Figures (7)  Tables (2)
    • Figure 1. 

      The planting mode and different performance of (a) trees and (b) fruits of Cj + LL and Pt + LL, and (c) the fruit quality data of peel color parameters, single fruit weight, total soluble solid and titratable acid of Cj + LL and Pt + LL at five different development stages. Cj + LL: Ziyang xiangcheng + Lane Late navel orange; Pt + LL: Poncirus trifoliate + Lane Late navel orange. DAF: days after flowering. Bars represent the standard error (n = 3). A single asterisk (*) represents statistically significant differences (p < 0.05). Analyzed using t test.

    • Figure 2. 

      The content of several mineral elements in different tissues of (a) Cj + LL and Pt + LL and (b) the content of ABA and IAA in the root, stem and leaf tissues of Cj + LL and Pt + LL. Cj + LL: Ziyang xiangcheng + Lane Late navel orange; Pt + LL: Poncirus trifoliate + Lane Late navel orange. Bars represent the standard error (n = 3). A single asterisk (*) represents statistically significant differences (p < 0.05). Analyzed using Student's t test.

    • Figure 3. 

      Global analysis of gene expression in different tissues of Cj + LL and Pt + LL. (a) The number of differentially expressed genes in the root, stem and leaf tissues. (b) Venn diagram showing the number of commonly and uniquely expressed genes in the root, stem and leaf tissues. (c) Heatmap showing the genes differentially expressed in the root, stem and leaf tissues. DEG: differentially expressed gene.

    • Figure 4. 

      Treemap showing the Gene Ontology (GO) enrichment analysis and the enriched KEGG pathways of the DEGs in the (a), (d) root tissue, (b) stem tissue and (c) leaf tissue of Cj + LL and Pt + LL. (a)−(c), biological processes; (d) KEGG pathways. Each rectangle is a single cluster representative. The representatives are joined into 'superclusters' of loosely related terms, visualized with different colors. The size of the rectangles may be adjusted to reflect either the p value or the frequency of the GO term in the underlying GO database. KEGG: Kyoto Encyclopedia of Genes and Genomes.

    • Figure 6. 

      The contents of (a) JA, (b) lignin, (c) GSH, (d) MDA and (e) H2O2 in Cj + LL and Pt + LL. JA: jasmonate; GSH: glutathione; ABA: abscisic acid; IAA: indole-3-acetic acid. A single asterisk (*) represents statistically significant differences (p < 0.05), and double asterisks (**) represent highly statistically significant differences (p < 0.01). Analyzed using Student's t test.

    • Figure 7. 

      Exogenous JA treatment of Cj seedlings with different concentrations under alkalinity stress. (a) Phenotypes of Cj seedlings; (b)−(c) contents of MDA and H2O2 in the root, stem and leaf tissues; (d) number of LRs of Cj seedlings. In this figure, the treatment groups are named 'C=concentration'. C = 0.5 indicates that the JA treatment concentration was 0.5 μM. Lowercase and capital letters represent statistically significant differences (p < 0.05) and highly statistically significant differences (p < 0.01), respectively. Data were analyzed using one-way ANOVA.

    • Figure 8. 

      Exogenous MeJA, SHAM and NAA treatment of Cj seedlings under alkalinity stress. (a) Phenotypes of Cj seedlings; (b) Number of LRs of Cj seedlings; (c) In situ accumulation of H2O2 and anti-O2· examined by histochemical staining with DAB and NBT in leaf tissue and the contents of MDA, H2O2 and anti-O2· in the root, stem and leaf tissues; (d) chlorophyll fluorescence imaging; (e) Fv/Fm ratios. Lowercase and capital letters represent statistically significant differences (p < 0.05) and highly statistically significant differences (p < 0.01), respectively. Data were analyzed using one-way ANOVA.

