Role of extracellular ATP in plants
ATP is a ubiquitous compound in all living cells; it not only provides the energy to drive many biochemical reactions, but also functions in signal transduction as a substrate for kinases, adenylatecyclases, etc. However, ATP was also shown to be an essential signaling agent outside of cells, where it is referred to as extracellular ATP (eATP). An extensive literature exists in animials implicating eATP in numerous cellular processes, including neurotransmission, immune responses, cell growth, and cell death. Initial observations of effects of eATP in animals were met with considerable skepticism. However, this changed when the plasma membrane-localized receptors, purinoceptors of the P2X and P2Y classes, were identified and shown to mediate the effects of eATP.
In contrast, relatively little has been done to examine the role of eATP in plants. However, over the past several years, eATP has been implicated in a variety of plant processes, including root-hair growth, stress responses, gravitropism, cell viability, pathogen responses and thigmotropism. A significant break through in the study of purinergic signaling (eATP response) in plants was our identification of the first, plant eATP receptor (Choi et al., 2015). DORN1 is a lectin receptor-like kinase and, therefore, identifies a new family of purinoreceptors (P2K).
The laboratory is continuing our characterization of P2K1 (DORN1) and other proteins involved in eATP recognition, as well as exploring the role that eATP signaling plays in plant growth and development. Our findings clearly implicate purinergic signaling in a variety of key plant processes suggesting that eATP is just as important and interesting in plants as it is in animals (including humans).
Selected, recent publications from the lab on this topic:
Elsa Matthus, Jian Sun, Limin Wang, Madhura G. Bhat, Amirah B. Mohamad-Sidik, Katie Wilkins, Nathalie Leblanc-Fournier, Valérie Legué, Bruno Moulia, Gary Stacey, Julia M. Davies. 2019. DORN1/P2K1 and purino-calcium signalling in plants; making waves with extracellular ATP. Ann. Bot. https://doi.org/10.17863/CAM.42662
Dongqin Chen, Nagib Ahsan, Jay J. Thelen, Gary Stacey. 2019. S-Acylation of plant immune receptors mediates immune signaling in plasma membrane nanodomains. BioRxiv doi: https://doi.org/10.1101/720482 270.
Dongqin Chen, Yangrong Cao, Hong Li, Daewon Kim, Nagib Ahsan, Jay Thelen, and Gary Stacey (2017) Extracellular ATP elicits DORN1-mediated RBOHD phosphorylation to regulate stomatal aperture. Nature Commun. 8: 2265. doi:10.1038/s41467-017-02340-3255.
Diwaker Tripathi, Tong Zhang, Abraham J. Koo, Gary Stacey, and Kiwamu Tanaka (2017) Extracellular ATP acts on jasmonate signaling to reinforce plant defense. Plant Physiol. 176: 511–523. DOI: https://doi.org/10.1104/pp.17.01477
Cao, Yangrong, Kiwamu Tanaka, Cuong T. Nguyen and Gary Stacey (2014) Extracellular ATP is a central signaling molecule in plant stress responses. Curr. Op. Plant Biol. 20: 82-87. https://doi.org/10.1016/j.pbi.2014.04.009
Choi, Jeongmin, Tanaka, Kiwamu, Cao, Yangrong, Xi, Yue, Qiu, Jing, Liang, Yan, Sang Yeol Lee, Stacey, Gary (2014) Identification of a plant receptor for extracellular ATP. Science Vol. 343 no. 6168 pp. 290-294. DOI: 10.1126/science.343.6168.290