Phenotype of knockout line atstar1. A, mRNA expression of AtSTAR1 in the wild type (WT) and atstar1 knockout line. RT-PCR analysis was performed to detect the mRNA expression of AtSTAR1 (35 cycles) and the internal control AtUBQ10 (25 cycles). B, Al sensitivity in the wild type and the knockout line. Seedlings were grown in a nutrient solution containing 0 or 2 μm Al at pH 5.0 for 7 d. C, Complementation test of the atstar1 knockout line. The wild type and atstar1 transformed with empty vector (VC) and AtSTAR1 (two lines), respectively, were grown in a nutrient solution containing 0 or 2 μm Al at pH 5.0 for 7 d. D, Flowering time of atstar1, als3, and the wild type. Plants were grown in a nutrient solution for 35 d.