06 July 2020
Receptors behind leaf adaptation to long-term change
Published online 26 August 2019
Understanding the genetic mechanisms underlying leaf responses to long-term environmental changes could lead to better crops.
When plants perform photosynthesis, they open tiny pores called stomata in their leaves to allow the exchange of important gases. The opening and closing of each stoma is controlled by two guard cells, which rapidly respond to changes in carbon dioxide levels, light and humidity through well-established molecular pathways. However, it is unclear exactly how stoma function might adapt to longer-term environmental changes to maximize photosynthesis efficiency.
Now, Alistair Hetherington at the University of Bristol, UK, and an international team of scientists, including a researcher at King Saud University in Saudi Arabia, have identified unique gene networks that promote stomata closure in response to long-term changes in darkness, high carbon dioxide concentrations, decreased humidity, and exposure to the hormone abscisic acid (ABA).
They found that all four of these external stimuli modulated the expression of members of a family of ABA receptor molecules, with subtle differences in which specific ABA receptors were most important for each stimulus. Overall, the results showed that ABA is crucial as a central regulator in determining stomata sensitivity and behaviour in response to long-term environmental changes.
"Our findings represent new and fundamental insights into how plants adapt to a changing environment,” says Hetherington. “By revealing the intricate molecular details that underlie these responses, they open up new avenues for those seeking to breed crops that use water and nutrients more efficiently.”
Dittrich, M. et al. The role of Arabidopsis ABA receptors from the PYR/PYL/RCAR family in stomatal acclimation and closure signal integration. Nat. Plants http://dx.doi.org/10.1038/s41477-019-0490-0 (2019).