Journal Article

Transcriptional regulation of strigolactone signalling in Arabidopsis

Wang, Anqi, Li, Xiaoqiang, Li, Jiayang, Guo, Hongyan, Lin, Tao, Xiong, Guosheng, Yang, Jun, Chu, Jinfang, Wang, Bing, Yu, Hong, Kou, Liquan, Shao, Ning, Wang, Lei, Ma, Haiyan

2020

Overview

Plant hormones known as strigolactones control plant development and interactions between host plants and symbiotic fungi or parasitic weeds 1 – 4 . In Arabidopsis thaliana and rice, the proteins DWARF14 (D14), MORE AXILLARY GROWTH 2 (MAX2), SUPPRESSOR OF MAX2-LIKE 6, 7 and 8 (SMXL6, SMXL7 and SMXL8) and their orthologues form a complex upon strigolactone perception and play a central part in strigolactone signalling 5 – 10 . However, whether and how strigolactones activate downstream transcription remains largely unknown. Here we use a synthetic strigolactone to identify 401 strigolactone-responsive genes in Arabidopsis , and show that these plant hormones regulate shoot branching, leaf shape and anthocyanin accumulation mainly through transcriptional activation of the BRANCHED 1 , TCP DOMAIN PROTEIN 1 and PRODUCTION OF ANTHOCYANIN PIGMENT 1 genes. We find that SMXL6 targets 729 genes in the Arabidopsis genome and represses the transcription of SMXL6 , SMXL7 and SMXL8 by binding directly to their promoters, showing that SMXL6 serves as an autoregulated transcription factor to maintain the homeostasis of strigolactone signalling. These findings reveal an unanticipated mechanism through which a transcriptional repressor of hormone signalling can directly recognize DNA and regulate transcription in higher plants. Many of the molecular targets of strigolactones—plant hormones involved in development and in interactions with symbiotic and parasitic organisms—are uncovered, revealing how strigolactones function and an intriguing role for self-regulation of a downstream transcription factor.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 38 / 38/90 / 38/91 / 631/449/1741/2672 / 631/449/2675 / 82 / 82/80 / 82/83 / 96 / 96/95 / Anthocyanins / Anthocyanins - biosynthesis / Arabidopsis / Arabidopsis - genetics / Arabidopsis - growth & development / Arabidopsis - metabolism / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Biosynthesis / Carotenoids / Deoxyribonucleic acid / DNA / Efficiency / Fungi / Gene Expression Regulation, Plant - genetics / Gene regulation / Genes / Genes, Plant - genetics / Genomes / Heterocyclic Compounds, 3-Ring - metabolism / Homeostasis / Hormones / Host plants / Humanities and Social Sciences / Lactones - metabolism / multidisciplinary / Phytohormones / Plant Growth Regulators - biosynthesis / Plant Growth Regulators - metabolism / Plant hormones / Plant Leaves - anatomy & histology / Plant Leaves - genetics / Plant Leaves - growth & development / Plant Leaves - metabolism / Plant Shoots - genetics / Plant Shoots - growth & development / Plant Shoots - metabolism / Promoter Regions, Genetic / Proteins / Science / Science (multidisciplinary) / Signal Transduction - genetics / Signaling / Transcription activation / Transcription factors / Transcription Factors - genetics / Transcription Factors - metabolism / Transcription, Genetic