Descripción del proyecto
Nuevos datos sobre el abecé del crecimiento de las plantas
Cuando una planta se inclina hacia el sol, crece hacia un estímulo luminoso, lo que se conoce como fototropismo. Este proceso lo inician los receptores de luz azul de la fototropina, que perciben los gradientes de luz para desencadenar la señalización descendente que conduce a la distribución asimétrica de la hormona del crecimiento auxina a través del tallo fotoestimulado. En el proyecto THyM, financiado con fondos europeos, se examinará de cerca una proteína transportadora dependiente de ATP (ABC, por sus siglas en inglés) de las plantas y su función en el fototropismo. Se comprobará si este tipo de transportador es necesario para el establecimiento del gradiente de luz a través del hipocótilo. Los hallazgos permitirán mejorar nuestra comprensión del establecimiento del gradiente de luz en un órgano fotosensorial vegetal.
Objetivo
Plants can reorient their growth towards a favorable light environment to optimize photosynthesis in a process called phototropism. This process is initiated by the phototropin blue light receptors, perceiving light gradients to trigger downstream signaling leading to the asymmetric distribution of auxin across the photo-stimulated stem. The Fankhauser lab showed that AtABC, an ABC (ATP-binding cassette) transporter family protein is important for phototropism. AtABC shares homology with Drosophila transporters, which are involved in eye pigment precursor transport and play a vital role in insect vision. In addition to reduced phototropism, Atabc mutants have transparent hypocotyls. The primary objective of this project is to understand the function of AtABC in phototropism and to test whether this transporter is required for light gradient establishment across the hypocotyl. First, I will characterize the Atabc mutant at the tissue, cellular and subcellular levels (e.g. staining for cell wall components) to determine what defect underlies the transparent hypocotyl phenotype. Using several approaches including confocal microscopy to visualize light-activated proteins and fiber-optic techniques, I will measure the light gradient across the hypocotyl of wild type and Atabc mutants. I will characterize phototropin signaling using biochemical and microscopic approaches to determine at which signaling step AtABC is required. To characterize AtABC, I will determine its expression pattern and subcellular localization using GFP-tagged AtABC. Together with the phenotypic characterization of the mutant, this will provide testable hypotheses regarding the substance(s) transported by AtABC. Finally, to determine the functional conservation of AtABC in other plants, I will characterize Brasicca rapa mutants defective in the orthologous gene. The functional characterization of AtABC may provide key insights into light gradient establishment in a plant photosensory organ.
Ámbito científico
Programa(s)
Régimen de financiación
MSCA-IF-EF-ST - Standard EFCoordinador
1015 LAUSANNE
Suiza