Mutation of DEP1 facilitates the improvement of plant architecture in Xian rice (Oryza sativa)

Plant architecture is a complex trait and has a profound impact on crop performance and productivity. We applied the CRISPR/Cas9 system to mutate the DEP1 gene, which has been reported to function as regulator of plant architecture, in elite Xian cultivar 'Huhan1509'. Sequencing analysis of T-0 transformed plants showed that the CRISPR/Cas9 system was highly efficient in mutagenesis of targeted DEP1 gene, with 30% of the homozygous mutations and 70% of the heterozygous mutations. T-2 homozygous mutants without T-DNA were further examined for the agronomic traits. The DEP1 mutants exhibited an altered plant architecture along with a shorter plant height and grain size and increased spikelets and grain density. Furthermore, phenotypes of raising primary branches and stem diameters were observed in the DEP1 mutants. Our results demonstrate that favourable alleles of the DEP1 gene, developed by CRISPR/Cas9 system, could be used to improve plant architecture in Xian rice.