1 材料与方法
1.1 材料
1.2 方法
1.2.1 基因组的测序和注释
1.2.2 系统发育分析
1.2.3 密码子相关参数计算
1.2.4 朱蕉密码子使用偏好性影响因素相关分析
表1 朱蕉叶绿体基因组基因功能分类Tab. 1 Functional classification of C. fruticosa chloroplast genome |
| 基因分类Gene type | 基因分组Group of gene | 基因名称Gene name |
|---|---|---|
| 其他基因 | 乙酰辅酶A羧化酶基因 | accD |
| 蛋白酶基因 | clpPc | |
| 细胞色素合成基因 | ccsA | |
| 膜蛋白基因 | cemA | |
| 成熟酶K基因 | matK | |
| 翻译起始密码子基因 | infA | |
| 假定叶绿体阅读框 | ycf1, ycf2(2), ycf3, ycf4 | |
| 光合系统基因 | NADH氧化还原酶基因 | ndhA, ndhB(2), ndhC, ndhD, ndhE, ndhF, ndhG, ndhH, ndhI, ndhJ, ndhK |
| ATP酶基因 | atpA, atpB, atpF, atpH, atpE, atpI | |
| 细胞色素b/f复合体基因 | petA, petB, petD, petG, petL, petN | |
| 光系统I基因 | psaA, psaB, psaC, psaI, psaJ | |
| 光系统II基因 | psbA, psbB, psbC, psbD, psbE, psbF, psbH, psbI, psbJ, psbK, psbL, psbM, psbN, psbT, psbZ | |
| 二磷酸核酮糖羧化酶大亚基基因 | rbcL | |
| 遗传系统基因 | RNA聚合酶亚基基因 | rpoA, rpoB, rpoC1, rpoC2 |
| 核糖体蛋白大亚基基因 | rpl14, rpl20, rpl16, rpl2(2), rpl22, rpl23(2), rpl32, rpl33, rpl36 | |
| rRNA基因 | rrn16(2), rrn23(2), rrn5(2), rrn4.5(2) | |
| 核糖体蛋白小亚基基因 | rps11, rps14, rps15, rps16, rps2, rps3, rps4, rps7(2), rps8, rps18, rps19(2) | |
| tRNA基因 | trnM-CAU, trnN-GUU(2), trnP-UGG, trnA-UGC(2), trnC-GCA, trnD-GUC, trnE-UUC, trnF-GAA, trnG-GCC, trnG-UCC, trnH-GUG(2), trnI-CAU(2), trnI-GAU(2), trnT-GGU, trnT-UGU, trnL-CAA(2), trnL-UAG, trnL-UAA, trnQ-UUG, trnR-ACG(2), trnR-UCU, trnS-GCU, trnS-GGA, trnS-UGA, trnV-GAC(2), trnW-CCA, trnfM-CAU, trnk-UUU, trnY-GUA |
注:标有上标(2)表示基因重复个数。 | |
Note: The superscript (2) indicates the number of gene duplication. |
1.2.5 最优密码子分析
1.2.6 朱蕉叶绿体基因组特征分析
2 结果与分析
2.1 朱蕉叶绿体基因组结构与特征
图1 朱蕉叶绿体基因组图谱不同的颜色代表不同基因的类型,大环内的基因按顺时针方向转录,大环外的基因按逆时针方向转录,GC含量为环内灰色区域。 Fig. 1 Gene map of C. fruticosa chloroplast genome Different colors represent different gene types, and the genes within the macroloop are transcribed clockwise, while genes outside the macroloop are transcribed counterclockwise, GC content is the gray area within the loop. |
2.2 系统发育分析
2.3 密码子相关性分析
表2 朱蕉叶绿体基因密码子的不同位置GC含量及ENC值Tab. 2 GC content and ENC value of different positions of chloroplast genomic codon in C. fruticosa |
| 基因Gene | GC1/% | GC2/% | GC3/% | GCall/% | ENC | 基因Gene | GC1/% | GC2/% | GC3/% | GCall/% | ENC |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ycf4 | 44.32 | 42.16 | 31.89 | 39.46 | 49.70 | psaB | 48.44 | 42.86 | 32.52 | 41.27 | 48.80 |
