Sathasivam Ramaraj, Bong Sun Ju, Park Chang Ha, Kim Ji Hyun, Kim Jae Kwang, Park Sang Un
Department of Crop Science, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea.
Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea.
ACS Omega. 2021 Dec 20;7(1):430-442. doi: 10.1021/acsomega.1c04802. eCollection 2022 Jan 11.
Watercress ( R. Br.) is an important aquatic herb species belonging to the family. It has various medicinal properties and has been utilized for the treatment of cancer and other diseases; however, currently available genomic information regarding this species is limited. Here, we performed the first comprehensive analysis of the carotenoid biosynthesis pathway (CBP) genes of , which were identified from next-generation sequencing data. We identified and characterized 11 putative carotenoid pathway genes; among these, nine full and two partial open reading frames were determined. These genes were closely related to CBP genes of the other higher plants in the phylogenetic tree. Three-dimensional structure analysis and multiple alignments revealed several distinct conserved motifs, including aspartate or glutamate residues, carotene-binding motifs, and dinucleotide-binding motifs. Quantitative reverse transcription-polymerase chain reaction results showed that the CBP was expressed in a tissue-specific manner: expression levels of , , , , , , and were highest in the flower, whereas , , , and were highest in the leaves. Stems, roots, and seeds did not show a significant change in the expression compared to the leaves and flowers. High-performance liquid chromatography analysis of the same organs showed the presence of seven distinct carotenoid compounds. The total carotenoid content was highest in the leaves followed by flowers, seeds, stems, and roots. Among the seven individual carotenoids, the levels of six carotenoids (i.e., 13-Z-β-carotene, 9-Z-β-carotene, E-β-carotene, lutein, violaxanthin, and β-cryptoxanthin) were highest in the leaves. The highest content was observed for lutein, followed by E-β-carotene, and 9-Z-β-carotene; these carotenoids were much higher in the leaves compared to the other organs. The results will be useful references for further molecular genetics and functional studies involving this species and other closely related species.
豆瓣菜（R. Br.）是十字花科的一种重要水生草本植物。它具有多种药用特性，已被用于治疗癌症和其他疾病；然而，目前关于该物种的基因组信息有限。在此，我们对从二代测序数据中鉴定出的豆瓣菜类胡萝卜素生物合成途径（CBP）基因进行了首次全面分析。我们鉴定并表征了11个假定的类胡萝卜素途径基因；其中，确定了9个完整和2个部分开放阅读框。在系统发育树中，这些基因与其他高等植物的CBP基因密切相关。三维结构分析和多序列比对揭示了几个不同的保守基序，包括天冬氨酸或谷氨酸残基、胡萝卜素结合基序和二核苷酸结合基序。定量逆转录-聚合酶链反应结果表明，CBP以组织特异性方式表达：NcPSY、NcPDS、NcZDS、NcCRTISO、NcLCYB、NcLCYE和NcCHYB在花中的表达水平最高，而NcLYCB、NcCHXB、NcVDE和NcZEP在叶中的表达水平最高。与叶和花相比，茎、根和种子的表达没有显著变化。对相同器官的高效液相色谱分析表明存在七种不同的类胡萝卜素化合物。总类胡萝卜素含量在叶中最高，其次是花、种子、茎和根。在七种单个类胡萝卜素中，六种类胡萝卜素（即13-Z-β-胡萝卜素、9-Z-β-胡萝卜素、E-β-胡萝卜素、叶黄素、紫黄质和β-隐黄质）在叶中的含量最高。叶黄素含量最高，其次是E-β-胡萝卜素和9-Z-β-胡萝卜素；这些类胡萝卜素在叶中的含量比其他器官高得多。这些结果将为涉及该物种和其他密切相关物种的进一步分子遗传学和功能研究提供有用的参考。
