Table I. Regulators and effectors of ROP signaling.
At, Arabidopsis thaliana; Hv, Hordeum vulgare (barley); Lj, Lotus japonicus; Mt, Medicago trancatula; Nt, Nicotiana tabacum (tobacco); Os, Oryza sativa (rice); Sl, Solanum lycopersicum (tomato); Zm, Zea mays (maize).
| Name | Process | Cellular Function |
Species | Reference |
|---|---|---|---|---|
| ROPs | ||||
| AtROP1 | Pollen tube growth, root growth, response to endophytic fungus | At | Fu et al. (2001); Gu et al. (2005); Lee et al. (2008); Venus and Oelmüller (2013) | |
| AtROP2 | Pavement cell growth, root hair initiation and growth, stomata opening, phytochrome-mediated light responses, ABA responses, transcriptional and translational regulation | At | Li et al. (2001); Fu et al. (2002, 2005); Jones et al. (2002); Fischer et al. (2006); Jeon et al. (2008); Ikeda et al. (2009); Hwang et al. (2011); Stanislas et al. (2015); Zhao et al. (2015); Hong et al. (2016); Zhang et al. (2016); Schepetilnikov et al. (2017); Wang et al. (2017) | |
| AtROP3 | Pollen growth, embryo and root development, auxin distribution | At | Expression data; Huang et al. (2014) | |
| AtROP4 | Pavement cell growth, root hair initiation and growth, pathogen response | At | Molendijk et al. (2001, 2008); Fu et al. (2005) | |
| AtROP5 | Pollen tube growth | At | Feng et al. (2016) | |
| AtROP6 | Pavement cell growth, root hair growth, ROS production, inhibition of endocytosis, root and lateral root development, salicylic acid-regulated pathogen response | At | Molendijk et al. (2001); Fu et al. (2005, 2009); Sorek et al. (2010); Poraty-Gavra et al. (2013); Venus and Oelmüller (2013); Wang et al. (2015) | |
| AtROP7 | Vascular development | At | Brembu et al. (2005); Wang et al. (2017) | |
| AtROP8 | Pollen nuclei migration in the central cell | At | Kawashima et al. (2014) | |
| AtROP9 | ABA and auxin responses, migration of pollen nuclei in pollen tubes | At | Li et al. (2013); Nibau et al. (2013); Choi et al. (2014) | |
| AtROP10 | ABA responses | At | Zheng et al. (2002); Xin et al. (2005); Choi et al. (2014) | |
| AtROP11 | ABA signaling, secondary cell wall patterning, root hair growth, inhibition of endocytosis | At | Bloch et al. (2005, 2011a, 2011b); Li et al. (2012b); Li and Liu (2012); Oda and Fukuda (2012); Yu et al. (2012) | |
| ZmROP2 | Regulation of asymmetric cell division during stomata development | Zm | Humphries et al. (2011) | |
| ZmROP9 | Regulation of asymmetric cell division during stomata development | Zm | Humphries et al. (2011) | |
| OsRAC1 | Pathogen response, lignin biosynthesis, activation of RBOH | Os | Kawasaki et al. (2006); Wong et al. (2007); Akamatsu et al. (2013); Nagano et al. (2016) | |
| NtRAC5 | Pollen tube growth | Nt | Kost et al. (1999); Klahre et al. (2006); Klahre and Kost (2006); Sun et al. (2015) | |
| HvRACB | Susceptibility to powdery mildew, regulation of cell growth | Hv | Schultheiss et al. (2002, 2005); Pathuri et al. (2008) | |
| HVRAC1 | Susceptibility to powdery mildew, regulation of cell growth, ROS production | Hv | Pathuri et al. (2008) | |
| HvRAC2 | Susceptibility to powdery mildew, regulation of cell growth | Hv | Pathuri et al. (2008) | |
| MtROP10 | Regulation of symbiotic interaction with rhizobium | Mt | Lei et al. (2015) | |
| LjROP6 | Regulation of symbiotic interaction with rhizobium | Lj | Ke et al. (2012) | |
| Cytoskeleton-associated ROP effectors | ||||
| RIC1 | Pollen tube growth, pavement cell growth, cell wall sensing | Actin severing and capping, cortical MT severing by KTN1 | At | Fu et al. (2005, 2009); Lin et al. (2013a); Zhou et al. (2015); Higaki et al. (2017) |
| RIC3 | Pollen tube growth | Actin disassembly | At | Gu et al. (2005); Lee et al. (2008) |
| RIC4 | Pollen tube growth, pavement cell growth, root growth, response to endophytic fungus | Actin assembly and bundling | At | Fu et al. (2005, 2009); Gu et al. (2005); Lee et al. (2008); Venus and Oelmüller (2013) |
| RISAP | Pollen tube growth | Actin-dependent vesicle transport | Nt | Stephan et al. (2014) |
| NtADF1 | Pollen tube growth | Actin depolymerization | Nt | Chen et al. (2002, 2003) |
| SCAR1-4 | Pavement cell growth, trichome growth, stomata development and asymmetric division | Actin branching | At, Zm | Uhrig et al. (2007); Basu et al. (2008); Facette et al. (2015) |
| SPK1 | Pavement cell and trichome growth | ROPGEF | At | Basu et al. (2008) |
| SRA1 | Pavement cell and trichome growth | Actin branching | At | Uhrig et al. (2007); Basu et al. (2008) |
| ICR1 | Vesicle trafficking, cell polarity | MT organization (putative) | At | Lavy et al. (2007); Hazak et al., (2010, 2014) |
| ICR2 | Unknown | MT organization (putative) | At | Lavy et al. (2007) |