| ycf3 | 46.75 | 40.83 | 40.83 | 39.64 | 59.44 | psaA | 52.06 | 43.41 | 34.49 | 43.32 | 51.97 |
| ycf2 | 42.65 | 33.94 | 37.19 | 37.92 | 52.88 | petA | 53.29 | 35.74 | 28.21 | 39.08 | 49.31 |
| ycf1 | 38.05 | 31.12 | 28.26 | 32.48 | 49.16 | ndhK | 42.17 | 42.57 | 27.71 | 37.48 | 50.17 |
| rps18 | 34.67 | 30.67 | 28.67 | 31.33 | 35.48 | ndhJ | 48.43 | 39.62 | 33.33 | 40.46 | 57.11 |
| rps14 | 47.52 | 46.53 | 31.68 | 41.91 | 40.66 | ndhI | 40.88 | 36.46 | 22.10 | 33.15 | 45.15 |
| rps11 | 55.32 | 58.16 | 21.28 | 44.92 | 48.49 | ndhH | 50.76 | 36.80 | 26.40 | 37.99 | 47.21 |
| rps8 | 40.00 | 41.48 | 26.67 | 36.05 | 42.11 | ndhG | 42.94 | 35.59 | 23.73 | 34.09 | 46.45 |
| rps7 | 50.00 | 45.51 | 24.36 | 39.96 | 48.58 | ndhF | 37.43 | 37.03 | 25.00 | 33.15 | 44.22 |
| rps4 | 48.51 | 40.10 | 28.22 | 38.94 | 49.91 | ndhE | 38.24 | 32.35 | 31.37 | 33.99 | 55.15 |
| rps3 | 44.10 | 34.93 | 27.07 | 35.37 | 48.17 | ndhD | 40.84 | 36.85 | 31.27 | 36.32 | 50.16 |
| rps2 | 42.62 | 42.62 | 30.80 | 38.68 | 49.42 | ndhC | 50.41 | 35.54 | 28.10 | 38.02 | 47.20 |
| rpoC2 | 46.43 | 37.11 | 28.38 | 37.30 | 49.19 | ndhB | 42.86 | 40.12 | 31.51 | 38.16 | 47.34 |
| rpoC1 | 51.46 | 37.32 | 31.20 | 39.99 | 52.38 | ndhA | 44.23 | 39.29 | 25.27 | 36.26 | 44.54 |
| rpoB | 50.14 | 38.38 | 29.04 | 39.18 | 48.64 | matK | 39.88 | 30.06 | 23.51 | 31.15 | 47.54 |
| rpoA | 47.35 | 35.88 | 28.53 | 37.25 | 51.27 | cemA | 40.43 | 28.26 | 31.30 | 33.33 | 52.57 |
| rpl22 | 42.15 | 39.67 | 28.10 | 36.64 | 47.87 | ccsA | 30.56 | 39.51 | 30.25 | 33.44 | 51.18 |
| rpl20 | 40.46 | 45.04 | 30.53 | 38.68 | 51.43 | atpI | 49.19 | 36.29 | 26.21 | 37.23 | 45.62 |
| rpl14 | 54.47 | 36.59 | 24.39 | 38.48 | 46.11 | atpF | 49.19 | 34.05 | 32.43 | 38.56 | 43.47 |
| rbcL | 57.97 | 43.89 | 27.74 | 43.20 | 47.26 | atpE | 51.49 | 41.04 | 32.84 | 41.79 | 51.91 |
| psbD | 52.82 | 43.22 | 33.05 | 43.03 | 45.79 | atpB | 56.65 | 41.33 | 31.45 | 43.15 | 49.56 |
| psbC | 54.01 | 46.41 | 32.28 | 44.23 | 44.87 | atpA | 55.51 | 39.76 | 29.13 | 41.47 | 47.62 |
| psbB | 55.01 | 46.56 | 32.42 | 44.66 | 51.21 | accD | 41.09 | 33.09 | 29.82 | 34.67 | 48.53 |
