Plant-biotic interactions under elevated CO2: A molecular perspective

Elevated levels of atmospheric CO2 are predicted to contribute to major climatic changes during the next 50-100 years. This can have a significant impact on future food security if such changes make crop plants vulnerable to biotic and abiotic stresses. Indeed, a growing body of recent studies highlighted in this review show that elevated CO2 (eCO(2)) directly and/or indirectly influence plant-biotic interactions. In many instances, eCO(2) alters phytohormone and reactive oxygen signalling, secondary metabolism as well as defence-associated development such as stomatal responses in the host. eCO(2) can also directly and/or indirectly influence pathogenesis-and herbivory-related traits in pest and pathogen populations although currently very little is known about the molecular mechanisms involved in such effects. In addition, eCO(2) alters predator-prey interactions by interfering with indirect defences and chemical communications in insect pests. A better understanding of molecular mechanisms involved in plant-biotic interactions under eCO(2) will be critical towards mitigation of potentially adverse effects of climate change on crop production.