Arabidopsis SNI1 and RAD51D regulate both gene transcription and DNA recombination during the defense response

Abstract

), the authors note that in Fig. 1D Right, the x-axis labels were transposed. The corrected figure and its legend appear below. MECs were isolated from BALB/c mice, cultured for 3 days, irradiated, and analyzed for %SP by Hoechst 33342 staining and flow cytometry. Radiation selectively increased the progenitor fraction (%SP) (P ϭ 0.015 for 2 Gy, 0.008 for 4 Gy, and 0.05 for 6 Gy by the two-tailed t test). (B) MCF-7 cells were analyzed for %SP by Hoechst 33342 staining and flow cytometry. Radiation selectively increased the progenitor fraction (%SP) (P ϭ 0.05 for 0 Gy vs. 4 Gy by the two-tailed t test). (C) Cells were analyzed for Sca1 in the SP 24 h after irradiation. Radiation selectively increased the Sca1 ϩ (progenitor) fraction within the SP by killing the more sensitive Sca1 Ϫ (nonprogenitor) cells (P Ͻ 0.05 for Sca1 ϩ to Sca1 Ϫ at 0 Gy vs. 2-8 Gy). The differences in effects of doses of 2 Gy vs. higher doses were not significant. (D) Anesthetized BALB/c mice were immobilized supine, and mammary glands (entire ventral surface) were irradiated. MECs were isolated 48 h after irradiation and analyzed immediately for Sca1 by flow cytometry. Radiation selectively increased the Sca1 ϩ (progenitor) fraction and decreased the Sca1 Ϫ (nonprogenitor)

CRT1 is a nuclear-translocated MORC endonuclease that participates in multiple levels of plant immunity

“…8; 43% of WT versus 72% of dKO at 80 mM mitomycin C), indicating enhanced mitomycin C tolerance. By contrast, the suppressor of sni1 1 (ssn1) mutant, which carries a mutation in RAD51, a key factor in R/R, was hypersensitive to mitomycin C, as previously reported 30 . This result indicate that the CRT1 family is involved in DNA repair, perhaps as a negative regulator.…”

“…To assess whether CRT1/CRH1 are involved in DNA R/R, the dKO was monitored for altered resistance to the DNA-damaging agent, mitomycin C. Consistent with earlier studies, WT plants grown in the presence of mitomycin C exhibited reduced ability to form true leaves 30 . True leaf formation in dKO plants was suppressed to a lesser extent than in WT ( Fig.…”

“…For instance, SNI1 (Suppressor of NPR1, Inducible) was proposed to mediate defence gene expression via histone modification 44 . Interestingly, several ssn mutants encode mutated versions of well-established DNA R/R proteins, such as RAD51D (SSN1), SWI/SNF (SSN2) and BRCA2A (SSN3) 30,45,46 . Mutations in any of the three SSN genes results in altered induction of pathogen-responsive genes and increased susceptibility/sensitivity to pathogens and DNAdamaging agents.…”

Negative Regulation of Systemic Acquired Resistance by Replication Factor C Subunit3 in Arabidopsis

“…When a genetic screen was conducted to search for genetic suppressors of sni1, it was found that a loss-of-function mutation in RAD51D suppresses sni1 phenotypes completely. Both SNI1 and RAD51D were found to play roles in PR gene transcription and DNA recombination (Durrant et al, 2007). To identify additional negative regulators of PR gene expression and SAR, we screened for mutants that are hypersensitive to SA induction and found one with similar phenotypes to sni1.…”

Análisis genético de la percepción del ácido salicílico en Arabidopsis thaliana. Caracterización de NRB4

“…Among the genes found to be relevant in the SA response, there are several DNA repair (Song et al 2011) and chromatin remodeling genes. Since these proteins play a role in forming complex relevant for transcription (Durrant et al 2007), perhaps NRB4 is required for the proper function of these proteins.…”