About This Project

Plants need efficient CO2 uptake to enhance photosynthesis (PS). However, high temperatures prompt stomatal closure, conserving water but raising leaf surface temperatures further and hindering PS. Climate change accelerates critical temperature thresholds for optimal PS. Our goal is to extend this threshold by combining and optimizing different light-gated ion-conducting proteins to manipulate stomata opening while retaining more water in mesophyll cells at high temperatures.

Ask the Scientists

What is the context of this research?

Plant photosynthesis is significantly influenced by both light intensity and temperature. Elevated light levels intensify photosynthesis, necessitating effective CO2 absorption to fulfill metabolic requirements. Nevertheless, excessive light raises temperatures, triggering stomatal closure for water conservation. This, however, also increases leaf surface temperatures, impeding PS. A recent publication in Nature pointed out that tropical forests are approaching critical temperature thresholds. Beyond these thresholds, the efficiency of photosynthetic machinery begins to decline. A decrease in photosynthesis will subsequently lower CO2 fixation, potentially exacerbating climate change.

What is the significance of this project?

To surpass this threshold, I propose to work on enhancing stomatal opening while maximizing water retention in cells amidst high light and temperature. My approach involves strategic modulation of ion flux in diverse plant tissues. Stomatal dynamics are intricately regulated by membrane potential. Water movement into or out of cells is dictated by osmolarity. Consequently, extending stomatal opening involves hyperpolarizing the guard cell and promoting net ion influx, effectively retaining water within cells. Achieving this can be facilitated through light-gated ion channels/pumps, capable of robust expression in plant cell plasma membranes and resilience to high temperatures.

What are the goals of the project?

The goal of the project is to improve the somata open while limiting water loss under environmental conditions of high light and temperature.

Two kinds of light-gated tools are aimed to be obtained by protein engineering and tested in plants.

1) Single or multiple light-gated tools that can be expressed in the plasma membrane and function well at high temperatures such as 40 to 50 °C, which could be used to hyperpolarize the membrane potential and open the stomata.

2) Combination of light-gated tools that can be expressed in the plasma membrane and function well at high temperatures, which can be used to enhance or at least to keep the intracellular osmolarity and retain the water.