Gßγ dimers mediate low K+ stress-inhibited root growth via modulating auxin redistribution in Arabidopsis.
Plant Cell Environ
; 2024 Aug 13.
Article
in En
| MEDLINE
| ID: mdl-39136400
ABSTRACT
In the investigation of heterotrimeric G protein-mediated signal transduction in planta, their roles in the transmittance of low K+ stimuli remain to be elucidated. Here, we found that the primary root growth of wild-type Arabidopsis was gradually inhibited with the decrease of external K+ concentrations, while the primary root of the mutants for G protein ß subunit AGB1 and γ subunits AGG1, AGG2 and AGG3 could still grow under low K+ conditions (LK). Exogenous NAA application attenuated primary root elongation in agb1 and agg1/2/3 but promoted the growth in wild-type seedlings under LK stress. Using ProDR5GFP, ProPIN1PIN1-GFP and ProPIN2PIN2-GFP reporter lines, a diminishment in auxin concentration at the radicle apex and a reduction in PIN1and PIN2 efflux carrier abundance were observed in wild-type roots under LK, a phenomenon not recorded in the agb1 and agg1/2/3. Further proteolytic and transcriptional assessments revealed an enhanced degradation of PIN1 and a suppressed expression of PIN2 in the wild-type background under LK, contrasting with the stability observed in the agb1 and agg1/2/3 mutants. Our results indicate that the G protein ß and γ subunits play pivotal roles in suppressing of Arabidopsis root growth under LK by modulating auxin redistribution via alterations in PIN1 degradation and PIN2 biosynthesis.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Plant Cell Environ
Journal subject:
BOTANICA
Year:
2024
Document type:
Article
Affiliation country:
China
Country of publication:
United States