The emergence and radiation of multicellular land plants was driven by crucial innovations to their body plans. The directional transport of the phytohormone auxin represents a key, plant-specific mechanism for polarization and patterning in complex seed plants. Here, we show that already in the early diverging land plant lineage, as exemplified by the moss Physcomitrella patens, auxin transport by PIN transporters is operational and diversified into ER-localized and plasma membrane-localized PIN proteins. Gain-of-function and loss-of-function analyses revealed that PIN-dependent intercellular auxin transport in Physcomitrella mediates crucial developmental transitions in tip-growing filaments and waves of polarization and differentiation in leaf-like structures. Plasma membrane PIN proteins localize in a polar manner to the tips of moss filaments, revealing an unexpected relation between polarization mechanisms in moss tip-growing cells and multicellular tissues of seed plants. Our results trace the origins of polarization and auxin-mediated patterning mechanisms and highlight the crucial role of polarized auxin transport during the evolution of multicellular land plants.

Cell Biology and Molecular Genetics and the Maryland Agricultural Experiment Station University of Maryland College Park MD 20742 USA

Department of Forest Genetics and Plant Physiology Umeå Plant Science Centre Swedish University of Agricultural Sciences 901 83 Umeå Sweden

Department of Plant Biology Uppsala BioCenter Linnean Centre of Plant Biology in Uppsala Swedish University of Agricultural Sciences 750 07 Uppsala Sweden

Department of Plant Systems Biology VIB and Department of Plant Biotechnology and Genetics Ghent University 9052 Gent Belgium

Department of Plant Systems Biology VIB and Department of Plant Biotechnology and Genetics Ghent University 9052 Gent Belgium; Institute of Science and Technology Austria Masaryk University 625 00 Brno Czech Republic

Department of Plant Systems Biology VIB and Department of Plant Biotechnology and Genetics Ghent University 9052 Gent Belgium; Mendel Centre for Genomics and Proteomics of Plants Systems Central European Institute of Technology Masaryk University 625 00 Brno Czech Republic

Plant Biology Department of Biology University of Fribourg 1700 Fribourg Switzerland

Komentář

Curr Biol. 2014 Dec 1;24(23):R1129-31. doi: 10.1016/j.cub.2014.10.047. PubMed

Citace poskytuje Crossref.org

CLAVATA modulates auxin homeostasis and transport to regulate stem cell identity and plant shape in a moss

ER-Localized PIN Carriers: Regulators of Intracellular Auxin Homeostasis

The Inhibitor Endosidin 4 Targets SEC7 Domain-Type ARF GTPase Exchange Factors and Interferes with Subcellular Trafficking in Eukaryotes

Telomere dynamics in the lower plant Physcomitrella patens

Three ancient hormonal cues co-ordinate shoot branching in a moss