Plant growth regulators control ozone damage to wheat yield

Area of Science:

• Agricultural Science
• Environmental Science
• Plant Physiology

Background:

• Tropospheric ozone (O3) negatively impacts plant health, leading to reduced crop yields.
• Understanding wheat's response to elevated O3 is crucial for food security.

Purpose of the Study:

• To investigate the efficacy of plant growth regulators Ethephon and Chlormequat in mitigating yield losses in wheat exposed to elevated O3.
• To determine the specific roles of these regulators in wheat's physiological and developmental responses to O3 stress.

Main Methods:

• A controlled factorial experiment exposing spring wheat to ambient or elevated O3 levels.
• Application of Ethephon and/or Chlormequat at flag-leaf emergence.
• Measurements included gas exchange, morphology, biomass, and yield components at harvest.

Main Results:

• Elevated O3 accelerated plant development and reduced grains per ear and ears per plant.
• Chlormequat treatment counteracted O3-induced yield reduction by preserving grain number, but not biomass.
• Ethephon provided partial protection against O3-induced biomass loss but did not significantly improve yield.

Conclusions:

• Plant growth regulators can influence wheat's response to tropospheric ozone.
• Chlormequat demonstrates potential for protecting wheat yield against O3 damage.
• Ozone's impact on developmental processes and resource allocation is a key factor in wheat yield reduction.