Jasmonic acid and salicylic acid signaling in fern Azolla filiculoides and its cyanobiont

The phytohormones jasmonic acid (JA) and salicylic acid (SA) play key roles in how plants respond to microbes. However, this interplay between JA, SA and microbes is less understood in non-angiosperm linages. de Vries and colleagues examine JA/SA signalling between the water fern Azolla filiculoides and its nitrogen-fixing cyanobiont Nostoc azollae. They use data from large-scale sequencing to show that Azolla filiculoides has genes for the production and the sensing of JA and SA. Azolla filiculoides responds to exogenously applied SA, and SA application modifies the gene expression and abundance of the cyanobiont, Nostoc azollae. This paper describes JA/SA signalling in ferns and describes how SA plays a role in communication between Azolla filiculoides and its cyanobiont Nostoc azollae. (Summary by Julia Miller) Plant, Cell & Env.  10.1111/pce.13131