Plant Molecular and Genomic Responses to Stresses in Projected Future CO₂ Environment

Abstract

The Earth has been undergoing climatic changes for centuries, driven by increasing concentration of atmospheric carbon dioxide (CO₂). The atmospheric CO₂ concentration has been predicted to reach 550–750 μmol mol⁻¹ by 2050, or twice as high as the current level. Much of the research in the last 20–30 years concerning elevated CO₂ (eCO₂) has been about how plants would respond to the eCO₂ at physiological levels. As eCO₂ can lead to more frequent drought or extreme high or low temperature, increasingly more research has focused on the interactions between eCO₂ and other abiotic stresses. How stresses may affect plant growth and development and productivity, as well as how agricultural practices may be altered to cope with these changes must be determined. These concerns have been the subject of numerous reviews. However, it is only in the last several years that data at the “omics” levels has been available to explore how necessary physiological changes may be brought about in a future complex environment. The systems biology approaches provide us an insight into the mechanism of plant responses to climatic changes at the genomics level. In this review, we present an overview of physiological effects of eCO₂ on plants, but focus on the interactions of eCO₂ with drought, high temperature, O₃, and multiple abiotic stresses, with particular emphasis at the molecular and genomics levels. We also provide perspectives on future research and emphasize the importance of integrated research on eCO₂ and multiple environmental stresses using systems biology approaches.

Keywords:

• abiotic stress
• climate change
• elevated CO₂
• environment
• plant physiology
• omics

ACKNOWLEDGMENTS

This research is supported in part by the Priority Academic of Jiangsu Province, and the Ministry of Education—Nanjing Agricultural University Project # KYT201004, and in part by the Tennessee Agricultural Experiment Station.