The seed-to-seedling transition is a brief and mysterious period (days) in a plant life cycle. A heterotrophic seed embryo must develop into an autotrophic photosynthesizing seedling, a metabolic conversion with rapid subsequent development of tissues. It is a stage thought to drive species diversity in natural communities. It is also a vulnerable stage, preceding establishment of plants (food and non-food plants) where limited materials are stored in the seed by its maturation. The long-term goal of my lab’s research is to understand the chemical basis of the seed-to-seedling transition, then apply that knowledge to horticultural production. By understanding this phase we also can utilize the unique chemical defense employed by plants for human and animal challenges, including nutrition, anti-oxidant cell defense, and toxins sensing in the environment. Some plants we have utilized for horticulture and medicine in depth include soybean, broccoli, jojoba, aspen. We would like to conduct projects in Cacao and microgreens.
We have used Arabidopsis thaliana as a genetic model to study the seed-to-seedling transition. We explore seedling development of the sole G protein system, notably the impact of the GPA1 (alpha subunit) effector proteins Pirin1 (cupin protein & dioxygenase) which affects quercetin (made from phenylalanine), and Arogenate dehydratase3 (ADT3) which forms phenylalanine. Alan M Turing wrote a theoretical paper (1952) on the chemical basis of morphogenesis in animal cells/tissues patterning, a black box still not understood. We have explored the prototypical patterning that occurs in the seed-to-seedling transition, and the intricate roles light, chemicals, and the force of water play to influence development.
We have reported that phenylalanine is an important part of a chemical basis of plant cell development and tissue morphogenesis of the leaf, where ADT3 is expressed in the cytosol, and phenylalanine formation precedes development (Para et al., 2016). This recent work represents a paradigm shift—this pathway is expressed and needed before development manifests in the terminal pattern of the cells concerned, in both mesophyll and epidermis. Phenylalanine is required directly for homeostasis of reactive oxygen species (ROS), and for correct functioning of the epidermis. No other amino acid could rescue the epidermal defects. The epidermis is the first line of plant defense and as an external layer makes an excellent system for study. We are investigating the 1) Metabolite requirements for cell growth and cell division; and, 2) Impact of abiotic signals on phenylalanine and specific phenylpropanoids like quercetin during the seed-to-seedling transition. We are further exploring how mycorrhyzae may influence these processes and how the force of water also may influence development.
Representative Publications (Complete list of publications on Google Scholar)
Office: 4268 MBRB, MC 567