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Cun Z, Zhang JY, Hong J, Yang J, Gao LL, Hao B, Chen JW. Integrated metabolome and transcriptome analysis reveals the regulatory mechanism of low nitrogen-driven biosynthesis of saponins and flavonoids in Panax notoginseng. Gene 2024; 901:148163. [PMID: 38224922 DOI: 10.1016/j.gene.2024.148163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/30/2023] [Accepted: 01/11/2024] [Indexed: 01/17/2024]
Abstract
BACKGROUND Nitrogen (N) is an important macronutrient involved in the biosynthesis of primary and secondary metabolites in plants. However, the metabolic regulatory mechanism of low-N-induced triterpenoid saponin and flavonoid accumulation in rhizomatous medicinal Panax notoginseng (Burk.) F. H. Chen remains unclear. METHODS To explore the potential regulatory mechanism and metabolic basis controlling the response of P. notoginseng to N deficiency, the transcriptome and metabolome were analysed in the roots. RESULTS The N content was significantly reduced in roots of N0-treated P. notoginseng (0 kg·N·667 m-2). The C/N ratio was enhanced in the N-deficient P. notoginseng. N deficiency promotes the accumulation of amino acids (L-proline, L-leucine, L-isoleucine, L-norleucine, L-arginine, and L-citrulline) and sugar (arabinose, xylose, glucose, fructose, and mannose), thus providing precursor metabolites for the biosynthesis of flavonoids and triterpenoid saponins. Downregulation of key structural genes (PAL, PAL3, ACC1, CHS2, PPO, CHI3, F3H, DFR, and FGT), in particular with the key genes of F3H, involved in the flavonoid biosynthesis pathway possibly induced the decrease in flavonoid content with increased N supply. Notoginsenoside R1, ginsenoside Re, Rg1, Rd, F1, R1 + Rg1 + Rb1 and total triterpenoid saponins were enhanced in the N0 groups than in the N15 (15 kg·N·667 m-2) plants. Higher phosphoenolpyruvate (an intermediate of glycolyticwith pathway metabolism) and serine (an intermediate of photorespiration) levels induced by N deficiency possibly promote saponin biosynthesis through mevalonic acid (MVA) and methylerythritol (MEP) pathways. Genes (MVD2, HMGS, HMGR1, HMGR2, DXR, and HMGR1) encoding the primary enzymes HMGS, HMGR, DXR, and MVD in the MVA and MEP pathways were significantly upregulated in the N0-treated P. notoginseng. The saponin biosynthesis genes DDS, DDS, CYP716A52, CYP716A47, UGT74AE2, and FPS were upregulated in the N-deficient plants. Upregulation of genes involved in saponin biosynthesis promotes the accumulation of triterpenoid saponins in the N0-grown P. notoginseng. CONCLUSIONS N deficiency enhances primary metabolisms, such as amino acids and sugar accumulation, laying the foundation for the synthesis of flavonoids and triterpenoid saponins in P. notoginseng. F3H, DDS, FPS, HMGR, HMGS and UGT74AE2 can be considered as candidates for functional characterisation of the N-regulated accumulation of triterpenoid saponins and flavonoids in future.
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Affiliation(s)
- Zhu Cun
- College of Agronomy & Biotechnology, Yunnan Agricultural University, Kunming, 650201, China; Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, 650201, China; National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, 650201, China
| | - Jin-Yan Zhang
- College of Agronomy & Biotechnology, Yunnan Agricultural University, Kunming, 650201, China; Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, 650201, China; National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, 650201, China
| | - Jie Hong
- College of Agronomy & Biotechnology, Yunnan Agricultural University, Kunming, 650201, China; Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, 650201, China; National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, 650201, China
| | - Jing Yang
- College of Agronomy & Biotechnology, Yunnan Agricultural University, Kunming, 650201, China; Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, 650201, China; National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, 650201, China
| | - Li-Lin Gao
- College of Agronomy & Biotechnology, Yunnan Agricultural University, Kunming, 650201, China; Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, 650201, China; National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, 650201, China
| | - Bing Hao
- College of Agronomy & Biotechnology, Yunnan Agricultural University, Kunming, 650201, China; Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, 650201, China; National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, 650201, China.
| | - Jun-Wen Chen
- College of Agronomy & Biotechnology, Yunnan Agricultural University, Kunming, 650201, China; Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, 650201, China; National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, 650201, China.
