Normal ovule (a female reproductive structure for producing seed) and fruit development are essential for good crop yield and quality. MicroRNAs (miRNAs), which are small (~21 nucleotides) non-coding RNAs, act as critical regulators to ensure precise control of many biological processes. Auxin, a prominent plant hormone, is crucial for ovule and fruit development. The auxin signal is translated into a robust pattern of gene expression by auxin-mediated release of AUXIN RESPONSE FACTOR (ARF) gene regulators, while miRNAs negatively regulate expressions of ARFs. Previous studies showed that miR160 and its target ARF genes play vital roles in ovule and early fruit development. However, how miR160 participates in the auxin signaling network remains unknown. Using integrated molecular genetic, cell biology, and systems biology approaches, the main goal of this research is to investigate the molecular mechanism by which miR160 and its target ARF genes coordinate to fine-tune auxin signaling to regulate ovule development in the model species Arabidopsis and early fruit development in the tomato. This project will not only provide new insight into the function of miRNA in auxin-mediated developmental processes, but also lead to important applications for improving yield and quality of tomato and many other agriculturally valuable crops. The generated data sets and materials will be made available through The Arabidopsis Information Resource (TAIR, www.arabidopsis.org), the NCBI Gene Expression Omnibus database (www.ncbi.nlm.nih.gov/geo), and the Tomato Genetics Resource Center (http://tgrc.ucdavis.edu) for research and teaching.
This internationally collaborative project will have multiple educational impacts. It will provide advanced training for a postdoctoral researcher and a graduate student. In addition, the project will promote science education and enable valuable hands-on research experiences in both the US and Israel by developing lab modules and educating undergraduate students as early as in their freshman year, including particularly students from underrepresented groups. Finally, plant biology workshops will be hosted for high school students.
