Transcriptome analysis identifies genes regulating self-compatibility, flowering time, and oil biosynthesis in Noug (Guizotia abyssinica).

Noug (Guizotia abyssinica) is an economically important oilseed crop in Ethiopia that contributes significantly to local edible oil production and is a good protein source in animal feed. Despite its agronomic importance, the molecular basis of key agronomic traits, such as self-compatibility, photoperiod sensitivity, and oil biosynthesis, remains poorly understood due to the limited availability of genomic resources. To bridge this knowledge gap, we conducted extensive transcriptome profiling of 30 phenotypically diverse noug genotypes through RNA sequencing and de novo assembly. Our analysis generated 409,309 unigenes with an N50 of 584 bp, representing an extensive transcriptomic resource currently available for this crop. A total of 2,547 differentially expressed genes (DEGs) were identified, among which 409 were particularly associated with fatty acid metabolism pathways. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed significant enrichment in lipid metabolism, stress response, and floral development pathways. Notably, many transcription factor families, such as bHLH, MYB, and WRKY, were differentially expressed between early- and late-flowering genotypes and high- and low-oil varieties, suggesting their regulatory roles in these traits. Transcriptome assembly revealed 58,852 putative transcription factors distributed in 51 families. This study provides fundamental genomic resources for marker-assisted breeding to improve productivity, oil quality, and stress resistance. The identified candidate genes present new opportunities for this underutilized yet agronomically valuable crop through modern biotechnological approaches.