Plants adjust cellular pressure to respond to environmental factors. The evolution of stomata played a major role in changing Earth’s atmosphere over the past 400 million years.
Stomata — plants’ microscopic pores—allow plants to control water loss and improve photosynthesis. A key breakthrough was the ability to adjust the pressure inside guard cells, which may be a unique feature of vascular plants.
Nearly all land plants rely on internal pressure to carry out vital processes like growth, reproduction, and survival. This internal pressure is central to how plants function. However, until recently, scientists had very limited ways to measure and study it, leaving much of its role in plant biology a mystery.
A traditional method of measuring pressure changes involves piercing cells with a fragile glass tube measuring a fraction of the width of a human hair. However, that tube breaks easily, and the process only works on species with larger cells.
Researchers at Yale School of the Environment have created a groundbreaking laser-based method to study how plants adjust internal cell pressure in response to their surroundings. This innovation allows scientists to measure cellular pressure in more species and at a much faster rate, opening up exciting possibilities for studying plant evolution and physiology.
One significant milestone of this study is its first application of the method to stomata in Bryophytes, a group of plants that includes mosses. This breakthrough could provide valuable insights into the evolution of Earth’s earliest plants and help enhance water-use efficiency in modern plant species.
A burst of light energy creates tiny bubbles by vaporizing liquid in plant cells. These bubbles last for only a fraction of a second, but their maximum size—captured by high-speed cameras—reveals the surrounding pressure. Researchers then studied how bubble size changes with light levels, helping them measure pressure adjustments.
This method was tested in over 40 plant species, including some with very small cells that were previously difficult to study. Understanding these pressure changes sheds light on how quickly stomata open and close, which affects the balance between carbon absorption and water loss. This balance, known as water use efficiency, is critical for agriculture.
Craig Brodersen, the Howard and Maryam Newman Professor of Plant Physiological Ecology and the study’s lead author, said, “These tools are an important first step in developing more water-efficient crop varieties and improving irrigation management in water-scarce environments.”
Journal Reference
- Craig R. Brodersen, Tim Brodribb, et al. In situ, cavitation bubble manometry reveals a lack of light-activated guard cell turgor modulation in bryophytes. PNAS. DOI: 10.1073/pnas.2419887122
Source: Tech Explorist
