Cloning and Expression of BsDFR in Bougainvillea spectabilis
-
摘要:
目的 克隆分析三角梅(Bougainvillea spectabilis)二氢黄酮醇-4-还原酶(Dihydroflavonol-4-reductase, DFR)基因(BsDFR),探讨其在三角梅苞片呈色中的作用。 方法 基于三角梅转录组数据,利用PCR技术克隆BsDFR基因,并通过生物信息学工具分析其分子特性;通过分子对接技术预测BsDFR底物特异性;采用实时荧光定量PCR分析该基因在不同颜色三角梅中的表达量差异。 结果 三角梅BsDFR基因(GenBank ID:ON417750)编码区全长987 bp,编码328个氨基酸。BsDFR理论相对分子质量为36.48 kDa,等电点pI为6.33;具有DFR特有的NADPH及底物特异结合位点,属于Asn型DFR;不具有跨膜结构及信号肽,定位于细胞质中;二级结构中α螺旋占比最多,三级结构预测显示为二聚体蛋白。底物对接模拟预测BsDFR对二氢山柰酚(Dihydrokaempferol, DHK)、二氢槲皮素(Dihydroquercetin, DHQ)和二氢杨梅素(Dihydromyricetin, DHM)3种底物均具有催化活性,与结构分析相吻合。进化树分析其与石竹目(Centrospermae)植物聚为一类。qRT-PCR分析发现其在橙色系三角梅中含量较高,进一步推测其主要底物为DHK,催化生成橙色系花青素(天竺葵素)的前体物质——无色天竺葵素苷元。 结论 BsDFR基因是一个典型的植物二氢黄酮醇-4-还原酶基因,主要与橙色系三角梅苞片色素合成有关。 Abstract:Objective The dihydroflavonol-4-reductase (DFR) gene in bracts of Bougainvillea spectabilis was cloned and characterized to study the role it plays in color formation. Method BsDFRwas cloned based on the transcriptome data on the ornamental plant to study the related bioinformatics. Molecular docking technology was employed to predict the substrate specificity, and qRT-PCR applied to examine the relative transcription levels of the genes in B. spectabilis of different colors. Result The full-length coding sequence of BsDFR (GenBank ID: ON417750) was 987 bp encoding 328 amino acids. The protein had a calculated molecular weight of 36.49 kDa and an isoelectric point of 6.33. It had the NADPH and substrate specific binding sites unique to DFR of Asn type without a transmembrane structure or signal peptide. The subcellular localization of the protein indicated it to be cytoplasmic. Alpha helices were the most abundant secondary structure of the protein, while the tertiary structure was a dimer. A substrate docking simulation, consistent with the structural analysis, predicted BsDFR to possess a catalytic activity on dihydrokaempferol, dihydroquercetin, and dihydromyricetin. The phylogenetic tree analysis grouped it along with caryophyllales plants. High expression of the gene was found in the orange B. spectabilis by qRT-PCR. It was speculated that the main substrate to be DHK, which was catalyzed by BsDFR into leucopelargonidin, a precursor of orange-colored anthocyanidin——pelargonidin. Conclusion BsDFR in B. spectabilis had typical molecular characteristics of the plant dihydroflavonol-4-reductase, which is associated with the pigment synthesis in the bracts of orange B. spectabilis. -
表 1 引物信息
Table 1. Primers applied
引物
Primers序列
Sequence(5′-3′)用途
UsageDFR F:ATGAGTGGAGGAGAAGAGCAAG 基因克隆
Gene cloningDFR R:TAAACTCTCCACTGTATCCTTGA 18S F:CAGAACATCTAAGGGCATCACA 荧光定量
Gene expression18S R:TAGTTGGTGGAGCGATTTGTCT DFRq F:AAGGCTCTGATGTGATGTGGTATG DFRq R:ACTATCGTTGAGGGTTGGTTGC -
[1] 徐夙侠, 王亮生, 舒庆艳, 等. 三角梅属植物的生物学研究进展 [J]. 植物学通报, 2008, 43(4):483−490.XU S X, WANG L S, SHU Q Y, et al. Progress of study of the biology of the resource plant Bougainvillea [J]. Chinese Bulletin of Botany, 2008, 43(4): 483−490.(in Chinese) [2] 常圣鑫, 杨光穗, 陈金花, 等. 世界三角梅产业发展历史及趋势 [J]. 热带农业科学, 2018, 38(1):71−77.CHANG S X, YANG G S, CHEN J H, et al. Development history and tendency of Bougainvillea industry all over the world [J]. Chinese Journal of Tropical Agriculture, 2018, 38(1): 71−77.