Unity Is Strength: The Power of Border Cells and Border-Like Cells in Relation with Plant Defense

Abstract

Production and release of root border cells and border-like cells are fundamental processes for plant survival and development. Both types of cells are viable components of the root system that regulate its interactions with living microorganisms of the rhizosphere. Border cells are released as individual cells, whereas border-like cells remain attached to each other into small groups or as sheets after their release from the root tip. So far, border-like cells have been observed only in species belonging to the Brassicaceae family including Arabidopsis. Border cells have been largely studied in the legume species pea; in contrast, relatively little information is available on border-like cells so far due to their recent discovery. In this chapter, we present and discuss the release, organization, and the role of these cells in root protection.