NSF Postdoctoral Fellowship in Biology FY 2021: Investigating the role of ARGONAUTE and small RNAs in heritable stress memory in plants

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2021, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. This research seeks to understand how plants interpret environmental stress signals and how these signals are transmitted across generations.

Plants have evolved complex mechanisms to tolerate recurring stress and can prime their offspring for subsequent stresses. Investigating how this transmission occurs is important to advancing scientific knowledge and provides societal benefits because understanding how plants can adapt rapidly to stressful environments, such as climate change effects, helps to mitigate challenges to food security.

The Fellow will use classical genetics and genomics techniques to investigate how epigenetic regulation, the control of gene expression, affects the ability of plants to form stress memories and transmit stress-induced epigenetic changes to offspring. Given the relevance of the study to agriculture, the Fellow will explain the work to audiences of diverse backgrounds through public-facing science communication, outreach, and teaching.

The study will focus on small RNA biology and the role of ARGONAUTE proteins, a highly-conserved yet functionally-diverse family of small RNA silencing effectors. There are 10 ARGONAUTEs in Arabidopsis, each providing unique and overlapping functions through interactions with small RNAs and co-factors. ARGONAUTEs are the gate-keepers of small RNA-mediated gene silencing because all small RNAs are dependent on their interaction with ARGONAUTE to target complementary messenger RNA and/or DNA for silencing.

Small RNA-ARGONAUTE interactions are necessary for proper development, defense against viruses, responding to environmental stresses, and epigenetic regulation in the germline, as expression of several ARGONAUTEs are restricted to reproductive tissues. Adding to this complexity, pseudouridine-modified small RNAs are enriched in the germline which may alter small RNA-ARGONAUTE interactions and therefore affect epigenetic inheritance.

Pseudouridine-modified RNAs are dynamic under heat stress in yeast, but they have yet to be characterized in plant stress memory. This research will dissect the function of germline ARGONAUTEs and pseudouridine RNA in stress memory formation and inheritance in plants by analyzing loss-of-function mutants paired with epigenomic profiling. The Fellow will receive expert training in these areas at Cold Spring Harbor Laboratory as well as from their world-renowned courses.

Broadening participation efforts will include outreach and teaching about epigenetic regulation and biotechnology at the DNA Learning Center in New York City.

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.