(in Chinese) [3] GROTEWOLD E. The genetics and biochemistry of floral pigments [J]. Annual Review of Plant Biology, 2006, 57: 761−780. doi: 10.1146/annurev.arplant.57.032905.105248 [4] HELLER W, FORKMANN G, BRITSCH L, et al. Enzymatic reduction of (+)-dihydroflavonols to flavan-3, 4-cis-diols with flower extracts from Matthiola incana and its role in anthocyanin biosynthesis [J]. Planta, 1985, 165(2): 284−287. doi: 10.1007/BF00395052 [5] MARTENS S, TEERI T, FORKMANN G. Heterologous expression of dihydroflavonol 4-reductases from various plants [J]. FEBS Letters, 2002, 531(3): 453−458. doi: 10.1016/S0014-5793(02)03583-4 [6] TANAKA Y, BRUGLIERA F, CHANDLER S. Recent progress of flower colour modification by biotechnology [J]. International Journal of Molecular Sciences, 2009, 10(12): 5350−5369. doi: 10.3390/ijms10125350 [7] GUTTERSON N. Anthocyanin biosynthetic genes and their application to flower color modification through sense suppression [J]. HortScience, 1995, 30(5): 964−966. doi: 10.21273/HORTSCI.30.5.964 [8] AIDA R, YOSHIDA K, KONDO T, et al. Copigmentation gives bluer flowers on transgenic torenia plants with the antisense dihydroflavonol-4-reductase gene [J]. Plant Science, 2000, 160(1): 49−56. doi: 10.1016/S0168-9452(00)00364-2 [9] 孙蓉, 刘姗, 高静雷, 等. 三角梅CHS基因的克隆及表达分析 [J]. 西北农业学报, 2021, 30(10):1565−1572. doi: 10.7606/j.issn.1004-1389.2021.10.014SUN R, LIU S, GAO J L, et al. Cloning and expression analysis of CHS gene from Bougainvillea spectabilis [J]. Acta Agriculturae Boreali-Occidentalis Sinica, 2021, 30(10): 1565−1572.(in Chinese) doi: 10.7606/j.issn.1004-1389.2021.10.014 [10] 孙蓉, 刘姗, 高静雷. 三角梅黄烷酮3-羟化酶基因的克隆及表达分析 [J]. 生物技术通报, 2022, 38(11):122−128. doi: 10.13560/j.cnki.biotech.bull.1985.2022-0048SUN R, LIU S, GAO J L. Cloning and expression analysis of flavanone 3-hydroxylase gene from Bougainvillea spectabilis [J]. Biotechnology Bulletin, 2022, 38(11): 122−128.(in Chinese) doi: 10.13560/j.cnki.biotech.bull.1985.2022-0048 [11] 于婷婷, 倪秀珍, 高立宏, 等. 高等植物二氢黄酮醇4-还原酶基因研究进展 [J]. 植物研究, 2018, 38(4):632−640. doi: 10.7525/j.issn.1673-5102.2018.04.020YU T T, NI X Z, GAO L H, et al. Advances in study of dihydroflavonol 4-reductase(DFR) genes of higher plants [J]. Bulletin of Botanical Research, 2018, 38(4): 632−640.(in Chinese) doi: 10.7525/j.issn.1673-5102.2018.04.020 [12] STAFFORD H A. Anthocyanins and betalains: Evolution of the mutually exclusive pathways [J]. Plant Science, 1994, 101(2): 91−98. doi: 10.1016/0168-9452(94)90244-5 [13] 胡可, 孟丽, 韩科厅, 等. 瓜叶菊花青素合成关键结构基因的分离及表达分析 [J]. 园艺学报, 2009, 36(7):1013−1022. doi: 10.3321/j.issn:0513-353X.2009.07.011HU K, MENG L, HAN K T, et al. Isolation and expression analysis of key genes involved in anthocyanin biosynthesis of Cineraria [J]. Acta Horticulturae Sinica, 2009, 36(7): 1013−1022.(in Chinese) doi: 10.3321/j.issn:0513-353X.2009.07.011 [14] NIELSEN K, DEROLES S C, MARKHAM K R, et al. Antisense flavonol synthase alters copigmentation and flower color in lisianthus [J]. Molecular Breeding, 2002, 9(4): 217−229. doi: 10.1023/A:1020320809654 [15] DAVIES K M, SCHWINN K E, DEROLES S C, et al. Enhancing anthocyanin production by altering competition for substrate between flavonol synthase and dihydroflavonol 4-reductase [J]. Euphytica, 2003, 131(3): 259−268. doi: 10.1023/A:1024018729349 [16] JOHNSON E T, YI H, SHIN B, et al. Cymbidium hybrida dihydroflavonol 4-reductase does not efficiently reduce dihydrokaempferol to produce orange pelargonidin-type anthocyanins [J]. The Plant Journal:for Cell and Molecular Biology, 1999, 19(1): 81−85. doi: 10.1046/j.1365-313X.1999.00502.x [17] 钟晓缘, 刘姗, 孙蓉, 等. 三角梅苞叶色彩参数和色素含量分析及蓝色转基因受体的筛选 [J]. 西北植物学报, 2022, 42(4):646−655. doi: 10.7606/j.issn.1000-4025.2022.04.0646ZHONG X Y, LIU S, SUN R, et al. Screening of blue transgenic receptor varieties in Bougainvillea spectabilis based on the analysis of color parameters and pigment content [J]. Acta Botanica Boreali-Occidentalia Sinica, 2022, 42(4): 646−655.(in Chinese) doi: 10.7606/j.issn.1000-4025.2022.04.0646 [18] JOHNSON E T, RYU S, YI H, et al. Alteration of a single amino acid changes the substrate specificity of dihydroflavonol 4-reductase [J]. The Plant Journal:for Cell and Molecular Biology, 2001, 25(3): 325−333. doi: 10.1046/j.1365-313x.2001.00962.x