TRANSCRIPTOME ANALYSIS OF LYCORIS RADIATA BULB TIPS AT DIFFERENT DEVELOPMENTAL STAGES

Lycoris radiata (L'Herit.) Herb is a commonly used medicinal-ornamental herb in China, and its growth rhythm is characterized as "flowers and leaves not meeting." In this research, transcriptomic analyses of L. radiata bulb tips were conducted at six developmental stages, specifically: LO (leafing out), RLE (rapid leaf extension), LMa (leaf maturity), LWi (leaf withering), Dor (dormancy), and Flo (flowering), to identify the differentially expressed genes (DEGs). There were 6,157 DEGs in RLE vs. LO, 18,193 in LMa vs. RLE, 4,362 in LWi vs. LMa, 5,800 in Dor vs. LWi and 7,373 in Flo vs. Dor. The KEGG pathways 'hormone signal transduction' and 'starch and sucrose metabolism' and the biological processes 'carbohydrate metabolism' and 'stress response' were significantly enriched by upregulated DEGs in LMa vs. RLE during leaf development. KEGG pathways of 'biosynthesis of amino acids,' 'circadian rhythm - plant,' and 'gap junction' were significantly enriched by upregulated DEGs in LWi vs. LMa, Dor vs. LWi, and Flo vs. Dor, respectively, during floral differentiation and flowering. Weighted gene coexpression network analysis (WGCNA) showed that genes encoding ribosomal proteins were identified as hub genes in both the RLE and Flo stages, and genes encoding 16.0 kDa heat shock protein and heat stress transcription Factor C-2a-like were respectively identified as RLE and LWi stage-specific hub genes. Together, these analyses provide a valuable reference for studying the molecular mechanism of L. radiata growth rhythm from the aspects of temperature adaptability, sugar signal transduction, sugar metabolism, and circadian rhythm.