Phenotype assay of the sls1 mutant and map-based cloning of SLS1. A, Phenotype comparison between wild-type Arabidopsis (Col) and lks1-2 and sls1 mutants. The seeds were germinated on Murashige and Skoog (MS) medium for 4 d, after which the seedlings were transferred to MS or LK (100 μm K+) medium for 10 d. B, Map-based cloning of sls1. The SLS1 gene encodes AtKC1. In the AtKC1 gene structure depicted, the black boxes represent exons and the lines represent introns. The sites of the G1494A point mutation in sls1 and the transfer DNA insertion (SALK_140579) in atkc1 are shown. BAC, Bacterial artificial chromosome. C, Sequence alignment of Arabidopsis Shaker K+ channels using DNAMAN software. The point mutation (G322D) of sls1 is located in the S6 region of the Shaker K+ channel.