Transcriptional and metabolic analyses of leaf responses to low phosphorus levels in quinoa heading stage

Quinoa, a globally significant crop, is highly susceptible to low phosphorus stress, which can significantly impair its production and quality. Therefore, it is necessary to study the molecular mechanisms of quinoa's response to low phosphorus stress must be investigated. In this study, we identified a total of 14,824 genes and 1788 metabolites using transcriptomic and metabolomic techniques. Compared to the control group, 1378 and 8548 differentially expressed genes (DEGs), as well as 210 and 362 differentially accumulated metabolites (DAMs), were identified in the low phosphorus-treated groups, respectively. Bioinformatics analysis showed that these DEGs and DAMs are associated with various biological processes,for instance glycolysis, starch and sugar metabolism, pyruvate metabolism, glycerophospholipid metabolism, photosynthetic biosequestration, galactose metabolism, and citric acid cycle. Moreover, the results of the co-expression analysis highlighted interactions among DEGs and DAMs, particularly in the associated path to starch and sugar metabolism, glycerophospholipid metabolism, photosynthetic biosequestration, and glycolytic metabolic pathways. These results suggest that quinoa responds to low-phosphorus stress through these metabolic pathways. Overall, this study enhances our understanding of quinoa's mechanism in response to phosphorus deficiency and provides a reference for molecular design breeding of quinoa adapted to phosphorus deficiency.