| psbA | 49.44 | 43.79 | 34.75 | 42.66 | 41.81 | Average | 46.45 | 39.14 | 29.47 | 38.29 | 48.40 |
注: GCall表示各密码子位置的平均GC含量。 | |
Note: GCall represents the average GC content at each codon position. |
表3 朱蕉叶绿体基因密码子参数的相关性分析Tab. 3 Correlation analysis of parameters of chloroplast genomic codon in C. fruticosa |
| 参数Paremeter | GC1 | GC2 | GC3 | GCall | ENC | |
|---|---|---|---|---|---|---|
| GC2 | 0.483** | |||||
| GC3 | 0.084 | 0.051 | ||||
| GCall | 0.845** | 0.785** | 0.371* | |||
| ENC | 0.061 | 0.001 | 0.420** | 0.134 | ||
| 密码子数N | -0.073 | -0.236 | 0.190 | -0.081 | 0.140 | |
注:*表示显著相关(P<0.05);**表示极显著相关(P<0.01)。 | |
Note: * indicates significant correlation (P<0.05); ** indicates extremely significant correlation (P<0.01). |
表4 朱蕉叶绿体基因组最优密码子的确定Tab. 4 Determination of optimal codons in the chloroplast genome of C. fruticosa |
| 氨基酸 Amino acid | 密码子 Codon | 高表达基因 High expression gene | 低表达基因 Low expression gene | △RSCU | 氨基酸Amino acid | 密码子Codon | 高表达基因High expression gene | 低表达基因 Low expression gene | △RSCU | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| RSCU | No. | RSCU | No. | RSCU | No. | RSCU | No. | ||||||
| Phe | UUU | 25 | 1.00 | 88 | 0.98 | 0.02 | Ile | AUU** | 40 | 1.58 | 91 | 1.21 | 0.37 |
| UUC | 25 | 1.00 | 91 | 1.02 | -0.02 | AUC | 17 | 0.67 | 63 | 0.84 | -0.17 | ||
| Ser | UCU* | 18 | 1.69 | 64 | 1.49 | 0.20 | AUA | 19 | 0.75 | 72 | 0.96 | -0.21 | |
| UCC | 13 | 1.22 | 52 | 1.21 | 0.01 | Thr | ACU*** | 25 | 2.27 | 41 | 1.52 | 0.75 | |
| UCA | 2 | 0.19 | 58 | 1.35 | -1.16 | ACC*** | 13 | 1.18 | 17 | 0.63 | 0.55 | ||
| UCG | 3 | 0.28 | 30 | 0.70 | -0.42 | ACA | 5 | 0.45 | 30 | 1.11 | -0.66 | ||
| AGU*** | 22 | 2.06 | 43 | 1.00 | 1.06 | ACG | 1 | 0.09 | 20 | 0.74 | -0.65 | ||
| AGC** | 6 | 0.56 | 11 | 0.26 | 0.30 | Lys | AAA* | 36 | 1.50 | 114 | 1.33 | 0.17 | |
| Tyr | UAU | 17 | 1.21 | 81 | 1.64 | -0.43 | AAG | 12 | 0.50 | 58 | 0.67 | -0.17 | |
| UAC** | 11 | 0.79 | 18 | 0.36 | 0.43 | Met | AUG | 23 | 1.00 | 63 | 1.00 | 0.00 | |
| Cys | UGU* | 5 | 1.43 | 18 | 1.33 | 0.10 | Val | GUU** | 20 | 1.86 | 39 | 1.51 | 0.35 |
| UGC | 2 | 0.57 | 9 | 0.67 | -0.10 | GUC | 2 | 0.19 | 16 | 0.62 | -0.43 | ||
| TER | UAA*** | 3 | 1.80 | 1 | 0.60 | 1.20 | GUA** | 17 | 1.58 | 33 | 1.28 | 0.30 | |
