MhNF‐YA1‐Like‐MhDnaJC76‐MhAAO3 Transcriptional Cascade Enhances ABA Biosynthesis and Drought Tolerance in Apple

ABSTRACT Drought, the most unfavorable and widespread environmental factor among abiotic stresses, has become a significant global issue that severely crop growth and yield. Nuclear factor‐Y (NF‐Y) transcription factors have well‐documented functions in regulating stress tolerance in plants. However, the specific functions and molecular mechanisms of NF‐YS in conferring drought tolerance in apples remain largely unexplored. Here, we reported that the NF‐Y transcription factor MhNF‐YA1‐like positively modulates drought stress tolerance in apple ( Malus domestica Borkh.). MhNF‐YA1‐like is transcriptionally upregulated in response to drought and abscisic acid (ABA) treatments. Overexpression of MhNF‐YA1‐like enhances drought tolerance in apples, whereas its silencing results in weakened drought tolerance. Further investigation reveals that MhNF‐YA1‐like directly binds to the promoter of MhAAO3 and activates its expression. Additionally, we identified MhDnaJC76 as an interacting protein of MhNF‐YA1, and MhDnaJC76 positively modulates apple drought tolerance. Furthermore, the interaction between MhNF‐YA1‐like and MhDnaJC76 significantly amplifies the regulatory effect of MhNF‐YA1‐like on MhAAO3 , thereby promoting ABA accumulation and consequently enhancing apple drought tolerance. Taken together, our findings elucidate a molecular framework by which the MhNF‐YA1‐like–MhDnaJC76 complex modulates drought tolerance in apples, thereby providing targets for developing drought‐tolerant crops.