School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China;
Proc Natl Acad Sci U S A. 2021 Apr 20;118(16). doi: 10.1073/pnas.2023278118.
The mechanisms underlying heterosis have long remained a matter of debate, despite its agricultural importance. How changes in transcriptional networks during plant development are relevant to the continuous manifestation of growth vigor in hybrids is intriguing and unexplored. Here, we present an integrated high-resolution analysis of the daily dynamic growth phenotypes and transcriptome atlases of young seedlings (parental ecotypes [Col-0 and Per-1] and their F hybrid). Weighted gene coexpression network analysis uncovered divergent expression patterns between parents of the network hub genes, in which genes related to the cell cycle were more highly expressed in one parent (Col-0), whereas those involved in photosynthesis were more highly expressed in the other parent (Per-1). Notably, the hybrid exhibited spatiotemporal high-parent-dominant expression complementation of network hub genes in the two pathways during seedling growth. This suggests that the integrated capacities of cell division and photosynthesis contribute to hybrid growth vigor, which could be enhanced by temporal advances in the progression of leaf development in the hybrid relative to its parents. Altogether, this study provides evidence of expression complementation between fundamental biological pathways in hybrids and highlights the contribution of expression dominance in heterosis.
杂种优势的机制尽管具有农业重要性，但长期以来一直存在争议。植物发育过程中转录网络的变化如何与杂种中生长活力的持续表现相关，这是一个有趣但尚未探索的问题。在这里，我们对年轻幼苗（亲本生态型[Col-0 和 Per-1]及其 F1 杂种）的每日动态生长表型和转录组图谱进行了综合的高分辨率分析。加权基因共表达网络分析揭示了网络枢纽基因的亲本之间不同的表达模式，其中与细胞周期相关的基因在一个亲本（Col-0）中表达更高，而与光合作用相关的基因在另一个亲本（Per-1）中表达更高。值得注意的是，杂种在幼苗生长过程中，在这两个途径中表现出时空上的高亲本主导的网络枢纽基因表达互补。这表明细胞分裂和光合作用的综合能力有助于杂种的生长活力，而杂种相对于其亲本在叶片发育进程中的时间推进可能会增强这种活力。总的来说，这项研究为杂种中基本生物学途径之间的表达互补提供了证据，并强调了杂种优势中表达主导作用的贡献。
