摘要
植物甘氨酸甜菜碱(glycine betaine,GB)普遍存在于植物、动物、细菌、藻类中,可在细胞质中累积达到一定水平以后调节渗透压,维持细胞的水分平衡,对于植物的渗透胁迫具有重要的作用。胆碱单加氧酶(choline monooxygenase,CMO)是植物GB生物合成途径的限速酶。本研究对168个基因组进行分析,其中131个基因组中含CMO同源基因,鉴定得到169个CMO成员。通过基因对选择压分析,结果表明该基因主要受纯化选择,只有7个基因对受到正向选择。另外,CMO基因家族被划分为6个亚家族,除F亚家族外,5个亚家族中均检测到正选择位点。Ring hydroxyl A结构域和Rieske结构域的选择压分析结果表明,2个结构域的dN/dS值呈极显著正相关,发生了协同进化。通过qRT-PCR分析显示玉米CMO基因在MgSO_(4)胁迫下表达整体表现为上调。本研究结果从多方面探讨了CMO基因的进化与表达情况,以期为后续深入利用该基因进行作物抗逆育种提供了理论依据。
Glycine betaine(GB)is a compatible solute widely found in plants,animals,bacteria,and algae,where it plays a key role in regulating osmotic pressure and maintaining cellular water balance upon accumulation in the cytoplasm.As such,GB is crucial for plant responses to osmotic stress.Choline monooxygenase(CMO)is a rate-limiting enzyme in the biosynthetic pathway of GB in plants.Among 168 genomes analyzed in this study,131 were found to contain homologous CMO genes,with a total of 169 CMO members identified.Selective pressure analysis revealed that most gene pairs have undergone purifying selection,while only seven gene pairs exhibited signs of positive selection.Phylogenetic analysis classified the CMO gene family into six subfamilies,with positive selection sites detected in five subfamilies except subfamily F.Further analysis of the Rieske domain and Ring-hydroxyl A domain showed a significant positive correlation between their dN/dS values,suggesting co-evolution.qRT-PCR analysis demonstrated that the expression of CMO genes in maize was upregulated under MgSO_(4)-induced stress.This study provides a comprehensive analysis of the evolution and expression of the CMO gene family,offering a theoretical foundation for the future application of CMO genes in improving crop tolerance to abiotic stress.
作者
王婷
段武丽
王蕊
刘海岚
Wang Ting;Duan Wu-Li;Wang Rui;Liu Hai-Lan(Maize Research Institute,Sichuan Agricultural University,Chengdu 611130,Sichuan,China)
出处
《作物学报》
北大核心
2026年第1期44-55,共12页
Acta Agronomica Sinica
基金
国家自然科学基金项目(32271984)资助。
关键词
植物甘氨酸甜菜碱
胆碱单加氧酶基因
选择压
纯化选择
玉米
plant glycine betaine
choline monooxygenase gene
selection pressure
purifying selection
maize
