Phytohormonal crosstalk under abiotic stress

Abstract

As sessile organisms, plants cannot escape from adverse conditions. Thus, responses to the changing environment are more complex than in animals that usually just try to flee. Plant responses to abiotic constrains involve changes in gene expression, protein activity, cellular metabolite, and ion levels and must be perfectly coordinated by phytohormones that are the compounds that transduce signals. Recent data indicate that the signaling pathways are not isolated but interconnected in complex networks. Moreover, supporting evidence points to specific transduction pathways in different types of tissues or organs. This chapter will revise molecular mechanisms conserved among different hormone signaling pathways, which accounts for their evolutive importance together with particular interactions. The work is organized in sections that contextualize crosstalks of the main phytohormones in particular physiological processes. Data revised in this chapter support the importance of finding divergent experimental systems in the future. Therefore, whereas simplified plant systems will allow finding new phytohormone crosstalks, considering the plant as a whole will provide further information among interactions that can be hidden at this point due to the massive use of model plants in early stages of growth or cultivated in artificial conditions. Specific hormone interactions could represent targets for breeding/managing for yield resilience under multiple stress situations.