The CCCH-tandem zinc-finger protein OsTZF1 positively regulates basal immunity but suppresses Piz-t-mediated blast resistance in rice

Plant nucleotide-binding leucine-rich repeat (NLR) immune receptors play a critical role in plant defense, but the mechanisms regulating their expression remain incompletely understood. Here, we report that the rice CCCH-tandem zinc-finger protein OsTZF1 interacts with both AvrPiz-t interacting protein 10 (APIP10) and the NLR protein Piz-t. OsTZF1 positively regulates rice immunity by increasing the transcript levels of OsSGT1 and OsKS4 through binding to the AAAGC motif. However, in Piz-t-carrying plants, knockout of OsTZF1 results in increased Piz-t transcript and protein levels, thus enhancing resistance to virulent strains of Magnaporthe oryzae without a growth penalty. Furthermore, we demonstrate that OsTZF1 can directly bind to the AAAGC motif of Piz-t, thereby repressing its expression level. Thus, OsTZF1 functions as a dual regulator: it activates general defense genes while suppressing Piz-t-mediated resistance to virulent strains, balancing resistance and growth. These findings reveal a strategy for engineering NLR-mediated resistance in crops by fine-tuning immune regulators to achieve both disease resistance and yield stability.