Disruption of miR156 binding site of the GW8 gene affects rice grain morphology in the variety ASD16

Abstract

Rice grain width is intricately governed by multiple aspects of grain development, such as cell division and expansion, thereby affecting overall grain morphology. Several key genes were identified and studied for their role in regulating grain width. OsSPL16/GW8 is a positive regulator of grain width by boosting grain weight, a major determinant of grain yield. The GW8 mRNA transcripts are cleaved by miR156, leading to reduced gene expression. In this study, we employed the CRISPR/Cas9 system to generate gw8 mutants with a disrupted GW8-miR156 binding site to enhance both grain morphology and yield in the ASD16 rice genetic background. Agrobacterium-mediated rice genetic transformation resulted in the generation of 25 putative gw8 mutants. Sanger sequencing revealed the presence of mutations within and outside the GW8-miR156 module. Notably, plants harboring mutations disrupting the GW8-miR156 module exhibited an altered grain morphology with awn and poor grain set. Further research is needed to unravel the pleiotropic effects associated with the GW8-miR156 module in rice.

Keywords

• rice
• grain width
• spl16 gene
• gw8
• mir156
• crispr/cas9