Fine-tuning <i>OsTCP19</i> expression offers broad adaptation scenarios for nitrogen-use efficiency improvement in rice

Inconsistent nitrogen application rates across global croplands necessitate the adaptation of different genetic alleles to optimize nitrogen-use efficiency (NUE) in agriculture. In rice (Oryza sativa L.), different TEOSINTE BRANCHED 1, CYCLOIDEA AND PROLIFERATING CELL FACTOR 19 (OsTCP19) alleles contribute to the geographical adaptation to soil fertility. The nitrogen-sensitive allele OsTCP19-H is predominantly found in low-nitrogen regions due to its superior tillering and yield accumulation capabilities. Conversely, the nitrogen-insensitive allele OsTCP19-L is more common in nitrogen-sufficient regions, though the precise factors affecting this distribution remain unknown. Here, we report that high-nitrogen levels lead to lodging in an OsTCP19-dependent manner. Overexpression of this gene modifies plant architecture, enhancing lodging resistance in rice. Importantly, fine-tuning OsTCP19 expression can confer lodging resistance without a yield penalty. This is particularly important as it alleviates yield loss from lodging under high-nitrogen conditions and, intriguingly, can result in a substantial increase in plot yield when combined with dense planting strategies. Furthermore, the distinct nitrogen sensitivity of different OsTCP19 alleles allows for substantial improvement in grain yield and NUE under certain nitrogen conditions. Thus, our findings suggest that genetic manipulation of a single gene, OsTCP19, could allow flexible adaptation to diverse planting scenarios, maximizing genetic benefits based on local nitrogen availability.