Work

Stress Granule‐Associated ZmCTU2 Confers Thermotolerance in Maize via Coordinated Regulation of Proteostasis and ROS Homeostasis

Year: 2026

Type: article

Abstract: The escalating global temperatures and intensifying heat stress events pose significant threats to maize productivity worldwide. Uncovering key thermotolerance genes and their functional mechanisms is thus critical for developing climate-resilient crops. Here, we report that ZmCTU2, a cytoplasmic tRNA thiolation factor, acts as a central regulator of heat tolerance in maize. Expression of ZmCTU2 correlates positively with kernel-setting under high temperatures. Overexpression of ZmCTU2 confers enhanced thermotolerance at both seedling and adult stages, improving survival and field yield under heat stress, whereas loss-of-function mutants of ZmCTU2 or its partner ZmCTU1 display severe seed developmental defects and lethality. Mechanistically, ZmCTU2 translocates to stress granules under thermal stress, where it recruits ZmCTU1 and ROS-scavenging peroxidases, shielding them from degradation. This dual recruitment facilitates synergistic protective responses: maintenance of tRNA thiolation to ensure translational fidelity, and stabilisation of antioxidative enzymes to bolster redox homeostasis. Our study identifies ZmCTU2 as a scaffold protein within stress granules that coordinates proteostatic and antioxidative pathways under heat stress, providing a valuable genetic resource for engineering thermotolerant maize.

Source: Plant Biotechnology Journal

DOI: 10.1111/pbi.70568