Table 1.
The responses of the Arabidopsis mutants plants of DNA methylation components, histone readers, and chromatin remodelers to different pathogens.
| Arabidopsis mutants | Phenotype | DNA methylation | Defense response | References |
|---|---|---|---|---|
| RdDM pathway components | ||||
| drm1/drm2/cmt3 (ddc) | Resistant to Pst, Pst(AvrPphB) and Pst(hrc−) (bacterium) | hypo | SA-dependent response is enhanced | Dowen et al., 2012; Luna et al., 2012; Yu et al., 2013; Cambiagno et al., 2021 |
| Susceptible to Ab (necrotrophic fungus) | JA-dependent defense is suppressed | Luna et al., 2012 | ||
| Susceptible to At (bacterium) | ABA-dependent response is enhanced | Gohlke et al., 2013 | ||
| drm1/drm2 | Susceptible to Pc (necrotrophic fungus) | hypo | JA-dependent defense is suppressed | Lopez et al., 2011 |
| Resistant to Pst | Primed state of defenses response | Yu et al., 2013; Cambiagno et al., 2021 | ||
| nrpd1 (PolIV) | Resistant to Pst | hypo | SA-dependent response is enhanced | Dowen et al., 2012 |
| nrpe1 (PolV) | Resistant to Pst | hypo | SA-dependent response is enhanced | Lopez et al., 2011 |
| Resistant to Hpa (biotrophic oomycete) | SA-dependent response is enhanced | Lopez Sanchez et al., 2016 | ||
| Susceptible to Pc and Bc (fungus) | JA-dependent defense is suppressed | Lopez et al., 2011; Lopez Sanchez et al., 2016 | ||
| nrpd1/nrpe1 (PolIV/ PolV) | Resistant to Pst | hypo | SA-dependent response is enhanced | Lopez et al., 2011 |
| Susceptible to Pc | JA-dependent defense is suppressed | Lopez et al., 2011 | ||
| nrpd2 (shared by PolIV and PolV) | Resistant to Pst | hypo | SA-dependent response is enhanced | Lopez et al., 2011; Yu et al., 2013 |
| Susceptible to Pc and Bc | JA-dependent defense is suppressed | Lopez et al., 2011 | ||
| drd1 | Susceptible to Pc | hypo | JA-dependent defense is suppressed | Lopez et al., 2011 |
| Resistant to Pst | SA-dependent response is enhanced | Dowen et al., 2012 | ||
| Resistant to Hpa | SA-dependent response is enhanced | Lopez Sanchez et al., 2016 | ||
| ago4 | Susceptible to Pst | hypo | RDR2 and DCL3 independent susceptibility | Agorio and Vera, 2007 |
| Susceptible to At | ABA-dependent response is enhanced | Gohlke et al., 2013 | ||
| rdr2 | Resistant to Pst | hypo | SA-dependent response is enhanced | Dowen et al., 2012 |
| Susceptible to Pc | JA-dependent defense is suppressed | Lopez et al., 2011 | ||
| rdr6 | Susceptible to Pst(AvrRpt2) | – | Loss sRNAs contribute to RPS2-mediated ETI | Katiyar-Agarwal et al., 2006 |
| Resistant to Pst | – | Dowen et al., 2012 | ||
| Susceptible to Bc | Loss the transfer siRNAs targets pathogen genes | Cai et al., 2018 | ||
| dcl2/3/4 | Resistant to Pst | hypo | – | Dowen et al., 2012 |
| Susceptible to Bc | – | Loss the transfer siRNAs targets pathogen genes | Cai et al., 2018 | |
| DNA methylation (drm1/drm2/cmt3 (ddc) and drm1/drm2 see above) | ||||
| cmt3 | Resistant to Hpa | hypo | SA-dependent response is enhanced | Lopez Sanchez et al., 2016 |
| met1 | Resistant to Pst, Pst(AvrPphB) and Pst(hrc−) | hypo | SA-dependent response is enhanced | Dowen et al., 2012; Yu et al., 2013 |
| DNA demethylation | ||||
| ros1 | Susceptible to Pst | hyper | Methylation at the promoter of RMG1 and RLP43 | Yu et al., 2013; Halter et al., 2021 |
| Resistant to Pc | JA-dependent defense is enhanced | Lopez Sanchez et al., 2016 | ||
| ros1/dml2/dml3 (rdd) and rdd DME RNAi | Susceptible to Fo (hemibiotrophic vascular fungus) | hyper | Fo responses gene is suppressed by DNA methylation | Schumann et al., 2019 |
| Chromatin remodelers and epigenetic regulators | ||||
| edm2 | Susceptible to Hpa | – | Control expression of RPP7 | Eulgem et al., 2007 |
| Resistant to Pst | NLRs unsuppressed | Lai et al., 2020 | ||
| pie1(swr1) | Resistant to Pst | – | Constitutive SAR response | March-Diaz et al., 2008 |
| clsy1 | Progeny is not prime to against Hpa | – | Transgenerational SAR is impaired | Luna and Ton, 2012 |
| ddm1 | Resistant to Pst | hypo | SA-dependent response is enhanced | Stokes et al., 2002; Cambiagno et al., 2021 |
| syd-4 | Resistant to Pst | – | SNC1 expression is enhanced | Johnson et al., 2015 |
| swp73a | Resistant to Pst(AvrRpt2) and Pst(AvrRps4) | – | NLRs unsuppressed | Huang et al., 2021 |
Pathogens include bacterial pathogens Pseudomonas syringae pv. tomato DC3000 (Pst, secreted effectors AvrPphB, AvrRpt2, AvrRps4, and type III secretion system mutant hrc−) and Agrobacterium tumefaciens (At), biotrophic oomycete Hyaloperonospora arabidopsidis (Hpa), hemibiotrophic vascular fungus Fusarium oxysporum (Fo), fungus Botrytis cinerea (Bc), Magnaporthe oryzae (Mo), necrotrophic fungus Plectosphaerella cucumerina (Pc), and Alternaria brassicicola (Ab).