摘要
【目的】植物谷氨酸脱羧酶(GAD)在γ-氨基丁酸(GABA)的生物合成中起关键作用,参与植物生长发育及逆境响应过程,但番茄GAD基因家族成员的功能分化和具体的分子调控网络仍未被揭示。旨在系统解析番茄GAD基因的生物学功能,为其在分子机制研究及遗传改良中的应用提供理论依据。【方法】通过生物信息学手段对番茄GAD基因家族成员进行染色体定位、基因结构、亲缘关系及组织特异性表达等分析。【结果】从番茄基因组中鉴定到5个GAD基因,分别位于1、3、4、5和11号染色体上,均具有典型的内含子-外显子结构。其编码的番茄GAD蛋白均为不稳定蛋白,主要定位于细胞质,二级结构以α-螺旋和无规则卷曲为主,活性中心及关键功能域进化上高度保守。番茄GAD基因与水稻、拟南芥同源基因序列相似性较高,但关键功能域存在特异性氨基酸变异。在广西野生番茄‘G173’中,GAD基因在根、茎、叶中均未检测到表达,而在花和果实中表达存在显著差异,其中Solyc01G00002和Solyc04G001008在花中表达量较高,Solyc03G002270在花和果实中的表达量接近。【结论】番茄GAD基因在基因结构和蛋白性质上存在显著差异,包含多个保守功能结构域。番茄GAD与拟南芥、水稻等物种GAD基因的同源关系较近,且在根、茎、叶、果实等不同组织中均呈现特异性表达模式,表明该基因家族可能广泛参与番茄的生长发育过程。
【Objective】Plant glutamate decarboxylase(GAD)plays a pivotal role in the biosynthesis ofγ-aminobutyric acid(GABA),which is involved in plant growth,development,and stress responses.However,the functional divergence among members of the tomato GAD gene family and their specific molecular regulatory networks remain unclear.This study aims to systematically characterize the tomato GAD gene family,including its genomic distribution,structural features,and evolutionary relationships,providing a theoretical basis for its application in molecular mechanism research and genetic improvement.【Method】Conduct a comprehensive bioinformatics analysis on the members of the tomato GAD gene family,including chromosome localization,gene structure,physicochemical properties of proteins,phylogenetic relationships and tissue-specific expression analysis.【Result】The tomato genome contains five glutamate decarboxylase(GAD)genes localized to chromosomes 1,3,4,5,and 11,all featuring canonical intron-exon structures.The encoded GAD proteins are unstable and predominantly cytoplasmic-localized,withα-helices and random coils constituting their dominant secondary structures;their active sites and functional domains are evolutionarily conserved.While tomato GAD genes show high sequence similarity to orthologs in Oryza sativa and Arabidopsis thaliana,specific amino acid variations exist within critical functional domains.In the wild tomato accession‘G173’(Guangxi origin),GAD genes exhibited no detectable expression in roots,stems,or leaves but displayed significant tissue-specific expression differences in flowers and fruits.Solyc01g00002 and Solyc04g001008 showed relatively high expression,whereas Solyc03g002270 maintained comparable expression levels in both floral and fruit tissues.【Conclusion】Tomato GAD genes exhibit significant variations in gene structure and protein properties,while containing multiple conserved functional domains.Phylogenetic analysis revealed that tomato GADs share close homology with their orthologs in species such as A.thaliana and O.sativa.Furthermore,they display distinct tissue-specific expression patterns in roots,stems,leaves,and fruits,suggesting that this gene family may play extensive roles in the growth and development of tomato.
作者
安翠环
黄春贵
郭泽安
甘桂云
荆子桓
AN Cuihuan;HUANG Chungui;GUO Zean;GAN Guiyun;JING Zihuan(College of Agricultural Engineering,Guangxi Vocational University of Agriculture,Nanning 530007,China;College of Agriculture,Guangxi University,Nanning 530004,China;Vegetable Research Institute,Guangxi Academy of Agricultural Sciences,Nanning,530007,China)
出处
《广东农业科学》
2025年第6期41-51,共11页
Guangdong Agricultural Sciences
基金
中央引导地方发展项目(桂科ZY23055021)
广西科技重大专项(桂科AA23062048)
南宁市厅级项目(QMRC-2401,XTKJ2509)。
关键词
番茄
GAD基因家族
生物信息学分析
蛋白结构
组织特异性表达
启动子元件
Solanum lycopersicum
GAD gene family
bioinformatics analysis
protein structure
tissue-specific expression
promoter element
