USAIN/CBHL 2024 Biennial Meeting

Heat waves, which are becoming more frequent and longer because of anthropogenic climate change, have already had an impact on economic growth and raised concerns about global sustainability, food security, and species conservation. Thermophilic plants thrive under heat and understanding their mechanisms and strategies can help us engineer heat resilience in other plants. Tidestromia oblongifolia, a thermophilic C4 plant that thrives in the harsh summer conditions of Death Valley (California), has an optimal rate of photosynthesis at 47ºC and can increase its biomass by 30% per day in Death Valley summer conditions. The thermoadaptation mechanisms of this extremophile remain a mystery. We are using an interdisciplinary approach that combines ecophysiology, genomics, transcriptomics, metabolomics, biochemistry, cell biology, and population genomics to understand the molecular and metabolic underpinnings of its thermoadaptation. Using phylogenomic methods in Tidestromia and related C3 and C4 Amaranthaceae species, we are investigating the role of gene family expansion in the evolution of thermal tolerance. We have collected seed from wild populations across the species range to identify novel heat-adaptive loci in the most extreme heat tolerant individuals. Understanding the mechanisms of its thermoadaptation may lead to the development of new crops and varieties more resilient to climate change.