Next Article in Journal
Genome-Wide Identification of the PIP5K Gene Family in Camellia sinensis and Their Roles in Metabolic Regulation
Previous Article in Journal
Replication of Known and Identification of Novel Associations in Biobank-Scale Datasets: A Survey Using UK Biobank and FinnGen
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Genes
Volume 15
Issue 7
10.3390/genes15070930
genes-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Genome-Wide Identification and Expression Analysis of Nitrate Transporter (NRT) Gene Family in Eucalyptus grandis

by
Guangyou Li
1,
Deming Yang
1,
Yang Hu
2,
Jianmin Xu
1 and
Zhaohua Lu
1,*
1
Key Laboratory of State Forestry and Grassland Administration on Tropical Forestry, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520, China
2
Xinhui Research Institute of Forestry Science, Jiangmen 529100, China
*
Author to whom correspondence should be addressed.
Genes 2024, 15(7), 930; https://doi.org/10.3390/genes15070930 (registering DOI)
Submission received: 24 June 2024 / Revised: 10 July 2024 / Accepted: 15 July 2024 / Published: 17 July 2024
(This article belongs to the Section Plant Genetics and Genomics)
Browse Figures
Versions Notes

Abstract

:
Eucalyptus grandis is an important planted hardwood tree worldwide with fast growth and good wood performance. The nitrate transporter (NRT) gene family is a major core involved in nitrogen (N) absorption and utilization in plants, but the comprehensive characterization of NRT genes in E. grandis remains mostly elusive. In this study, a total of 75 EgNRT genes were identified from the genome of E. grandis that were distributed unevenly across ten chromosomes, except Chr9. A phylogenetic analysis showed that the EgNRT proteins could be divided into three classes, namely NRT1, NRT2 and NRT3, which contained 69, 4 and 2 members, respectively. The cis-regulatory elements in the promoter regions of EgNRT genes were mainly involved in phytohormone and stress response. The transcriptome analysis indicated that the differentially expressed genes of leaf and root in E. grandis under different N supply conditions were mainly involved in the metabolic process and plant hormone signal transduction. In addition, the transcriptome-based and RT-qPCR analysis revealed that the expression of 13 EgNRT genes, especially EgNRT1.3, EgNRT1.38, EgNRT1.39 and EgNRT1.52, was significantly upregulated in the root under low-N-supply treatment, suggesting that those genes might play a critical role in root response to nitrate deficiency. Taken together, these results would provide valuable information for characterizing the roles of EgNRTs and facilitate the clarification of the molecular mechanism underlying EgNRT-mediated N absorption and distribution in E. grandis.

1. Introduction

Nitrogen (N) is an essential nutrient for plant growth and development, as it is required for the synthesis of chlorophyll, protein, nucleic acid and other secondary metabolites [1,2]. Under insufficient N supply, plant growth is inhibited, resulting in a decrease in product yield and quality. However, the excessive application of N fertilizer not only could not effectively increase yield but could also cause soil ecological damage and environmental pollution. The excessive use of N fertilizer leads to a serious waste of agricultural inputs in the long term. Therefore, understanding the biological and molecular mechanisms of N uptake and distribution in plants is critical to improve N-use efficiency and reduce nitrogen apply in crops.
Nitrate (NO3−) is one of the major forms of N uptake and utilization in higher plants [3]. Plants have developed high-affinity (HATS) and low-affinity nitrate-uptake systems (LATS) to cope with environments with low or high NO3− concentrations to ensure an efficient N uptake [4]. Nitrate transporters (NRTs) have been proven to play a vital role in the nitrogen absorption of plants. The NRT family genes have been identified in many plants, such as cucumber [5], radish [6], rice [7], maize [8], Populus [9,10] and pineapple [11]. The NRT gene family could be classified into NRT1, NRT2 and NRT3. NRT1 belongs to the PEPTIDE TRANSPORTERS (PTR) family of the MAJOR FACILITATOR SUPER (MFS) family. AtNRT1.1 is the first identified NO3− transporter that contributes to both low- and high-affinity N uptake. The expression of AtNRT1.1 is regulated by auxin signaling in both the shoots and roots [12], and AtNRT1.1 is involved in stomatal opening and drought susceptibility in Arabidopsis [13].
NRT2 belongs to the NITRATE/NITRITE PORTER (NNP) subfamily of MFS family. A total of seven NRT2 genes have been identified in Arabidopsis, among which AtNRT2.1, AtNRT2.2, AtNRT2.4 and AtNRT2.5 are expressed in the root and participate in HATS. NRT2.1 and NRT2.2 are the major and minor contributors to the nitrate-inducible high-affinity transport system (IHATS), respectively. The disruption of NRT2.1 and NRT2.2 in Arabidopsis showed significant inhibition of HATS, and the N influx via the LATS was unaffected. The contribution of NRT2.2 was increased when the function of NRT2.1 was lost, leading to a partial compensation [14]. NRT2.4 is a nitrate transporter localized to the plasma membrane, which has a role in both the roots and shoots of Arabidopsis under N starvation [15]. NRT3, also called NAR2, is essential for HATS of the NRT2 protein in plants [16]. The interaction between NRT2 and NRT3 is required for HATS [17]. AtNRT3.1 interacts with almost all AtNRT2 family members except for AtNRT2.7 in Arabidopsis [18]. OsNAR2.1 interacted with OsNRT2.1, OsNRT2.2 and OsNRT2.3a to enhance their functions in NO3− absorption and transport, but it cannot do so with OsNRT2.3b [19].
E. grandis is the widely planted hardwood tree worldwide [20]. Fast growth and good wood performance are the characteristics of E. grandis, which requires a large amount of nutrients, including N fertilizer. Therefore, the clarification of the molecular mechanisms underlying N uptake and utilization is crucial for NUE improvement in E. grandis. NRT genes, as the major nitrate transporter, and their function have been extensively characterized in several plants. The chromosomal-level genome of E. grandis was published [21], but the information on EgNRT genes was poorly understood. In this study, a total of 75 NRT genes were identified based on the genome of E. grandis. The chromosomal location, genetic structure and phylogenetic relationship of the EgNRT gene family were explored, and the expression profiles of EgNRT genes under low and high N supply were investigated. These findings would provide a basis for further studies on the functions of EgNRT genes and facilitate the clarification of the molecular regulatory network of N uptake and transportation in E. grandis.