    • Gene IDFPKMlog2 Ratio
      (Cj + LL_root/Pt + LL_root)
      ProbabilityGene name
      Pt + LL_rootCj + LL_root
      H+-transporting ATPase
      Cs6g0349013.806.03−1.200.83ATPase 4
      Cs5g0436032.3512.96−1.320.86ATPase 11
      Cs5g083700.627.443.600.89ATPase
      Cs2g13550320.97115.17−1.480.89F-type H+-transporting ATPase subunit beta
      Cs7g145200.624.642.900.82V-type H+-transporting ATPase subunit H
      Cs3g255506.750.85−2.990.86V-type H+-transporting ATPase subunit a
      Cs3g2556012.035.59−1.110.81V-type H+-transporting ATPase subunit a
      Aquaporin
      Cs7g25610125.6652.03−1.270.87Aquaporin PIP 2-1
      Cs7g31410148.7722.09−2.750.92Aquaporin PIP 1-1
      Cs6g1167010.041.80−2.480.87Aquaporin PIP 2-2
      Cs6g1170014.955.82−1.360.84Aquaporin PIP2-1
      Cs5g0871015.092.82−2.420.89Aquaporin TIP2-2
      Cs7g28650447.9551.70−3.120.93Aquaporin TIP1-1
      Cs8g1790011.522.95−1.970.86Aquaporin TIP1-3
      Cs2g043704.2820.432.250.89Aquaporin NIP1-2
      JA biosynthesis and signal transduction
      Cs9g0521015.71133.923.090.93PKT
      Cs5g1788024.2352.721.120.86OPR2
      Cs5g1792038.68125.161.690.90OPR2
      Cs6g0863013.0448.651.900.90ACX
      Cs1g1738043.1290.511.070.86LOX3
      orange1.1t0377337.65113.441.590.89LOX2
      orange1.1t0437621.70114.642.400.92LOX2
      orange1.1t0046422.5346.721.050.85JAR1
      Cs1g17210153.01442.861.530.89JAZ
      Cs1g1722070.18182.711.380.88JAZ
      Cs7g02820232.46521.601.170.87JAZ10
      Cs7g3160031.2717.16−0.870.81COI1
      ABA biosynthesis and signal transduction
      Cs1g226206.4032.662.350.91ABA1
      Cs6g140307.3720.571.480.86ABA2
      Cs6g1938055.00495.163.170.94ABA 8'-hydroxylase
      Cs8g1914013.735.495−1.320.84HAI2
      Cs9g180205.2912.541.250.824PP2C
      orange1.1t00478136.2236.88−1.890.904PYL9
      orange1.1t0102662.7821.28−1.560.894PYR1
      Cs1g1938037.8714.395−1.400.87SnRK2.5
      Cs4g059900.012.127.730.807SnRK2
      Cs1g1991011.74532.31.460.87SnRK2
      Auxin signal transduction
      Cs4g0452012.7129.771.230.86ARF7
      Cs4g0702033.1514.08−1.240.86ARF19
      Cs3g2586027.1511.37−1.260.86ARF5
      Cs2g054405.551.43−1.9640.80ARF3
      Cs1g1396018.2567.951.900.90IAA15
      Cs9g0810018.6658.731.650.89IAA22B
      Cs4g182408.7751.102.540.91IAA29
      Cs6g0799047.9919.56−1.290.87AUX1
      Cs1g221401.246.172.320.84GH3.1
      Cs5g320309.9027.821.490.87GH3.6
      Cs4g1272043.5417.55−1.310.87SAUR72
      Cs7g0303029.7813.75−1.110.85SAUR
      orange1.1t0255020.2152.501.380.87SAUR
      Cs5g3250014.396.51−1.140.82TIR1
      Cytokinin signal transduction
      Cs5g3214039.7516.12−1.300.87AHP
      orange1.1t0185060.9215.39−1.980.90ARR-A
      Cs7g0794056.7013.82−2.040.91ARR-A
      Cs9g0276016.876.64−1.350.85ARR-B
      Cs7g0618020.059.22−1.120.84ARR-B
      Cs2g1976010.393.45−1.590.84CRE1
      Phenylpropanoid biosynthesis (lignin biosynthesis)
      orange1.1t02755199.8975.86−1.400.88CCR1
      Cs7g2494032.0881.541.350.88PAL4
      Cs6g11940263.56143.15−0.880.83PAL1
      Cs8g1588016.645.42−1.620.874CL
      orange1.1t02041308.63637.331.050.86Peroxidase 15
      Cs2g2811042.0914.10−1.580.89Peroxidase 4
      orange1.1t029474.35574.874.100.96OMT1
      orange1.1t0368670.367.03−3.320.94OMT1
      Cs1g1266019.9494.942.250.91CCOAMT
      Cs1g2245074.5434.48−1.110.86CCOAMT
      Vitamin E biosynthesis
      Cs7g175607.8016.061.040.82PDS1
      Cs7g1525036.259.42−1.940.89G-TMT
      Cs9g178401.899.442.320.87HPT1
      Cs3g0392010.382.98−1.800.85HPT1
      Cs9g195201.6718.183.450.92HPT1
      orange1.1t053520.7112.254.110.93HPT1
      Glutathione metabolism
      Cs5g32800416.341032.871.310.88GST
      Cs1g0237022.367.25−1.620.88GGT
      Cs5g03830169.05659.591.960.90GPX
      Cs6g1931094.55217.631.200.87G6PD
      orange1.1t0266534.8313.39−1.380.87GR

