Plant secondary metabolites have a rich historical significance as they play essential roles in influencing numerous mechanisms important for plant development, productivity, and health. The review by Dixon and Dickinson (2024) presents research about plant secondary metabolites from the last hundred years, connecting us to the legacy of scientific exploration. It discusses old approaches, recent advancements, and new technologies in plant science that have increased our understanding regarding the origin, production, and possible utilization of secondary metabolites.
In the synthetic biology research field, both primary and secondary metabolisms became fundamental to engineer pathways with applications in medicine, renewable energy sources, agriculture, and potentially, optimum nutrient management. As highlighted by Dixon and Dickinson (2024), synthetic biology applied to plant secondary metabolite (PSM) research will revolutionize our understanding of plant functions. Based on these, we will be able to introduce new plant traits, such as developing genetically encoded biosensors, advancing environmental clean-up or biofortification programs, depending on the nutrient in question.
Secondary metabolites modulate plant nutrition in various ways. They can directly influence soil-microbial interactions, enhance microbial activity in the rhizosphere, or promote beneficial interactions with soil microbes. Certain secondary metabolites can stimulate the growth of mycorrhizal fungi, which in turn extend the root system and enhance nutrient uptake, particularly that of phosphorus. Secondary metabolites in root exudates can alter soil chemistry and make nutrients more available to plants.
Towards the top of the soil, plant secondary metabolites may directly influence nutrient transporters, enhancing nutrient uptake efficiency, and allowing plants to absorb essential elements more effectively. Indirectly, plant secondary metabolites can play a role in nutrient management and availability as they modulate abiotic stress responses (e.g., drought, salinity). Importantly, plant secondary metabolites also serve as essential signaling molecules that influence physiological nutrient uptake and assimilation processes. For instance, flavonoids can interact with nutrient signaling pathways, affecting how plants respond to nutrient availability.
Future research will focus on improving the uptake, transport, and accumulation of plant nutrients by modulating metabolite-based communication between plants and microbes. Modifying PSM pathways and engineering secondary metabolites are potential approaches to enhance the health and productivity of plants. Yet, for their successful implementation, some significant challenges need to be overcome. For example, identifying natural product biosynthesis pathways remains complicated despite progress. Practical engineering will depend on discovering essential pathway genes and implementing adjustable synthetic regulatory circuits. Investigating these pathways and systems will undoubtedly unlock further benefits by optimizing plant performance and resilience in a changing world.
