Medicinal Plant Research 2024, Vol.14, No.1, 31-44 http://hortherbpublisher.com/index.php/mpr 33 As of March 2024, there have been no complete reports on the genomic information of Dioscorea species, severely limiting both basic research and industrial development of yams. Genome data deficiency significantly hampers various fields of study, including taxonomy and evolutionary analysis (Kron et al., 2007), particularly in gene cloning and genome sequencing initiatives (Rabinowicz and Bennetzen, 2006). The Dioscorea genus exhibits a complex genome characterized by high repeat content, heterozygosity, and large genome size, posing challenges for de novo sequencing and assembly of the yam genome. Currently, PCR-based sequencing of the 18S rRNA gene sequence and comparative sorting can serve as a method for yam germplasm identification (Liu et al., 2001). The chloroplast genome of yams is highly conserved in gene content, structure, and gene order, containing numerous functional chloroplast genes, suggesting future research avenues in chloroplast genome and genetic studies through high-throughput sequencing. 2.2 Structural genomic features The structural genomic features of yam include various elements that contribute to its functional and adaptive evolution. For instance, the presence of low methyl-esterified pectin in the tuber of yam indicates a complex polysaccharide structure, which includes homogalacturonan and highly branched rhamnogalacturonan I regions (Ma et al., 2018). The genetic resources of Chinese yam (Dioscorea opposita) constitute a monophyletic group that evolved from Dioscorea species with diploid rhizome compositions in different directions. The Asian and African groups have a chromosome base number X=10, while the American group has X=9 chromosomes (Chin et al., 1985). RNA-Seq analysis of various tissues of Guinea yam (Dioscorea rotundata) predicted a genome containing 26,198 genes. Approximately 5,557 genes were found to have orthologs in maize, rice, and Arabidopsis, while 12,625 genes did not show direct or paralogous orthologs in these species. Furthermore, QTL-seq analysis of genomic regions determining plant sex in 253 plants revealed that a segment on pseudo-chromosome 11 is homozygous in male plants but heterozygous in females. This suggests that the ZZ genotype consistently produces male plants, whereas the ZW genotype is less stable, typically producing female plants but occasionally hermaphroditic or male plants as well (Tamiru et al., 2017).. 2.3 Functional genomic elements Functional genomic elements in Dioscorea opposita play a critical role in its medicinal properties and adaptive evolution. Transcriptome analysis has identified key pathways and hormone activities involved in microtuber formation, which is essential for the plant's growth and development (Terauchi et al., 1991). Transcription factors (TFs) are key components regulating signal transduction pathways in organisms, capable of modulating the expression of downstream stress-responsive genes (Zhu et al., 2020). WRKY, a plant-specific transcription factor, plays crucial roles in responses to abiotic stresses, regulating processes such as adventitious root development (McGregor, 2006), seed germination and dormancy (Huang et al., 2019), leaf senescence (Tian and Zhang, 2024), and flowering time (Yu et al., 2013). It contains highly conserved sequences like WRKYGQK and a zinc-finger motif (CX4-7CX22-23HXH/C) (Jang et al., 2010). The first WRKY gene family member SPF1 was cloned from sweet potato in 1994 (Ishiguro and Nakamura, 1994), and subsequent systematic explorations and functional identifications of WRKY transcription factor families have been conducted in various species including Arabidopsis thaliana (Eulgem et al., 2000), strawberry (Fragaria×ananassa Duch.) (Wei et al., 2016), kiwifruit (Actinidia chinensis Planch.) (Jing and Liu, 2018), rice (Oryza sativa) (Wu et al., 2005), and tobacco (Nicotiana tabacum L.) (Xiang et al., 2016) based on genomic and transcriptomic data. In yam research, four proteins interacting with DoWRKY40 were identified using yeast two-hybrid technology, involved in plant growth and development, cell cycle regulation, cell proliferation, signal transduction, and environmental stress responses. These proteins include the transcription factor EGL1, DNA-binding protein BIN4, protein phosphatase 2C, and BAG family molecular chaperone regulator 7 (Analysis of YamDoWRKY40 Gene Expression Characteristics and Interacting Proteins). Research on the mechanism of anthocyanin accumulation in purple yam involves studying aspects such as the expression of anthocyanin synthesis-related genes, exploration of key genes, expression of transcription regulatory factors, and cloning of anthocyanin synthesis-related genes from four perspectives. The process of anthocyanin accumulation is dynamic and regulated by multiple genes; genes involved in anthocyanin synthesis such as F3’HandF3’5’H may be related to plant growth and development (Yan Ruixia, 2014, Nanjing
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