Generation of new rice germplasms with low amylose content by CRISPR/CAS9-targeted mutagenesis of the FLOURY ENDOSPERM 2 gene

Xiaohong Song; Zhihui Chen; Xi Du; Bin Li; Yunyan Fei; Yajun Tao; Fangquan Wang; Yang Xu; Wenqi Li; Jun Wang; Guohua Liang; Yong Zhou; Xiaoli Tan; Yulong Li; Jie Yang

doi:10.3389/fpls.2023.1138523

Generation of new rice germplasms with low amylose content by CRISPR/CAS9-targeted mutagenesis of the FLOURY ENDOSPERM 2 gene

Front Plant Sci. 2023 Mar 13:14:1138523. doi: 10.3389/fpls.2023.1138523. eCollection 2023.

Authors

Xiaohong Song^{1

2}, Zhihui Chen^{2

3}, Xi Du^{2

3}, Bin Li^{1

2}, Yunyan Fei^{2

3}, Yajun Tao^{2

3}, Fangquan Wang^{2

3}, Yang Xu^{2

3}, Wenqi Li^{2

3}, Jun Wang^{2

3}, Guohua Liang^{2

3}, Yong Zhou^{2

3}, Xiaoli Tan¹, Yulong Li¹, Jie Yang^{1

2

3}

Affiliations

¹ School of Life Science, Jiangsu University, Zhenjiang, Jiangsu, China.
² Institute of Food Crops, Jiangsu Academy of Agricultural Sciences/Key Laboratory of Germplasm Innovation in Downstream of Huaihe River Ministry of Agriculture and Rural Affairs, Nanjing, Jiangsu, China.
³ Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.

Abstract

FLOURY ENDOSPERM 2 (FLO2), encoding a tetratricopeptide repeat domain (TPR)-containing protein located in the nucleus, is considered to be a regulatory protein that controls the biosynthesis of seed storage substances. The diversity of flo2 allele is attributable for the variations in grain appearance, amylose content (AC), and physicochemical properties, influencing the eating and cooking quality (ECQ) of rice. In this study, we used CRISPR/Cas9 to introduce loss-of-function mutations into the FLOURY ENDOSPERM 2 gene in Suken118 (SK118), a widely cultivated elite japonica rice variety in Jiangsu, China. Physiochemical analyses of the flo2 mutants were congruent with previous studies, exhibiting lowered AC and viscosity, risen gel consistency (GC) and gelatinization temperature (GT) values, which were all instrumental to the improvement of ECQ. However, the wrinkled opaque appearance and the decrease in grain width, grain thickness and grain weight imply trade-offs in grain yield. Despite the ex-ante estimation for low yielding, the superior ECQ in these novel genotypes generated by using genome editing approach may have the potential for formulating high value specialty food.

Keywords: CRISPR/Cas9; FLOURY ENDOSPERM 2; amylose content (AC); eating and cooking quality (ECQ); genome editing; japonica rice.

Grants and funding

This work was funded by Project of Seeds innovation in Jiangsu (GBGS [2021]001), Natural Science Foundation of Jiangsu Province (BK20190255) and the Exploratory Project of the Jiangsu Academy of Agricultural Sciences (ZX (21)1201).