Table 3.
Changes in the relative expression levels of selected genes for the biosynthesis of phenolic compounds measured by qRT-PCR.
| Fold change in gene expression | ||||
|---|---|---|---|---|
| Drought | Active photorespiration | |||
| WT | Ljgln2-2 | WT | Ljgln2-2 | |
| GENE PRODUCT | ||||
| PAL | 3.06 ± 1.15 | 7.86 ± 2.43 | 1.90 ± 0.59 | 10.78 ± 2.50 |
| C4H | 2.39±0.78 | 10.7 ± 4.72 | 1.21±1.16 | 16.12 ± 3.22 |
| 4CL | 1.09±0.62 | 5.14 ± 1.67 | 1.29±0.41 | 1.93 ± 0.79 |
| CHS | 3.76 ± 0.45 | 9.59 ± 2.04 | 2.54±1.70 | 13.85 ± 5.12 |
| CHI | 1.52±0.51 | 2.66 ± 0.65 | 2.02 ± 0.40 | 9.65 ± 2.53 |
| F3H | 0.86±0.36 | 0.68±0.33 | 0.58 ± 0.08 | 0.38 ± 0.09 |
| FLS | 0.74±0.40 | 0.78±0.40 | 0.63 ± 0.02 | 0.55 ± 0.01 |
| DFR | 1.70±1.12 | 3.21 ± 1.63 | 0.83±0.20 | 8.16 ± 1.34 |
| ANS | 1.16±0.39 | 1.28±0.58 | 0.27 ± 0.15 | 0.41 ± 0.18 |
| LAR | 1.06±0.21 | 0.87±031 | 0.40 ± 0.22 | 0.36 ± 0.24 |
| ANR | 1.21±1.03 | 1.34±0.96 | 0.26 ± 0.19 | 0.71 ± 0.33 |
| PKR | 1.16±0.77 | 1.75±0.44 | 2.68±1.58 | 13.04 ± 3.30 |
| IFS | 1.59±0.64 | 5.06 ± 2.13 | 2.11 ± 0.49 | 8.85 ± 2.45 |
| HI4′OMT | 1.17±0.72 | 2.08 ± 0.42 | 1.87±1.22 | 13.42 ± 6.61 |
| HID | 1.38±1.01 | 1.64±1.10 | 1.98 ± 0.69 | 13.67 ± 5.74 |
| I2′H | 1.26±0.60 | 8.16 ± 3.12 | 3.24 ± 0.79 | 17.47 ± 7.16 |
| IFR | 1.69±0.98 | 2.50±0.65 | 1.19±0.38 | 28.99 ± 17.53 |
| VR | 2.95 ± 1.54 | 18.82 ± 7.49 | 2.50 ± 0.89 | 16.38 ± 9.98 |
| PTR | 1.85±0.86 | 2.94 ± 1.01 | 3.32 ± 1.04 | 22.25 ± 11.32 |
The levels of transcript for each gene under control conditions in each genotype were taken as 1.00. Numbers in red mean significant difference between control and stress conditions for each genotype according to Student's t test (p < 0.05). Transcript levels have been measured for three independent biological replicates. The gene products highlighted in blue belong to the entry of the pathway, black highlights the enzymes of the central flavonoid biosynthetic pathway, gray highlights enzymes for anthocyanins and protoanthocyanidins biosynthesis and in red are highlighted enzymes for isoflavonoid biosynthesis. The abbreviations for the enzyme activities are: PAL, phenylalanine-ammonia lyase; 4CL, 4-Coumarate:CoA ligase; C4H, cinnamate-4-dehydrogenase; CHS, chalcone synthase; CHI, chalcone isomerase; F3H, flavanone 3β-hydroxylase; FLS, flavonol synthase; DFR, dihydroflavonol reductase; ANS, anthocyanin synthase; LAR, leucoanthocyanidin reductase; ANR, anthocyanidin reductase; PKR, polyketide reductase also called chalcone reductase; IFS, isoflavone synthase; HI4'OMT, 2,4,7′-Hydroxyisoflavanone 4′-O-methyltransferase; HID, isoflavanone dehydratase; I2′H, isoflavone 2′-hydroxylase; IFR, isoflavone reductase; VR, vestitone reductase; and PTR, pterocarpan reductase. CHS and CHI are reported as belonging to the flavonoid biosynthetic pathway but are also fundamental for the biosynthesis of isoflavonoids. Expression data were normalized using the geometric mean of three housekeeping genes: L. japonicus protein phosphatase 2A (LjPp2A; chr2.CM0310.22), L. japonicus ubiquitin carrier protein 10 (LjUbc10; chr1.TM0487.4), and L. japonicus polyubiquitin 4 (LjUbq4; chr5.CM0956.27), that were selected among the most stably expressed genes in plants (Czechowski et al., 2004). Data are the mean ± S.D. of three independent biological replicates.