Peroxisomal fatty acid β-oxidation negatively impacts plant survival under salt stress.

Peroxisomal β-oxidation is the sole pathway for metabolic breakdown of fatty acids to generate energy and carbon skeletons in plants, is essential for oilseed germination and plays an important role in growth, development and cellular homeostasis. Yet, this process also produces cytotoxic reactive oxygen species (ROS) as byproducts. We recently showed that disruption of fatty acid β-oxidation enhance plant survival under carbon starvation conditions. Here, we extend these findings by demonstrating that blocking fatty acid import into peroxisomes reduces ROS accumulation and increases plant tolerance to salt stress, whereas increasing fatty acid flux into the β-oxidation pathway has opposite effects. Together, these results support the view that peroxisomal β-oxidation of fatty acids enhances stress-induced ROS production, thereby negatively impacting plant survival under adverse environmental conditions.