Figure 2.

Tolerance enhancement to osmotic, salt, heat, and cold stresses in yeast by overexpression of DBF2 or At-DBF2. DY yeast cells were grown for 16 hr in YPD (rich medium), and cell density was adjusted to OD₆₀₀ at 2. Serial dilutions, 1:10, were made at each step. Ten microliters of each dilution was spotted on solid YPD medium (control) supplemented with 2 M sorbitol (osmotic stress), 1.2 M NaCl (salt stress), or 4 μl H₂O₂ as described (26) (oxidative stress) and incubated at 28°C or at 42°C (heat stress) or at 4°C (cold stress) for 3 days. (1), DY; (2), DY transformed with DBF2-containing pYX212 (pYX-YDBF2); (3), DY transformed with vector alone; and (4), DY transformed with the At-DBF2-contating pX212 (pYX-AtDBF2).