This project is aimed at leveraging structural biology in combination with biochemistry and plant biology methods to elucidate the sensing mechanism of strigolactones (SLs), an emerging and unique class of plant hormones that regulate many aspects of plant growth and development. Although SL research has a short history, rapid progress has been made in unveiling its critical role in controlling plant physiology and rhizosphere signaling. Despite these significant advances, several key questions concerning the mechanisms of hormone perception, signal transduction, and regulation of hormone metabolism remain unanswered. This project will support an integrated research, education, and outreach program that focuses on the study of the structure-function of SL signaling regulation by utilizing advanced interdisciplinary approaches. The knowledge generated from this project may have far reaching impacts in understanding the biology of the SL pathway and advancing technologies in agriculture, including germination control of crops and parasitic weeds. Additionally, as an integral part of the research activities, this project will create a unique teaching platform and outreach program to encourage young students to pursue knowledge in STEM with two major implementations: (a) developing a modern biochemistry classroom by implementing an interactive curriculum that integrates advanced visualization tools; (b) promoting STEM education for underrepresented groups by pioneering engaging workshops to inspire the next generation of scientists.
The recent identification of the key components of SL signaling, including a hydrolase receptor, an E3 ubiquitin (Ub) ligase, and a family of AAA+ ATPase chaperonin-like transcriptional repressor proteins, open up new avenues of investigation on the evolution, biochemistry, and physiology of this pathway and its impacts on a diverse array of developmental processes. However, a mechanistic understanding of the signal transduction pathway for this class of plant growth regulators will remain elusive until the structure and biochemical function of the SL signaling complex are elucidated. Therefore, the main research objectives of this project are to: (1) Study biochemically, structurally, and in planta the functional state of the SL-signaling complex. (2) Reveal the mode of action of AAA+ ATPase chaperonin-like transcriptional repressor proteins, and their role in regulation of SL physiological responses. (3) Elucidate the molecular basis of SL-dependent association with the ubiquitin proteasome system, in particularly with the MAX2 ubiquitin ligase, and the transcriptional repressors, by utilizing structural biology and plant biology approaches. Outcomes of this research may not only close a critical gap in understanding the biology of the SL pathway but may also uncover new paradigms in plant signaling and the ubiquitin proteasome pathway.
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.
