Genome regulatory mechanisms mediating abscisic acid stress hormone response and stomatal aperture control in plants

The National Institute of General Medical Sciences awarded $419,296 to the University of Maryland, College Park on July 10, 2026 under the Biomedical Research and Research Training program (CFDA 93.859) to conduct research on genome regulatory mechanisms mediating abscisic acid stress hormone response and stomatal aperture control in plants.

The research program investigates how plants coordinate gene and genome activity in response to environmental stress, focusing on drought adaptation. The work uses Arabidopsis thaliana guard cells as a model system to examine how environmental signals including abscisic acid concentration and atmospheric CO2 levels regulate stomatal pore size on leaf surfaces. The research combines cell-type specific genomics and proteomics assays with physiological studies to dissect molecular mechanisms underlying abscisic acid-dependent chromatin remodeling and transcriptome reprogramming. The program also explores how osmotic and turgor pressure changes in guard cells during stomatal movements regulate chromatin structure and function in the nucleus, and investigates stress memory mechanisms in plants.

The award carries a period of performance from July 10, 2026 through May 31, 2031. Work is performed in College Park, Maryland. The assistance type is a project grant, which funds investigator-initiated basic biomedical research of high scientific and technical merit selected through NIH peer review.

Abstract

The focus of our research program is to understand how organisms coordinate gene and genome activity with a changing and stressful environment. To support a stationary lifestyle, plants evolved sophisticated mechanisms to adjust to environmental stresses including drought, a major challenge to agricultural productivity both domestically and worldwide which negatively impacts human health and nutrition. In our lab, we use the arabidopsis thaliana guard cell as a model system for investigating the mechanisms that connect environmental conditions to plant genome structure and activity. Guard cells are specialized cells that integrate multiple environmental cues to optimally control the size of microscopic pores on the leaf surface known as stomata. For example, changes in the concentration of the plant hormone abscisic acid (ABA), a key regulator of stress responses, and changes in atmospheric CO2 concentration are well known signals that trigger adjustments in stomatal pore size. Stomatal regulation is essential for minimizing water loss while allowing CO2 uptake from the atmosphere for photosynthesis. This research will build on our prior discoveries to dissect the molecular mechanisms underlying ABA-dependent chromatin remodeling and transcriptome reprogramming. We will deploy a combination of cell-type specific genomics/proteomics assays and physiological studies to investigate the role of transcriptional regulation in the stomatal adaptation to stress and subsequent stress "memory" in plants. Our research will advance a model wherein disparate environmental signals are integrated by gene regulation to optimize stomatal responses. Furthermore, we will explore how the exceptional changes in the osmotic or turgor pressure of guard cells during stomatal movements regulate the structure and function of chromatin in the nucleus. We anticipate that our discoveries will have fundamental significance to the study of transcriptional control by the environment and provide new strategies to improve plant resilience to stress, a topic of major relevance to agriculture and human nutrition.