2017/10/18 by Camille Fonouni‐Farde, Camille Fonouni-Farde, Anna Kisiała +6 · 60 citations
Agricultural and Biological Sciences · #Agronomic Practices and Intercropping Systems #Auxin #Bacteria #Biochemistry #Biology #Botany #Cell biology #Cytokinin #Epidermis (zoology) #Gene #Genetics #Gibberellin #Legume Nitrogen Fixing Symbiosis #Lotus japonicus #Medicago truncatula #Mutant #Nod factor #Plant nutrient uptake and metabolism #Root hair #Root nodule #Signal transduction #Symbiosis
paper · open access · doi:10.1104/pp.17.00919
published in PLANT PHYSIOLOGY 175(4), 1795-1806 (Oxford University Press)
openalex publication_date 2017/10/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In legume plants, low-nitrogen soils promote symbiotic interactions with rhizobial bacteria, leading to the formation of nitrogen-fixing root nodules. Among critical signals regulating this developmental process are bacterial Nod Factors (NFs) and several plant hormones, including cytokinins (CKs) and gibberellins (GAs). Here, we show in Medicago truncatula that GA signaling mediated by DELLA1 decreases the amount of bioactive CKs in roots and negatively impacts the Cytokinin Response1 (CRE1)-dependent NF activation of a subset of CK-signaling genes as well as of the CK-regulated Nodulation Signaling Pathway2 and Ethylene Response Factor Required for Nodulation1 early nodulation genes. Consistently, a dominant-active DELLA1 protein can partially rescue the reduced nodulation of the cre1 mutant and triggers the formation of nodule-like structures when expressed in the root cortex or in the root epidermis. This suggests a model where the DELLA1-mediated GA signaling interplays with the CRE1-dependent CK pathway to regulate early nodulation in response to both NF and CK signals critical for this symbiotic interaction.