Extracellular ATP acts as a damage-associated molecular pattern (DAMP) signal in plants

Abstract

As sessile organisms, plants have evolved effective mechanisms to protect themselves from environmental stresses. Damaged (i.e., wounded) plants recognize a variety of endogenous molecules as danger signals, referred to as damage-associated molecular patterns (DAMPs). ATP is among the molecules that are released by cell damage, and recent evidence suggests that ATP can serve as a DAMP. Although little studied in plants, extracellular ATP is well known for its signaling roles in animals, including acting as a DAMP during the inflammatory response and wound healing. If ATP acts outside the cell, then it is reasonable to expect that it is recognized by a plasma membrane-localized receptor. Recently, DORN1, a lectin receptor kinase, was shown to recognize extracellular ATP in Arabidopsis. DORN1 is the founding member of a new purinoceptor subfamily, P2K (P2 receptor kinase), which is plant-specific. P2K1 (DORN1) is required for ATP-induced cellular responses (e.g., cytosolic Ca2+ elevation, MAPK phosphorylation, and gene expression). Genetic analysis of loss-of-function mutants and overexpression lines showed that P2K1 participates in the plant wound response, consistent with the role of ATP as a DAMP. In this review, we summarize past research on the roles and mechanisms of extracellular ATP signaling in plants, and discuss the direction of future research on extracellular ATP as a DAMP signal.

Wounding Triggers Callus Formation via Dynamic Hormonal and Transcriptional Changes

“…Wound stress that causes a defense response is perceived through so-called damage-associated molecular patterns. Damage-associated molecular patterns include the cell wall derivative oligogalacturonic acid (Bishop et al, 1981) and extracellular ATP Tanaka et al, 2014), the latter of which, upon perception, triggers cytoplasmic calcium signaling and a burst of reactive oxygen species. These local wound signals are then translated into electrical and chemical signals and often transmitted to other parts of plants.…”

The Effect of Fruit Bearing on Low-molecular-weight Metabolites in Stems of Satsuma Mandarin (<i>Citrus unshiu</i> Marc.)

“…In addition, it is used in signal transduction pathways by kinases that phosphorylate proteins and lipids in the cell. Recent research has suggested that extracellular ATP functions as a signaling agent (Tanaka et al, 2014). Thus, ATP has several functions and it is thought that its level affects a wide range of metabolic processes.…”

Systems and synthetic biology perspective of the versatile plant-pathogenic and polysaccharide-producing bacterium Xanthomonas campestris

“…A substantial part of these exoenzymes are glycosidases and other polysaccharidedegrading enzymes that breach plant cell walls, thereby generating smaller carbohydrate compounds. Plants have evolved mechanisms to recognize such damage-associated microbial patterns (DAMPs) and subsequently initiate defence against the microbial hazard [124,249]. The carbohydrate compounds arising as debris from plant cell wall penetration can be scavenged by xanthomonads and are assumed to be used as a valuable resource for energy and building blocks in the metabolism.…”