Arabidopsis thaliana Raw sequence reads. Arabidopsis thaliana

Narciclasine, an amaryllidaceae alkaloid isolated from Narcissus tazetta bulbs, employs a broad range of functions on plant development and growth. However, its molecular interactions that modulate these roles in plants are not fully understood. To elucidate the global responses of Arabidopsis roots to short-term narciclasine exposure, we first measured the accumulation of H2O2 and O2•– with histochemical staining, and then profiled the gene expression pattern in Arabidopsis root tips treated with 0.5 µM narciclasine across different exposure times by RNA-seq. Physiological measurements showed a significant increase in H2O2 began at 30 to 60 min of narciclasine treatment and O2•– accumulated by 120 min. Compared with controls, 236 genes were upregulated and 54 genes were downregulated with 2 hrs of narciclasine treatment, while 968 genes were upregulated and 835 genes were down-regulated with 12 hrs of treatment. The Gene Ontology analysis revealed that the differentially expressed genes were highly enriched during oxidative stress, including those involved in the “regulation of transcription”, “response to oxidative stress”, “plant-pathogen interaction”, “ribonucleotide binding”, “plant cell wall organization”, and “ribosome biogenesis”. Moreover, Kyoto Encyclopedia of Genes and Genomes pathway enrichment statistics suggested that carbohydrate metabolism, amino acid metabolism, amino sugar and nucleotide sugar metabolism, and biosynthesis of phenylpropanoid and secondary metabolites were significantly inhibited by 12 hrs of narciclasine exposure. Hence, our results demonstrate that hormones and H2O2 are important regulators of narciclasine signaling and help to uncover the factors involved in the molecular interplay between narciclasine and phytohormones in Arabidopsis root cells.