A C2H2 Zinc Finger Protein, OsZOS2-19, Modulates ABA Sensitivity and Cold Response in Rice

Abstract Cold stress is a major factor limiting rice (Oryza sativa L.) productivity, making it crucial to understand the molecular mechanisms underlying stress responses to develop resilient crops. In this study, we characterized OsZOS2-19, a cold- and abscisic acid (ABA) -responsive C2H2 zinc finger protein, which functions as a transcriptional repressor. Overexpression of OsZOS2-19 in rice lines increases sensitivity both cold and ABA, reducing cold tolerance, disrupting osmotic balance, and impairing reactive oxygen species (ROS) scavenging. RNA sequencing revealed that OsZOS2-19 overexpression interfered with key stress-response pathways, including those associated with sugar metabolism and glutathione biosynthesis. These findings suggest that OsZOS2-19 negatively regulates cold tolerance and ABA sensitivity by modulating ROS accumulation and osmotic balance, offering new insights into cold adaptation in rice.