Details

Autor(en) / Beteiligte

• Huerta-Venegas, Pedro Iván
• Raya-González, Javier
• López-García, Claudia Marina
• Barrera-Ortiz, Salvador
• Ruiz-Herrera, León Francisco
• López-Bucio, José

Titel

Mutation of MEDIATOR16 promotes plant biomass accumulation and root growth by modulating auxin signaling

Ist Teil von

• Plant science (Limerick), 2022-01, Vol.314, p.111117-111117, Article 111117

Ort / Verlag

Ireland: Elsevier B.V

Erscheinungsjahr

2022

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• •Mutation of MEDIATOR16 (MED16) promotes primary root growth and lateral root formation influencing mitosis in meristems.•MED16 is a repressor of plant biomass production.•Mutation of MED16 confers primary root growth resistance to the auxin transport inhibitor N-1-naphthylphthalamic acid.•Cell division and elongation are targets of MED16 for root growth resistance to NPA. The MEDIATOR complex influences the transcription of genes acting as a RNA pol II co-activator. The MED16 subunit has been related to low phosphate sensing in roots, but how it influences the overall plant growth and root development remains unknown. In this study, we compared the root growth of Arabidopsis wild-type (WT), and two alleles of MED16 (med16-2 and med16-3) mutants in vitro. The MED16 loss-of-function seedlings showed longer primary roots with higher cell division capacity of meristematic cells, and an increased number of lateral roots than WT plants, which correlated with improved biomass accumulation. The auxin response reported by DR5:GFP fluorescence was comparable in WT and med16-2 root tips, but strongly decreased in pericycle cells and lateral root primordia in the mutants. Dose-response analysis supplementing indole-3-acetic acid (IAA), or the auxin transport inhibitor N-1-naphthylphthalamic acid (NPA), indicated normal responses to auxin in the med16-2 and med16-3 mutants regarding primary root growth and lateral root formation, but strong resistance to NPA in primary roots, which could be correlated with cell division and elongation. Expression analysis of pPIN1::PIN1::GFP, pPIN3::PIN3::GFP, pIAA14:GUS, pIAA28:GUS and 35S:MED16-GFP suggests that MED16 could mediate auxin signaling. Our data imply that an altered auxin response in the med16 mutants is not necessarily deleterious for overall growth and developmental patterning and may instead directly regulate basic cellular programmes.