Figure 2.

p102 from tobacco and wheat is a functional HSP101 that complements a thermotolerance defect in yeast. (A) SL304A, the hsp104 mutant containing pGAL1–NtHSP101 or pGAL1–TaHSP101, was grown to an early exponential stage in SGM (an OD of 0.06 or 1.8 × 10⁶ cells/ml) prior to assaying for thermotolerance. The expression vector, pYES2, was used as a negative control and pYS104, containing HSP104, was used as a positive control. The percentage of survival at 50°C was plotted as a function of the length of treatment. (B) SL304A(pGAL1–NtHSP101) was grown in galactose, glucose, or raffinose prior to assaying for thermotolerance. SL304A(pYES2) grown in galactose was included as a negative control. (C) Thermotolerance conferred by tobacco HSP101 in late-exponential yeast (an OD of 1.2 or 3.6 × 10⁷ cells/ml) was examined.