Work

Dual gene engineering of SsdTPS and SsSCS boosted secondary metabolites synthesis and drought tolerance via activation of metabolic and stress signaling pathways

Year: 2026

Type: article

Abstract: In the face of escalating global climate change and water scarcity, deciphering and improving crop drought tolerance mechanisms has become a pivotal research focus in both agricultural and horticultural fields. The response and regulation of metabolite synthesis pathways in plants under stress play a crucial role in establishing stress tolerance mechanisms. Salvia sclarea , an aromatic crop that integrates both economic value and medicinal characteristics, has garnered significant attention in the horticultural and agricultural sectors due to its secondary metabolite, sclareol, which exhibits medicinal properties and aromatic traits. However, the potential effects of its synthetic pathways on the regulatory mechanism under water deficiency and the role of endogenous sclareol in drought stress tolerance remain elucidation. Our findings showed that drought stress triggered the up-regulation of gene SsSCS in the sclareol synthesis pathway. Ectopic co-overexpression of the two sclareol synthesis genes ( SsdTPS , SsSCS ) in transgenic N. benthamiana positively modulated the response and regulation to drought stress by up-regulating gene expression in the MEP pathway and ABA signaling pathway, and promoted the accumulation of sclareol and ABA within the plants. Meanwhile, the co-overexpression enhanced the expression of genes in the phenylpropanoid pathway and the response of the ROS scavenging system in transgenic plants, increased the lignin content in the plants, and reduced oxidative stress damage. These conferred the plants with an enhanced drought resistance phenotype, and increased the content of secondary metabolites. The findings provide theoretical support for investigating the regulatory mechanisms of drought stress in Salvia sclarea , advance functional studies of medicinal plant resources, and offer a novel perspective for breeding innovations aimed at improving drought tolerant crops. • SsSCS gene in the sclareol biosynthesis pathway of Salvia sclarea exhibited up-regulation in response to drought stress. • Overexpression of the SsSCS gene played a proactive role in the drought tolerance of transgenic plants. • Co-overexpression positively affected MEP and ABA pathways, leading to significant accumulation of sclareol and ABA. • Co-overexpression of SsSCS and SsdTPS boosts lignin accumulation and modulates ROS genes to mitigate oxidative stress.

Source: Industrial Crops and Products

DOI: 10.1016/j.indcrop.2026.122810