Transcriptomic and metabolomic profiling provide insight into the role of sugars and hormones in leaf senescence of Pinellia ternata

Abstract Pinellia ternata , an environmentally sensitive medicinal plant, undergoes leaf senescence twice a year, affecting its development and yield. However, the underlying mechanism of this phenomenon is still largely unexplored. In this study, a typical senescent population model was constructed, and an integrated analysis of transcriptomic and metabolomic profiles of P. ternata was conducted using obviously different leaf senescence phenotypes in this model. The result showed that two key modules associated with leaf senescence based on weighted correlation network analysis (WGCNA) were key components for leaf senescence. Further analysis revealed that genes in these two modules were mainly enriched in sugar and hormone signaling pathways, respectively. A network of unigenes and metabolisms related to the obtained two pathways revealed that D-arabitol and 2MeScZR played key roles in leaf senescence. Additionally, a total of 130 hub genes were discovered in this network, and they were categorized into three classes based on connectivity. A total of 34 hub genes and 13 metabolites were further analyzed through a pathway map, the potential crosstalk between sugar and hormone metabolisms might be an underlying reason of leaf senescence in P. ternata . These findings address the knowledge gap regarding leaf senescence in P. ternata , providing candidate germplasms for molecular breeding and laying theoretical basis for the realization of finely regulated cultivation in future.