Xiong Hongchun; Guo Huijun; Fu  Meiyu; Xie Yongdun; Zhao Linshu; Gu Jiayu; Zhao Shirong; Ding Yuping; Du Qidi; Zhang Jiazi; Qiu Lin; Xie Xiaomei; Zhou Libin; Chen Zhongxu; Liu Luxiang. 

Plant Biotechnology Journal, 2023, IF 13.80

DOI:10.1111/pbi.14111

ABSTRACT:

Hexaploid wheat (Triticum aestivum), a major staple crop, has a remarkably large genome of similar to 14.4 Gb (containing 106 913 high-confidence [HC] and 159 840 low-confidence [LC] genes in the Chinese Spring v2.1 reference genome), which poses a major challenge for functional genomics studies. To overcome this hurdle, we performed whole-exome sequencing to generate a nearly saturated wheat mutant database containing 18 025 209 mutations induced by ethyl methanesulfonate (EMS), carbon (C)-ion beams, or gamma-ray mutagenesis. This database contains an average of 47.1 mutations per kb in each gene-coding sequence: the potential functional mutations were predicted to cover 96.7% of HC genes and 70.5% of LC genes. Comparative analysis of mutations induced by EMS, gamma-rays, or C-ion beam irradiation revealed that gamma-ray and C-ion beam mutagenesis induced a more diverse array of variations than EMS, including large-fragment deletions, small insertions/deletions, and various non-synonymous single nucleotide polymorphisms. As a test case, we combined mutation analysis with phenotypic screening and rapidly mapped the candidate gene responsible for the phenotype of a yellow-green leaf mutant to a 2.8-Mb chromosomal region. Furthermore, a proof-of-concept reverse genetics study revealed that mutations in gibberellic acid biosynthesis and signalling genes could be associated with negative impacts on plant height. Finally, we built a publically available database of these mutations with the corresponding germplasm (seed stock) repository to facilitate advanced functional genomics studies in wheat for the broad plant research community.