The integration of plant–soil interactions into crop improvement frameworks is a timely and important direction, and this paper makes a valuable case for leveraging root system architecture (RSA) and rhizosphere processes to enhance sustainability. However, a core assumption underpinning this argument deserves more critical scrutiny: namely, the idea that RSA traits can be effectively selected and deployed across diverse environments to optimize resource acquisition and yield stability.
Root traits such as deeper rooting, increased lateral branching, and greater surface area are context-dependent in both function and fitness. The metabolic cost of maintaining expansive root systems, particularly in high-input or water-abundant systems, is not trivial, and may reduce carbon availability for reproductive development. In many cases, the ecological advantage of root proliferation is strongly conditioned by local soil constraints and management intensity. Yet the paper treats these traits as broadly beneficial, without sufficiently addressing the physiological trade-offs or potential for negative yield feedbacks.
Further, the proposal to breed for root plasticity overlooks a critical limitation: plastic traits often exhibit low heritability and are difficult to fix within breeding populations. This raises practical challenges for genetic gain and long-term trait stability, especially under field-level environmental heterogeneity. The tension between responsive plasticity and stable trait expression, particularly under stress stacking or fluctuating soil conditions, is a major constraint that remains unaddressed in the paper’s framework.
Finally, while the review mentions beneficial root–microbiome interactions, it does not engage with the dynamic and often unpredictable nature of these relationships in field settings, where multiple environmental and microbial signals interact simultaneously. Without models that incorporate genotype × environment × management interactions and temporal trait variability, the proposed root-centered strategies may fall short of delivering consistent agronomic benefits.
In light of these points, a more cautious interpretation of the role of RSA in sustainable intensification may be warranted. It would be valuable for the authors to clarify how they envision navigating these physiological, genetic, and ecological trade-offs in future breeding and agronomy programs. Such clarification is essential if the root-based strategies outlined in the paper are to be realistically applied beyond controlled environments.