Responsable del Programa: Georgina Hernández D, Ph.D.

This research program studies PLANTS, as a representative model of eukaryotic systems, analyzing the interactions between plants and microorganisms. The program includes four research groups lead by: Georgina Hernández, Mario Serrano, Alexandre Tromas and Damien Formey.

Three research lines from the Program study of the legume-rhizobia symbiosis. Plants form the legume family have developed the capacity to grown in nitrogen-deprived soils by interacting with soil bacteria known as rhizobia. The two partners have co-evolved towards a complex and positive interaction for both of them, where symbiotic nitrogen fixation takes place to capture directly the atmospheric nitrogen thus to maintain plant growth.

1. Georgina Hernández’s group. Its research line is the functional genomics of common bean (Phaseolus vulgaris), the most important legume for human consumption, with focus in transcriptomics both of protein-coding mRNAs as well as non-coding small RNAs identified as key regulators. The main objective is to decipher new global regulators of the common bean – rhizobia symbiosis, including transcriptional  (transcription factors) and post-transcriptional regulators (microRNAs). In addition, the group explores the post-transcriptional regulation by “Alternative Splicing in the common bean- rhizobia symbiosis.

2. Damien Formey’s group. Its research line is the characterization and evolution of the small RNAs involved in the plant-microbe interactions. Using the Phaseolus vulgaris / Rhizobium interaction model, the project focuses on the microRNAs and PhasiRNAs regulating the symbiotic nitrogen fixation, from the diffusible factors exchange to the senescence of the symbiotic organs called nodules. Many of these small RNAs are common bean-specific and provide new insights into the co-evolution between the bacteria and their host.

3. Alexandre Tromas’s group. Its research line is the regulation of cytoskeleton during the symbiotic nitrogen fixation. It has been established that accommodation of micro-endosymbionts like rhizobia inside the plant cell is an active process that requires proper cytoskeleton rearrangement. The Rho-GTPases (named ROP in Plants), considered as “molecular switches”, are known to activate the rearrangement of actin, one of the main cytoskeleton components. The main objective is to understand which cytoskeleton rearrangement complexes are involved in the accommodation of symbiotic bacteria and understand when and where they are relocalized and activated in Lotus japonicus (model legume) root hairs.

Another research line from the Program studies the plant innate immunity.

Mario Serrano’s group. Its research line is the characterization of the plant innate immunity to the necrotrophic fungus Botrytis cinerea (grey mold), has been classified as the second most important plant pathogen. The first interaction between the plant and the fungal organism takes place at the epidermis, where not only the plant has the first physical barrier, that includes the plant cuticle in aerial organs, but also where the organisms are recognized and potentially the plant immune responses are triggered. The objective of the project is to identify and characterize of the molecular elements that link the degradation of the cuticle and the induction of the plant innate immunity, using the plant-pathogen system Arabidopsis thaliana-Botrytis cinerea using traditional genetics and chemical genomics methods.