Gibberellin signaling mediates lateral root inhibition in response to K+-deprivation

Abstract The potassium ion (K+) is vital for plant growth and development, K+-deprivation leads to reduced crop yields. Here we describe phenotypic, transcriptomic, mutant analyses investigate the signaling mechanisms mediating root architectural changes in Arabidopsis (Arabidopsis thaliana) Columbia. We showed effects on architecture are mediated through a reduction cell division lateral (LR) meristems, rate of LR initiation but density unaffected, primary only slightly. This was primarily regulated gibberellic acid (GA) signaling, which accumulation growth-inhibitory DELLA proteins. short phenotype rescued by exogenous application GA not auxin or inhibition ethylene signaling. RNA-seq analysis upregulation transcription factors JUNGBRUNNEN1 (JUB1) C-repeat-binding factor (CBF)/dehydration-responsive element-binding 1 regulon, known regulate levels that DELLAs. Transgenic overexpression JUB1 CBF1 enhanced responses K+ stress. Attenuation response occurred mutants target gene SFR6, implicating role JUB1, CBF1, SFR6 regulation via propose this represents mechanism limit horizontal conditions where available deeper soil.