Transcription factors ERF74/77/108/125 enhance thermotolerance in rice by regulating common and distinct...

Heat stress severely impacts crop productivity, necessitating the identification of key regulatory genes for improving thermotolerance. Here, we demonstrate that the rice nuclear-localized AP2/ERF transcription factors ERF74/77/108/125 function as critical regulators of heat stress responses. Loss-of-function mutant seedlings of ERF74/77 or ERF108/125 exhibit increased heat sensitivity, whereas overexpression of each ERF74, ERF77, ERF108 or ERF125 individually enhances thermotolerance, indicating their positive role in heat adaptation. These ERFs activate heat-responsive genes, with ERF74/77 and ERF108/125 sharing common targets while maintaining distinct regulatory networks. Mechanistically, ERF74/77/108/125 directly bind to the promoter of HsfA2c, a central heat shock transcription factor, and activate its expression. Genetic evidence confirms that HsfA2c is essential for mediating thermotolerance in rice. Our findings reveal a hierarchical regulatory module where ERF74/77/108/125 orchestrate heat stress responses by activating distinct and common downstream genes including HsfA2c, providing potential targets for engineering climate-resilient rice.