Halotolerant species are adapted to dealing continually with hyperosmotic environments, having evolved strategies that are uncommon in other organisms. The HOG pathway is the master system that regulates the cellular adaptation under these conditions; nevertheless, apart from the importance of Debaryomyces hansenii as an organism representative of the halotolerant class, its HOG1 pathway has been poorly studied, due to the difficulty of applying conventional recombinant DNA technology. Here we describe for the first time the phenotypic characterisation of a null HOG1 mutant of D. hansenii. Dhhog1Δ strain was found moderately resistant to 1 M NaCl and sensitive to higher concentrations. Under hyperosmotic shock, DhHog1 fully upregulated transcription of DhSTL1 and partially upregulated that of DhGPD1. High osmotic stress lead to long-term inner glycerol accumulation that was partially dependent on DhHog1. These observations indicated that the HOG pathway is required for survival under high external osmolarity but dispensable under low and mid-osmotic conditions. It was also found that DhHog1 can regulate response to alkali stress during hyperosmotic conditions and that it plays a role in oxidative and endoplasmic reticulum stress. Taken together, these results provide new insight into the contribution of this MAPK in halotolerance of this yeast.

耐盐物种已适应不断变化的高渗环境，其进化策略在其他生物中并不常见。HOG途径是在这些条件下调节细胞适应的主要系统。但是，除了汉逊德巴利酵母作为具有耐盐性的生物的代表的重要性外，由于难以应用常规的重组DNA技术，对其HOG1途径的研究还很少。在这里，我们描述了第一次空的表型特征HOG1的突变D.逊。Dhhog1Δ发现该菌株对1 M NaCl具有中等抵抗力，并且对较高浓度敏感。在高渗休克下，DhHog1完全上调了DhSTL1的转录，部分上调了DhGPD1的转录。高渗透压导致长期内部甘油蓄积，这部分取决于DhHog1。这些观察结果表明HOG途径对于在高外部渗透压下存活是必需的，但是在低和中等渗透压条件下是必需的。还发现DhHog1可以调节高渗条件下对碱胁迫的反应，并且它在氧化和内质网应激中起作用。综上所述，这些结果为该MAPK在该酵母的耐盐性中的贡献提供了新的见识。