ERF1 inhibits lateral root emergence by promoting local auxin accumulation with altered distribution and repressingARF7expression

Abstract

SummaryLateral roots (LRs) are crucial for plants to sense environmental signals in addition to water and nutrient absorption. Auxin is key for LR formation, but the underlying mechanisms are not fully understood. Here we report thatArabidopsisERF1 inhibits LR emergence by promoting local auxin accumulation with altered distribution and regulating auxin signaling. Loss ofERF1increases LR density compared with the wild type, whereasERF1overexpression causes the opposite phenotype. ERF1 enhances auxin transport by upregulatingPIN1andAUX1, resulting in excessive auxin accumulation in the endodermal, cortical, and epidermal cells surrounding LR primordia. Furthermore, ERF1 repressesARF7transcription, consequently affecting the expression of cell wall remodeling genes that facilitate LR emergence. Together, our study reveals that ERF1 integrates environmental signals to promote local auxin accumulation with altered distribution and repressARF7, consequently inhibiting LR emergence in adaptation to fluctuating environments.HighlightsERF1 functions as a negative regulator of lateral root emergenceERF1 enhances rootward and shootward auxin transport by directly upregulating the expression ofPIN1andAUX1, resulting in high local auxin accumulation and abnormal auxin distribution in the endodermal, cortical, and epidermal cells overlying lateral root primordiaERF1 represses the transcription ofARF7and cell wall remodeling genes in lateral root emergence