Abstract
Multicellular organisms depend on cell-to-cell communication to coordinate both development and environmental responses across diverse cell types. Intercellular signaling is particularly critical in plants because development is primarily postembryonic and continuous over a plant's life span. Additionally, development is impacted by restrictions imposed by a sessile lifestyle and limitations on relative cell positions. Many non-cell-autonomous signaling mechanisms are known to function in plant development, including those involving receptor kinases, small peptides, and mobile transcription factors. In this review, we focus on recent findings that highlight novel mechanisms in intercellular signaling during development. New details of small RNA movement, including microRNA movement, are discussed, as well as protein movement and distribution of reactive oxygen species (ROS) in ROS signaling. Finally, a novel temporal mechanism for lateral root positioning and the implications for intercellular signaling are considered.