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

Abstract

ATR, a DNA damage signaling kinase, is required for cell cycle checkpoint regulation and detecting DNA damage caused by genotoxic factors including Al3+ ions. We analyzed the function of the HvATR gene in response to chemical clastogen-maleic acid hydrazide (MH). For this purpose, the Al-tolerant barley TILLING mutant hvatr.g was used. We described the e ects of MH on the nuclear genome of hvatr.g mutant and its WT parent cv. “Sebastian”, showing that the genotoxic e ect measured by TUNEL test and frequency of cells with micronuclei was much stronger in hvatr.g than in WT. MH caused a significant decrease in the mitotic activity of root cells in both genotypes, however this e ect was significantly stronger in “Sebastian”. The impact of MH on the roots cell cycle, analyzed using flow cytometry, showed no di erences between the mutant and WT.