ArgentinaCountry of destination:
Plants belonging to the legume family are able to interact symbiotically with nitrogen fixing bacteria named rhizobia, allowing these plants to grow in agricultural systems with low nitrogen inputs and thus to be important actors of sustainable agriculture. This symbiotic interaction leads to the formation of a new organ on the roots of the host plants, called nodule, inside which N2 is fixed for the benefit of the plant. Nodule development is controlled by the nuclear factor Y (NF-Y) transcription factor (TF) NF-YA1. The heterotrimeric NF-Y complex is composed of the DNA-binding subunit NF-YA associated with two histone-like subunits NF-YB and NF-YC. Interestingly NF-Y is both a sequence specific TF, binding CCAAT boxes, but also shows nucleosome-like properties, promoting chromatin accessibility for other master TFs. Indeed, NF-YA1 of M.truncatula is rapidly, strongly and specifically expressed during nodule development, and knock-out mutant lines only form few small nodules that lack a functional meristem. The aim of this project is to thoroughly understand the mode of action of MtNF-YA transcription factors in nodule development. We will determine using ChIP-Seq the binding sites for this TF during nodule development. In addition, comparative transcriptome analysis using RNA-Seq in WT, mutant and overexpression backgrounds will be performed. The combination of these approaches will identify direct target genes of NF-Y complexes. We will also identify and characterize proteins interacting with NF-YA1 to regulate gene expression and chromatin structure by CoIP of chromatin related proteins coupled to mass spectrometry. Data generated in this project could help defining new strategies to promote better nodule development in legume crops during adverse conditions and to transfer nodule development into non-nitrogen-fixing crops thereby contributing to the ongoing worldwide effort to increase biological nitrogen fixation in agriculture.
I obtained my Biotechnology and Molecular Biology Degree in 2011 from the National University of La Plata, Argentina. I defended my PhD in 2015 under the supervision of Dr. Maria Eugenia Zanetti and Dr. Flavio Blanco at the Institute of Biotechnology and Molecular Biology of the National University of La Plata - Argentina. During my PhD, I characterized transcription factors playing essential roles in the root nodule symbiosis established between Phaseolus vulgaris (common bean) and Rhizobium etli. In particular, I studied the function of a transcription factor of the GRAS family and the heterotrimeric Nuclear Factor Y (NF-Y), consisting of the NF-YA, NF-YB and NFYC subunits. During my PhD I worked as a professor assistant in different courses of the UNLP. In the context of an ANR project entitled “NODCCAAT” obtained by Andreas Niebel and thanks to AgreenSkills+ program, I joined Andreas Niebel/Fernanda de Carvalho-Niebel group in April 2016. I initiated a postdoctoral project to thoroughly understand the mode of action of NF-Y transcription factors during nodule development in the model plant Medicago truncatula.
Zanetti ME, Rípodas C, Niebel A, 2017. Plant NF-Y transcription factors: Key players in plant-microbe interactions, root development and adaptation to stress. Biochim Biophys Acta., 860(5):645-654.
Baudin M., Laloum T., Lepage Agnes, Rípodas C., Ariel F., Frances L., Crespi M., Gamas P., Blanco F., Zanetti M. E., de Carvalho-Niebel F. and Niebel A., 2015. A phylogenetically conserved group of NF-Y transcription factors interact to control nodulation in legumes. Plant Physiology. Doi: 10.1104/pp.15.01144.
C. Rípodas, M. Castaingts, J. Clúa, F. A. Blanco and M. Zanetti, 2015. Annotation, Phylogeny and Expression Analysis of the Nuclear Factor Y Gene Families in Common Bean (Phaseolus vulgaris). Frontiers in Plant Science. Doi: 10.3389/fpls.2014.00761.
C. Rípodas, M. Battaglia, J. Clua, M. Baudin, M. O. Aguilar, A. Niebel, M. E. Zanetti, F. A.Blanco, 2014. The NF-YC1 interacting protein SIN1, a member of the GRAS family, is required for nodule organogenesis, infection thread progression and lateral root growth. Plant Physiology, 164(3):1430-42.
C. Rípodas, J. Clua, M. Battaglia, M. Baudin, A. Niebel, E. Zanetti, F. A. Blanco, 2014. Transcriptional regulators of legume-rhizobia symbiosis: nuclear factors Ys and GRAS are two for tango. Plant Signaling and Behaviour; 9:e28847. Doi:10.4161/psb.28847.
2016-2018 AgreenSkills+ fellowship;
2014-2016 Type II PhD Fellowship granted by Argentine National Scientific Research Council (CONICET);
2011-2014 Type I PhD Fellowship granted by National Agency of Science and Technology;
2014 EMBO short-term fellowship grated by the European Molecular Biology Organization (EMBO). Short investigation stay in the Laboratoire des interactions plantes micro-organismes. UMR INRA/CNRS - Toulouse – France. March to June 2014;
2013 ASPB fellowship grated by the American Society of Plant Biologysts (ASPB) to attend the PBL congress in Providence, Rhode Island – USA.