| dc.description.abstract | In the context of sustainable agricultural practices, exploring plant-based strategies for enhancing crop resilience and productivity is crucial. This review delves into the roles of coumarins, a group of phenolic compounds, in mediating iron (Fe) uptake in plants, particularly under Fe-deficient conditions prevalent in alkaline soils. By modulating the chemical environment of the rhizosphere, coumarins play a pivotal role in Fe solubilization and acquisition through a reduction-based Strategy 1, which is predominantly utilized by non-grass species. This strategy involves the secretion of coumarins into the rhizosphere, facilitated by specific transport proteins, to chelate Fe from insoluble complexes, thereby enhancing its bioavailability for plant uptake. The biosynthesis of coumarins, such as scopoletin and fraxetin, is intricately regulated by environmental cues and genetic factors, with key enzymes like feruloyl CoA 6’hydroxylase 1 and scopoletin 8-hydroxylase catalyzing crucial steps in their synthesis. The involvement of the MYB72 transcription factor, regulated by pH and microbial interactions in the rhizosphere, highlights a sophisticated mechanism by which plants not only respond to Fe deficiency, but also manipulate the microbiota in the rhizosphere to optimize nutrient uptake and defend against pathogens. Moreover, coumarins exhibit antimicrobial properties, contributing to plant defense strategies by inducing systemic resistance and altering the microbial community structure towards a beneficial consortium. This dual functionality of coumarins – enhancing both nutrient uptake and pathogen resistance - presents a viable target for agricultural biotechnology, aimed at developing crops with increased resilience to environmental stresses and reduced dependency on chemical fertilizers and pesticides. The dynamic interaction between coumarins and the soil microbiome, mediated through processes such as the secretion of root exudates and recruitment of beneficial microbes, underscores the potential of integrating coumarin-based strategies into sustainable farming practices. By fostering a beneficial rhizosphere microbiome, plants can enhance growth and sustainability. Future research should focus on the genetic and metabolic engineering of coumarin pathways to harness their full potential in agriculture, thus contributing to the development of more sustainable and environmentally friendly crop management systems. | |
