Functional characterization of the Glyoxalase-I (<i>PdGLX1</i>) gene family in date palm under abiotic stresses

Methylglyoxal (MG), a cytotoxic oxygenated short aldehyde, is a by-product of various metabolic reactions in plants, including glycolysis. The basal level of MG in plants is low, whereby it acts as an essential signaling molecule regulating multiple cellular processes. However, hyperaccumulation of MG under stress conditions is detrimental for plants as it inhibits multiple developmental processes, including seed germination, photosynthesis, and root growth. The evolutionarily conserved glyoxalase system is critical for MG detoxification, and it comprises of two-enzymes, the glyoxalase-I and glyoxalase-II. Here, we report the functional characterization of six putative glyoxalase-I genes from date palm (<i>Phoenix dactylifera</i> L.) (<i>PdGLX1</i>), by studying their gene expression under various environmental stress conditions and investigating their function in bacteria (<i>Escherichia coli</i>) and yeast (<i>Saccharomyces cerevisiae</i>) mutant cells. The putative <i>PdGLX1</i> genes were initially identified using computational methods and cloned using molecular tools. The <i>PdGLX1</i> gene expression analysis using quantitative PCR (qPCR) revealed differential expression under various stress conditions such as salinity, oxidative stress, and exogenous MG stress in a tissue-specific manner. Further, <i>in vivo</i> functional characterization indicated that overexpression of the putative <i>PdGLX1</i> genes in <i>E. coli</i> enhanced their growth and MG detoxification ability. The putative <i>PdGLX1</i> genes were also able to complement the loss-of-function MG hypersensitive GLO1 (YML004C) yeast mutants and promote growth by enhancing MG detoxification and reducing the accumulation of reactive oxygen species (ROS) under stress conditions as indicated by flow cytometry. These findings denote the potential importance of <i>PdGLX1</i> genes in MG detoxification under stress conditions in the date palm.

甲基乙二醛（Methylglyoxal, MG）是一类具有细胞毒性的含氧短链醛类化合物，亦是植物体内包括糖酵解在内的多种代谢反应的副产物。植物体内的基础MG水平较低，此时它可作为关键信号分子调控多种细胞进程。但在胁迫条件下，MG的过度积累会对植物产生毒害作用，抑制种子萌发、光合作用、根系生长等多种发育过程。在进化上保守的乙二醛酶系统（glyoxalase system）是MG解毒的核心途径，该系统由两种酶组成：乙二醛酶I（glyoxalase-I）与乙二醛酶II（glyoxalase-II）。本研究针对海枣（*Phoenix dactylifera* L.）中的6个推定乙二醛酶I基因（*PdGLX1*）开展功能表征研究，具体通过分析这些基因在多种环境胁迫条件下的表达模式，并探究其在大肠杆菌（*Escherichia coli*）与酿酒酵母（*Saccharomyces cerevisiae*）突变体细胞中的功能。研究人员首先通过计算生物学方法鉴定得到这些推定*PdGLX1*基因，并利用分子生物学工具完成克隆。通过定量PCR（quantitative PCR, qPCR）对*PdGLX1*基因的表达分析显示，其在盐胁迫、氧化胁迫以及外源MG胁迫等多种条件下呈现差异表达，且表达具有组织特异性。进一步的体内（in vivo）功能表征结果表明，在大肠杆菌中过表达推定*PdGLX1*基因可增强其生长能力与MG解毒能力。此外，这些推定*PdGLX1*基因还能够互补功能缺失型MG敏感酵母突变体GLO1（YML004C）的缺陷；通过流式细胞术分析可知，其可通过增强MG解毒能力、减少胁迫条件下活性氧（reactive oxygen species, ROS）的积累来促进酵母生长。上述研究结果表明，海枣*PdGLX1*基因在胁迫条件下的MG解毒过程中具有潜在的重要作用。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于海枣中Glyoxalase-I（PdGLX1）基因家族在非生物胁迫下的功能表征，通过计算方法和实验验证（如基因表达分析和体内功能测试）揭示了这些基因在甲基乙二醛解毒和胁迫响应中的关键作用。研究发现，PdGLX1基因在盐度、氧化胁迫等条件下能增强解毒能力并减少活性氧积累，为海枣的抗逆性研究提供了重要数据。