Orientation Improvement of Grain Length and Grain Number in Rice by Using CRISPR/Cas9 System

Journal Article / 2017

SHEN Lan, LI Jian, FU Yaping, WANG Junjie, HUA Yufeng, JIAO Xiaozhen, YAN Changjie, WANG Kejian

【Objective】Gene orientation editing has become an important way for molecular breeding. We evaluated the improvement effects on the target traits following the construction of GS3 and Gn1a loss-of-function mutants so as to lay a solid foundation for high-yielding rice breeding. 【Method】GS3 and Gn1a were selected as targets for gene editing, which control the grain size and grain number in rice, respectively. The pC1300-2×35S:: Cas9-gGS3-gGn1a expression vector was constructed for knocking out both GS3 and Gn1a by using CRISPR/Cas9 system, and transformed into four good quality rice varieties by the Agrobacterium-mediated method. And the properties of mutations and the target traits were analyzed in the transgenic lines.【Result】The sequencing results showed the GS3 and Gn1a in four rice varieties were successfully edited. In T0 generation, we obtained mutants with frame shift mutations in GS3 and Gn1a in four rice varieties. In T1 generation, the marker-free plants were screened for analyzing the agronomic traits in four genetic backgrounds. For the agronomic characters, the gs3 and gs3gn1a mutants had the longer grain length and the increased 1000-grain weight compared to the wild type, and the gs3gn1a mutants had more grains per panicle compared to the gs3 mutants.【Conclusion】CRISPR/Cas9-mediated gene editing can improve rice target traits, which has great potential in orientation improvement of rice varieties.