Transcriptome Reprogramming Associated with Autoimmunity Reveals Key Points of the Growth-Defence Trade-off in Arabidopsis thaliana

Abstract

Growth and defence are inversely correlated processes requiring balance for optimal fitness. While each is well studied, their regulatory trade-offs are less understood. Using DANGEROUS MIX (DM) autoimmune plants with stunted growth in Arabidopsis thaliana, we investigated the balancing act. Transcriptome analysis of three DM cases and pathogen-treated seedlings identified two major modules representing defence and growth. These core modules, comprising 4,712 genes ([~]17% of the transcriptome), were sufficient for projecting the trade-off across immune transcriptome meta-datasets. Removing all three ADR1s, the helper NLRs, reversed the expression patterns of both modules and shifted the trade-off balance. ADR1s had a stronger impact on growth-associated RLK genes than on defence genes. Autoimmune plants also showed greater chromatin accessibility changes in growth loci than in defence loci. Our findings suggest an unexpected mechanism where immune signalling, partly mediated by ADR1s, actively suppresses growth genes, providing a strategy to regulate the growth-defence trade-off.