IAA3-Mediated repression of PIF proteins coordinates light and auxin signaling in < i > Arabidopsis < /i >

In this study, we identified a direct link between the light and a uxin signaling pathways mediated by the auxin transcriptional repressor IAA3 and light-controlled PIF transcription factors inArabidopsis. The gain-of-function mutation inIAA3 caused hyposensitivity to light, whereas disruption ofIAA3 led to an elongated hypocotyl under different light intensity conditions, indicating that IAA3 is required in light regulated hypocotyl growth. Genetic studies showed that the function of IAA3 in hypocotyl elongation is dependent on PIFs. Our data further demonstrated that IAA3 interacts with PIFsin vitro andin vivo, and it attenuates the DNA binding activities of PIFs to the target genes. Moreover, IAA3 negatively regulates the expression of PIFs-dependent genes. Collectively, our study reveals an interplay mechanism of light and auxin on the regulation of hypocotyl growth, coordinated by the IAA3 and PIFs transcriptional regulatory module.

Source: PLoS Genetics - February 18, 2021 Category: Genetics & Stem Cells Authors: Yulin Xi Source Type: research