TY - JOUR T1 - Epistatic Transcription Factor Networks Differentially Modulate Arabidopsis Growth and Defense JF - bioRxiv DO - 10.1101/583047 SP - 583047 AU - Baohua Li AU - Michelle Tang AU - CĂ©line Caseys AU - Ayla Nelson AU - Marium Zhou AU - Xue Zhou AU - Siobhan M. Brady AU - Daniel J. Kliebenstein Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/03/20/583047.abstract N2 - Plants integrate internal and external signals to finely coordinate growth and defense allowing for maximal fitness within a complex environment. One common model for the relationship between growth and defense is a trade-off model in which there is a simple negative interaction between growth and defense theoretically driven by energy costs. However, there is a developing consensus that the coordination of growth and defense likely involves a more conditional and intricate connection. To explore how a transcription factor network may coordinate growth and defense, we used high-throughput phenotyping to measure growth and flowering in a set of single and pairwise mutants previously linked to the aliphatic glucosinolate defense pathway. Showing the link between growth and aliphatic glucosinolate defense, 17 of the 20 tested TFs significantly influence plant growth and/or flowering time. These effects were conditional upon the environment, age of the plant and more critically varied amongst the phenotypes when using the same genotype. The phenotypic effects of the TF mutants on SC GLS accumulation and on growth were not correlated, which indicating that there is not a simple energetic trade-off for growth and defense. We propose that large transcription factor networks create a system to integrate internal and external signals and separately modulate growth and defense traits.Significant Statement The relationship between plant growth and plant defense is critical to understanding plant fitness or yield and is often described as a simple trade-off model. However, this model is under extensive research and is a highly debated research topic. We used a large-scale phenotyping approach to study the dynamics of plant growth in a transcriptional factor (TF) mutant population in the model plant Arabidopsis that regulates the defense pathway, aliphatic glucosinolates (GLS). We showed that these TFs have significant effects on plant growth that is heavily influenced by epistasis and the environment. Critically, the effects of these TFs on growth and defense were largely independent and had little evidence supporting a simple trade off model. Instead, we propose that the TFs independently coordinate plant growth and plant defense. As our study tested a fraction of the total potential TFs influencing growth, our findings indicate that there is high potential to use TFs to promote both plant growth and defense simultaneously for modern agriculture in the ever-changing environment. ER -