カスパリー線の形成に必要なチロシン硫酸化ペプチドホルモン

抄録

To adapt ever-changing situations, multicellular organisms have developed several types of extracellular barriers as a result of evolutionary convergence.　Plant roots establish two types of extracellular barriers, namely Casparian strip （CS） and suberin lamellae, inside of the roots, not on their surface.　The Casparian strips mainly consist of lignin, a highly hydrophobic chemical, which blocks free diffusion of ions or small molecules across endodermal cell layers.　Despite of the physiological importance, the mechanisms underlying functional Casparian strip formation are not yet uncovered.　Recently, two independent groups identified exactly the same peptide-receptor pair for Casparian strip maturation by completely different approaches.　Geldner’s group in Lausanne identified the pair by forward genetics and database search, while Matsu-bayashi’s group in Nagoya identified the pair by in silico and biochemical screens.　This review focuses on how these two groups identified the sulfated peptides, CIF1/2 （Casparian strip integrity factors 1/2）, and how these peptides function on the Casparian strips.　Furthermore, we discuss the mode of action of the peptides during CS maturation in developmental context and their roles under physiological or stress conditions.