Kalariya Kuldeepsingh A, Mevada Ravina R, Das Manish
ICAR-Directorate of Medicinal & Aromatic Plants Research, Boriyavi, 387310 Anand, Gujarat, India.
ICAR-Directorate of Medicinal & Aromatic Plants Research, Boriyavi, 387310 Anand, Gujarat, India.
J Genet Eng Biotechnol. 2024 Mar;22(1):100344. doi: 10.1016/j.jgeb.2023.100344. Epub 2024 Feb 13.
Gymnema sylvestre R.Br. is famous medicinal plant among diabetics for its gymnemic acid content. It also contains flavonoids, which are an essential component in various other products. Though some molecular information on the biosynthesis of gymnemic acid, polyoxypregnane, micro RNAs and photosynthetic efficiency is available, there is no gene level information available on the biosynthesis of flavonoids in this plant. RNA was extracted from winter-collected Gymnema sylvestre leaves and cDNA libraries were prepared and used for next generation sequencing. De novo transcriptome assembly were prepared and Coding DNA Sequences (CDS) of 13 major genes involved in flavonoids biosynthesis were identified from transcriptome data. Phenylalanine ammonia lyase gene containing full-length CDS was employed for in silico protein modelling and subsequent quality assessment. These models were then compared against publicly available databases. To confirm the identification of these genes, a similarity search was conducted using the NCBI BLAST tool.
Therefore, in the present study, an effort has been made to provide molecular insights into flavonoid biosynthesis pathway by examining the expressed transcripts in G.sylvestre. Gene sequences of total thirteen major genes viz., phenylalanine ammonia lyase, 4-coumarate CoA ligase, cinnamic acid 4-hydroxylase, shikimate O-hydroxycinnamoyl transferase, coumaroyl quinate (coumaroyl shikimate) 3'-monooxygenase, caffeoyl-CoA O-methyltransferase, chalcone synthase, chalcone isomerase, naringenin 3-dioxygenase, flavanol synthase, flavonoid 3'-monooxygenase, Flavanone 7-O-glucoside 2″-O-beta-L-rhyamnosyltransferase and leucoanthocyanidin dioxygenase were identified and a putative pathway of flavonoids biosynthesis has been illustrated based on transcriptome data.
This transcriptome study has contributed gene-level insights into the biosynthesis of flavonoids in plants as a whole and represents the first report within a non-model plant, Gymnema sylvestre perticullarly.
匙羹藤是一种因含有匙羹藤酸而在糖尿病患者中闻名的药用植物。它还含有黄酮类化合物，这是其他各种产品中的重要成分。尽管已有一些关于匙羹藤酸、多氧孕烷、微小RNA生物合成以及光合效率的分子信息，但关于该植物中黄酮类化合物生物合成的基因水平信息尚不存在。从冬季采集的匙羹藤叶片中提取RNA，制备cDNA文库并用于下一代测序。进行了从头转录组组装，并从转录组数据中鉴定出参与黄酮类化合物生物合成的13个主要基因的编码DNA序列（CDS）。使用包含全长CDS的苯丙氨酸解氨酶基因进行了蛋白质的计算机模拟及后续质量评估。然后将这些模型与公开可用的数据库进行比较。为确认这些基因的鉴定，使用NCBI BLAST工具进行了相似性搜索。
因此，在本研究中，已通过检查匙羹藤中表达的转录本，努力提供对黄酮类化合物生物合成途径的分子见解。总共鉴定出13个主要基因的序列，即苯丙氨酸解氨酶、4-香豆酰辅酶A连接酶、肉桂酸4-羟化酶、莽草酸O-羟基肉桂酰转移酶、香豆酰奎尼酸（香豆酰莽草酸）3'-单加氧酶、咖啡酰辅酶A O-甲基转移酶、查尔酮合酶、查尔酮异构酶、柚皮素3-双加氧酶、黄烷醇合酶、黄酮类化合物3'-单加氧酶、黄烷酮7-O-葡萄糖苷2″-O-β-L-鼠李糖基转移酶和无色花青素双加氧酶，并基于转录组数据阐明了黄酮类化合物生物合成的假定途径。
这项转录组研究为整个植物中黄酮类化合物的生物合成提供了基因水平的见解，并且特别代表了非模式植物匙羹藤中的首份报告。
