Ectopic Expression of ZmATF2 Encoding a Histone Acetyl‐Transferase From Maize Simultaneously Promotes Salt Tolerance and Tillering of Japonica Rice

As the human population is growing and the environment is degrading, breeding resilient and high-yield crop cultivars is a practical strategy for food security. Genetic modifications including transgenic techniques require identification and functional characterization of resource genes for higher yield and resilience. Histone acetylation is associated with gene activation and plays important roles in both plant development and stress responses in plants. Maize is a typical C4 crop with a high capacity for resilience and assimilation, but few of its histone acetyltransferase genes (HAT) have been identified and functionally characterized. In this study, we identified 14 HAT genes in maize and analyzed their expression patterns. Zm00001eb109790 (ZmATF2) encodes a putative histone acetyltransferase located in the nucleus. The overexpression of ZmATF2 enhanced salt tolerance and increased the total yield per plant through boosting the tillering of transgenic rice, which was accompanied by heightened histone acetylation and altered expression patterns of a plethora of development-related genes and stress-responsive genes. Treatment with a chemical inhibitor of histone acetyltransferases dampened the salt tolerance conferred by ZmATF2, further supporting the role of ZmATF2 as a histone acetyltransferase in transgenic rice. This study systematically analyzed the ZmHAT family and revealed the role of ZmATF2 in salt stress response and plant development using rice as a model plant. Our results provide a genetic modification-based strategy for simultaneously improving stress tolerance and yield in rice plants.