What Makes the Wood? Exploring the Molecular Mechanisms of Xylem Acclimation in Hardwoods to an Ever-Changing Environment

Wood, also designated as secondary xylem, is the major structure that gives trees and other woody plants stability for upright growth and maintains the water supply from the roots to all other plant tissues. Over recent decades, our understanding of the cellular processes of wood formation (xylogenesis) has substantially increased. Plants as sessile organisms face a multitude of abiotic stresses, e.g., heat, drought, salinity and limiting nutrient availability that require them to adjust their wood structure to maintain stability and water conductivity. Because of global climate change, more drastic and sudden changes in temperature and longer periods without precipitation are expected to impact tree productivity in the near future. Thus, it is essential to understand the process of wood formation in trees under stress. Many traits, such as vessel frequency and size, fiber thickness and density change in response to different environmental stimuli. Here, we provide an overview of our current understanding of how abiotic stress factors affect wood formation on the molecular level focussing on the genes that have been identified in these processes.