Decoding the sugar-strigolactone crosstalk: new frontier in plant growth and stress resilience

Plants continuously integrate metabolic and hormonal signals to coordinate growth, development, and responses to environmental stimuli. Among these signals, sugars and strigolactones (SLs) have emerged as central regulators. Beyond serving as metabolic fuels, sugars act as signaling molecules that govern key developmental transitions and stress responses. SLs, a relatively recent addition to the phytohormone family, play pivotal roles in shaping plant architecture, modulating resource allocation, and facilitating environmental adaptation. While the individual signaling functions of sugars and SLs are well documented, their crosstalk remains an emerging and largely underexplored area of plant biology. This review synthesizes current knowledge on both the independent and interactive roles of sugar and SL signaling across critical developmental processes, including seed germination, hypocotyl elongation, root and shoot architecture, flowering, senescence, and plant responses to abiotic and biotic stress. By analyzing antagonistic and synergistic interactions, we point out several potential integrative hubs where metabolic and hormonal signals converge to fine-tune the final decision. Notably, the nodal roles of BRC1/TB1 (BRANCHED1/TEOSINTE BRANCHED1), FT (FLOWERING LOCUS T), in mediating sugar-SL crosstalk in shoot branching, flowering, respectively, are highlighted. We also explore how sugar-SL interplay influences seed germination and plant adaptation to environmental stresses through shared regulators such as TOR (Target of Rapamycin) kinase, SnRK1 (Sucrose non-fermenting-1 Related Kinase 1), and SMXLs (Suppressor of MAX2-Like proteins). Understanding these interactions not only deepens our knowledge of fundamental plant biology but also offers new insights for improving the performance and resilience of crop and horticultural species.