PhD student Louisiana State University Baton rouge, Louisiana
Body of Abstract: Magnesium is an important plant macronutrient involved in many molecular processes. For example, as the central atom of chlorophyll, Mg2+ plays an important role in photosynthesis. However, it can be toxic to plant growth when soil Mg2+ levels exceed 8.5 mM. Plant responses to deficient levels of magnesium has been studied extensively compared to the minimal studies conducted to investigate why and how high Mg2+ levels can be toxic to plant growth. High levels of magnesium can be naturally found in serpentine soils on Earth, as well as several sites examined by the rovers in the Martian regolith. In this study we investigated how high levels of Mg2+ can affect plant growth and how stress adapted plants may show resilient growth under soils or substrates naturally high in Mg2+. We used Arabidopsis thaliana, a model plant known to be highly sensitive to high levels of magnesium, and Schrenkiella parvula, an extremophyte model that can withstand high levels of magnesium to compare and identify plant responses that allow resilient growth under high Mg2+. We examined the physiological responses to high levels of magnesium using plants grown in soil, in hydroponics, and on agar plates. These results highlight efficient traits and biological process we could test with more targeted molecular data in future experiments to deduce the genetic mechanisms underlying plant responses to Mg2+ toxicity. This will provide important insight when designing future crops that can grow in poor soils whether available soils are similar to serpentine soils on Earth or Mg2+-rich substrates in habitats found on Mars.