Mechanism of Trehalose Control of Shoot Development

Cold Spring Harbor Laboratory, Cold Spg Hbr NY

Investigators

Abstract

Plant growth and development relies on the availability of resources, including sugars produced through photosynthesis, however how plants coordinate these processes is largely unknown. This project will study genes in plants that produce a type of sugar called trehalose-6-phosphate (T6P) that acts as an important hormone in plants, similar to insulin in humans. The researchers have found unexpected properties of the enzymes that produce T6P, including presence in cell nuclei, and association with proteins that bind to ribonucleic acids. They also found that different enzymes in the same pathway form a physical complex that may coordinate its activity. The project will investigate the structural organization of this complex, using a high resolution method called cryo-electron microscopy, and explore how it coordinates plants growth. By providing insight into the roles of T6P in metabolic signaling and plant growth, the project outcomes will provide a clearer understanding of crop plant growth, with relevance to agricultural productivity. The researchers will also contribute to outreach and education by training high school students as well as a post-doctoral researcher. The project PI directs the Cold Spring Harbor Laboratory Partners for The Future Program, which mentors high school students, and allows them to experience life in a cutting-edge research laboratory. The project will expand this program, with a focus on providing needs-blind mentoring and research opportunities to high school students from under-represented groups and supporting their scientific development. Trehalose-6-phosphate (T6P) is an important regulator of sugar metabolism and growth in plants, with specific roles in branching, flowering time and stress resilience. However, the molecular mechanisms by which T6P controls these processes is unknown. This proposal aims to understand the mechanism by which RAMOSA3 (RA3), which encodes a trehalose phosphate phosphatase (TPP) enzyme, controls maize shoot branching. RA3 accumulates in nuclear puncta, undergoes phase separation, and interacts with RNA binding proteins and trehalose phosphate synthase (TPS) proteins. These findings suggest that RA3 uses an unconventional moonlighting activity to control the expression of developmental programs in response to metabolic signals. The project will use multiple approaches at cellular, proteomic and genomic scales to ask how an enzyme implicated in sugar signaling controls plant development. This research has the potential to elucidate a clearer understanding of T6P signaling, which is relevant to plant metabolism, stress signaling, flowering and inflorescence architecture, all of which are important factors in crop productivity. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.