LS carried out the experimental work, performed the statistical analyses and drafted the manuscript. VH participated in the design of the study and assisted the experimental work. JAS contributed to the experimental design, data analysis and writing. All authors read and approved the final manuscript.
The authors thank Gérard Felix and Lionel Saunois for their technical assistance with the experimental work and Jennifer Tedman from Sainsbury Laboratory for providing the laboratory H. arabidopsis strains. We are also grateful to two anonymous reviewers whose comments greatly improved our manuscript.