Acid stress induces cross-protection for cadmium tolerance of multi-stress-tolerant Pichia kudriavzevii by regulating cadmium transport and antioxidant defense system
Acid stress induces cross-protection for cadmium tolerance of multi-stress-tolerant Pichia kudriavzevii by regulating cadmium transport and antioxidant defense system
复制标题
酸胁迫通过调节镉转运和抗氧化防御系统诱导耐多重胁迫毕赤酵母的镉耐受性交叉保护
DOI：
10.1016/j.jhazmat.2018.11.101
复制
发表时间：
2019-03-15
影响因子：
13.6
通讯作者：
Wang, Yueqi
中科院分区：
文献类型：
--
作者：
Li, Chunsheng;Xu, Ying;Wang, Yueqi
镉（Cd）的毒性是限制微生物去除Cd的主要因素。在多重胁迫交叉保护的基础上，酸胁迫显著提高了库氏毕赤酵母对Cd的耐受性。RNA-Seq结果表明，磷酸戊糖途径、柠檬酸循环（TCA循环）、糖酵解/糖异生、过氧化物酶体和谷胱甘肽代谢等基因的差异表达量在酸胁迫下均显著上调。通过上调与ATP合成相关的基因（GSTY 1、ALD 5、ADH 4、ADH 6、MDH 2、IDH 1、IDH 2和ATP 19）和与Cd转运相关的基因（GSTY 2、GTO 2、GLO 2和YOR 1）的表达，以及提高细胞内GSH水平和GST活性，降低了Cd对库氏毕赤酵母的毒性。YOR 1介导的Cd外排在细胞内Cd水平下降中起关键作用。酸胁迫明显提高了SOD、POD和CAT基因表达水平和活性，抑制了Cd诱导的活性氧爆发和蛋白质、膜脂的氧化损伤。此外，HSP 12的表达增强保护了库氏马桑免受Cd胁迫的伤害。这些结果为构建适合于水环境中Cd去除的健壮菌株提供了重要线索。
The toxicity of cadmium (Cd) is the major limitation to its removal using microorganisms. The Cd tolerance of Pichia kudriavzevii was obviously enhanced by acid stress based on multi-stress cross-protection. RNA-Seq showed that most differentially expressed genes (DEGs) in the Pentose phosphate pathway, Citrate cycle (TCA cycle), Glycolysis/Gluconeogenesis, Peroxisome and Glutathione metabolism were up-regulated by acid stress. The up-regulated expression of genes related to ATP synthesis (GOR1, ALD5, ADH4, ADH6, MDH2, IDH1, IDH2, and ATP19) and Cd transport (GSTY2, GTO2, GLO2, and YOR1), and the improvement of intracellular GSH level and GST activity, reduced the Cd toxicity towards P. kudriavzevii. Cd efflux by YOR1 played a key role in the decline of intracellular Cd level. Acid stress obviously improved the gene expression levels and activities of antioxidant enzymes (SOD, POD, and CAT), which inhibited the Cd-induced ROS outburst and oxidative damage of proteins and membrane lipids. In addition, the enhanced expression of HSP12 protected P. kudriavzevii from the damage of Cd stress. These results provide some important clues to reconstruct robust strains using for Cd removal in aquatic environments.