High throughput profiling of tocochromanols in leaves and seeds of Arabidopsis and Maize

Abstract

Background: Tocochromanols are a group of lipid-soluble antioxidants produced by all plants and include the tocopherols, which are ubiquitous in the plant kingdom, and the biosynthetically-related compounds tocotrienols, which along with tocopherols commonly occur in seed of monocots. Most tocochromanols have some level of vitamin E activity, with α-tocopherol being the highest, and as such are essential nutrients in the human diet. Tocochromanols are particularly abundant in seeds and are critical for maintaining seed longevity and proper germination and as seed oils are a major component of the human diet, they are an important source of dietary vitamin E. In vegetative tissues, tocochromanols are important components in plant responses to stressful environments and can accumulate to high levels in response to various stresses including high light, heat, and dark. Results: We report a robust, high throughput extraction and HPLC analysis method to quantify the levels of tocopherols and tocotrienols in leaves and seeds of plants, using Arabidopsis and maize tissues as examples. Conclusion: The described method provides a rapid, high-throughput, cost-effective approach to quantifying the composition and content of tocopherols, and if needed simultaneously tocotrienols, in vegetative tissues and seeds. Optimized extraction methods are described for the two tissue types and have been used to study tocochromanol (vitamin E) natural variation in seed of large Arabidopsis and maize diversity panels, to assess gene function in T-DNA and Mu-tagged populations of Arabidopsis and maize, respectfully, and study the impact of environmental stresses, including high light stress, heat stress, and dark on tocopherols content and composition of vegetative tissue.