New to this Edition:

• A new chapter titled Biotic Interactions—replacing the Fifth-Edition Chapter 13 on Secondary Metabolites and Plant Defense—discusses the integrated signaling responses to a spectrum of biological agents.
• A completely rewritten chapter on Abiotic Stress discusses the use of genomics, systems biology, imaging, and bioinformatics tools in the study of abiotic stress. Recent efforts to develop drought-tolerant maize and flood-tolerant rice are described, as well as the role of ABA receptors, newly-identified regulatory networks, epigenetic changes in response to abiotic stress, and rapid systemic signaling.
• The pathway of all nutrients essential in the human diet begins with plant roots "mining" the soil for mineral elements; the Sixth Edition explicitly examines the linkage between plant nutrition and human health.
• The response of plants to rising atmospheric levels of carbon dioxide depends most strongly on their nitrogen status. The Sixth Edition describes the newly discovered mechanism for this dependence and how it will influence food quality in the future.
• Exciting new findings on the mechanisms of mycorrhizal associations and symbiotic nitrogen fixation will be added, providing insights about the interdependence of plants and microorganisms.