CYP707As are effectors of karrikin and strigolactone signalling pathways in Arabidopsis thaliana and parasitic plants

• DOI: 10.1111/pce.13594
• Publication Date: 2019-05-28T03:27:54Z
• Authors: Guillaume Brun; Séverine Thoiron; Lukas Braem; Jean‐Bernard Pouv...; Grégory Montiel; Marc‐Marie Lechat; Philippe Simier; Kris Gevaert; Sofie Goormachtig; Philippe Delavault
• Keywords: Strigolactone; Orobanche; Obligate parasite; Orobanchaceae; Parasitic plant; Spore germination

Karrikins stimulate Arabidopsis thaliana germination, whereas parasitic weeds of the Orobanchaceae family have evolved to respond host-exuded compounds such as strigolactones, dehydrocostus lactone, and 2-phenylethyl isothiocyanate. In Phelipanche ramosa, strigolactone-induced germination was shown require one CYP707A proteins involved in abscisic acid catabolism. Here, gene expression were analysed investigate role CYP707As both plants upon perception stimulants, after using pharmacological inhibitors mutants disrupting signals. genes up-regulated treatment with effective stimulants Arabidopsis. Obligate exhibited intensified up-regulation increased sensitivity inhibitor abscinazole-E2B, cyp707a still positively responded stimulation. Arabidopsis, regulation required canonical karrikin signalling pathway KAI2/MAX2/SMAX1 transcription factor WRKY33. Finally, WRKY33 also modulated root architecture response synthetic strigolactone rac-GR24, wrky33-1 a shoot hyperbranched phenotype. This study suggests that lack host-independent obligate parasites is associated an exacerbated induction are new players variety strigolactone/karrikin responses.