RESULTS: During the course of genetic mapping studies aimed at understanding the mechanisms underlying natural variation in ethanol-induced cross protection against H2O2, we found that a key H2O2 scavenging enzyme, cytosolic catalase T (Ctt1p), was absolutely essential for cross protection in a wild oak strain. This suggested the absence of other compensatory mechanisms for acquiring H2O2 resistance in that strain background under those conditions. In this study, we found surprising heterogeneity across diverse yeast strains in whether CTT1 function was fully necessary for acquired H2O2 resistance. Some strains exhibited partial dispensability of CTT1 when ethanol and/or salt were used as mild stressors, suggesting that compensatory peroxidases may play a role in acquired stress resistance in certain genetic backgrounds. We leveraged global transcriptional responses to ethanol and salt stresses in strains with different levels of CTT1 dispensability, allowing us to identify possible regulators of these alternative peroxidases and acquired stress resistance in general.
CONCLUSIONS: Ultimately, this study highlights how superficially similar traits can have different underlying molecular foundations and provides a framework for understanding the diversity and regulation of stress defense mechanisms.
结果:在旨在了解乙醇诱导的H2O2交叉保护天然变异的机制的遗传作图研究过程中,我们发现了一种关键的H2O2清除酶,胞质过氧化氢酶T(Ctt1p),对于野生橡树株的交叉保护是绝对必要的。这表明在那些条件下,在该菌株背景中不存在用于获得H2O2抗性的其他补偿机制。在这项研究中,我们发现,在不同的酵母菌株中,CTT1功能是否是获得性H2O2抗性所必需的,存在令人惊讶的异质性。当乙醇和/或盐用作轻度应激源时,一些菌株表现出CTT1的部分可分配性,这表明在某些遗传背景下,补偿性过氧化物酶可能在获得性胁迫抗性中起作用。我们利用了具有不同CTT1可分配性水平的菌株对乙醇和盐胁迫的全局转录反应,使我们能够确定这些替代过氧化物酶的可能调节因子和获得的一般应激抗性。
结论:最终,这项研究强调了表面相似的性状如何具有不同的潜在分子基础,并为理解压力防御机制的多样性和调节提供了一个框架。