ATANN3 Is Involved in Extracellular ATP-Regulated Auxin Distribution in Arabidopsis thaliana Seedlings

Abstract

Extracellular ATP (eATP) plays multiple roles in plant growth and development, and stress responses. It has been revealed that eATP suppresses growth and alters the growth orientation of the root and hypocotyl of Arabidopsis thaliana by affecting auxin transport and localization in these organs. However, the mechanism of the eATP-stimulated auxin distribution remains elusive. Annexins are involved in multiple aspects of plant cellular metabolism, while their role in response to apoplastic signals remains unclear. Here, by using the loss-of-function mutations, we investigated the role of AtANN3 in the eATP-regulated root and hypocotyl growth. Firstly, the inhibitory effects of eATP on root and hypocotyl elongation were weakened or impaired in the AtANN3 null mutants (atann3–1 and atann3–2). Meanwhile, the distribution of DR5-GUS and DR5-GFP indicated that the eATP-induced asymmetric distribution of auxin in the root tips or hypocotyl cells occurred in wild-type control plants, while in atann3–1 mutant seedlings, it was not observed. Further, the eATP-induced asymmetric distribution of PIN2-GFP in root-tip cells or that of PIN3-GFP in hypocotyl cells was reduced in atann3–1 seedlings. Finally, the eATP-induced asymmetric distribution of cytoplasmic vesicles in root-tip cells was impaired in atann3–1 seedlings. Based on these results, we suggest that AtANN3 may be involved in eATP-regulated seedling growth by regulating the distribution of auxin and auxin transporters in vegetative organs.

The intrinsically disordered C‐terminus of purinoceptor P2K1 fine‐tunes plant responses to extracellular ATP

“…Extracellular ATP (eATP) has been shown to play multiple roles in plant growth and development, including root growth and stress responses [6,18,20,40,41]. It has been reported that eATP suppresses growth and alters the growth orientation of the root and hypocotyl of Arabidopsis by affecting hormone signaling pathways [6,[41][42][43][44]. Some reports suggest that the P2K1 receptor is partially involved in eATP-mediated plant growth [44].…”

CPK28 is a modulator of purinergic signaling in plant growth and defense

“…Current evidence suggests that important secondary messengers, Ca 2+ and reactive oxygen species (ROS), mediate the signaling events following eATP perception by P2K1 (Choi et al., 2014; Demidchik et al., 2009; Gilroy et al., 2016; Jeter et al., 2004; Marcec et al., 2019; Tanaka et al., 2010; Tripathi et al., 2018). Additionally, eATP has been found to play a role in regulating plant growth and development, although the involvement of P2K1 in these processes has not been fully understood (Tang et al., 2003; Tonón et al., 2010; Xu et al., 2023; Zhu et al., 2020). Recent research has identified eATP‐responsive genes through transcriptomics (Jewell et al., 2019), leading to the development of a reliable tool for monitoring eATP signaling responses (Sowders & Tanaka, 2023).…”

Rice OsANN9 Enhances Drought Tolerance through Modulating ROS Scavenging Systems

“…In general, the C-terminal core of annexin contains four annexin repeats, and each repeat has five short α-helices [9,10]. Previous studies have shown that annexins participate in regulating diverse aspects of plant growth and development as well as responses to stress [11,12]. For example, the overexpression of TdANN6 enhanced salt/osmotic stress tolerance by increasing catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) activities in durum wheat [13].…”