Rice-specific miR1850.1 targets NPR3 to regulate cold stress response

Area of Science:

• Plant Biology
• Genetics
• Molecular Biology

Background:

• Cold stress significantly reduces rice yields in temperate regions.
• Improving cold tolerance is crucial for rice production security.
• The role of microRNAs in rice cold-stress response remains largely unexplored.

Purpose of the Study:

• Investigate the function of rice-specific pri-miR1850 and its products in cold stress.
• Elucidate the molecular mechanisms underlying cold tolerance regulation by microRNAs.
• Identify targets for enhancing cold tolerance in japonica rice varieties.

Main Methods:

• Utilized gain- and loss-of-function genetic approaches in japonica rice.
• Analyzed the regulation of pri-miR1850, miR1850.1, and miR1850.2 under cold stress.
• Identified NPR3 as a target gene of miR1850.1 through transcript cleavage and translational repression analysis.

Main Results:

• Rice pri-miR1850 and its mature products, miR1850.1 and miR1850.2, are downregulated by cold stress.
• miR1850.1 negatively regulates cold tolerance in young-seedling and booting stages.
• miR1850.1 suppresses NPR3 expression; cold stress leads to NPR3 upregulation via alleviated repression and transcriptional activation.
• The miR1850.1-NPR3 module influences rice disease resistance and grain yield.

Conclusions:

• Discovered a novel cold-signaling network involving miR1850.1 and NPR3 in rice.
• miR1850.1 acts as a negative regulator of cold tolerance by targeting NPR3.
• The miR1850.1-NPR3 module presents potential targets for engineering climate-resilient japonica rice.