Journal Article

Different pathways act downstream of the CEP peptide receptor CRA2 to regulate lateral root and nodule development

Australian Research Council DP150104250 Australian National University International PhD Scholarship A.W. Howard Fellowship Grains Research and Development Corporation Hons scholarship Centre National de la Recherche Scientifique Agence Nationale de la Recherche Labex Saclay Plant Science Lidex "Plant Phenotyping Pipeline" Endeavour fellowship, Australian National University (ANU), Reid, Dugald, Institut des Sciences des Plantes de Paris-Saclay (IPS2 (UMR_9213 / UMR_1403)) ; Institut National de la Recherche Agronomique (INRA)-Université Paris-Sud - Paris 11 (UP11)-Université Paris Diderot - Paris 7 (UPD7)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS), Aarhus University [Aarhus], Laffont, Carole, Patel, Neha, Frugier, Florian, Mohd-Radzman, Nadiatul A, Ivanovici, Ariel, Djordjevic, Michael A, John Innes Centre [Norwich] ; Biotechnology and Biological Sciences Research Council (BBSRC), Imin, Nijat, Stougaard, Jens

2016

Overview

C-TERMINALLY ENCODED PEPTIDEs (CEPs) control root system architecture in a non-cell-autonomous manner. In Medicago truncatula, MtCEP1 affects root development by increasing nodule formation and inhibiting lateral root emergence by unknown pathways. Here, we show that the MtCEP1 peptide-dependent increase in nodulation requires the symbiotic signaling pathway and ETHYLENE INSENSITIVE2 (EIN2)/SICKLE (SKL), but acts independently of SUPER NUMERIC NODULES. MtCEP1-dependent inhibition of lateral root development acts through an EIN2-independent mechanism. MtCEP1 increases nodulation by promoting rhizobial infections, the developmental competency of roots for nodulation, the formation of fused nodules, and an increase in frequency of nodule development that initiates at proto-phloem poles. These phenotypes are similar to those of the ein2/skl mutant and support that MtCEP1 modulates EIN2-dependent symbiotic responses. Accordingly, MtCEP1 counteracts the reduction in nodulation induced by increasing ethylene precursor concentrations, and an ethylene synthesis inhibitor treatment antagonizes MtCEP1 root phenotypes. MtCEP1 also inhibits the development of EIN2-dependent pseudonodule formation. Finally, mutants affecting the COMPACT ROOT ARCHITECTURE2 (CRA2) receptor, which is closely related to the Arabidopsis CEP Receptor1, are unresponsive to MtCEP1 effects on lateral root and nodule formation, suggesting that CRA2 is a CEP peptide receptor mediating both organogenesis programs. In addition, an ethylene inhibitor treatment counteracts the cra2 nodulation phenotype. These results indicate that MtCEP1 and its likely receptor, CRA2, mediate nodulation and lateral root development through different pathways.

• Publisher: Oxford University Press ; American Society of Plant Biologists,CCSD,American Society of Plant Biologists
• Subject: CELL BIOLOGY / Ethylenes - metabolism / Life Sciences / Medicago truncatula - cytology / Medicago truncatula - genetics / Medicago truncatula - growth & development / Medicago truncatula - metabolism / Phenotype / Plant Growth Regulators - metabolism / Plant Proteins - genetics / Plant Proteins - metabolism / Plant Root Nodulation / Plant Roots - cytology / Plant Roots - genetics / Plant Roots - growth & development / Plant Roots - metabolism / Receptors, Peptide - metabolism / Rhizobium - physiology / Vegetal Biology
• ISBN: 9780003813036, 0003813037