Strigolactones Play an Important Role in Shaping Exodermal Morphology via a KAI2-Dependent Pathway

Guowei Liu , Marina Stirnemann , Christian Gübeli , Susanne Egloff , Pierre-Emmanuel Courty (1) , Sylvain Aubry (2) , Michiel Vandenbussche (3) , Patrice Morel (3) , Didier Reinhardt , Enrico Martinoia (4) , Lorenzo Borghi

1 Department of Biology
2 Department of Plant Sciences (Cambridge, UK)
3 RDP - Reproduction et développement des plantes
4 Inst Plant Biol

The majority of land plants have two suberized root barriers: the endodermis and the hypodermis (exodermis). Both barriers bear non-suberized passage cells that are thought to regulate water and nutrient exchange between the root and the soil. We learned a lot about endodermal passage cells, whereas our knowledge on hypodermal passage cells (HPCs) is still very scarce. Here we report on factors regulating theHPC number in Petunia roots. Strigolactones exhibit a positive effect, whereas supply of abscisic acid (ABA), ethylene, and auxin result in a strong reduction of the HPC number. Unexpectedly the strigolactone signaling mutant d14/dad2 showed significantly higher HPC numbers than the wild-type. In contrast, its mutant counterpart max2 of the heterodimeric receptor DAD2/MAX2 displayed a significant decrease in HPC number. A mutation in the Petunia karrikin sensor KAI2 exhibits drastically decreased HPC amounts, supporting the hypothesis that the dimeric KAI2/MAX2 receptor is central in determining the HPC number.

Domaines: Sciences du Vivant [q-bio]; Biologie du développement; Biologie végétale

Guowei Liu, Marina Stirnemann, Christian Gübeli, Susanne Egloff, Pierre-Emmanuel Courty, et al.. Strigolactones Play an Important Role in Shaping Exodermal Morphology via a KAI2-Dependent Pathway. iScience, 2019, 17, pp.144-154. ⟨10.1016/j.isci.2019.06.024⟩. ⟨hal-02389739⟩