Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Jeudi 6 novembre 2008
Amphi 208 (Cœur d’Ecole) à 14h
Yellow Stripe1-Like 4 and 6, two putative transporters implicated in iron homeostasis in Arabidopsis
BPMP, équipe Transport et signalisation du fer
Iron (Fe) is an essential element for all plants and plays a critical role in respiration, photosynthesis, cell division and other cellular functions. However, excess free iron is potentially toxic to the cell because of its propensity to react with oxygen and generate harmful free radicals. In addition, Fe is relatively insoluble in aqueous solutions. Plants have developed ligands to facilitate the solubility, availability and transport of Fe. Among these molecules, citrate and nicotianamine (NA), a S-adenosyl methionine derivative, have been identified as Fe chelators in vivo. Since the identification of the genes controlling the root acquisition of iron, the control of inter- and intracellular distribution has become an important challenge for the understanding of metal homeostasis. The Yellow Stripe1-Like (YSL) transporters, composed of eight members in Arabidopsis thaliana, are serious candidates for the transport of NA-metal chelates across plant cell membranes. Loss-of-function mutations in AtYSL1 and in the double mutant atysl1atysl3 have revealed their roles in metal (copper, zinc, iron) distribution and in seed loading. The remaining YSL proteins are distributed in two subfamilies, AtYSL4, 6 and AtYSL5,7 and 8. In this work we have focused on the AtYSL4 and 6 sub-family. To understand the role of these transporters, we have isolated the single mutants, generated the double mutant ysl4ysl6, and obtained an antibody against YSL6. Furthermore, several fusions with YFP and GFP have been generated to study their subcellular localization. We will present new results on these two genes that support their role in iron homeostasis.
Contact : Cathy Curie