Judul: Flower Color Characterization, Metabolite Profiling and Flavonoid-Related Gene Expression in Sudamala Barak Marigold Flowers (Tagetes patula).
Abstrak: Marigold (Tagetes spp.) is a floricultural plant belonging to the Asteraceae family and is extensively cultivated in Indonesia, particularly in the province of Bali, where it is used as a prop in religious ceremonies. Marigold flowers exhibit limited color variations including yellow, orange, and red, with flower color being a critical characteristic that determines the commercial value of floricultural plants. Therefore, there is a need to develop marigold varieties to enhance flower color variation. Traditional breeding techniques such as hybridization and mutation have limitations due to their random nature, which hinders the creation of specific flower color variations. These challenges can be addressed through biotechnology-based breeding techniques such as genetic engineering, which require information on biochemical contents and gene expression patterns in desired pigment biosynthesis pathways. Sudamala Barak Marigold (T. patula) exhibits a unique red color change in its flowers from early to late developmental stages, likely originating from carotenoid, flavonoid, and anthocyanin pigments. This research aims to investigate flower color changes, identify metabolite profiles, and analyze gene expression patterns related to the flavonoid biosynthesis pathway across four stages of flower development. The genetic material used in this study includes Sudamala Barak marigold flowers at four developmental stages: closed buds (stage 1), semi-open buds (stage 2), open flowers (stage 3), and fully open flowers (stage 4). Sudamala Barak marigolds were clonally propagated using cuttings and grown at the Pasir Sarongge Experimental Garden, Cianjur, West Java, at an altitude of 1100 meters above sea level (masl). In metabolomic analysis, samples were extracted and metabolized with 70% methanol containing 0.1% HCl, and the data obtained were analyzed using MetaboAnalyst software. For gene expression analysis, RNA extraction and cDNA synthesis were performed, and the data were processed using Livak and Schmittgen methods. From this research, Sudamala Barak marigold flowers experienced a color change from moderate reddish brown at stage 1 to strong orange at stage 4. A total of 58 compounds have been identified during four stages of development, with 32 compounds present in all stages. The main compound groups include amino acids, phenols, flavonoids and terpenoids, where flavonoids, especially flavonols such as patuletin, isorhamnetin, and others, are thought to contribute to the formation of yellow color in flowers. Gene expression analysis shows that early biosynthesis genes (CHS, CHI, F3H) and late biosynthesis genes (F3'H, DFR, ANS, UFGT, OMT) play a role in pigment formation, with the highest expression occurring at different stages. It was confirmed that the red color of the flowers was caused by anthocyanins., Marigold (Tagetes spp.) merupakan tanaman florikultura yang termasuk ke dalam famili Asteraceae dan banyak dibudidayakan di Indonesia khususnya provinsi Bali karena digunakan sebagai salah satu properti dalam upacara keagamaan. Bunga marigold memiliki variasi warna terbatas yaitu kuning, oranye dan merah, sedangkan warna bunga merupakan ciri penting yang menentukan nilai komersial tanaman florikultura. Oleh karena itu, diperlukan perakitan varietas marigold untuk meningkatkan variasi warna bunga. Teknik pemuliaan seperti hibridisasi dan mutasi memiliki kelemahan yakni bersifat acak, sehingga belum dapat diciptakan variasi warna bunga yang spesifik. Kendala tersebut dapat diatasi dengan teknik pemuliaan berbasis bioteknologi seperti rekayasa genetik yang memerlukan
Keyword: gene expression, metabolit sekunder, ekpresi gen, analisis LCMS tidak tertarget, analisis kuantitatif PCR, quantitative PCR analysis, secondary metabolites, flavonoid, flavonoid, untargeted LCMS analysis