Evolution of Plant Architecture in Driven by the Locus.

The genetic control of plant architecture in crops is critical for agriculture and understanding morphological evolution. This study showed that an open reading frame (ORF) of the rice domestication gene appeared 3.4-3.9 million years ago (Mya). Subsequently, it acquired a novel protein-coding gene function in the genome of (~0.3-0.4 Mya). This extremely young gene and its paralogous C2H2 genes located nearby define the prostrate architecture of and, thus, are of adaptive significance for wild rice in swamp and water areas. However, selection for dense planting and high yield during rice domestication silenced the gene and caused the loss of the locus containing functional C2H2 paralogs; hence, domesticated lines exhibit an erect plant architecture. Analysis of the stepwise origination process of and its evolutionary genetics revealed that this zinc-finger coding gene may have rapidly evolved under positive selection and promoted the transition from non- or semi-prostrate growth to prostrate growth. A transgenic assay showed that from exerts a stronger function compared with sequences from other species. However, the analysis of the expression levels of in different species suggests that the transcriptional regulation of has played an important role in its evolution. This study provides the first strong case showing how a fundamental morphological trait evolved in species driven by a gene locus.