Infection of plants triggers a switch of resources from growth to defense characterized by considerable transcriptional reprogramming involving thousands of genes. In Current Biology, Dong and colleagues use Arabidopsis to identify the transcription factor TBF1 as a key component of this switch from growth to defense. Infection results in the recognition of microbe-associated molecular patterns, which leads to effector-triggered immunity. In addition, infection triggers a longer-lived systemic response mediated by salicylic acid. Both these defense pathways result in the derepression of TBF1, which allows it to directly regulate nearly 3,000 genes. Among the effects is repression of growth-related genes, such as those encoding molecules involved in chloroplast function, as well as the positive regulation of immune-related genes. Infection normally results in less growth as resources are shifted to defense; however, this effect is alleviated in plants with mutant TBF1. TBF1 is therefore involved in sensing the metabolic changes associated with infection and in placing the host plant onto a 'war footing'.

Curr. Biol. (24 January 2012) doi:10.1016/j.cub.2011.12.015