2. Materials and Methods

2.1. Plant Materials

The experiment was carried out at the greenhouse of the Research Institute of Tropical Forestry, Chinese Academy of Forestry (23°11′ N, 113°23′ E), in 2023. E. grandis (Qinglong) clones were used as the experiment material and obtained from tissue culture. Eighteen healthy and uniform seedlings (seedling height about 39 cm and ground diameter of 3.5 mm) were planted into polypropylene containers with coconut husk. Nine plants each were treated with high N (HN: 119 mg/L) and low N (LN: 29.25 mg/L). The concentrations of other nutrient elements were similar for each treatment (P 15.5 mg/L, K: 298.0 mg/L, Mg: 48.1 mg/L, Ca: 210 mg/L, B: 0.5 mg/L, Mn: 0.5 mg/L, Zn: 0.5 mg/L, Cu: 0.5 mg/L, Mo: 0.5 mg/L and Fe: 5.6 mg/L). Each plant was watered with 100 mL of the corresponding nutrient solution. Each treatment contains 3 replicates and 3 plants for each replication. After the 24 h treatment, the leaves (on the third expanded leaf from the top) and roots for each treatment were sampled and stored in liquid nitrogen.

2.2. Identification and Characterization of NRT Genes in E. grandis

The sequences of 62 Arabidopsis NRT proteins were downloaded from the TAIR database (https://www.arabidopsis.org/, accessed on 5 April 2024). The public genome of E. grandis (GCA_000612305.2) was used as a reference genome for the custom database. To identify EgNRT genes, a BLASTP search according to AtNRT protein sequences was performed in E. grandis genomes with an E-value < 0.01. The potential sequences were submitted to the Pfam (http://pfam.sanger.ac.uk/search, accessed on 9 April 2024) and SMART (http://smart.embl-heidelberg.de/, accessed on 9 April 2024) to assess the NRT domains [22]. After removing the sequences without the PTR2, MFS1 or NAR2 domain, the reliable EgNRT proteins were obtained. The characterization of EgNRT genes, including the number of amino acids, the isoelectric point (pI), molecular weight (Mw) and grand average of hydropathicity (GRAVY), were calculated using the ProtParam tool of the ExPASy Server (https://web.expasy.org/protparam/, accessed on 11 April 2024).

2.3. Chromosomal Localization and Phylogenetic Analysis of EgNRT Proteins

The information about the chromosome localization of EgNRT genes was obtained from the GFF3 file of the E. grandis genome database and visualized using the TBtools software (v2.0906) according to the manufacturer’s instructions [23]. For the phylogenetic analysis, the multiple sequence alignments of AtNRT and EgNRT proteins were generated by Clustal W. Phylogenetic trees were constructed from multiple sequence alignments using the neighbor-joining method on the p-distance with pairwise deletion and 1000 bootstraKp replicates in MEGA 6. The phylogenetic tree was further visualized using Evolview (http://www.evolgenius.info/evolview/, accessed on 15 April 2024) [24].

2.4. Gene Structure and Conserved Motif Analysis of EgNRT Proteins

The conserved motifs of EgNRT protein were identified using multiple expectation maximization in the motif elicitation (MEME ver. 5.1.1, http://meme-suite.org, accessed on 15 April 2024) program, with a maximum of 10 motifs and a width of motifs of 6–50 aa. The information about gene structure for EgNRT genes was obtained from the GFF3 file of the E. grandis genome database. The gene structure and conserved motif within the phylogenetic tree of EgNRT proteins were visualized by TBtools software (v2.0906), according to the manufacturer’s instructions [23].

2.5. Cis-Element Analysis of EgNRT Gene Promoters

The upstream 2 kb sequence of the transcription start site (TSS) for each EgNRT gene was extracted by TBtools software as the presumptive promoter. The promoter sequences of EgNRT genes were loaded into the PlantCARE (http://bioinformatics.psb.ugent.be/webtools/plantcare/html/, accessed on 18 April 2024) database to identify potential cis-elements and further visualized by TBtools software (v2.0906) [23].

2.6. RNA Sequencing

The leaf and root tissues of E. grandis under low and high N supply were collected for transcriptome analysis. Total RNA was extracted by an RNA Simple Total RNA Extraction Kit (Tiangen biotech, Beijing Ltd. Co., Beijing, China), following the manufacturer’s instructions. The integrity, purity and concentration of total RNA were detected by 1% agarose gel electrophoresis and NanoDrop® ND-1000 portable UV-Vis Spectrophotometer (Thermo Scientific, Waltham, MA, USA). RNA sequencing libraries were prepared as described previously [25]. Genes with FDR < 0.05 and |log2(foldchange)| ≥ 1 found by DESeq2 were assigned as differentially expressed. A gene ontology (GO) enrichment analysis of the differentially expressed genes (DEGs) was implemented by the GOseq R packages-based Wallenius non-central hyper-geometric distribution. KOBAS (v 3.0.3) software was employed to test the statistical enrichment of differential expression genes in the KEGG pathways. Heatmaps for expression profiles of EgNRT genes based on the transcriptome data were generated with TBtools software [23].

2.7. Real Time Quantitative Polymerase Chain Reaction (RT-qPCR)

Using a HiScript III 1st Strand cDNA Synthesis Kit (+gDNA wiper) (Vazyme Biotechnology Co., Nanjing, China), reverse transcripts qualified RNA samples into cDNA, following the manufacturer’s instructions. A RT-qPCR analysis was performed in a BioRad CFX96 Real-Time PCR platform (BioRad, Hercules, CA, USA). The specific program parameters were set according to the manufacturer’s instructions of Taq Pro Universal SYBR qPCR Master Mix (Vazyme Biotechnology Co., Nanjing, China). Three biological replicates were carried out. The relative expression levels were calculated by the 2−ΔΔCT method, with the Eucons08 gene as the internal references [26]. Primers for RT-qPCR were designed using NCBI Primer-BLAST software (v 2.15.0) and are listed in Supplementary Table S1.

2.8. Statistical Analysis

Data were analyzed using SPSS statistical software (SPSS 20.0, IBM, Armonk, NY, USA). One-way analysis of variance was used to determine statistical significance among multiple range tests.

3. Results

3.1. Genome-Wide Characterization of NRT Genes in E. grandis

To identify the candidate EgNRT genes, the sequences of 62 Arabidopsis NRT proteins were used to search through BLAST based on the E. grandis genome database. Subsequently, the retrieved putative genes were filtered through SMART and NCBI Batch CD search to remove proteins with incomplete domains. A total of 75 EgNRT family genes were obtained, including 69 EgNRT1/NPF, 4 EgNRT2 and 2 EgNRT3/NAR2 members (Table 1). The length of EgNRT proteins ranges from 205 aa (EgNRT3.1) to 649 aa (EgNRT1.29), and the molecular weight ranges from 22.29 (EgNRT3.1) to 71.60 (EgNRT1.29) kDa. In addition, the predicted pI values of the EgNRT proteins were in the range of 5.09 (EgNRT1.42)~9.66 (EgNRT1.2), and 61 EgNRT members belong to alkaline proteins (pI > 7). The instability index of EgNRT proteins ranges from 24.58 (EgNRT1.22) to 46.36 (EgNRT1.51), and six of the structures were unstable (instability index > 40). There were only three hydrophilic proteins (EgNRT1.11, EgNRT3.1 and EgNRT3.2) in EgNRT members, and the rest were hydrophobic proteins.
The chromosomal location analysis showed that 75 EgNRT family genes were distributed unevenly on the ten chromosomes (Chr) (Figure 1). The largest number of EgNRT genes was detected on Chr 2 (17 genes), followed by Chr 10 and 11, each with 10 genes. Chr6 possesses nine genes; two chromosomes (Chr7 and Chr8) contain seven genes; Chr1 contains six genes; and Chr3 and Chr5 have five and three genes, respectively. The lowest number was on Chr 4, with only one EgNRT gene. Moreover, no EgNRT member was identified on Chr 9. In addition, it was observed that many EgNRT1 members were located on Chr1, 2, 6, 8, 10 and 11 in adjacent positions, indicating a replication event during evolution.

