Convergent selection of a WD40 protein that enhances grain yield in maize and rice

• Published in: Science (American Association for the Advancement of Science) Vol. 375; no. 6587; p. eabg7985
• Main Authors: Chen, Wenkang, Chen, Lu, Zhang, Xuan, Yang, Ning, Guo, Jianghua, Wang, Min, Ji, Shenghui, Zhao, Xiangyu, Yin, Pengfei, Cai, Lichun, Xu, Jing, Zhang, Lili, Han, Yingjia, Xiao, Yingni, Xu, Gen, Wang, Yuebin, Wang, Shuhui, Wu, Sheng, Yang, Fang, Jackson, David, Cheng, Jinkui, Chen, Saihua, Sun, Chuanqing, Qin, Feng, Tian, Feng, Fernie, Alisdair R., Li, Jiansheng, Yan, Jianbing, Yang, Xiaohong
• Format: Journal Article
• Language: English
• Published: United States The American Association for the Advancement of Science 25.03.2022
• Subjects: Agricultural production; Agronomy; Biosynthesis; Breeding; Calories; Cereal crops; Cereals; Cofactors; Convergence; Corn; Crop improvement; Crop yield; Crops; Domestication; Dormancy; Economic importance; Edible Grain - genetics; Evolution; Evolutionary genetics; Field tests; Forage; Gene mapping; Genes; Genes, Plant; Genetic modification; Genome editing; Genomes; Grain; Homology; Kernels; Metabolic pathways; Molecular evolution; Oryza - genetics; Phenotypes; Phylogeny; Plant Breeding; Plant Proteins - classification; Plant Proteins - genetics; Proteins; Quantitative trait loci; Rice; Rice fields; Seed dispersal; Selection, Genetic; Starch; Sucrose; WD40 Repeats - genetics; Zea luxurians; Zea mays - genetics
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.abg7985

A better understanding of the extent of convergent selection among crops could greatly improve breeding programs. We found that the quantitative trait locus KRN2 in maize and its rice ortholog, OsKRN2 , experienced convergent selection. These orthologs encode WD40 proteins and interact with a gene of unknown function, DUF1644, to negatively regulate grain number in both crops. Knockout of KRN2 in maize or OsKRN2 in rice increased grain yield by ~10% and ~8%, respectively, with no apparent trade-offs in other agronomic traits. Furthermore, genome-wide scans identified 490 pairs of orthologous genes that underwent convergent selection during maize and rice evolution, and these were enriched for two shared molecular pathways. KRN2 , together with other convergently selected genes, provides an excellent target for future crop improvement. Maize and rice are important sources of human calories and have been, mostly independently, subject to human selection for thousands of years, often for similar traits such as grain yield. W. Chen et al . examined the genomes of accessions of domestic maize and its wild relative, teosinte, for evolutionary signals of selection. From these sequences, the authors identified a quantitative trait locus in maize that increased kernel row number. Fine mapping determined that this locus contains a candidate gene, KRN2 . Gene-editing experiments of KRN2 and its homolog in rice determined that a similar phenotype increasing grain number per plant could be recapitulated. Thus, identifying genes under selection in one cereal provides useful fodder for crop improvements. —LMZ Convergent selection of KRN2 and other genes in maize and rice provide insight for crop improvement.