| MIDD1 | Secondary cell wall deposition in metaxylem cells | Localized MT depolymerization through AtKinesin-13A | At | Mucha et al. (2010); Oda et al. (2010); Oda and Fukuda (2012) |
| HvRBK1 | Basal resistance to pathogenic fungi | MT stability | Hv | Huesmann et al. (2012) |
| Non-cytoskeleton-associated ROP effectors | ||||
| RIC7 | Stomata movement | Vesicle trafficking | At | Hong et al. (2016) |
| HvRIC171 | Pathogen response | Fungal penetration susceptibility | Hv | Schultheiss et al. (2008) |
| RBK1 | Pathogen response | Receptor-like cytoplasmic kinase | At | Molendijk et al. (2008) |
| RBK2 | Pathogen response | Receptor-like cytoplasmic kinase | At | Molendijk et al. (2008) |
| NCRK | Pathogen response | Receptor-like cytoplasmic kinase | At | Molendijk et al. (2008) |
| AtRLCK VI_A3 | Pathogen response | Receptor-like cytoplasmic kinase | At | Reiner et al. (2015) |
| ABI1 | ABA signaling | PP2C phosphatases | At | Li et al. (2012a) |
| ABI2 | ABA signaling | PP2C phosphatases | At | Yu et al. (2012) |
| CPL1 | Transcriptional regulation | Pol II CTD phosphatase | At | Zhang et al. (2016) |
| TOR | Auxin response | Translation control | At | Schepetilnikov et al. (2017) |
| RBOHB/D | Pathogen response | NADPH oxidase | Os | Wong et al. (2007); Kosami et al. (2014); Nagano et al. (2016) |
| ROPGAPs | ||||
| MAGAP | Response to pathogenic fungi | Polar organization of cortical MT | Hv | Hoefle et al. (2011) |
| PHGAP1 | Cell division plane selection | PH domain ROPGAP: positioning of the cortical division zone regulator kinesin-12 POK1 | At | Stöckle et al. (2016) |
| PHGAP2 | Cell division plane selection | PH domain ROPGAP: positioning of the cortical division zone regulator kinesin-12 POK1 | At | Stöckle et al. (2016) |
| ROPGAP3 | Secondary wall pits in metaxylem | Local MT destabilization | At | Oda and Fukuda (2012) |
| RhoGAP1 | Pollen tube polar growth | Regulation of ROP activity | Nt | Klahre and Kost (2006); Sun et al. (2015) |
| REN1 | Pollen tube polar growth | Regulation of ROP activity | At | Hwang et al. (2008) |
| ROPGAP1 | Pollen tube polar growth | Actin organization | At | Fu et al. (2001); Hwang et al. (2010) |
| ROPGAP4 | Response to oxygen deprivation | Regulation of ROS levels | At | Baxter-Burrell et al. (2002) |
| ROPGEFs | ||||
| SPK1 | Pavement cells and trichome growth | Dock-like ROPGEF | At | Basu et al. (2008) |
| ROPGEFs1/8/9/12/14 | Pollen tube growth | Mediate PRK6 signaling and AtPRK2 signaling | At | Zhang and McCormick (2007); Chang et al. (2013) |
| ROPGEF4 | Secondary wall pits in metaxylem, ABA responses, cell wall sensing | MT destabilization | At | Li and Liu (2012); Oda and Fukuda (2012); Huang et al. (2013) |
| ROPGEF7 | Regulation of embryo and root development | Regulation of PLETHORA2 expression | At | Chen et al. (2011) |
| ROPGEF1 | Root hair and embryo development, ABA responses | Mediate FER signaling | At | Duan et al. (2010); Li and Liu (2012); Liu et al. (2017) |
| ROPGEF10 | ABA responses | Mediate FER signaling | At | Huang et al. (2013) |
| OsSWAP70 | Responses to pathogens | Putative Dbl-like ROPGEF | Os | Yamaguchi et al. (2012) |
| RhoGDIs | ||||
| AtRhoGDI1/SCN1 | Regulation of ROP2 and RBOHC distribution at root hair initiation sites, pollen tube growth | At | Carol et al. (2005); Hwang et al. (2010); Feng et al. (2016) | |
| AtRhoGDI2a | Pollen tube growth | At | Hwang et al. (2010); Feng et al. (2016) | |
| AtRhoGDI2b | Pollen tube growth | At | Hwang et al. (2010); Feng et al. (2016) | |
| RLKs | ||||
| FERONIA | Root hair growth, pollen tube rupture, defense responses | Cell wall sensor and a signaling scaffold, signals through ROPGEFs | At | Duan et al. (2010, 2014); Yu et al. (2012); Huang et al. (2013); Stegmann et al. (2017) |
| THESEUS | Defense responses | Cell wall sensor signaling through ROPGEFs | At | Höfte (2015); Qu et al. (2017a) |
| PRK6 | Pollen tube growth | LURE receptor signaling through ROPGEFs | At | Takeuchi and Higashiyama (2016) |
| AtPRK2 | Pollen tube growth | Plasma membrane LRK that signals through ROPGEFs | At | Chang et al. (2013) |
| SlPRK1 | Pollen tube germination and growth | Plasma membrane LRK signaling through ROGEFS | Sl | Kaothien et al. (2005) |
| SlPRK2 | Pollen tube germination and growth | Plasma membrane LRK signaling through ROGEFS | Sl | Kaothien et al. (2005) |
| OsCEBiP/OsCERK1 | Pathogen response | Plasma membrane LRK that senses chitin and signals through ROPGEFs | Os | Akamatsu et al. (2013) |
| MtNFP | Symbiotic interaction with rhizobium | Interacts with GTP-MtROP10 | Mt | Lei et al. (2015) |
| LjNFR5 | Symbiotic interaction with rhizobium | Interacts with GTP-LjROP6 | Lj |
Ke et al. (2012) |