3.2. Phylogenetic and Structure Analysis of the EgNRT Genes

To compare the evolutionary relationships of the NRT gene family in E. grandis, a phylogenetic tree was generated using EgNRT and AtNRT full-length protein sequences (Figure 2). The result showed that the NRT protein of Arabidopsis and E. grandis could be divided into three classes—NRT1, NRT2 and NRT3—which contained 69, 4 and 2 EgNRT family members, respectively. The NRT1 class could be further subdivided into four groups. To investigate the structural characteristics of EgNRT proteins, ten conserved motifs were identified through a MEME database search (Figure 3a). The results show that most NRT1 members have 6~10 conserved motifs, and all of them contain motif 1, motif 5, motif 8 and motif 9, suggesting that those might be the most conserved motifs in the NRT1 family. However, the NRT2 and NRT3 genes possess 1~5 motif, and no conserved motif was identified in EgNRT3.1.
The gene structure of the EgNRT family was visualized to further explore the structural divergence (Figure 3b). The results showed that the length of EgNRT family gene sequences varied greatly, with the longest (EgNRT1.5) DNA sequence length approaching 10 kb, and the shortest (EgNRT1.9) less than 1 kb. The number distribution of the exon–intron structure of the EgNRT gene family members also varied greatly, with the exon number ranging from 2 to 8 and the intron number ranging from 1 to 7, among which EgNRT1.43 has the highest exon number and eight EgNRT members have the lowest exon number. Many genes from the same branch are similar in structure. EgNRT1.22, EgNRT1.23 and EgNRT1.24 possess a similar structure and motif, suggesting that those genes might be functionally redundant. It is noteworthy that many genes from the same branch were different in structure, such as EgNRT1.41/EgNRT1.44, indicating that these genes might diverge functionally during evolution.

3.3. Cis-Element Analysis of EgNRT Genes Promoters

The characterization of cis-elements in the 2 kb upstream promoter sequences of EgNRT genes was analyzed by the PlantCARE database. Several crucial cis-elements involved in plant growth and development, phytohormones responsiveness and stress response were identified in the promoter region of EgNRT genes (Figure 4a and Supplementary Table S2). Approximately 71.2% of EgNRT genes contained light-responsive elements, including the 3-AF1 binding site, 4cl-CMA1b, 4cl-CMA2b, AAAC-motif, GT1-motif and Sp1, indicating that the expression of those EgNRT genes might be regulated by light signaling. Three auxin-responsive elements were found in the promoter region of 45 EgNRT genes, and the ABREs (abscisic acid-response elements) were distributed in 69 EgNRT genes. In addition, both the CGTCA motif and TGACG motif were identified in almost all EgNRT genes, suggesting that most EgNRT genes might participate in MeJA-mediated biological process. Gibberellin-responsive elements (GARE-motif, P-box and TATC-box) and a salicylic acid-responsive element (TCA-element) were found in the promoter region of 52 and 38 EgNRT genes. Moreover, about 45.2%, 58.9% and 42.3% of EgNRT family members contained drought-induction elements (MBS), low-temperature elements (LTR) and defense and stress responsiveness (TC-rich repeats), respectively (Figure 4b). The WUN-motif (wound-responsive element) exists in only three EgNRT genes (EgNRT1.18, EgNRT1.50 and EgNRT1.57). These results indicate that the EgNRT genes were widely involved in plant growth and development, phytohormones responses and the stress-response process.

3.4. RNA-Seq Analysis of Root and Leaf in E. grandis under Low and High N Supply

To investigate the nitrogen-response genes in Eucalyptus, an RNA sequencing (RNA-seq) analysis was performed with the leaf and root under low and high N supply. A total of 347 differentially expressed genes (DEGs, |Log2FoldChange| > 2, FDR < 0.05) were identified in the EgLL vs. EgHL group, including 307 upregulated and 40 downregulated DEGs (Figure 5a,b). For the EgLR vs. EgHR group, a total of 4812 DEGs were identified, including 2726 upregulated and 2086 downregulated DEGs (Figure 5c). The gene ontology (GO) term enrichment analysis showed that the DEGs of the EgLL vs. EgHL and EgLR vs. EgHR group were mainly involved in metabolic process, cellular process, membrane, membrane part, binding and catalytic process (Supplementary Figure S1). The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the DEGs of the EgLL vs. EgHL group were mainly involved in plant hormone signal transduction, amino sugar and nucleotide sugar metabolism, and plant–pathogen interaction, while the DEGs of the EgLR vs. EgHR group were responsible for plant hormone signal transduction, ribosomes, phenylpropanoid biosynthesis and carbon metabolism (Supplementary Figure S2).

