Strigolactone Signaling in Plant Systems

Strigolactones are a class of carotenoid‐derived phytohormones that play multifaceted roles in plant growth, development and interaction with the environment. Initially discovered as rhizosphere signals that stimulate hyphal branching of arbuscular mycorrhizal fungi and trigger germination of parasitic weed seeds, strigolactones have since been recognised for their central function in regulating shoot branching, root system architecture and responses to nutrient limitation and abiotic stress. Biosynthesis begins in the plastid with the conversion of β‐carotene to carlactone, which is then transformed by cytochrome P450 enzymes into various bioactive strigolactones. Perception occurs through the α/β‐hydrolase receptor DWARF14 (D14), which binds intact strigolactone molecules to initiate a signalling cascade that leads to the ubiquitin‐mediated degradation of repressor proteins and consequent transcriptional reprogramming. Through modulation of auxin transport, interaction with abscisic acid pathways and feedback regulation of biosynthetic genes, strigolactone signalling integrates internal developmental cues and external environmental signals to optimise shoot and root architecture, enhance drought and nutrient‐stress resilience, and coordinate beneficial symbioses. The global significance of this pathway spans sustainable agriculture, where manipulation of strigolactone production or perception offers routes to improve crop yield, reduce fertiliser use and control parasitic weeds, to ecological applications in managing plant community dynamics.

Research from Nature Portfolio

Recent studies have elucidated molecular details of strigolactone biosynthesis and perception that refine our understanding of its dual functionality. Work on rice has revealed that transcriptional regulation of a MAX1‐like cytochrome P450 gene, Os1900, underpins fertiliser‐mediated control of tiller number. Mutations in the Os1900 promoter were shown to fine‐tune the conversion of carlactone to carlactonoic acid, enabling increased grain yield under reduced fertiliser regimes, thus demonstrating a practical approach for sustainable crop improvement. Complementing these findings, structural and biochemical analyses of the Arabidopsis D14 receptor have confirmed that intact strigolactone molecules induce the active signalling state, while subsequent hydrolytic cleavage by D14 deactivates the hormone. This dual‐functional receptor model resolves long‐standing debates about strigolactone perception and establishes a framework for the rational design of synthetic analogues that either stabilise the signalling‐competent form or modulate deactivation, with potential applications in agronomy and weed control.

Strigolactone Signaling in Plant Systems publication trend

The graph below shows the total number of articles in strigolactone signaling in plant systems across all publications each year (not limited to Nature Index journals).

Technical terms

Strigolactone: Carotenoid‐derived plant hormone regulating branching, root architecture and symbiotic signalling.

Phytohormone: Endogenous signalling molecule that orchestrates plant growth, development and stress responses.

Xylem: Vascular tissue responsible for long‐distance transport of water, minerals and signalling compounds.

MAX1‐like gene: Cytochrome P450 enzyme catalysing the oxidation of carlactone to carlactonoic acid in strigolactone biosynthesis.

DWARF14 (D14): α/β‐hydrolase receptor that perceives intact strigolactone molecules and subsequently deactivates them via hydrolysis.

Auxin: Indole‐3‐acetic acid and related compounds that regulate cell elongation, division and directional transport in plants.

References

1. Fertilization controls tiller numbers via transcriptional regulation of a MAX1-like gene in rice cultivation. Nature Communications (2023).
2. Strigolactone perception and deactivation by a hydrolase receptor DWARF14. Nature Communications (2019).
3. Strigolactones Are Transported through the Xylem and Play a Key Role in Shoot Architectural Response to Phosphate Deficiency in Nonarbuscular Mycorrhizal Host Arabidopsis. Plant Physiology (2010).
4. Strigolactones are involved in phosphate- and nitrate-deficiency-induced root development and auxin transport in rice. Journal of Experimental Botany (2014).
5. Low levels of strigolactones in roots as a component of the systemic signal of drought stress in tomato. New Phytologist (2016).