MEDIATOR16 orchestrates local and systemic responses to phosphate scarcity in Arabidopsis roots

27 de octubre de 2020

Te invitamos a leer el artículo: “MEDIATOR16 orchestrates local and systemic responses to phosphate scarcity in Arabidopsis roots” publicado en New Phytologist, a cargo del profesor investigador Dr. Luis Herrera y su equipo de trabajo de la UGA-Langebio.

Autores: Javier Raya-Gonzalez^1,2 , Jonathan Odilón Ojeda-Rivera¹, Javier Mora-Macias¹, Araceli Oropeza-Aburto¹, Leon Francisco Ruiz-Herrera³, Jose Lopez-Bucio³ and Luis Herrera-Estrella^1,4.

1. Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, 36821 Campus Irapuato, Guanajuato,México.
2. Facultad de Químico Farmacobiología, Avenida Tzintzuntzan 173, Col. Matamoros, Morelia, Michoacan, México.
3. Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolas de Hidalgo. Edificio B3, Ciudad Universitaria, Morelia, Michoacan 58030, México.
4. Department of Plant and Soil Science, Institute of Genomics for Crop AbioticStress Tolerance (IGCAST), Texas Tech University, Box 42122, Lubbock, TX 79409, USA.

Felicitamos al estudiantado y profesorado que contribuyeron en esta investigación por su arduo trabajo.

Abstract: Phosphate (Pi) is a critical macronutrient for the biochemical and molecular functions ofcells. Under phosphate limitation, plants manifest adaptative strategies to increase phosphatescavenging. However, how low phosphate sensing links to the transcriptional machineryremains unknown.The role of the MEDIATOR (MED) transcriptional co-activator, through its MED16 subunit in Arabidopsis root system architecture remodelingin response to phosphate limitation was assessed.Its critical function acting over the SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1)-ALUMINUM-ACTIVATED MALATE TRANSPORT1 (ALMT1) signaling module was testedthrough a combination of genetic, biochemical, and genome-widetranscriptomicapproaches.Root system configuration in response to phosphate scarcity involved MED16 functioning,which modulates the expression of a large set of low-phosphate-induced genes that respondto local and systemic signals in the Arabidopsis root tip, including those directly activated bySTOP1. Biomolecular fluorescence complementation analysis suggests that MED16 is requiredfor the transcriptional activation of STOP1 targets, including the membrane permease ALMT1, to increase malate exudation in response to low phosphate.Our results unveil the function of a critical transcriptional component, MED16, in the rootadaptive responses to a scarce plant macronutrient, which helps understanding how plantcells orchestrate root morphogenesis to gene expression with the STOP1-ALMT1 module.

Keywords: Arabidopsis thaliana, malate, Mediator complex, phosphate starvation, plant nutrition, root system architecture