Tropospheric ozone and plants: absorption, responses, and consequences

Area of Science:

• Environmental Science
• Plant Biology
• Agricultural Science

Background:

• Ozone (O₃) is a major gaseous pollutant and a significant threat to global agriculture.
• Unsustainable resource utilization has increased O₃ levels, exacerbating climate change impacts.
• Plants are particularly vulnerable to O₃, which enters through stomata and affects cellular functions.

Purpose of the Study:

• To provide a comprehensive overview of plant-ozone interactions.
• To summarize existing research on plant responses to O₃ at various biological levels.
• To highlight the implications of O₃ for crop yield and plant defense mechanisms.

Main Methods:

• Review of existing literature on plant responses to O₃.
• Analysis of morphological, physiological, cellular, and biochemical effects of O₃.
• Inclusion of data from high-throughput omics technologies (transcriptomics, proteomics, metabolomics).

Main Results:

• Ozone exposure leads to direct cellular damage, oxidative stress (ROS, H₂O₂), premature senescence, and altered gene/protein expression.
• Photosynthesis machinery is impaired, decreasing crop yield and causing characteristic "foliar injury" symptoms.
• Elevated O₃ stress induces plant antioxidative defense systems, and omics studies have identified numerous O₃-responsive components.

Conclusions:

• Plant "foliar injury" symptoms serve as reliable biomonitors for O₃ under natural conditions.
• Omics technologies have generated valuable inventories of O₃-responsive plant components.
• Developing O₃-tolerant plants using biomarkers and understanding signaling pathways is a future goal, with some ameliorating agents identified.