3.5. Expression Profiles of EgNRT Genes under Low and High N Supply

The expression profiles of EgNRT genes were further analyzed using the transcriptome data (Figure 6a). As expected, tissue-specific and N-response expressions were observed for EgNRT genes. Among all EgNRT genes, 24 members showed no expression (FPKM < 1) in the four samples. EgNRT1.13, EgNRT1.17, EgNRT1.34, EgNRT1.39, EgNRT1.40, EgNRT1.52 and EgNRT2.1 were mainly expressed in the leaf, while EgNRT1.22, EgNRT1.23, EgNRT1.24, EgNRT1.29, EgNRT1.31, EgNRT1.55, EgNRT1.66, EgNRT1.67, EgNRT1.68 and EgNRT3.1 were mainly expressed in the root. Compared to the low-N treatment, the expressions of four EgNRT genes, namely EgNRT1.19, EgNRT1.25, EgNRT1.29 and EgNRT3.1, were significantly induced in the leaf under high-N conditions. In addition, the expression of EgNRT1.3, EgNRT1.14, EgNRT1.34, EgNRT1.35, EgNRT1.38, EgNRT1.39 and EgNRT2.3 had little changes in the leaf but was significantly downregulated in the root under high-N conditions. On the contrary, the expressions of EgNRT1.17, EgNRT1.40, EgNRT1.43, EgNRT1.65 and EgNRT2.1 were significantly downregulated in the root. It is noteworthy that the expression of EgNRT2.4 was upregulated in the leaf and downregulated in the root. To verify the reliability of transcriptome data, the expression patterns of 15 EgNRT genes were evaluated by RT-qPCR analysis. The results revealed that the expression trends of these genes were basically in accordance with the transcript-abundance changes from RNA-seq data (Figure 6b). Compared to low-N treatment, the expressions of EgNRT1.14, EgNRT1.17, EgNRT1.34, EgNRT1.35, EgNRT1.43, EgNRT1.50, EgNRT1.65, EgNRT2.3 and EgNRT2.4 were significantly downregulated in both the leaf and root. The expressions of EgNRT1.3, EgNRT1.38, EgNRT1.39 and EgNRT1.52 were significantly downregulated in the root, indicating that those genes might play vital roles in the root’s NO3− transport process. In addition, EgNRT1.40 was significantly upregulated in the root, suggesting that it might be involved in LATS. Moreover, the expression of EgNRT2.1 was significantly downregulated in the leaf, demonstrating that it might participate in the N distribution of the leaf under high N supply.

4. Discussion

NRT genes play vital roles in regulating plant N uptake and distribution to adapt to different nutrient conditions. The NRT family genes have been identified in several herbs and wood plants, such as cucumber [5], radish [6], rice [7], maize [8], Populus [9,10] and pineapple [11]. Up until now, the identification and characterization of the EgNRT gene family have not been comprehensively investigated, thus creating a barrier to the genetic improvement of NUE in E. grandis plants. Here, a total of 75 EgNRT genes were identified at the genome level based on the E. grandis genome. The isoelectric point (pI), molecular weight, chromosome location, genetic structure, domain architecture, phylogenetic relationship and expression profiles of these EgNRT genes were characterized (Table 1); this was the first systematic characterization of the NRT gene family in E. grandis. Similar to other plants, the EgNRT gene family contains a large number of NRT1 and a few NRT2 and NRT3 gene members [5,7,10]. Compared with NRT genes in Arabidopsis, the number of EgNRT genes have only a slight increase. Several NRT genes were highly conserved in Arabidopsis and E. grandis during evolution, indicating that the functions of these genes are relatively well conserved.
Besides being a nutrient, nitrate also plays an important signaling role in plant development and environmental response; the interactions between the signaling pathways of nitrate and phytohormones to bring about changes in physiology and morphology have been revealed [12,27,28,29]. Nitrate could regulate the biosynthesis and signaling of phytohormones, including auxin, cytokinin, GA, ABA, MeJA and SA, while the feedback from hormonal signaling modulates the absorption and metabolism of NO3− [15,30,31]. In this study, many cis-elements involved in the phytohormonal response were found in the promoters of EgNRT genes (Figure 4a and Supplementary Table S1), indicating that EgNRT genes were integrated into the growth regulatory network mediated by phytohormones. Furthermore, the DEGs of root and leaf in E. grandis under different N condition were mainly related to the plant hormone signal transduction pathway based on the KEGG-enrichment analysis (Supplementary Figure S2), indicating that similar interactions between the signaling pathways of nitrate and phytohormones might exist in E. grandis. Furthermore, the exploration of the transcriptional regulatory network of nitrogen uptake and distribution mediated by EgNRT genes can facilitate our understanding of the interaction between nitrate and phytohormones’ signaling.
The NRT family members perform diverse functions in the uptake and distribution of nitrate across the entire plant organism [3]. The tissue-specific expression of NRT-family genes has been observed in several species, such as Arabidopsis, rice, cucumber and poplar [5,9,16,32]. Herein, the transcriptome and RT-qPCR analysis showed that most of the EgNRT genes exhibited leaf- or root-specific expression patterns, suggesting that EgNRT genes were involved in regulating the development of different tissues (Figure 6). EgNRT1.13, EgNRT1.17, EgNRT1.34, EgNRT1.39, EgNRT1.40, EgNRT1.52 and EgNRT2.1 have higher expression in the leaf, while in the root, it was undetected, suggesting that its role in leaf rather than root, while EgNRT1.22, EgNRT1.23, EgNRT1.24, EgNRT1.29, EgNRT1.31, EgNRT1.55, EgNRT1.66, EgNRT1.67, EgNRT1.68 and EgNRT3.1 were the opposite. AtNRT1.1 was the first identified and the most extensively explored NRT member in Arabidopsis, and it is expressed widely in roots and shoots [33,34,35]. As a homologous gene, EgNRT1.8 displayed a higher expression in the root. The expression levels of most EgNRT genes were upregulated at a NO3− concentration, which may lead to the strong nitrogen absorption ability under low-N-supply conditions in E. grandis. The subfamily NRT2 belongs to the high-affinity transport system proteins, which play critical roles in N uptake at low nitrate concentrations [36,37]. Among the four EgNRT2 members identified in this study, the expressions of EgNRT2.3 and EgNRT2.4 were induced by a low-N-supply condition in the leaf and root (Figure 6), indicating that EgNRT2.3 and EgNRT2.4 play an essential role in nitrate acquisition and remobilization. It is worth noting that the expression of EgNRT2.1 was significantly downregulated only in the leaf. EgNRT2.2 showed a stable expression trend under different NO3− concentrations, suggesting that it may be a constitutive sensor, particularly in the roots, which are the primary uptake sites for nitrate. The precise exact function of these EgNRT genes in response to low-nitrogen conditions remains to be further investigated.

Supplementary Materials

The following supporting information can be downloaded at https://www.mdpi.com/article/10.3390/genes15070930/s1, Figure S1: GO analysis of DEGs in EgLL vs. EgHL and EgLR vs. EgHR group. BP, biological process. CC, cellular component. MF, molecular function; Figure S2: KEGG-enrichment analysis of DEGs in EgLL vs. EgHL and EgLR vs. EgHR group; Table S1: The potential cis-elements in the promoter region of 75 EgNRT genes; Table S2: Primers used in this study.

Author Contributions

Conceptualization, G.L. and Z.L.; methodology, G.L. and Z.L.; software, G.L. and Z.L.; validation, Y.H. and J.X.; formal analysis, G.L. and D.Y.; investigation, G.L. and D.Y.; resources, Y.H., J.X. and Z.L.; data curation, G.L. and Z.L.; writing—original draft preparation, G.L.; writing—review and editing, Y.H., J.X. and Z.L.; visualization, G.L.; supervision, Z.L.; project administration, Z.L.; funding acquisition, G.L. All authors have read and agreed to the published version of the manuscript.

