Abiotic stresses severely impact plant development, leading to a significant reduction in plant growth and crop yields. Among these stresses, the continuous rise in soil salinity due to climate change poses a major agronomic problem (1). The root is the first organ to sense salt stress in the soil and is considered fundamental for propagating the stress response to all plant organs. Therefore, unraveling the molecular mechanisms that cause salt-dependent inhibition of root growth is crucial (2).
To uncover these mechanisms, we ran the bioinformatic software SWItchMiner (3) on transcriptomes of salt-exposed Arabidopsis thaliana roots, enabling the identification of a specific group of genes associated with significant changes in a biological system. Combining in vivo and in silico experiments, we found that genes related to the catabolism of the plant hormone cytokinin are major descriptors of salt-dependent root growth inhibition. Through grafting experiments (4), we also discovered that these genes are crucial not only for salt-dependent root inhibition but also for transmitting stress signals from the root to the shoot, inhibiting plant development. Our results shed light on how soil-derived salt induces physiological changes in the whole plant and will also allow the generation of plants that are tolerant to salt stress.