Miscanthus is a commercial lignocellulosic biomass crop owing to its high biomass productivity and low chemical input requirements. Interspecific Miscanthus hybrids with high biomass yield were shown to have low concentrations of starch and sucrose but high concentrations of fructose. We performed a transcriptional RNA-seq analysis between selected Miscanthus hybrids with contrasting values for these phenotypes to clarify how these phenotypes are genetically controlled. We observed that genes directly involved in the synthesis and degradation of starch and sucrose were down-regulated in high yielding Miscanthus hybrids. At the same time, glycolysis and export of triose phosphates were up-regulated in high yielding Miscanthus hybrids. Our results evidence a direct relationship between high expression of essential enzymatic genes in the starch and sucrose pathways, high starch concentrations, and lower biomass production. The strong interconnectivity between genotype, chemotype and agronomic traits opens the door to use the expression of well-characterised genes in the starch and sucrose pathway for the early selection of high biomass yielding genotypes from large Miscanthus populations.

中文翻译：

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与芒草杂种产量变化相关的淀粉和蔗糖代谢基因差异表达

芒草是一种商业化的木质纤维素生物质农作物，因为其生物量生产率高且化学物质输入需求低。具有高生物量产量的种间芒草杂种显示出具有低浓度的淀粉和蔗糖，但是具有高浓度的果糖。我们在选定的芒草杂种之间进行了转录RNA-seq分析，并具有这些表型的对比值，以阐明这些表型是如何遗传控制的。我们观察到直接参与淀粉和蔗糖的合成和降解的基因在高产量的芒草杂种中被下调。同时，高产的芒草杂种的糖酵解和磷酸三糖的输出上调。我们的结果证明了淀粉和蔗糖途径中必需酶基因的高表达，高淀粉浓度和较低生物量产量之间存在直接关系。基因型，化学型和农艺性状之间的强大关联性为利用从大量芒草种群中早期选择高生物量高产基因型的淀粉和蔗糖途径中表现良好的基因表达打开了大门。