Funding

This work was funded by the Fundamental Research Funds for the Central Non-Profit Research Institution of CAF (Nos. CAFYBB2022SY017 and CAFYBB2021SY001) and the National Key Research and Development Program of China during the 14th five-year plan Period (2023YFD2201003 and 2022YFD2200203).

Data Availability Statement

The data reported in this paper were deposited in the Genome Sequence Archive (Genomics, Proteomics and Bioinformatics 2021) in National Genomics Data Center, China National Center for Bioinformation/Beijing Institute of Genomics, Chinese Academy of Sciences (GSA: CRA017129), and are publicly accessible at https://ngdc.cncb.ac.cn/gsa (accessed on 17 June 2020).

Acknowledgments

We thank Qiaowen Wei from National High-Tech Base for Forest Seed Breeding (Gaoyao) for providing research materials.

Conflicts of Interest

The authors declare that they have no conflict of interest.

References

  1. Garnett, T.; Plett, D.; Heuer, S.; Okamoto, M. Genetic approaches to enhancing nitrogen-use efficiency (NUE) in cereals: Challenges and future directions. Funct. Plant Biol. 2015, 42, 921–941. [Google Scholar] [CrossRef] [PubMed]
  2. Xuan, W.; Beeckman, T.; Xu, G.H. Plant nitrogen nutrition: Sensing and signaling. Curr. Opin. Plant Biol. 2017, 39, 57–65. [Google Scholar] [CrossRef] [PubMed]
  3. Wang, Y.Y.; Hsu, P.K.; Tsay, Y.F. Uptake, allocation and signaling of nitrate. Trends Plant Sci. 2012, 17, 458–467. [Google Scholar] [CrossRef] [PubMed]
  4. Gojon, A.; Krouk, G.; Perrine, W.F.; Laugier, E. Nitrate transceptor(s) in plants. J. Exp. Bot. 2011, 62, 2299–2308. [Google Scholar] [CrossRef] [PubMed]
  5. Migocka, M.; Warzybok, A.; Kłobus, G. The genomic organization and transcriptional pattern of genes encoding nitrate transporters 1 (NRT1) in cucumber. Plant Soil 2012, 364, 254–260. [Google Scholar] [CrossRef]
  6. Ding, M.C.; He, M.; Zhang, W.L.; Han, Y.; Zhang, X.Y.; Zhang, X.L.; Zhu, Y.L.; Wang, Y.; Liu, L.W.; Xu, L. Genome-wide identification and expression analysis of RsNRT gene family reveals their potential roles in response to low-nitrogen condition in radish (Raphanus sativus L.). Sci. Hortic. 2023, 321, 112273. [Google Scholar] [CrossRef]
  7. Plett, D.; Toubia, J.; Garnett, T.; Tester, M.; Kaiser, N.B.; Baumann, U. Dichotomy in the NRT gene families of dicots and grass species. PLoS ONE 2010, 5, e15289. [Google Scholar] [CrossRef]
  8. Jia, L.H.; Hu, D.S.; Wang, J.B.; Liang, Y.Y.; Li, F.; Wang, Y.; Han, Y.L. Genome-wide identification and functional analysis of nitrate transporter genes (NPF, NRT2 and NRT3) in Maize. Int. J. Mol. Sci. 2023, 24, 12941. [Google Scholar] [CrossRef]
  9. Bai, H.; Euring, D.; Volmer, K.; Janz, D.; Polle, A. The nitrate transporter (NRT) gene family in poplar. PLoS ONE 2013, 8, e72126. [Google Scholar] [CrossRef]
  10. Zhao, L.; Chen, P.F.; Liu, P.; Song, Y.P.; Zhang, D.Q. Genetic effects and expression patterns of the nitrate transporter (NRT) gene family in Populus tomentosa. Front. Plant Sci. 2021, 12, 661635. [Google Scholar] [CrossRef]
  11. Li, W.M.; Yan, M.K.; Hu, B.Y.; Priyadarshani, S.V.G.N.; Hou, Z.M.; Ojolo, P.S.; Xiong, J.J.; Zhao, H.M.; Qin, Y. Characterization and the expression analysis of nitrate transporter (NRT) gene family in pineapple. Trop. Plant Biol. 2018, 11, 177–191. [Google Scholar] [CrossRef]
  12. Guo, F.Q.; Wang, R.C.; Crawford, M.N. The Arabidopsis dual-affinity nitrate transporter gene AtNRT1.1 (CHL1) is regulated by auxin in both shoots and roots. J. Exp. Bot. 2002, 53, 835–844. [Google Scholar] [CrossRef] [PubMed]
  13. Guo, F.Q.; Young, J.; Crawford, M.N. The nitrate transporter AtNRT1.1 (CHL1) functions in stomatal opening and contributes to drought susceptibility in Arabidopsis. Plant Cell 2003, 15, 107–117. [Google Scholar] [CrossRef] [PubMed]
  14. Li, W.B.; Wang, Y.; Okamoto, M.; Crawford, N.M.; Siddiqi, M.Y.; Glass, D.M.A. Dissection of the AtNRT2.1:AtNRT2.2 inducible high-affinity nitrate transporter gene cluster. Plant Physiol. 2007, 143, 425–433. [Google Scholar] [CrossRef] [PubMed]
  15. Kiba, T.; Kudo, T.; Kojima, M.; Sakakibara, H. Hormonal control of nitrogen acquisition: Roles of auxin, abscisic acid, and cytokinin. J. Exp. Bot. 2011, 62, 1399–1409. [Google Scholar] [CrossRef] [PubMed]
  16. Feng, H.M.; Fan, X.R.; Yan, M.; Liu, X.Q.; Miller, J.A.; Xu, G.H. Multiple roles of nitrate transport accessory protein NAR2 in plants. Plant Signal. Behav. 2011, 6, 1286–1289. [Google Scholar] [CrossRef]
  17. Okamoto, M.; Kumar, A.; Li, W.; Wang, Y.; Siddiqi, M.Y.; Crawford, N.M.; Glass, A.D.M. High-affinity nitrate transport in roots of Arabidopsis depends on expression of the NAR2-like gene AtNRT3.1. Plant Physiol. 2006, 140, 1036–1046. [Google Scholar] [CrossRef] [PubMed]
  18. Kotur, Z.; Mackenzie, N.; Ramesh, S.; Tyerman, S.D.; Kaiser, B.N.; Glass, A.D. Nitrate transport capacity of the Arabidopsis thaliana NRT2 family members and their interactions with AtNAR2.1. New Phytol. 2012, 194, 724–731. [Google Scholar] [CrossRef]
