Molecular mechanisms involved in adventitious root formation

Rooting capacity is one of the economically important factors lost during the juvenile to mature phase change. The difficulties in propagation of promising clones of fruit trees, rootstocks, ornamental woody plants, and forest trees are a serious obstacle in breeding programs that are generally based on the production of rooted cuttings. Understanding the molecular basis of adventitious roots (AR) formation will contribute to our ability to design biotechnological solutions, not only for the benefit of agriculture but also for biomass, renewable energy, and biofuel production. For more detailed reviews on AR formation, the reader may refer to the following references: Dech (2009), Geiss et al. (2009), Lanteri et al. (2009), Ludwig-Müller (2009), and Pijut et al. (2011). In this chapter, we mainly summarize the latest research results, with a glance on some previous works performed on woody plants as the assay system. While woody plants are those that suffer the most from difficulties in rooting, they are not an easy system for biochemical and molecular studies. On the other hand, the research on AR formation using herbaceous model plants has elucidated several potential molecular mechanisms although these plants are practically easy to root. Therefore, this review combines and compares data obtained from both plant systems.