Plant G proteins: Versatile signaling hubs for synergistic improvement of agronomic traits

Prioritizing defense responses often restricts growth and yield, forming a growth-defense conflict that limits crop productivity and threatens global food security. Traditionally attributed to resource allocation constraints, this trade-off is governed by sophisticated signaling regulatory networks. Plant G proteins act as pivotal molecular switches that initiate cellular signal transduction, and they extensively integrate plant growth, development, and stress adaptation. Recent studies have uncovered their multifaceted coordination roles in regulating crop yield and stress resistance, and elite alleles of G proteins have been identified and applied in molecular design breeding. However, the pleiotropy of most G proteins hinders the concerted control of yield and stress resilience, leading to trait divergence, which represents a key bottleneck for breeding high-yield and stress-tolerant crops. Here, we summarize the regulatory networks of G protein subunits in yield and quality traits and stress responses, dissect the mechanisms underlying G protein-mediated growth-resistance decoupling, and propose precision strategies to simultaneously enhance these agronomic traits. This review provides theoretical and practical guidance for developing high-performance crop varieties.