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Zhou X, Xiang X, Zhang M, Cao D, Du C, Zhang L, Hu J. Combining GS-assisted GWAS and transcriptome analysis to mine candidate genes for nitrogen utilization efficiency in Populus cathayana. BMC PLANT BIOLOGY 2023; 23:182. [PMID: 37020197 PMCID: PMC10074878 DOI: 10.1186/s12870-023-04202-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 03/29/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND Forest trees such as poplar, shrub willow, et al. are essential natural resources for sustainable and renewable energy production, and their wood can reduce dependence on fossil fuels and reduce environmental pollution. However, the productivity of forest trees is often limited by the availability of nitrogen (N), improving nitrogen use efficiency (NUE) is an important way to address it. Currently, NUE genetic resources are scarce in forest tree research, and more genetic resources are urgently needed. RESULTS Here, we performed genome-wide association studies (GWAS) using the mixed linear model (MLM) to identify genetic loci regulating growth traits in Populus cathayana at two N levels, and attempted to enhance the signal strength of single nucleotide polymorphism (SNP) detection by performing genome selection (GS) assistance GWAS. The results of the two GWAS analyses identified 55 and 40 SNPs that were respectively associated with plant height (PH) and ground diameter (GD), and 92 and 69 candidate genes, including 30 overlapping genes. The prediction accuracy of the GS model (rrBLUP) for phenotype exceeds 0.9. Transcriptome analysis of 13 genotypes under two N levels showed that genes related to carbon and N metabolism, amino acid metabolism, energy metabolism, and signal transduction were differentially expressed in the xylem of P. cathayana under N treatment. Furthermore, we observed strong regional patterns in gene expression levels of P. cathayana, with significant differences between different regions. Among them, P. cathayana in Longquan region exhibited the highest response to N. Finally, through weighted gene co-expression network analysis (WGCNA), we identified a module closely related to the N metabolic process and eight hub genes. CONCLUSIONS Integrating the GWAS, RNA-seq and WGCNA data, we ultimately identified four key regulatory genes (PtrNAC123, PtrNAC025, Potri.002G233100, and Potri.006G236200) involved in the wood formation process, and they may affect P. cathayana growth and wood formation by regulating nitrogen metabolism. This study will provide strong evidence for N regulation mechanisms, and reliable genetic resources for growth and NUE genetic improvement in poplar.
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Affiliation(s)
- Xinglu Zhou
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Xiaodong Xiang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Min Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Demei Cao
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Changjian Du
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Lei Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China.
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.
| | - Jianjun Hu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China.
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.
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Liu C, Duan N, Chen X, Li X, Zhao N, Cao W, Li H, Liu B, Tan F, Zhao X, Li Q. Transcriptome Profiling and Chlorophyll Metabolic Pathway Analysis Reveal the Response of Nitraria tangutorum to Increased Nitrogen. PLANTS (BASEL, SWITZERLAND) 2023; 12:895. [PMID: 36840241 PMCID: PMC9962214 DOI: 10.3390/plants12040895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/04/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
To identify genes that respond to increased nitrogen and assess the involvement of the chlorophyll metabolic pathway and associated regulatory mechanisms in these responses, Nitraria tangutorum seedlings were subjected to four nitrogen concentrations (N0, N6, N36, and N60: 0, 6, 36, and 60 mmol·L-1 nitrogen, respectively). The N. tangutorum seedling leaf transcriptome was analyzed by high-throughput sequencing (Illumina HiSeq 4000), and 332,420 transcripts and 276,423 unigenes were identified. The numbers of differentially expressed genes (DEGs) were 4052 in N0 vs. N6, 6181 in N0 vs. N36, and 3937 in N0 vs. N60. Comparing N0 and N6, N0 and N36, and N0 and N60, we found 1101, 2222, and 1234 annotated DEGs in 113, 121, and 114 metabolic pathways, respectively, classified in the Kyoto Encyclopedia of Genes and Genomes database. Metabolic pathways with considerable accumulation were involved mainly in anthocyanin biosynthesis, carotenoid biosynthesis, porphyrin and chlorophyll metabolism, flavonoid biosynthesis, and amino acid metabolism. N36 increased δ-amino levulinic acid synthesis and upregulated expression of the magnesium chelatase H subunit, which promoted chlorophyll a synthesis. Hence, N36 stimulated chlorophyll synthesis rather than heme synthesis. These findings enrich our understanding of the N. tangutorum transcriptome and help us to research desert xerophytes' responses to increased nitrogen in the future.
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Affiliation(s)
- Chenggong Liu
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Na Duan
- Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou 015200, China
- National Long-Term Scientific Research Base of Ulan Buh Desert Comprehensive Control, National Forestry and Grassland Administration, Dengkou 015200, China
| | - Xiaona Chen
- Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou 015200, China
- National Long-Term Scientific Research Base of Ulan Buh Desert Comprehensive Control, National Forestry and Grassland Administration, Dengkou 015200, China
| | - Xu Li
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Naqi Zhao
- Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou 015200, China
- National Long-Term Scientific Research Base of Ulan Buh Desert Comprehensive Control, National Forestry and Grassland Administration, Dengkou 015200, China
| | - Wenxu Cao
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Huiqing Li
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Bo Liu
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Fengsen Tan
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Xiulian Zhao
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Qinghe Li
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
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