Chen W, Chen L, Zhang X, Yang N, Guo J, Wang M, Ji S, Zhao X, Yin P, Cai L, Xu J, Zhang L, Han Y, Xiao Y, Xu G, Wang Y, Wang S, Wu S, Yang F, Jackson D, Cheng J, Chen S, Sun C, Qin F, Tian F, Fernie AR, Li J, Yan J, Yang X.

Science. 2022 Mar 25;375(6587): eabg7985. doi: 10.1126/science.abg7985.

Abstract

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.

See https://pubmed.ncbi.nlm.nih.gov/35324310/

https://www.science.org/doi/10.1126/science.abg7985?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed

Figure 1: Shared selected orthologous genes in maize and rice for convergent phenotypic shifts during domestication and improvement.

By comparing 3163 selected genes in maize and 18,755 selected genes in rice, we identified 490 orthologous gene pairs, including KRN2 and its rice ortholog OsKRN2, as having been convergently selected. Knockout of KRN2 in maize or OsKRN2 in rice increased grain yield by increasing kernel rows and secondary panicle branches, respectively.