Examinando por Autor "Borassi, C."

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    A cell surface arabinogalactan-peptide influences root hair cell fate
    (Blackwell Publishing Ltd, 2020-08) Borassi, C.; Gloazzo Dorosz, J.; Ricardi, M.M.; Carignani Sardoy, M.; Pol Fachin, L.; Marzol E.; Mangano, S.; Rodríguez Garcia, D.R.; Martínez Pacheco, J.; Rondón Guerrero, Y.D.C.; Velasquez, S.M.; Villavicencio, B.
    Root hairs (RHs) develop from specialized epidermal trichoblast cells, whereas epidermal cells that lack RHs are known as atrichoblasts. The mechanism controlling RH cell fate is only partially understood. RH cell fate is regulated by a transcription factor complex that promotes the expression of the homeodomain protein GLABRA 2 (GL2), which blocks RH development by inhibiting ROOT HAIR DEFECTIVE 6 (RHD6). Suppression of GL2 expression activates RHD6, a series of downstream TFs including ROOT HAIR DEFECTIVE 6 LIKE-4 (RSL4) and their target genes, and causes epidermal cells to develop into RHs. Brassinosteroids (BRs) influence RH cell fate. In the absence of BRs, phosphorylated BIN2 (a Type-II GSK3-like kinase) inhibits a protein complex that regulates GL2 expression. Perturbation of the arabinogalactan peptide (AGP21) in Arabidopsis thaliana triggers aberrant RH development, similar to that observed in plants with defective BR signaling. We reveal that an O-glycosylated AGP21 peptide, which is positively regulated by BZR1, a transcription factor activated by BR signaling, affects RH cell fate by altering GL2 expression in a BIN2-dependent manner. Changes in cell surface AGP disrupts BR responses and inhibits the downstream effect of BIN2 on the RH repressor GL2 in root epidermis. © 2020 The Authors. New Phytologist © 2020 New Phytologist Trust
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    Apoplastic class III peroxidases PRX62 and PRX69 promote Arabidopsis root hair growth at low temperature
    (Nature Research, 2022-03) Pacheco, J.; Ranocha, P.; Kasulin, L.; Fusari, C.; Servi, L.; Aptekmann, A.; Gabarain, V.; Peralta, J.; Borassi, C.; Marzol, E.; Rodríguez-Garcia, D.; del Carmen Rondón Guerrero, Y.; Sardoy, M.; Ferrero, L.; Botto, J.; Meneses, C.; Ariel, F.; Nadra, A.; Petrillo, E.; Dunand, C.; Estevez, J.
    Root Hairs (RHs) growth is influenced by endogenous and by external environmental signals that coordinately regulate its final cell size. We have recently determined that RH growth was unexpectedly boosted when Arabidopsis thaliana seedlings are cultivated at low temperatures. It was proposed that RH growth plasticity in response to low temperature was linked to a reduced nutrient availability in the media. Here, we explore the molecular basis of this RH growth response by using a Genome Wide Association Study (GWAS) approach using Arabidopsis thaliana natural accessions. We identify the poorly characterized PEROXIDASE 62 (PRX62) and a related protein PRX69 as key proteins under moderate low temperature stress. Strikingly, a cell wall protein extensin (EXT) reporter reveals the effect of peroxidase activity on EXT cell wall association at 10 °C in the RH apical zone. Collectively, our results indicate that PRX62, and to a lesser extent PRX69, are key apoplastic PRXs that modulate ROS-homeostasis and cell wall EXT-insolubilization linked to RH elongation at low temperature.