The CCCH Zinc Finger Gene PgCCCH50 from Pearl Millet Confers Drought and Salt Tolerance through an ABA-Dependent PgAREB1-PgCCCH50 Module

Abstract

Abiotic stresses like drought and salinity severely constrain crop productivity. Pearl millet (Pennisetum glaucum L.), a stress-resilient cereal of global importance, is ideal for deciphering genetic adaptation. Although CCCH zinc finger proteins play key roles in plant stress responses, members with multiple regulatory functions remain unknown in this crop. This study analyzed 53 CCCH genes in pearl millet, examining their phylogeny, structure, chromosomal localization, and promoter cis-elements. Expression profiling revealed seven CCCH genes responsive to multiple stresses. Functional characterization of PgC3H50 showed that its overexpression in Arabidopsis conferred enhanced tolerance to drought and salt, evidenced by improved physiological parameters and upregulation of stress-responsive genes. We discovered that the ABA-responsive transcription factor PgAREB1(ABSCISIC ACID RESPONSIVE ELEMENT BINDING PROTEIN 1) directly binds to ABRE cis-elements in the PgC3H50 promoter and activates its transcription, validated by yeast one-hybrid, dual-luciferase, and EMSA assays. This defines a novel PgAREB1-PgC3H50 regulatory module within the ABA-mediated stress signaling pathway. Our findings provide a valuable genetic resource for the pearl millet CCCH family and unveil a promising candidate gene and transcriptional regulatory module for engineering crops with improved tolerance to drought and salinity. HighlightThis study reports the first genome-wide analysis of the CCCH family in pearl millet and identifies the novel PgAREB1-PgCCCH50 module as essential for salt and drought tolerance.