Negative regulation of conserved RSL class I bHLH transcription factors evolved independently among land plants

作者：Honkanen, Suvi; Thamm, Anna; Arteaga-Vazquez, Mario A.; Dolan, Liam^*

来源：eLife, 2018, 7: e38529.

DOI：10.7554/eLife.38529

• ROOT HAIR DEVELOPMENT
• EPIDERMAL-CELL DIFFERENTIATION
• ARABIDOPSIS ROOT
• MARCHANTIA-POLYMORPHA
• LATERAL INHIBITION
• GENES
• EVOLUTION
• CAPRICE
• FAMILY
• DIVERSIFICATION

Basic helix-loop-helix transcription factors encoded by RSL class I genes control a gene regulatory network that positively regulates the development of filamentous rooting cells - root hairs and rhizoids - in land plants. The GLABRA2 transcription factor negatively regulates these genes in the angiosperm Arabidopsis thaliana. To find negative regulators of RSL class I genes in early diverging land plants we conducted a mutant screen in the liverwort Marchantia polymorpha. This identified FEW RHIZOIDS1 (MpFRH1) microRNA (miRNA) that negatively regulates the RSL class I gene Mp RSL1. The miRNA and its mRNA target constitute a feedback mechanism that controls epidermal cell differentiation. MpFRH1 miRNA target sites are conserved among liverwort RSL class I mRNAs but are not present in RSL class I mRNAs of other land plants. These findings indicate that while RSL class I genes are ancient and conserved, independent negative regulatory mechanisms evolved in different lineages during land plant evolution.

• 出版日期2018-8-23