Reduced stomatal density in bread wheat leads to increased water-use efficiency

Area of Science:

• Agricultural Science
• Plant Biology
• Genetics

Background:

• Wheat is a vital crop often grown in arid regions, necessitating improved water-use efficiency (WUE).
• Stomatal density is a key factor influencing plant water transpiration and carbon assimilation.

Purpose of the Study:

• To investigate if manipulating epidermal patterning factor (EPF) gene expression to decrease wheat stomatal density can enhance water-use efficiency.
• To assess the impact of reduced stomatal density on wheat grain yield under various environmental conditions.

Main Methods:

• Overexpression of EPF genes in wheat to alter stomatal development.
• Quantification of stomatal density and measurement of grain yield.
• Evaluation of plant performance under normal, drought, and elevated CO2 conditions.

Main Results:

• Severe reduction in stomatal density led to decreased wheat yields.
• Moderate reduction (<50%) in stomatal density, particularly before tillering, maintained yields comparable to control plants.
• Plants with moderate stomatal density reduction showed increased intrinsic water-use efficiency and comparable yields under drought and elevated CO2.

Conclusions:

• EPF-mediated control of stomatal development in wheat aligns with observations in other grasses.
• Moderate reduction of stomatal density is a viable strategy to enhance wheat water-use efficiency without compromising yield.
• Stomatal density presents a target trait for breeding climate-resilient wheat for water-limited environments.