Local auxin biosynthesis acts downstream of brassinosteroids to trigger root foraging for nitrogen.
Nat Commun
; 12(1): 5437, 2021 09 14.
Article
de En
| MEDLINE
| ID: mdl-34521826
ABSTRACT
Lateral roots (LRs) dominate the overall root surface of adult plants and are crucial for soil exploration and nutrient acquisition. When grown under mild nitrogen (N) deficiency, flowering plants develop longer LRs to enhance nutrient acquisition. This response is partly mediated by brassinosteroids (BR) and yet unknown mechanisms. Here, we show that local auxin biosynthesis modulates LR elongation while allelic coding variants of YUCCA8 determine the extent of elongation under N deficiency. By up-regulating the expression of YUCCA8/3/5/7 and of Tryptophan Aminotransferase of Arabidopsis 1 (TAA1) under mild N deficiency auxin accumulation increases in LR tips. We further demonstrate that N-dependent auxin biosynthesis in LRs acts epistatic to and downstream of a canonical BR signaling cascade. The uncovered BR-auxin hormonal module and its allelic variants emphasize the importance of fine-tuning hormonal crosstalk to boost adaptive root responses to N availability and offer a path to improve soil exploration by expanded root systems in plants.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Arabidopsis
/
Racines de plante
/
Protéines d'Arabidopsis
/
Tryptophan transaminase
/
Brassinostéroïdes
/
Mixed function oxygenases
/
Acides indolacétiques
/
Azote
Langue:
En
Journal:
Nat Commun
Sujet du journal:
BIOLOGIA
/
CIENCIA
Année:
2021
Type de document:
Article
Pays d'affiliation:
Allemagne