Figure 7. The cross-talk between thermal adaptation and cell wall stress resistance is not mediated via stress cross-protection.

(A) Stress cross-protection in C. albicans wild-type cells (NGY152: Table 1) was not observed for cells pre-treated with a heat stress and then subjected to cell wall stress, but was observed for cells exposed to a secondary oxidative stress. The data represent cell survival after exposure to a 30°C–42°C heat shock followed by a subsequent cell wall (CFW, CR), osmotic (NaCl) or peroxide (H₂O₂) stress (see Materials and Methods) and the data are expressed relative to unstressed cells (dark bars). Control cells (grey bars), were not exposed to the prior 30°C–42°C heat shock. (B) The reciprocal assay was performed, whereby C. albicans wild type cells were exposed to a prior stress (cell wall: CFW, CR; osmotic: NaCl; peroxide: H₂O₂) followed by a 30°C–42°C heat shock (dark bars). These data are expressed relative to unstressed cells. Control cells (grey bars) correspond to cells exposed only to the 30°C–42°C heat shock. (C) Wild type, hog1Δ (JC50) or cap1Δ cells (JC128: Table 1) were pre-treated with a 30°C–42°C heat shock, followed by a H₂O₂ stress (dark bars). Control cells (grey bars) were not exposed to the 30°C–42°C heat shock. The data represent the level of survival compared to unstressed cells. All data are the means from three independent assays: ** paired, two-tailed t-test, p<0.01.