Lectins are fundamental to plant life and have important roles in cell-to-cell communication; development and defence strategies. At the cell surface; lectins are present both as soluble proteins (LecPs) and as chimeric proteins: lectins are then the extracellular domains of receptor-like kinases (LecRLKs) and receptor-like proteins (LecRLPs). In this review; we first describe the domain architectures of proteins harbouring G-type; L-type; LysM and malectin carbohydrate-binding domains. We then focus on the functions of LecPs; LecRLKs and LecRLPs referring to the biological processes they are involved in and to the ligands they recognize. Together; LecPs; LecRLKs and LecRLPs constitute versatile recognition systems at the cell surface contributing to the detection of symbionts and pathogens; and/or involved in monitoring of the cell wall structure and cell growth.

Lateral roots are crucial for increasing surface area of root systems to explore heterogeneous soil environments. Major advances have recently been made in the model plant Arabidopsis thaliana to elucidate the cellular basis of lateral root development and the underlying gene regulatory networks that control morphogenesis of the new root organ. This has provided the foundation on which to understand the sophisticated adaptive mechanisms that regulate how plants pattern their root branching to match the spatial availability of resources like water and nutrients in their external environment. We review new insights into the molecular, cellular and environmental regulation of LR development in Arabidopsis.