The μ subunit of Arabidopsis adaptor protein-2 is involved in effector-triggered immunity mediated by membrane-localized resistance proteins

Noriyuki Hatsugai, Rachel Hillmer, Shohei Yamaoka, Ikuko Hara-Nishimura, Fumiaki Katagiri

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Endocytosis has been suggested to be important in the cellular processes of plant immune responses. However, our understanding of its role during effector-triggered immunity (ETI) is still limited. We have previously shown that plant endocytosis, especially clathrin-coated vesicle formation at the plasma membrane, is mediated by the adaptor protein-2 (AP-2) complex and that loss of the μ subunit of AP-2 (AP2M) affects plant growth and floral organ development. Here, we report that AP2M is required for full-strength ETI mediated by the disease resistance (R) genes RPM1 and RPS2 in Arabidopsis. Reduced ETI was observed in an ap2m mutant plant, measured by growth of Pseudomonas syringae pv. tomato DC3000 strains carrying the corresponding effector genes avrRpm1 or avrRpt2 and by hypersensitive cell death response and defense gene expression triggered by these strains. In contrast, RPS4-mediated ETI and its associated immune responses were not affected by the ap2m mutation. While RPM1 and RPS2 are localized to the plasma membrane, RPS4 is localized to the cytoplasm and nucleus. Our results suggest that AP2M is involved in ETI mediated by plasma membrane-localized R proteins, possibly by mediating endocytosis of the immune receptor complex components from the plasma membrane.

Original languageEnglish (US)
Pages (from-to)345-351
Number of pages7
JournalMolecular Plant-Microbe Interactions
Issue number5
StatePublished - May 2016

Bibliographical note

Funding Information:
We are grateful to the Arabidopsis Biological Resource Center at Ohio State University for providing the Arabidopsis T-DNA insertion mutant seeds. This work was supported by a grant from the National Science Foundation, IOS-1121425 to F.K., by Grants-in-Aid for Scientific Research (grant numbers 22000014 to I. Hara-Nishimura and 23570043 to N. Hatsugai) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, by the Sumitomo Foundation (N. Hatsugai) and by the Global Center of Excellence Program "Formation of a Strategic Base for Biodiversity and Evolutionary Research: From Genome to Ecosystem" of MEXT (I. Hara-Nishimura).

Publisher Copyright:
© 2016 The American Phytopathological Society.


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