1. Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340, USA
2. Department of Energy-Plant Research Laboratory,
3. Department of Biochemistry and Molecular Biology,
4. Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA
5. Present address: USDA Plant Gene Expression Center, 800 Buchanan Street, Albany, California 94710, USA.

Correspondence to: John Browse¹ Correspondence and requests for materials should be addressed to J.B. (Email: jab@wsu.edu).

Abstract

Jasmonate and related signalling compounds have a crucial role in both host immunity and development in plants, but the molecular details of the signalling mechanism are poorly understood. Here we identify members of the jasmonate ZIM-domain (JAZ) protein family as key regulators of jasmonate signalling. JAZ1 protein acts to repress transcription of jasmonate-responsive genes. Jasmonate treatment causes JAZ1 degradation and this degradation is dependent on activities of the SCF^COI1 ubiquitin ligase and the 26S proteasome. Furthermore, the jasmonoyl–isoleucine (JA–Ile) conjugate, but not other jasmonate-derivatives such as jasmonate, 12-oxo-phytodienoic acid, or methyl-jasmonate, promotes physical interaction between COI1 and JAZ1 proteins in the absence of other plant proteins. Our results suggest a model in which jasmonate ligands promote the binding of the SCF^COI1 ubiquitin ligase to and subsequent degradation of the JAZ1 repressor protein, and implicate the SCF^COI1–JAZ1 protein complex as a site of perception of the plant hormone JA–Ile.

1. Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340, USA
2. Department of Energy-Plant Research Laboratory,
3. Department of Biochemistry and Molecular Biology,
4. Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA
5. Present address: USDA Plant Gene Expression Center, 800 Buchanan Street, Albany, California 94710, USA.

Correspondence to: John Browse¹ Correspondence and requests for materials should be addressed to J.B. (Email: jab@wsu.edu).

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.