| UGA | 1 | 0.60 | 2 | 1.20 | -0.60 | GUG | 4 | 0.37 | 15 | 0.58 | -0.21 | ||
| UAG | 1 | 0.60 | 2 | 1.20 | -0.60 | Ala | GCU*** | 36 | 2.44 | 41 | 1.89 | 0.55 | |
| Trp | UGG | 13 | 1.00 | 53 | 1.00 | 0.00 | GCC | 7 | 0.47 | 15 | 0.69 | -0.22 | |
| Pro | CCU*** | 19 | 2.53 | 33 | 1.17 | 1.36 | GCA | 13 | 0.88 | 21 | 0.97 | -0.09 | |
| CCC | 0 | 0.00 | 22 | 0.78 | -0.78 | GCG | 3 | 0.20 | 10 | 0.46 | -0.26 | ||
| CCA | 8 | 1.07 | 32 | 1.13 | -0.06 | Asp | GAU | 16 | 1.14 | 132 | 1.67 | -0.53 | |
| CCG | 3 | 0.40 | 26 | 0.92 | -0.52 | GAC*** | 12 | 0.86 | 26 | 0.33 | 0.53 | ||
| His | CAU | 16 | 1.45 | 54 | 1.59 | -0.14 | Gly | GGU** | 25 | 1.56 | 33 | 1.25 | 0.31 |
| CAC* | 6 | 0.55 | 14 | 0.41 | 0.14 | GGC** | 10 | 0.63 | 8 | 0.30 | 0.33 | ||
| Arg | CGU*** | 21 | 1.48 | 26 | 0.94 | 0.54 | GGA | 23 | 1.44 | 43 | 1.62 | -0.18 | |
| CGC | 4 | 0.28 | 13 | 0.47 | -0.19 | GGG | 6 | 0.38 | 22 | 0.83 | -0.45 | ||
| CGA** | 22 | 1.55 | 32 | 1.16 | 0.39 | Glu | GAA* | 40 | 1.43 | 107 | 1.22 | 0.21 | |
| CGG | 5 | 0.35 | 22 | 0.80 | -0.45 | GAG | 16 | 0.57 | 69 | 0.78 | -0.21 | ||
| AGA | 26 | 1.84 | 50 | 1.81 | 0.03 | Leu | UUA*** | 29 | 2.05 | 51 | 1.06 | 0.99 | |
| AGG | 7 | 0.49 | 23 | 0.83 | -0.34 | UUG* | 25 | 1.76 | 73 | 1.52 | 0.24 | ||
| Gln | CAA | 19 | 1.09 | 56 | 1.30 | -0.21 | CUU | 12 | 0.85 | 74 | 1.54 | -0.69 | |
| CAG* | 16 | 0.91 | 30 | 0.70 | 0.21 | CUC | 4 | 0.28 | 22 | 0.46 | -0.18 | ||
| Asn | AAU | 39 | 1.30 | 118 | 1.56 | -0.26 | CUA | 12 | 0.85 | 49 | 1.02 | -0.17 | |
| AAC* | 21 | 0.70 | 33 | 0.44 | 0.26 | CUG | 3 | 0.21 | 20 | 0.42 | -0.21 | ||
注:*表示△RSCU≥0.08,**表示△RSCU≥0.3,***表示△RSCU≥0.5;带下划线的密码子表示RSCU>1,加粗的密码子为最优密码子。 | |
Note: * indicates △RSCU≥0.08, ** indicates △RSCU≥0.3, *** indicates △RSCU≥0.5; The codon with underline indicates RSCU>1 and the bold codon indicates the optimal codon. |
2.4 密码子使用偏好性影响因素
表5 朱蕉叶绿体基因的ENC分布频率Tab. 5 Frequency of ENC distribution in chloroplast genes of C. fruticosa |
| 组段 Class range | 组中值 Class mid value | 频数 Frequency number | 频率 Frequency |
|---|---|---|---|
| -0.15~-0.05 | -0.10 | 1 | 0.021 |
| -0.05~0.05 | 0.00 | 20 | 0.426 |
| 0.05~0.15 | 0.10 | 19 | 0.404 |
| 0.15~0.25 | 0.20 | 6 | 0.128 |
| 0.25~0.35 | 0.30 | 1 | 0.021 |
| 合计 | 47 | 1.000 |
