Feng Honglin, Zhang Jing, Powell Adrian F, Buttelmann Gretta L, Yang Lily, Yan Ethan, Wang Fumin, Broyles Steven B, Jander Georg, Strickler Susan R
Boyce Thompson Institute Ithaca New York USA.
Department of Entomology Louisiana State University AgCenter Baton Rouge Louisiana USA.
Plant Direct. 2025 Mar 18;9(3):e70031. doi: 10.1002/pld3.70031. eCollection 2025 Mar.
Tropical milkweed () serves as a host plant for monarch butterflies () and other insect herbivores that can tolerate the abundant cardiac glycosides that are characteristic of this species. Cardiac glycosides, along with additional specialized metabolites, also contribute to the ethnobotanical uses of . To facilitate further research on milkweed metabolism, we assembled the 197-Mbp genome of a fifth-generation inbred line of into 619 contigs, with an N50 of 10 Mbp. Scaffolding resulted in 98% of the assembly being anchored to 11 chromosomes, which are mostly colinear with the previously assembled common milkweed () genome. Assembly completeness evaluations showed that 98% of the BUSCO gene set is present in the genome assembly. The transcriptomes of six tissue types (young leaves, mature leaves, stems, flowers, buds, and roots), with and without defense elicitation by methyl jasmonate treatment, showed both tissue-specific gene expression and induced expression of genes that may be involved in cardiac glycoside biosynthesis. Expression of a gene, the predicted first gene in the cardiac glycoside biosynthesis pathway, was observed only in the stems and roots and was induced by methyl jasmonate. Together, this genome sequence and transcriptome analysis provide important resources for further investigation of the ecological and medicinal uses of .
热带马利筋（）是黑脉金斑蝶（）和其他能够耐受该物种特有的大量强心苷的食草昆虫的寄主植物。强心苷以及其他特殊代谢产物也促成了马利筋的民族植物学用途。为了促进对马利筋代谢的进一步研究，我们将一个第五代自交系马利筋的1.97亿碱基对基因组组装成619个重叠群，N50为1000万碱基对。构建支架后，98%的组装序列被锚定到11条染色体上，这些染色体大多与先前组装的普通马利筋（）基因组共线性。组装完整性评估表明，98%的BUSCO基因集存在于马利筋基因组组装中。六种组织类型（幼叶、成熟叶、茎、花、芽和根）在经过茉莉酸甲酯处理诱导防御和未诱导防御的情况下的转录组，既显示了组织特异性基因表达，也显示了可能参与强心苷生物合成的基因的诱导表达。一种基因的表达，该基因被预测为强心苷生物合成途径中的第一个基因，仅在茎和根中观察到，并被茉莉酸甲酯诱导。总之，这个基因组序列和转录组分析为进一步研究马利筋的生态和药用用途提供了重要资源。
