College of Life Sciences, Capital Normal University, Beijing 100048, China.
Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing University of Agriculture, Beijing 102206, China.
Int J Mol Sci. 2019 Nov 14;20(22):5723. doi: 10.3390/ijms20225723.
The moss is tolerant of highly saline environments. In plants, salinity stress may induce the production of toxic reactive carbonyl species (RCS) and oxidative damage. Aldo-keto reductases (AKRs) are a large group of NADP-dependent oxidoreductases involved in RCS detoxification. However, many members in this superfamily remain uncharacterized. In this study, we cloned and characterised a putative AKR1 from , named PpAKR1A. Notably, the transcription level of was induced by salt and methylglyoxal (MG) stress, and the recombinant PpAKR1A protein catalysed the reduction of toxic aldehydes. knockout mutants of () were sensitive to NaCl and MG treatment, as indicated by much lower concentrations of chlorophyll and much higher concentrations of MG and HO than those in WT plants. Meanwhile, plants exhibited decreases in the MG-reducing activity and reactive oxygen species-scavenging ability in response to salt stress, possibly due to decreases in the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). Our results indicate that PpAKR1A is an aldo-keto reductase that detoxifies MG and thus plays an important role in salt stress tolerance in .
该苔藓能够耐受高盐环境。在植物中，盐胁迫可能会诱导产生有毒的活性羰基物质（RCS）和氧化损伤。醛酮还原酶（AKR）是一组参与 RCS 解毒的 NADP 依赖性氧化还原酶。然而，这个超家族中的许多成员仍未被描述。在这项研究中，我们从 中克隆并鉴定了一个假定的 AKR1，命名为 PpAKR1A。值得注意的是， 的转录水平受到盐和甲基乙二醛（MG）胁迫的诱导，重组 PpAKR1A 蛋白催化有毒醛的还原。 的敲除突变体（ ）对 NaCl 和 MG 处理敏感，表现在比 WT 植物更低的叶绿素浓度和更高的 MG 和 HO 浓度。同时， 植物对盐胁迫的 MG 还原活性和活性氧清除能力下降，可能是由于超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）等抗氧化酶的活性降低所致。我们的结果表明，PpAKR1A 是一种醛酮还原酶，能够解毒 MG，因此在 对盐胁迫的耐受性中发挥重要作用。
