Abstract
Plants have evolved mechanisms to tolerate toxic levels of Al on acid soils, but the underlying resistance mechanisms remain to be elucidated. Previously, we have showed that OsSTAR1 was essential for Al tolerance in rice. Here, we characterized its orthologue gene AtSTAR1 in Arabidopsis. A knockout mutant of AtSTAR1 showed hypersensitive to Al, but not sensitive to other metals including Cd and La. Complementation test confirmed that AtSTAR1 was responsible for the Al-sensitive phenotype in the mutant. Different from OsSTAR1, which was mainly expressed in the roots, this gene was expressed in the roots as well as the aerial parts. The expression of this gene was relatively constitutive and did not respond to Al or other metals and low pH. AtSTAR1 was located at root tip region and stomata of young leaf. Furthermore, rice OsSTAR1 was able to rescue the Al-inhibited root elongation in atstar1 mutant.