  19. Yan, M.; Fan, X.R.; Feng, H.M.; Miller, A.J.; Shen, Q.R.; Xu, G.H. Rice OsNAR2.1 interacts with OsNRT2.1, OsNRT2.2 and OsNRT2.3a nitrate transporters to provide uptake over high and low concentration ranges. Plant Cell Environ. 2011, 34, 1360–1372. [Google Scholar] [CrossRef]
  20. Marília, G.S.C.; Paulo, M.; Tiago, S.B. Insights into temperature modulation of the Eucalyptus globulus and Eucalyptus grandis antioxidant and lignification subproteomes. Phytochemistry 2017, 137, 15–23. [Google Scholar]
  21. Myburg, A.; Grattapaglia, D.; Tuskan, G. The genome of Eucalyptus grandis. Nature 2014, 510, 356–362. [Google Scholar] [CrossRef]
  22. Krouk, G. Hormones and nitrate: A two-way connection. Plant Mol. Biol. 2016, 91, 599–606. [Google Scholar] [CrossRef] [PubMed]
  23. Guan, P.Z. Dancing with Hormones: A current perspective of nitrate signaling and regulation in Arabidopsis. Front. Plant Sci. 2017, 8, 1697. [Google Scholar] [CrossRef] [PubMed]
  24. Landrein, B.; Formosa-Jordan, P.; Malivert, A.; Schuster, C.; Melnyk, W.C.; Yang, W.B.; Turnbull, C.; Meyerowitz, M.E.; Locke, C.W.J.; Jönsson, H. Nitrate modulates stem cell dynamics in Arabidopsis shoot meristems through cytokinins. Proc. Natl. Acad. Sci. USA 2018, 115, 201718670. [Google Scholar] [CrossRef] [PubMed]
  25. Mounier, E.; Pervent, M.; Ljung, K.; Gojon, A.; Nacry, P. Auxin-mediated nitrate signalling by NRT1.1 participates in the adaptive response of Arabidopsis root architecture to the spatial heterogeneity of nitrate availability. Plant Cell Environ. 2014, 37, 162–174. [Google Scholar] [CrossRef] [PubMed]
  26. Vega, A.; O’Brien, J.A.; Gutierrez, R.A. Nitrate and hormonal signaling crosstalk for plant growth and development. Curr. Opin. Plant Biol. 2019, 52, 155–163. [Google Scholar] [CrossRef] [PubMed]
  27. Okamoto, M.; Vidmar, J.J.; Glass, A.D.M. Regulation of NRT1 and NRT2 gene families of Arabidopsis thaliana: Responses to nitrate provision. Plant Cell Physiol. 2003, 44, 304–317. [Google Scholar] [CrossRef]
  28. Nazoa, P.; Vidmar, J.J.; Tranbarger, T.J.; Mouline, K.; Damiani, I.; Tillard, P.; Zhuo, D.; Glass, D.M.A.; Touraine, B. Regulation of the nitrate transporter gene AtNRT2.1 in Arabidopsis thaliana: Responses to nitrate, amino acids and developmental stage. Plant Mol. Biol. 2003, 52, 689–703. [Google Scholar] [CrossRef]
  29. Alvarez, J.M.; Vidal, E.A.; Gutiérrez, R.A. Integration of local and systemic signaling pathways for plant N responses. Curr. Opin. Plant Biol. 2012, 15, 185–191. [Google Scholar] [CrossRef]
  30. Zhang, X.; Cui, Y.N.; Yu, M.; Su, B.D.; Gong, W.; Baluška, F.; Komis, G.; Šamaj, J.; Shan, X.Y.; Li, J.X. Phosphorylation-mediated dynamics of nitrate transceptor NRT1.1 regulate auxin flux and nitrate signaling in lateral root growth. Plant Physiol. 2019, 181, 480–498. [Google Scholar] [CrossRef]
  31. Lezhneva, L.; Kiba, T.; Feriabourrelier, A.B.; Lafouge, F.; Boutet-Mercey, S.; Zoufan, P.; Sakakibara, H.; Daniel-Vedele, F.; Krapp, A. The Arabidopsis nitrate transporter NRT2.5 plays a role in nitrate acquisition and remobilization in nitrogen-starved plants. Plant J. 2015, 80, 230–241. [Google Scholar] [CrossRef] [PubMed]
  32. Gu, C.S.; Song, A.P.; Zhang, X.X.; Wang, H.B.; Li, T.; Chen, Y.; Jiang, J.F.; Chen, F.D.; Chen, S.M. Cloning of chrysanthemum high-affinity nitrate transporter family (CmNRT2) and characterization of CmNRT2.1. Sci. Rep. 2016, 6, 23462. [Google Scholar] [CrossRef] [PubMed]
  33. Letunic, I.; Khedkar, S.; Bork, P. SMART: Recent updates, new developments and status in 2020. Nucleic Acids Res. 2020, 49, D458–D460. [Google Scholar] [CrossRef] [PubMed]
  34. Chen, C.J.; Chen, H.; Zhang, Y.; Thomas, R.H.; Frank, H.M.; He, Y.H.; Xia, R. TBtools: An integrative toolkit developed for interactive analyses of big biological data. Mol. Plant 2020, 13, 1194–1202. [Google Scholar] [CrossRef] [PubMed]
  35. Subramanian, B.; Gao, S.H.; Lercher, J.M.; Hu, S.N.; Chen, W.H. Evolview v3: A webserver for visualization, annotation, and management of phylogenetic trees. Nucleic Acids Res. 2019, 47, W270–W275. [Google Scholar] [CrossRef] [PubMed]
  36. Xiao, Y.F.; Li, J.J.; Zhang, Y.; Zhang, X.N.; Liu, H.L.; Qin, Z.H.; Chen, B.W. Transcriptome analysis identifies genes involved in the somatic embryogenesis of Eucalyptus. BMC Genom. 2020, 21, 803. [Google Scholar] [CrossRef]
  37. Van, B.M.; Proost, S.; Wischnitzki, E.; Movahedi, S.; Scheerlinck, C.; Van, P.Y.; Vandepoele, K. Dissecting plant genomes with the PLAZA comparative genomics platform. Plant Physiol. 2012, 158, 590–600. [Google Scholar]
Genes 15 00930 g001
Figure 1. Chromosomal locations for the EgNRT genes on ten chromosomes. The chromosome number is represented at each bar top. Mb, megabase.
Figure 1. Chromosomal locations for the EgNRT genes on ten chromosomes. The chromosome number is represented at each bar top. Mb, megabase.
Genes 15 00930 g001
Genes 15 00930 g002
