Improving yield-related traits by editing the promoter and distal regulatory region of heading date genes Ghd7 and PRR37 in elite rice variety Mei Xiang Zhan 2.

Abstract

Key message: We revealed that editing the promoter and distal regulatory region of the pleiotropic genes Ghd7 and PRR37 reduces their ability to delay heading date while improving their capacity to boost crop yield, offering valuable resources for rice breeding. Heading date is a crucial agronomic characteristic in rice that governs the adaptability to different latitudes and the yield of various varieties. Optimizing the heading date of superior cultivars in breeding practice can significantly broaden their potential planting areas. Ghd7 and PRR37 are pivotal genes that control heading date and enhance agronomic traits. In the elite indica rice variety Mei Xiang Zhan 2 (MXZ2), we used CRISPR/Cas9 technology to effectively generate homozygous mutant lines with a gradient change in heading date by multi-target editing the promoter and distal regulatory region of Ghd7 and PRR37. Various degrees of down-regulation of Ghd7 or PRR37 expression, impaired gene functions, and advancement of the heading date were observed in the mutant lines. Certain mutant lines exhibited an early heading date and increased yield while preserving the exceptional quality of MXZ2. Our study revealed that editing the promoter and distal regulatory region of the pleiotropic genes Ghd7 and PRR37 reduces their ability to delay heading date while improving their capacity to boost crop yield, offering valuable resources for rice breeding.