Comprehensive Analysis of Ghd7 Variations Using Pan-Genomics and Prime Editing in Rice

TL;DR

This study explores variations in the Ghd7 gene in rice and uses gene editing to improve rice seed production efficiency.

Contribution

The study integrates pan-genomics and prime editing to identify and correct Ghd7 variations in rice for improved agronomic traits.

Findings

977 rice accessions were found to carry structural variations in the Ghd7 locus.

A splice-site mutation in haplotype H6 causes abnormal mRNA splicing in Ghd7.

Prime editing restored Ghd7 function, delaying heading date and improving hybrid seed production.

Abstract

The Ghd7 gene in rice plays a crucial role in determining heading date, plant height, and grain yield. However, the variations in Ghd7 and their functional implications across different rice accessions are not fully understood. Based on the release of a large amount of rice genome data in recent years, we investigated Ghd7 through pan-genome analysis of 372 diverse rice varieties and figured out the structural variations (SVs) in the Ghd7 locus. However, due to the high cost of pan-genomes, most genomes are based on next-generation sequencing (NGS) data now. Therefore, we developed a method for identifying SVs using NGS data and Polymerase Chain Reaction (PCR) based on the results of pan-genome analysis and identified 977 accessions carrying such SVs of Ghd7. Furthermore, we identified 46 single-nucleotide polymorphisms (SNPs) and one insertion-deletion (InDel) in the coding region of Ghd7. They are classified into 49 haplotypes. Notably, a splice-site mutation in haplotype H6 causes aberrant mRNA splicing. Using prime editing (PE) technology, we successfully restored the functional of Ghd7 in Yixiang 1B (YX1B), delaying the heading date by approximately 16 days. This modification synchronized the heading date between YX1B and the restorer line Yahui 2115 (YH2115R), enhancing the hybrid rice seed production efficiency. In conclusion, our findings highlight the potential of integrating pan-genomics and precision gene editing to accelerate crop improvement and enhance agronomic traits.

Figures