Genetic insights into hippeastrum species: A comparative transcriptomic analysis

Authors: GOPALA, VAISHALI - Oak Ridge Institute For Science And Education (ORISE); Nageswara Rao, Madhugiri; GOVINDARAJULU, RAJANIKANTH - Q2 Solutions; MEEROW, ALAN - Arizona State University; Singh, Sukhwinder

Submitted to: Journal of Biosciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2025
Publication Date: 8/30/2025
Citation: Gopala, V.M., Nageswara Rao, M., Govindarajulu, R., Meerow, A., Singh, S. 2025. Genetic insights into hippeastrum species: A comparative transcriptomic analysis. Journal of Biosciences. https://doi.org/10.1007/s12038-025-00565-9.
DOI: https://doi.org/10.1007/s12038-025-00565-9

Interpretive Summary: The genus Hippeastrum, commonly referred to as Amaryllis, is a vibrant flowering plant that originates from bulbs. It is primarily found in the tropical and subtropical regions of the Americas, particularly in Brazil and the Andes mountains of Peru, Bolivia, and Argentina. The research involved hybridizing Hippeastrum brasilianum (known for its white and fragrant flowers) with H. papilio (which has colorful butterfly-shaped blooms) to create a hybrid that features brightly colored and fragrant flowers. However, the absence of detailed genomic resources for Hippeastrum has restricted molecular studies, with traditional approaches depending on morphological and cytological evaluations. The transcriptome analysis of both parent species and the hybrid was conducted in this study. Analysis of differential gene expression revealed that genes related to terpenoid biosynthesis were upregulated in H. brasilianum, which contributes to its unique fragrance profile, whereas their downregulation in H. papilio and the hybrid indicates a reduction in scent. The increased expression of genes involved in flavonoid and phenylpropanoid biosynthesis in H. papilio and the hybrid resulted in enhanced production of anthocyanins, leading to striking pigmentation. This study offers valuable insights into the genetic foundations of flower color and fragrance in Hippeastrum species, providing guidance for breeding programs aimed at improving ornamental traits and developing new ornamental plants for stakeholders.

Technical Abstract: Hippeastrum species and hybrids, valued for their vibrant flowers and ease of cultivation, are significant in ornamental industry. This study employed de novo transcriptome analysis to investigate the molecular basis of floral color and fragrance in Hippeastrum brasilianum, Hippeastrum papilio and their F-1 hybrid. A high-quality transcriptome was assembled from 637,934,284 paired-end reads, resulting in 557,833 high-confidence transcripts. BUSCO analysis confirmed the assembly's completeness, with 94.5% of eukaryotic, 88.1% of monocot, and 90.7% of land plant genes identified as complete. Differential gene expression analysis revealed genes involved in monoterpene, diterpenoid, and sesquiterpenoid biosynthesis were upregulated in H. brasilianum, contributing to its distinct fragrance profile, while their downregulation in H. papilio and the hybrid suggests a loss of scent, consistent with previous fragrance analyses in Hippeastrum species. The upregulation of flavonoid and phenylpropanoid biosynthesis genes in H. papilio and the hybrid enhanced anthocyanin production, leading to vibrant pigmentation, whereas H. brasilianum showed reduced expression, aligning with its white flowers. GO and KOG classifications highlighted the prominence of metabolic and cellular processes, supporting their roles in floral trait development. These findings provide a molecular framework for understanding floral trait variation in Hippeastrum, offering insights for breeding programs aimed at enhancing ornamental qualities.