btn1Δ ist2Δ strains are sensitive to NaCl. Wild-type (B-11718), ist2Δ (B-14884), btn1Δ (B-13048), btn2Δ (B-14847), btn1Δ ist2Δ (B-14830), and btn1Δ btn2Δ (B-13049) strains were serially diluted. Wild type, ist2Δ, btn2Δ, and btn1Δ cells grew normally, whereas ist2Δ btn1Δ and btn1Δ btn2Δ strains exhibited sensitivity of growth. Note that strains with a deletion of RHB1 (rhb1Δ, btn1Δ rhb1Δ, and btn2Δ rhb1Δ strains) did not show a similar genetic interaction. Plates were incubated at 30°C for 2 days.