Al-Tolerant Barley Mutant Shows the ATR-Regulated DNA Damage Response to Maleic Acid Hydrazide.

ATR, a DNA damage signaling kinase, is required for cell cycle checkpoint regulation and detecting DNA damage caused by genotoxic factors including Al ions. We analyzed the function of the gene in response to chemical clastogen-maleic acid hydrazide (MH). For this purpose, the Al-tolerant barley TILLING mutant was used. We described the effects of MH on the nuclear genome of mutant and its WT parent cv. "Sebastian", showing that the genotoxic effect measured by TUNEL test and frequency of cells with micronuclei was much stronger in than in WT. MH caused a significant decrease in the mitotic activity of root cells in both genotypes, however this effect was significantly stronger in "Sebastian". The impact of MH on the roots cell cycle, analyzed using flow cytometry, showed no differences between the mutant and WT.