Figure 2. Phylogenetic analysis of NRT protein involved 62 Arabidopsis NRT protein and 75 E. grandis NRT protein sequences. Blue and red circles represent the AtNRT proteins and radish EgNRT proteins, respectively. The NRT1, NRT2 and NRT3 groups are marked in green, pink and sky blue, respectively.
Figure 2. Phylogenetic analysis of NRT protein involved 62 Arabidopsis NRT protein and 75 E. grandis NRT protein sequences. Blue and red circles represent the AtNRT proteins and radish EgNRT proteins, respectively. The NRT1, NRT2 and NRT3 groups are marked in green, pink and sky blue, respectively.
Genes 15 00930 g002
Genes 15 00930 g003
Figure 3. Phylogenetic analysis, motif distribution and gene structure of EgNRT genes. (a) Phylogenetic tree of 75 EgNRT proteins using the neighbor-joining method, and the conserved domain architecture of the EgNRT proteins. The motifs 1 to 10 are highlighted with different colored boxes. (b) Exon–intron structure for each EgNRT gene. The yellow bars indicate UTR, and the green bars refer to exons (CDS).
Figure 3. Phylogenetic analysis, motif distribution and gene structure of EgNRT genes. (a) Phylogenetic tree of 75 EgNRT proteins using the neighbor-joining method, and the conserved domain architecture of the EgNRT proteins. The motifs 1 to 10 are highlighted with different colored boxes. (b) Exon–intron structure for each EgNRT gene. The yellow bars indicate UTR, and the green bars refer to exons (CDS).
Genes 15 00930 g003
Genes 15 00930 g004
Figure 4. Characterization of cis-elements in the promoter regions of EgNRT genes. (a) Distribution of cis-elements in different colored rectangles. (b) The number of EgNRT genes harboring different cis-elements.
Figure 4. Characterization of cis-elements in the promoter regions of EgNRT genes. (a) Distribution of cis-elements in different colored rectangles. (b) The number of EgNRT genes harboring different cis-elements.
Genes 15 00930 g004
Genes 15 00930 g005
Figure 5. Differentially expressed genes (DEGs) of leaf and root in E. grandis under low- and high-N-supply conditions. (a) The display of DEGs in four groups. EgLL (leaf under low N supply), EgLR (root under low N supply), EgHL (leaf under high N supply) and EgHR (root under high N supply). (b) The upregulated and downregulated DEGs in EgLL vs. EgHL group. (c) The upregulated and downregulated DEGs in EgLR vs. EgHR group.
Figure 5. Differentially expressed genes (DEGs) of leaf and root in E. grandis under low- and high-N-supply conditions. (a) The display of DEGs in four groups. EgLL (leaf under low N supply), EgLR (root under low N supply), EgHL (leaf under high N supply) and EgHR (root under high N supply). (b) The upregulated and downregulated DEGs in EgLL vs. EgHL group. (c) The upregulated and downregulated DEGs in EgLR vs. EgHR group.
Genes 15 00930 g005
Genes 15 00930 g006
Figure 6. The expression profiles of EgNRT genes in leaf and root under different N-supply conditions. (a) Heatmap showing EgNRT genes expression pattern in leaf and root under different N-supply conditions. (b) Validation of 15 EgNRT genes’ expression data from RNA-Seq by RT-qPCR. Different lowercase letters indicate significant differences at level p-value = 0.05.
Figure 6. The expression profiles of EgNRT genes in leaf and root under different N-supply conditions. (a) Heatmap showing EgNRT genes expression pattern in leaf and root under different N-supply conditions. (b) Validation of 15 EgNRT genes’ expression data from RNA-Seq by RT-qPCR. Different lowercase letters indicate significant differences at level p-value = 0.05.
Genes 15 00930 g006
Table 1. Characterization of EgNRT family genes in E. grandis.
Table 1. Characterization of EgNRT family genes in E. grandis.
Gene NameGene IDChromosomeStartEndLength (aa)Molecular Weight (kDa)Theoretical pIInstability IndexGravy
EgNRT1.1KAK3410094.1Chr1026,452,832 26,456,837 60066.50 8.99 41.06 0.167
EgNRT1.2KAK3417242.1Chr842,098,203 42,099,747 47953.77 9.66 34.99 0.258
EgNRT1.3KAK3417244.1Chr842,112,816 42,118,538 59266.43 9.28 31.56 0.228
EgNRT1.4KAK3426575.1Chr642,080,525 42,083,773 57162.29 6.90 39.33 0.410
EgNRT1.5KAK3426576.1Chr642,080,525 42,089,987 57162.25 6.83 40.74 0.413
EgNRT1.6KAK3426577.1Chr642,086,125 42,089,987 57161.94 6.83 40.73 0.424
EgNRT1.7KAK3431236.1Chr549,790,727 49,794,988 57263.81 9.15 34.49 0.283
EgNRT1.8KAK3441088.1Chr221,269,805 21,274,259 59365.43 9.03 35.09 0.285
EgNRT1.9KAK3444550.1Chr18,907,636 8,908,499 26129.19 8.99 32.01 0.183
EgNRT1.10KAK3444551.1Chr18,912,563 8,913,917 32636.52 8.21 37.83 0.082
EgNRT1.11KAK3444552.1Chr18,962,732 8,964,089 32636.59 8.79 39.60 −0.012
EgNRT1.12KAK3415186.1Chr89,882,107 9,884,471 52758.26 9.60 28.56 0.308
EgNRT1.13KAK3418198.1Chr855,988,616 55,991,440 58765.54 8.96 37.33 0.271
EgNRT1.14KAK3419514.1Chr7828,051 832,508 60867.37 9.06 45.91 0.187
EgNRT1.15KAK3421958.1Chr746,265,830 46,267,324 34337.87 8.94 45.76 0.372
EgNRT1.16KAK3421969.1Chr746,339,254 46,341,108 44248.17 9.25 36.47 0.333
EgNRT1.17KAK3423094.1Chr677,443 80,673 59665.65 9.11 31.77 0.292
