The exporter of the auxin precursor indole-3-butyric acid (IBA), ABCG36/PDR8/PEN3, from the model plant Arabidopsis has recently been proposed to also function in the transport of the phytoalexin camalexin. Based on these bonafide substrates, it has been suggested that ABCG36 functions at the interface between growth and defense. Here, we provide evidence that ABCG36 catalyzes the direct, ATP-dependent export of camalexin across the plasma membrane. We identify the leucine-rich repeat receptor kinase, QIAN SHOU KINASE1 (QSK1), as a functional kinase that physically interacts with and phosphorylates ABCG36. Phosphorylation of ABCG36 by QSK1 unilaterally represses IBA export, allowing camalexin export by ABCG36 conferring pathogen resistance. As a consequence, phospho-dead mutants of ABCG36, as well as qsk1 and abcg36 alleles, are hypersensitive to infection with the root pathogen Fusarium oxysporum, caused by elevated fungal progression. Our findings indicate a direct regulatory circuit between a receptor kinase and an ABC transporter that functions to control transporter substrate preference during plant growth and defense balance decisions.

College of Life Sciences Ritsumeikan University Shiga 525 8577 Japan

Department Biochemistry of Plant Interactions Leibniz Institute of Plant Biochemistry Weinberg 3 06120 Halle Germany

Department Molecular Signal Processing Leibniz Institute of Plant Biochemistry Weinberg 3 06120 Halle Germany

Department of Biology ETH Zurich Universitätstrasse 2 8092 Zurich Switzerland

Department of Biology University of Fribourg 1700 Fribourg Switzerland

Department of Plant Molecular Physiology Institute of Bioorganic Chemistry Polish Academy of Sciences Z Noskowskiego 12 14 61 704 Poznań Poland; Department of Biochemistry and Biotechnology Poznan University of Life Sciences Dojazd 11 60 632 Poznań Poland

Department of Plant Molecular Physiology Institute of Bioorganic Chemistry Polish Academy of Sciences Z Noskowskiego 12 14 61 704 Poznań Poland; NanoBioMedical Centre Adam Mickiewicz University Wszechnicy Piastowskiej 3 61 614 Poznań Poland

Mendel Centre for Plant Genomics and Proteomics Masaryk University CEITEC MU Kamenice 5 Building A26 625 00 Brno Czech Republic

Zentrum für Molekularbiologie der Pflanzen Pflanzenphysiologie Universität Tübingen Auf der Morgenstelle 32 72076 Tübingen Germany

Nat Plants. 2023 Jun;9(6):850. doi: 10.1038/s41477-023-01455-4. PubMed

Citace poskytuje Crossref.org

HSP90 differentially stabilizes plant ABCB-type auxin transporters on the plasma membrane