Four auxin-like compounds can selectively regulate plant development (PNAS)

Plants have developed their own strategies to ensure developmental plasticity, such as the use of phytohormones. The phytohormone auxin affects multiple aspects of plant development. Auxin is perceived via a co-receptor complex called TIR1/AFB-AUX/IAA, and SCF TIR1/AFB degrades AUX/IAA proteins to liberate the downstream transcription factors, leading to the auxin response. However, the degradation rate of various AUX/IAAs differs a lot. To better characterize the complicated auxin response, Vain et al. have isolated and characterized four auxin agonists (RN1 to 4) from a chemical biology screen. These molecules can selectively promote or inhibit AUX/IAA degradation in a dose-dependent manner, contributing to specific auxin responses at transcriptional, biochemical and morphological levels. The discovery of auxinic compounds is helpful for us to study the specific mechanisms of auxin response in Arabidopsis, and also beneficial to develop agrochemicals to boost agriculture and forestry for the world. (Summary by Nanxun Qin) PNAS 10.1073/pnas.1809037116