- Scientists at Nagoya University have discovered how a type of amino acid threonine (Thr881) regulates stomatal opening in plants, a step required for optimal photosynthesis.
What are stomatal openings?
- Stomata are small pores on plant leaves that allow for gas exchange.
- They specifically absorb the carbon dioxide required for photosynthesis.
How does light cause stomata to open?
- In reaction to red and blue light, researchers discovered a unique regulatory mechanism that involves the phosphorylation of the plasma membrane proton pump’s 881st threonine residue (Thr881).
- Phosphorylation, the process of adding or removing a phosphate group from amino acids, serves as a regulatory switch that influences protein structure and function.
- The study concentrated on the phosphorylation of Thr881 and its significance in stomatal opening.
- They discovered phosphorylation in response to both red and blue light, emphasising the link between photosynthesis and light signalling.
The Significance of Thr881 Phosphorylation
- Mutant experiments established the importance of Thr881 phosphorylation in stomatal opening.
- Plants producing a mutant proton pump lacking Thr881 phosphorylation had lower stomatal aperture and transpiration rates, highlighting the regulatory importance of this amino acid residue.
- The study identified Thr881 and Thr948 as critical phosphorylation sites for the activation of the enzyme H+-ATPase, which is required for stomatal opening.
- Manipulating Thr881 may provide opportunities for improving plant growth, increasing carbon dioxide absorption, and lowering fertiliser use.
Source: https://www.sciencedaily.com/releases/2024/03/240326103923.htm#:~:text=Summary%3A,key%20role%20in%20this%20process.