sanchis, S.; Marini, N.; Balanzá Pérez, V.; Ballester Fuentes, P.; Navarrete Gomez, ML.; Oliveira, AC.... (2014). The effect of NGATHA altered activity on auxin signaling pathways within the Arabidopsis gynoecium. Frontiers in Plant Science. 5:210-1-210-11. https://doi.org/10.3389/fpls.2014.00210S210-1210-11

Two euAGAMOUS genes control C-function in Medicago truncatula

[EN] C-function MADS-box transcription factors belong to the AGAMOUS (AG) lineage and specify both stamen and carpel identity and floral meristem determinacy. In core eudicots, the AG lineage is further divided into two branches, the euAG and PLE lineages. Functional analyses across flowering plants strongly support the idea that duplicated AG lineage genes have different degrees of subfunctionalization of the C-function. The legume Medicago truncatula contains three C-lineage genes in its genome: two euAG genes (MtAGa and MtAGb) and one PLENA-like gene (MtSHP). This species is therefore a good experimental system to study the effects of gene duplication within the AG subfamily. We have studied the respective functions of each euAG genes in M. truncatula employing expression analyses and reverse genetic approaches. Our results show that the M. truncatula euAG- and PLENA-like genes are an example of subfunctionalization as a result of a change in expression pattern. MtAGa and MtAGb are the only genes showing a full C-function activity, concomitant with their ancestral expression profile, early in the floral meristem, and in the third and fourth floral whorls during floral development. In contrast, MtSHP expression appears late during floral development suggesting it does not contribute significantly to the C-function. Furthermore, the redundant MtAGa and MtAGb paralogs have been retained which provides the overall dosage required to specify the C-function in M. truncatula.This work was funded by grants BIO2009-08134 and BIO2012-39849-C02-01 from the Spanish Ministry of Economy and Competitiveness and the Ramon y Cajal Program (RYC-2007-00627 to CGM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Serwatowska, J.; Roque Mesa, EM.; Gómez Mena, MC.; Constantin, GD.; Wen, J.; Mysore, KS.; Lund, OS.... (2014). Two euAGAMOUS genes control C-function in Medicago truncatula. 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