Faculty of Biosciences, Institute of Biosciences and Technology, Shri Ramswaroop Memorial University, Lucknow Deva Road, Barabanki, Uttar Pradesh, 225003, India.
Banaras Hindu University, Varanasi, 221005, India.
J Plant Res. 2022 Nov;135(6):823-852. doi: 10.1007/s10265-022-01408-6. Epub 2022 Sep 6.
Plant glutathione S-transferases are an ancient protein superfamily having antioxidant activity. These proteins are primarily involved in diverse plant functions such as plant growth and development, secondary metabolism, signaling pathways and defense against biotic and abiotic stresses. The current study aimed to comprehensively identify and characterize the GST gene family in the medicinally important crop Papaver somniferum. A total of 93 GST proteins were identified belonging to eight GST classes and found to be majorly localized in the cytoplasm. All GST genes were found on eleven opium chromosomes. Gene duplication analysis showed segmental duplication as a key factor for opium GST gene family expansion under strong purifying selection. Phylogenetic analysis with gymnosperm, angiosperm and bryophyte revealed the evolution of GSTs earlier than their division into separate groups and also prior to the divergence of monocot and dicot. The secondary structure prediction showed the dominance of α-helices indicative of PsomGSTs as structurally stable and elastic proteins. Gene architecture showed the conservation of number of exons across the classes. MEME analysis revealed only a few class specific and many across class conserved motifs. Ser was found to be the active site residue of tau, phi, theta and zeta class and Cys was catalytic residue of DHAR, lambda and GHR class. Promoter analyses identified many cis-acting regulatory elements related to hormonal, cellular, stress and light response functions. Ser was the key phosphorylation site. Only three glycosylation sites were found across the 93 PsomGSTs. 3D structure prediction was also performed and was validated. Interactome analyses revealed the correlation of PsomGSTs with glutathione metabolizing proteins. Gene enrichment analysis and KEGG pathway analyzed the involvement of PsomGSTs in three major pathways i.e. glutathione metabolism, tyrosine metabolism and ascorbate metabolism. The outcome revealed high model quality of PsomGSTs. The results of the current study will be of potential significance to understand the functional and structural importance of the GST gene family in opium, a medicinally important crop.
植物谷胱甘肽 S-转移酶是具有抗氧化活性的古老蛋白质超家族。这些蛋白质主要参与植物的多种功能，如植物生长和发育、次生代谢、信号通路以及对生物和非生物胁迫的防御。本研究旨在全面鉴定和描述药用作物罂粟中 GST 基因家族。共鉴定出 93 种 GST 蛋白，属于 8 种 GST 类，主要定位于细胞质中。所有 GST 基因都位于鸦片的 11 条染色体上。基因复制分析表明，片段复制是鸦片 GST 基因家族在强净化选择下扩张的关键因素。与裸子植物、被子植物和苔藓植物的系统发育分析表明，GSTs 的进化早于它们分为不同的组，也早于单子叶植物和双子叶植物的分化。二级结构预测显示α-螺旋占主导地位，表明 PsomGSTs 是结构稳定且有弹性的蛋白质。基因结构显示，各类型的外显子数量保持一致。MEME 分析显示，只有少数特定类别和许多跨类别保守基序。丝氨酸被确定为 tau、phi、theta 和 zeta 类的活性位点残基，半胱氨酸是 DHAR、lambda 和 GHR 类的催化残基。启动子分析确定了许多与激素、细胞、应激和光反应功能相关的顺式作用调节元件。丝氨酸是关键的磷酸化位点。在 93 个 PsomGSTs 中只发现了三个糖基化位点。还进行了 3D 结构预测和验证。互作分析显示 PsomGSTs 与谷胱甘肽代谢蛋白的相关性。基因富集分析和 KEGG 途径分析表明，PsomGSTs 参与了三个主要途径，即谷胱甘肽代谢、酪氨酸代谢和抗坏血酸代谢。结果显示，PsomGSTs 的模型质量很高。本研究的结果对于理解 GST 基因家族在药用作物鸦片中的功能和结构重要性具有潜在意义。
