As global temperatures rise, researchers have uncovered the intricate mechanisms that allow plants to adapt and respond to this environmental challenge. By studying the microscopic pores on plant leaves, called stomata, scientists have discovered two distinct pathways that plants use to regulate their cooling and carbon dioxide intake processes. This research holds important implications for improving agricultural resilience and understanding the broader impacts of climate change on ecosystems. Stomata, Photosynthesis
Reveals the Genetic(ally-Related) Process
Stomata are tiny pores on the leaf surface of plants that are essential for plant physiology. These pores open and close to allow plants to “breathe,” controlling water loss, but they also simultaneously permit carbon dioxide—the essential ingredient of photosynthesis and plant growth—to enter the plant from the atmosphere. It has long been observed how plants “sweat” to lower their temperatures by opening up the stomatal pores when it gets warmer.
But the genetic and molecular details of this temperature-mediated stomatal response have remained a mystery for more than 100 years. Or so it thought until a team of researchers from the University of California San Diego School of Biological Sciences cracked open the mystery. Led by Ph. In a recent study by Nattiwong Pankasem, a Ph. D. student and Julian Schroeder, professor at UC San Diego), the researchers have pieced together an intricate snapshot of how plants cope with the heat—and what that means for future climate change.
Two roads for the stomatal response
The study, published in the journal New Phytologist, found that plants use two methods to control their stomatal opening as the temperature rises.
This first route is through carbon dioxide sensors that perceive quick heating inside plant leavers. This causes photosynthesis to rise, and carbon dioxide levels to drop. This causes the stomatal pores to open so that all of the newly available carbon dioxide can be brought inside for plant growth and development.
However, the scientists also found a second more extreme heat response pathway for temperatures that are even higher. In these cases, photosynthesis is ultimately lost. Significantly, the second heat response pathway operates through a completely different and novel mechanism that does not rely on the carbon dioxide sensor system or work in concert with responses driven by photosynthesis. Instead, the stomata open as a mechanism to cool directly, and for this plant to be able to « sweat » in short.
Effects on Agriculture and Ecosystems
It raises considerable implications. According to Nattiwong Pankasem, “The effect of this second mechanism where plants would open their stomata but not gain from it in terms of photosynthesis is to reduce the water use efficiency for crop plants. A simple Oceanic plants to prefer more water per unit of CO2 absorbed, based on our research. That could result in more transpiration of plants in ecosystems, which in turn causes large-scale effects on the hydrological cycle under global warming and directly affect irrigation planning for crop production.
The team is now investigating the molecular and genetic mechanisms controlling this alternative heat response pathway. Their work is furthering our scientific knowledge, and could help in developing strategies for building agricultural resilience and mitigating the overall consequences of climate change on ecosystems.
