Structure-guided reprogramming of DELLA turnover for a sustainable Green Revolution in rice

The Green Revolution of the 1960s significantly boosted cereal yields but incurred substantial environmental costs due to overreliance on chemical fertilizer inputs; thus, future agricultural sustainability demands improved nitrogen-use efficiency (NUE). The semi-dwarf Green Revolution varieties (GRVs) characterized by elevated DELLA protein accumulation introduce a fundamental trade-off, increasing lodging resistance and harvest index at the expense of diminished biomass and grain productivity per plant, and require high nitrogen fertilizer inputs to achieve maximum yield potential under high planting density. Here we show that gibberellin (GA)-bound GA-INSENSITIVE DWARF1 (GID1) induces multi-level conformational changes in DELLA protein, affecting its N-terminal DELLA and VHYN/DPT/S and C-terminal VVLV and SAW motifs, thereby facilitating recognition by the SKP1-CULLIN-F-box (SCF) ubiquitin ligase complex and subsequent proteasomal degradation. We also performed structure-guided engineering of the rice SLENDER RICE1 (SLR1)-GID1-GID2 complex and created a series of dwarf alleles exhibiting a continuous spectrum of plant heights in elite cultivars. Notably, the dominant alleles slr1^Y94A and slr1^Y580A achieved superior yield and enhanced NUE over conventional sd1-containing GRVs. Reprogramming DELLA turnover thus enables to break the long-standing trade-off between high yield and fertilizer dependency, offering a strategy toward a more sustainable and productive Green Revolution.