广西植物2026，Vol.46Issue(5)：862-875,14.DOI:10.11931/guihaia.gxzw202509017
不同氮素形态配比对马大相思幼苗生长及转录组响应的分析
Transcriptome response analsis of Acacia mangium × A.auriculiformis seedlings and growth to different nitrogen form ratios
摘要
Abstract
In order to investigate the regulatory mechanisms underlying asexual growth and gene expression in Acacia mangium × A.auriculiformis clone AMA308 in response to different nitrogen form ratios,asexual tissue-cultured seedlings were used as materials,five different NH4+/NO3-ratios(0∶10,3∶7,5∶5,7∶3,10∶0)were applied to Hoagland nutrient solution.After 30 days of hydroponic culture,transcriptome sequencing was performed on the Illumina platform,and differentially expressed genes(DEGs)were screened using edgeR with the criteria of|log2 FC|＞1 and FDR＜0.05.KEGG enrichment analysis and quantitative real-time PCR(RT-qPCR)validation were conducted to verify the sequencing results.The results were as follows:(1)The number of DEGs in both root and leaf tissues increased significantly with the elevated proportion of nitrate in the nutrient solution,and root DEGs were consistently more abundant than leaf DEGs.(2)Root DEGs were significantly enriched in ribosome-related pathways(P＜0.001),whereas leaf DEGs were predominantly enriched in metabolic pathways,secondary metabolite biosynthesis,and plant hormone signal transduction pathways.(3)A total of 88 DEGs were identified in nitrogen metabolism pathways,covering 11 key functional nodes including nitrate transport,nitrate reduction,and glutamine synthesis.Among these DEGs,18 were down-regulated and 13 were up-regulated in roots with increasing NO3-ratio;in leaves,13 were down-regulated and 9 were up-regulated.(4)Three genes belonging to the AMT1 subfamily were detected,which were expressed in both roots and leaves but showed significantly higher expression levels in roots.Two of these genes were ammonium-inducible and exhibited up-regulated expression with increasing NO3-ratio,while the expression of AMT1.1 was unaffected by external ammonium concentration and displayed distinct tissue-specific expression patterns between roots and leaves.(5)RT-qPCR validation demonstrated that the correlation coefficients between the expression levels of the four genes and the transcriptome data were ≥0.79(P＜0.05)with the transcriptome sequencing data,confirming the high reliability of the RNA-Seq results.Collectively,this study demonstrates that Acacia mangium × A.auriculiformis modulates root and leaf responses to variable nitrogen forms via distinct molecular mechanisms.Ribosomal pathway enrichment in roots enhances protein synthesis capacity to facilitate efficient nitrogen uptake and assimilation,while enrichment of metabolic pathways in leaves optimizes nitrogen allocation to photosynthetic products and secondary metabolites,thereby supporting both photosynthetic performance and stress adaptation.This research elucidates the molecular basis of coordinated root-leaf responses to nitrogen forms for Acacia mangium × A.auriculiformis and provides theoretical support and candidate genes for precise nitrogen application during its seedling stage.关键词
马大相思/氮素形态/转录组测序/差异表达基因/铵转运蛋白Key words
Acacia mangium × A.auriculiformis/nitrogen form/transcriptome sequencing/differentially expressed genes(DEGs)/ammonium transporter分类
农业科技引用本文复制引用
王力涵,王旭阳,徐放,白青松,廖焕琴,张卫华..不同氮素形态配比对马大相思幼苗生长及转录组响应的分析[J].广西植物,2026,46(5):862-875,14.基金项目
国家自然科学基金(32271918). （32271918）
