Fig. 6: IDRs are critical for AtMCM10 function in DNA damage response.

a The subcellular localizations of truncated AtMCM10s upon NaCl treatment in the root tip cells of Arabidopsis. The pro35S:GFP:MCM10/Atmcm10-1, pro35S:GFP:MCM10-ΔIDR1/Atmcm10-1, pro35S:GFP:MCM10-ΔIDR2/Atmcm10-1, and pro35S:GFP:MCM10-ΔIDR1/2/Atmcm10-1 transgenic lines were treatment with or without 150 mM NaCl for 24 h. Bars = 5 μm. b Statistical analyses of AtMCM10 and variants puncta upon NaCl treatment in (a). Data were presented as median with interquartile range, whiskers extending to 1.5× the interquartile range, and individual data points plotted as dots (n = 25 nuclei). *** indicate significant differences by one-way ANOVA followed determined by Tukey’s HSD test (p ≤ 0.01). c Representative phenotypes of pro35S:GFP:MCM10/Atmcm10-1, pro35S:GFP:MCM10-ΔIDR1/Atmcm10-1 and pro35S:GFP:MCM10-ΔIDR2/Atmcm10-1 upon Zeb or NaCl treatment. Seeds were germinated on 1/2 MS medium with or without 5 mg/L Zeb or 100 mM NaCl, and were grown for 10 d. Bar = 1 cm. d Statistical analyses of primary root lengths of seedlings presented in (c). Data were presented as mean ± SD (n = 16 seedlings), and lowercase letters indicate significant differences by one-way ANOVA followed determined by Tukey’s HSD test (p ≤ 0.05). e A proposed working model of AtMCM10 in DNA damage response. During SDSA-mediated intermolecular HR repair, Zeb, MMC or high salinity stress induces DSBs that primarily activate ATM kinase, initiating a repair cascade through phosphorylation of downstream effectors. The process involves three coordinated mechanistic steps: (1) end resection generates ssDNA overhangs at DSB sites, (2) these ssDNA intermediates nucleate AtMCM10 LLPS, and (3) the resulting biomolecular condensates could create a specialized microenvironment that facilitates efficient strand annealing following RAD51-mediated invasion. Created in BioRender. Yang, Y. (2025) https://BioRender.com/ex5o3v5.