Anthropogenic factors such as climate change, harsh agricultural practices, and mining have contributed to increases in soil salinization and heavy metal contamination. Highly saline environments drastically lower yield for crop species and elevated levels of toxic metals like cadmium are carcinogenic in the environment. Some plants that have evolved in high-salinity habitats or in soils with heavy metals could be used to remediate contaminated soils. Halophytes are plants with various adaptations that allow them to survive and reproduce in saline conditions. General mechanisms for salt tolerance/uptake in halophytes are hypothesized to help deal with other stresses like heavy metals. Plants with these traits could be utilized to extract salt and heavy metals from affected soils in a process called phytoremediation. We plan to develop Sea Rocket (Cakile maritima) in the Mustard family as a model system to understand mechanisms of salt (NaCl) and cadmium uptake and tolerance, as it has been shown to accumulate both. As part of this study, we will hydroponically grow C. maritima in different stress treatments using salt and cadmium. As the plants uptake the pollutants, the conductivity of the solution will change. We will develop an automated pipeline to track these changes in real-time using conductivity sensors. In addition, we will sample root and leaf tissues at various time points to measure salt and cadmium uptake using ICP-OES elemental analysis. This data will provide insights into salt and cadmium uptake/tolerance and paves a path toward efficient and viable solutions improving phytoremediation approaches.

Climate change and harsh agricultural practices are increasing the amount of salt and heavy metals in soil, drastically decreasing the amount of arable land while simultaneously lowering crop yields. However, some plants grown in poor soil have adapted diverse mechanisms to cope with harsh environments. It has been hypothesized that the biochemical mechanisms responsible for salt tolerance overlaps with heavy metal tolerance, yet the similarities in these mechanisms are still unknown. Lessons from naturally salt and heavy metal tolerant plants can be applied to crops to increase resilience or be used in phytoremediation efforts. Here, we use the salt and heavy metal tolerant plant Cakile maritima as a model system for phytoremediation by using a large-scale multi-omics approach, combining ionomics, metabolomics, transcriptomics, and genomics, to understand the metabolic responses following NaCl and cadmium stress. We have developed an automated pipeline for tracking salinity, as well as using elemental analysis to monitor intracellular concentrations. We will perform RNA-seq to understand patterns of differential gene expression, gather a list of candidate genes, and use comparative genomics to understand the potential influence of ancient polyploidy on stress tolerance. Combining this with metabolomics will enable a fully integrated understanding of salt stress response and allow us to know if Cakile maritima is predisposed for salt stress or has a rapid stress response. Coupling this with transcriptomics will allow us to identify important pathways and neofunctionalized genes that may be specific for C. maritima stress response and be applied to crop species to enhance resilience.