北京林业大学学报2026，Vol.48Issue(6)：106-115,10.DOI:10.12171/j.1000-1522.20260249
异源过表达桉树EgrNAC13提高拟南芥低温和高盐抗性
Overexpression of Eucalyptus EgrNAC13 in Arabidopsis thaliana enhances tolerance to cold and salinity
摘要
Abstract
[Objective]This study aimed to investigate the function and potential regulatory mechanisms of the EgrNAC13,a stress responsive NAC(SNAC)gene,in the abiotic stress responses of Eucalyptus grandis,particularly under cold and salinity conditions.The findings are expected to provide valuable genetic resources and a theoretical foundation for improving abiotic stress tolerance in Eucalyptus through molecular marker-assisted breeding.[Method]Multiple sequence alignment and phylogenetic analyses of EgrNAC13 and its homologs from different plant species were conducted to characterize its protein structure and evolutionary relationships.A EgrNAC13 overexpression vector,driven by 35S,was constructed and transformed into Arabidopsis thaliana.Based on transgene expression analysis of EgrNAC13 in transgenic lines,two overexpression lines were selected for cold and salt stress treatments,and their stress responsive phenotypes were evaluated.In addition,the potential regulatory mechanisms of EgrNAC13 were preliminarily explored by measuring superoxide dismutase(SOD)and peroxidase(POD)activities,as well as by analyzing the expression patterns of key cold responsive genes including AtCBF1,AtCBF2 and AtRD29A by qRT-PCR at different time points during cold treatment.[Result]Phylogenetic analysis revealed clear evolutionary divergence of EgrNAC13 between monocotyledonous and dicotyledonous plants,as well as between woody and herbaceous species.The protein exhibited high amino acid sequence conservation among Myrtaceae species.The NAM domain sequences of EgrNAC13 homologous proteins from different species are highly similar,indicating functional conservation among these proteins.Transgenic Arabidopsis lines overexpressing EgrNAC13 displayed significantly enhanced tolerance to both cold and salinity stress.Following exposure to-6℃,the survival rates of EgrNAC13-OE1 and EgrNAC13-OE5 reached 81.6%and 85.1%,respectively,which were significantly higher than that of the wild type(32.3%).Under both cold and salt stress conditions,SOD activity was significantly higher in the overexpression lines than in the wild type.POD activity,however,was significantly elevated only under salt stress.This indicate that EgrNAC13 can improve plant stress tolerance to low temperature and high salt stress by enhancing the scavenging capacity of reactive oxygen species.During cold treatment,the expression levels of AtCBF1 and AtCBF2 in the overexpression lines were significantly upregulated at 3 h and 12 h of 4℃treatment,respectively.In contrast,AtRD29A expression was consistently and significantly induced in the overexpression lines under both normal and cold treatment conditions.Therefore,EgrNAC13 mediates plant responses to low temperature stress mainly by regulating the CBF pathway.[Conclusion]EgrNAC13,a highly conserved NAC transcription factor in Myrtaceae species,significantly enhances cold and salt tolerance in transgenic Arabidopsis by increasing antioxidant enzyme activities,particularly SOD and POD.Moreover,EgrNAC13 may mediate stress responses mainly through CBF-dependent pathways.These findings provide a foundation for further elucidation of the stress resistance functions and molecular mechanisms of EgrNAC13 in Eucalyptus and offer promising genetic resources for stress tolerant breeding programs.关键词
巨桉/NAC转录因子/分子功能/低温/高盐/抗逆育种/基因表达Key words
Eucalyptus grandis/NAC transcription factor/molecular function/low temperature/salt stress/stress-resistant breeding/gene expression分类
农业科技引用本文复制引用
曹真,倪晓祥,程龙军..异源过表达桉树EgrNAC13提高拟南芥低温和高盐抗性[J].北京林业大学学报,2026,48(6):106-115,10.基金项目
浙江省农业(林木)新品种选育重大科技专项(2021C02070-6). （林木）