EgNRT1.18KAK3431109.1Chr547,014,489 47,017,668 59966.28 9.01 32.54 0.492
EgNRT1.19KAK3440113.1Chr24,017,890 4,021,277 57763.27 9.12 42.37 0.407
EgNRT1.20KAK3440606.1Chr29,819,211 9,821,092 39543.55 8.51 30.53 0.475
EgNRT1.21KAK3441424.1Chr228,576,333 28,578,626 52758.26 8.38 36.16 0.433
EgNRT1.22KAK3404455.1Chr119,062,109 9,066,244 59565.80 8.82 24.58 0.234
EgNRT1.23KAK3404456.1Chr119,062,616 9,066,244 54660.81 8.90 25.43 0.243
EgNRT1.24KAK3404457.1Chr119,062,446 9,066,244 54660.81 8.90 25.43 0.243
EgNRT1.25KAK3422698.1Chr752,269,257 52,274,320 58465.32 8.99 34.99 0.254
EgNRT1.26KAK3425311.1Chr628,102,756 28,106,418 60266.84 9.56 34.21 0.211
EgNRT1.27KAK3426574.1Chr642,076,124 42,080,091 57962.82 6.03 37.39 0.336
EgNRT1.28KAK3427971.1Chr651,701,358 51,705,252 53659.13 8.02 42.99 0.253
EgNRT1.29KAK3421328.1Chr738,221,725 38,225,022 64971.60 9.02 36.52 0.252
EgNRT1.30KAK3421701.1Chr744,006,688 44,012,020 58264.52 8.96 32.12 0.260
EgNRT1.31KAK3439365.1Chr379,521,298 79,525,885 57663.02 9.04 31.88 0.358
EgNRT1.32KAK3405187.1Chr1117,678,784 17,681,533 59866.32 9.35 34.37 0.077
EgNRT1.33KAK3406913.1Chr1137,923,342 37,928,314 59566.16 9.01 39.35 0.274
EgNRT1.34KAK3409078.1Chr1012,946,580 12,949,871 56361.71 9.07 34.88 0.401
EgNRT1.35KAK3409870.1Chr1024,836,710 24,840,859 57063.65 8.69 24.92 0.198
EgNRT1.36KAK3417246.1Chr842,197,856 42,202,878 59565.56 9.17 31.11 0.287
EgNRT1.37KAK3417247.1Chr842,217,236 42,223,672 59665.61 9.26 33.40 0.286
EgNRT1.38KAK3421394.1Chr739,895,137 39,900,397 58164.11 5.63 31.42 0.271
EgNRT1.39KAK3430197.1Chr521,446,821 21,449,295 54360.23 5.78 32.58 0.170
EgNRT1.40KAK3434719.1Chr435,140,519 35,145,774 59766.46 6.76 32.68 0.153
EgNRT1.41KAK3442420.1Chr245,896,146 45,898,996 63770.20 6.05 29.04 0.303
EgNRT1.42KAK3442480.1Chr246,229,753 46,235,956 58464.35 5.09 32.84 0.297
EgNRT1.43KAK3442482.1Chr246,237,521 46,244,731 42847.59 6.15 38.10 0.212
EgNRT1.44KAK3443531.1Chr256,169,871 56,174,670 58464.21 7.79 28.69 0.328
EgNRT1.45KAK3444549.1Chr18,900,093 8,901,821 52358.40 8.37 39.65 0.375
EgNRT1.46KAK3404606.1Chr1111,376,427 11,378,235 52557.69 9.20 39.38 0.447
EgNRT1.47KAK3408803.1Chr1010,440,073 10,443,789 58263.44 8.90 41.94 0.360
EgNRT1.48KAK3408804.1Chr1010,462,388 10,465,144 54459.73 8.80 36.80 0.347
EgNRT1.49KAK3408805.1Chr1010,487,412 10,490,375 54559.40 9.09 35.42 0.287
EgNRT1.50KAK3410139.1Chr1026,946,074 26,949,565 52859.27 8.18 45.59 0.324
EgNRT1.51KAK3440094.1Chr23,808,628 3,811,132 61768.95 9.40 46.36 0.183
EgNRT1.52KAK3442757.1Chr250,546,560 50,549,464 45250.09 8.43 29.64 0.146
EgNRT1.53KAK3443072.1Chr252,890,529 52,894,671 64670.57 9.21 38.27 0.277
EgNRT1.54KAK3446521.1Chr137,349,479 37,352,842 62769.13 8.39 36.76 0.162
EgNRT1.55KAK3409854.1Chr1024,732,599 24,735,325 57063.96 8.85 28.49 0.249
EgNRT1.56KAK3445120.1Chr120,129,841 20,134,001 57163.91 8.12 24.92 0.206
EgNRT1.57KAK3406767.1Chr1136,353,120 36,355,616 60667.99 9.11 38.27 0.182
EgNRT1.58KAK3406769.1Chr1136,380,891 36,384,668 58964.90 9.28 34.47 0.345
EgNRT1.59KAK3406773.1Chr1136,422,757 36,425,873 61768.93 8.59 35.14 0.176
EgNRT1.60KAK3406774.1Chr1136,444,862 36,448,073 59766.05 9.21 38.63 0.253
EgNRT1.61KAK3426578.1Chr642,086,125 42,089,987 40444.60 6.74 39.95 0.460
EgNRT1.62KAK3440091.1Chr23,792,284 3,794,705 60066.73 9.31 35.27 0.270
EgNRT1.63KAK3440092.1Chr23,808,628 3,811,132 60066.84 9.28 34.88 0.251
EgNRT1.64KAK3440093.1Chr23,803,834 3,806,399 57564.00 9.30 35.81 0.202
EgNRT1.65KAK3426647.1Chr642,459,508 42,462,203 53358.96 8.86 43.17 0.205
EgNRT1.66KAK3435815.1Chr38,569,729 8,573,136 53758.92 7.50 37.84 0.447
EgNRT1.67KAK3435907.1Chr311,297,439 11,301,408 63269.37 5.98 41.14 0.402
EgNRT1.68KAK3439164.1Chr376,588,303 76,591,154 58664.67 9.29 36.47 0.256
EgNRT1.69KAK3439166.1Chr376,595,223 76,597,726 57463.13 9.11 43.35 0.360
EgNRT2.1KAK3408717.1Chr109,727,832 9,729,792 53057.47 8.86 39.08 0.324
EgNRT2.2KAK3416771.1Chr833,614,452 33,616,983 50854.83 8.51 35.42 0.390
EgNRT2.3KAK3410216.1Chr1027,433,602 27,437,118 37839.93 6.29 33.94 0.580
EgNRT2.4KAK3443186.1Chr253,783,851 53,786,418 50354.02 8.82 34.37 0.407
EgNRT3.1KAK3439874.1Chr21,786,661 1,788,242 20522.29 9.21 38.46 −0.092
EgNRT3.2KAK3439873.1Chr21,769,131 1,772,134 32035.90 6.26 38.76 −0.238
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Li, G.; Yang, D.; Hu, Y.; Xu, J.; Lu, Z. Genome-Wide Identification and Expression Analysis of Nitrate Transporter (NRT) Gene Family in Eucalyptus grandis. Genes 2024, 15, 930. https://doi.org/10.3390/genes15070930

AMA Style

Li G, Yang D, Hu Y, Xu J, Lu Z. Genome-Wide Identification and Expression Analysis of Nitrate Transporter (NRT) Gene Family in Eucalyptus grandis. Genes. 2024; 15(7):930. https://doi.org/10.3390/genes15070930

Chicago/Turabian Style

Li, Guangyou, Deming Yang, Yang Hu, Jianmin Xu, and Zhaohua Lu. 2024. "Genome-Wide Identification and Expression Analysis of Nitrate Transporter (NRT) Gene Family in Eucalyptus grandis" Genes 15, no. 7: 930. https://doi.org/10.3390/genes15070930

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop