PRJNA860563
Positive feedback between TOR singling, energy metabolism and lysine acetylation drives heterosis in elite hybrid rice
Heterosis refers to the superior performance of the hybrid compared with its parental lines. Despite several genetic models and different molecular pathways proposed to explain heterosis, it remains unclear how cells integrate complementary gene expression, metabolic accumulation and/or hormone signaling to drive heterotic growth. In this work, using multiple omics combined with biochemical analyses, we showed an enhanced TORC1 signaling of the elite hybrid rice Shanyou 63 (SY63) relative to the parental lines, which was associated with accumulation of growth-promoting (translation, cell division) and energy metabolic (glycolysis and TCA) proteins energy metabolic activities, and superior growth of panicle meristem. Metabolism of nuclear-cytosolic acetyl-Coenzyme A was also enhanced in the hybrid, which paralleled with increases of histone H3 acetylation to selectively target growth-promoting and metabolic genes expression. Lysine acetylation of cellular proteins including TORC1, ribosomal proteins, and energy metabolic enzymes was also augmented and/or remodeled, potentially modulating their activities. The data revealed that the positive feedback loop between TOR-signaling, energy-producing metabolic activity, lysine acetylation, and growth-promoting gene expression is a mechanism underling the superior growth rate of the hybrid. The results implied that an enhanced activity in hybrids would drive and sustain the TOR signaling feedback loop to promote superior growth, which may represent a general mechanistic model for heterosis.