DISSERTATION RESEARCH: The evolution of selenium hyperaccumulation in Stanleya (Brassicaceae)

硒在原子上类似于硫，因此它可以取代蛋白质中的硫。意外地掺入硒可能会导致人类、牲畜和野生动物患病甚至死亡。然而，硒也是许多动物、原核生物和藻类所必需的微量营养素，尽管目前尚不清楚硒在陆地植物中的作用。有四个属的植物被认为是硒超积累植物(积累0.1%的干重硒)，包括美国西部的Stanleya(王子羽毛；十字花科)。斯坦利雅包括7种，其中一种(Stanleya Pinnata)是一种已知的硒超积累植物。这个项目的目的是在种内关系的背景下推断硒的积累、耐受性、定位和化学形态多样化的过程，以更好地了解是哪些DNA变化导致了这些生理变化。通过了解哪些DNA变化导致了硒的积累和耐受性，我们可以改善作物的植物修复(利用植物进行环境清理)和生物强化。据估计，缺硒每年给畜牧业生产者造成5.45亿美元的损失。新月浑子能将硒代谢成一种健康的抗癌形式，了解这一生理途径可能会改善人类和牲畜的作物。

Selenium is atomically similar to sulfur and because of this relationship it can replace sulfur in proteins. Accidental incorporation of selenium can cause disease and even death in humans, livestock and wildlife. Yet selenium is also an essential micronutrient for many animals, prokaryotes and algae, though there is no known function of selenium in land plants. There are four plant genera with species recognized as selenium hyperaccumulators (accumulating 0.1% dry weight selenium), including Stanleya (prince's plume; Brassicaceae) in the western United States. Stanleya includes seven species, one of which (Stanleya pinnata) is a known selenium hyperaccumulator. The goal of this project is to infer the process of diversification of selenium accumulation, tolerance, localization and chemical form in the context of intraspecific relationships within Stanleya to better understand which DNA changes caused these physiological changes. By understanding which DNA changes gave rise to selenium accumulation and tolerance we can improve crops for both phytoremediation (environmental clean-up using plants) and biofortification. Selenium deficiency is estimated to cause $545 million in losses to livestock producers every year. Stanleya pinnata metabolizes selenium into a healthy anti-carcinogenic form, and understanding this physiological pathway may lead to improved crops for both humans and livestock.