Physiological and transcriptomic analysis reveal the regulation of adventitious root formation in Cinnamomum parthenoxylon cuttings.

Cinnamomum parthenoxylon is a significant essential oil plant in southern China, however, the challenge of rooting cuttings poses a hindrance to its development and widespread cultivation. Adventitious root (AR) formation is a vital mechanism for plants to acclimate to environmental changes, yet the precise regulatory mechanisms governing this process remain largely unknown. This study investigated the morphological, physiological, and transcriptomic alterations during AR formation in C. parthenoxylon. Our findings revealed that the AR in C. parthenoxylon originated from callus tissue. Nutrients, enzymes, and plant hormones exerted crucial functions in cutting propagation, with some gradually shifting roles in the rooting process until the pivotal stage of root primordium initiation. Analysis of differentially expressed genes (DEGs) highlighted the significance of auxin, ethylene, and plant wound signaling pathways in regulating AR. Furthermore, 14 hub genes were identified through protein-protein interaction (PPI) networks, shedding light on key molecular players. Understanding the dynamics involved in AR formation enhances our comprehension of the regulatory mechanisms, offering insights for optimizing cutting treatment methods.