Complementary capability of cell division and photosynthesis triggers growth vigor in Arabidopsis hybrids

Mechanism behind heterosis has remained a mystery for a very long time despite its agricultural importance. Here, we report an integrated analysis of the phenotypes and transcriptomes of early shoot and true leaf during seedling growth at high-temporal-resolution in two Arabidopsis ecotypes and their F1 hybrid. We identify the core gene co-expression networks underlying the dynamic regulations of transcriptomes and their sophisticated differences between hybrid and parents. We provide the first evidence of spatiotemporally transcriptional dominant complementation in hybrid between the network hub genes involved in cell division and photosynthesis, respectively. Our findings highlight the pivotal roles of functionally dominant allelic action and expression complementation of fundamental biological pathways in growth heterosis. mRNA profiles of early seedling shoot at 3-8 days after sowing (DAS) and the first true leaf at 7-21 DAS in Arabidopsis ecotypes Col-0, Per-1 and their F1 hybrid (Col-0 × Per-1), including three biological replicates