Format: ORAL

Isabel Johnson, Pramod Pantha, Kieu Tran, Richard Garcia, and Maheshi Dassanayake

Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA

Agriculture faces increasing challenges from climate change, introducing complex stressors that reduce crop yields. Rising sea levels and prolonged droughts drive reliance on salt-contaminated water for irrigation. Additionally, extensive use of synthetic fertilizers elevates CO2 emissions and risks depleting non-renewable nutrients like phosphorus. As low-nutrient and high-salt soils become more common, these stresses frequently co-occur, complicating crop responses. When crops face combined stressors, their responses are often integrated rather than additive, presenting a novel challenge. Most stress experiments focus on single variables, leaving the effects of combined stresses largely unexplored. Therefore, developing solutions based on plant biology and genetics to design stress-resilient crops is increasingly important. Extremophytes, wild plants adapted to multiple environmental stresses, can provide insights into enhancing resilient crop growth. Schrenkiella parvula and Eutrema salsugineum are extremophyte models in the Brassicaceae family related to Arabidopsis thaliana. Their reference genomes were recently updated with chromosome-level assemblies. We examined genomic, transcriptomic, metabolic, ionomic, and physiological responses of these two extremophytes to compare their potential adaptive mechanisms in response to high salt and other stresses. S. parvula often adjusted its root architecture in response to single and compound stresses, while E. salsugineum showed minimal change in primary root growth under similar stresses, indicating physiological and genetic diversity within extremophytes in the same family. S. parvula shows stress-ready transcriptomes, while E. salsugineum shows stress-ready metabolomes under salt exposure. Additionally, our results identified several antioxidant and nutrient recycling pathways active under stress conditions in each species. These studies in extremophytes suggest how key genes in stress response pathways may function differently promoting stress-resilient traits, synchronized across developmental stages and tissues, distinguishing extremophytes from stress-sensitive plants. Understanding the genetic mechanisms of these adaptive traits can significantly influence current and future crop development strategies, with extremophytes offering a valuable genetic resource for transformative crop design.