      Table 1. 

      A list of some of the important differentially expressed genes in the root tissue between Cj + LL and Pt + LL.

    • Gene IDStem (FPKM)Leaf (FPKM)Gene
      name
      Pt + LL
      _stem
      Cj + LL
      _stem
      log2 Ratio
      (Cj + LL_stem /
      Pt + LL_stem)
      ProbabilityPt + LL
      _leaf
      Cj + LL
      _ leaf
      log2 Ratio
      (Cj + LL_leaf /
      Pt + LL_leaf)
      Probability
      Phenylpropanoid biosynthesis
      Cs1g1178024.5656.531.200.8722.3674.581.740.90HCT
      Cs4g019307.5216.541.140.80HCT
      Cs1g1266020.3462.341.620.89CCoAOMT
      Cs6g1194072.42157.961.130.87PAL
      Cs6g209508.000.12−6.060.9014.820.08−7.530.96OMT1
      orange1.1t052186.3924.561.940.88OMT1
      orange1.1t0535428.118.83−1.670.88OMT1
      Cs8g0497027.459.07−1.600.87CAD
      orange1.1t020362.8710.971.940.83Peroxidase15
      orange1.1t020412.6114.312.450.87Peroxidase15
      orange1.1t0204416.2643.461.420.87Peroxidase15
      alpha-Linolenic acid metabolism
      Cs1g1738015.0745.381.590.89LOX3
      Cs2g2100029.4995.151.690.90HPL1
      orange1.1t0437626.9211.80−1.190.8415.3535.871.220.85LOX2
      ABA biosynthesis
      Cs5g1437013.5835.271.380.87NCED1
      Cs8g1878018.0747.401.390.87ABA 8'-hydroxylase
      Cs8g059401.809.712.430.84ABA 8'-hydroxylase
      Cs6g1938043.574.88−3.160.93ABA 8'-hydroxylase
      Plant hormone signal transduction
      Cs1g1583032.4914.61−1.150.84IAA26
      Cs1g1396037.5997.301.370.88IAA15
      Cs2g178606.2116.411.400.83CRE1
      Cs3g2312016.0334.301.100.84Cyclin D3
      orange1.1t0185013.8146.121.740.89ARR-A
      Cs5g048108.0432.932.030.89ARR5
      Cs4g153606.9817.241.310.82PP2C

      Table 2. 

      List of some of the important differentially expressed genes in the stem and leaf tissues between Cj + LL and Pt + LL.