Signalling in systemic plant defence-roots put in hard graft

Abstract

Roots are increasingly recognized as key regulators of aboveground interactions between plants and other organisms. In this issue of Journal of Experimental Botany, Agut et al. (pages 5711-5723) enrich our understanding of the underground signalling mechanisms in the shoot-root-shoot (SRS) loop that regulates canopy-wide defence responses after a leaf is attacked.