The Plant Actin Cytoskeleton Responds to Signals from Microbe-Associated Molecular Patterns

PLoS Pathogens

Jessica L. Henty-Ridilla¹  Christopher J. Staiger¹  Jiejie Li¹  Jeff H. Chang²  Brad Day³  Masaki Shimono³ 

[1] Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America;Department of Botany and Plant Pathology, and Molecular and Cellular Biology Program and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America;Department of Plant Pathology, Michigan State University, East Lansing, Michigan, United States of America

关键词: Actin filaments;    Actins;    Cytoskeleton;    Arabidopsis thaliana;    Pseudomonas syringae;    Cotyledons (botany);    Seedlings;    Leaves;   

DOI  :  10.1371/journal.ppat.1003290

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Plants are constantly exposed to a large and diverse array of microbes; however, most plants are immune to the majority of potential invaders and susceptible to only a small subset of pathogens. The cytoskeleton comprises a dynamic intracellular framework that responds rapidly to biotic stresses and supports numerous fundamental cellular processes including vesicle trafficking, endocytosis and the spatial distribution of organelles and protein complexes. For years, the actin cytoskeleton has been assumed to play a role in plant innate immunity against fungi and oomycetes, based largely on static images and pharmacological studies. To date, however, there is little evidence that the host-cell actin cytoskeleton participates in responses to phytopathogenic bacteria. Here, we quantified the spatiotemporal changes in host-cell cytoskeletal architecture during the immune response to pathogenic and non-pathogenic strains of Pseudomonas syringae pv. tomato DC3000. Two distinct changes to host cytoskeletal arrays were observed that correspond to distinct phases of plant-bacterial interactions i.e. the perception of microbe-associated molecular patterns (MAMPs) during pattern-triggered immunity (PTI) and perturbations by effector proteins during effector-triggered susceptibility (ETS). We demonstrate that an immediate increase in actin filament abundance is a conserved and novel component of PTI. Notably, treatment of leaves with a MAMP peptide mimic was sufficient to elicit a rapid change in actin organization in epidermal cells, and this actin response required the host-cell MAMP receptor kinase complex, including FLS2, BAK1 and BIK1. Finally, we found that actin polymerization is necessary for the increase in actin filament density and that blocking this increase with the actin-disrupting drug latrunculin B leads to enhanced susceptibility of host plants to pathogenic and non-pathogenic bacteria.

【 授权许可】

CC BY