Knowing how switchgrass (Panicum virgatum L.) responds and adapts to phosphorus (P)‐limitation will aid efforts to optimize P acquisition and use in this species for sustainable biomass production. This integrative study investigated the impacts of mild, moderate, and severe P‐stress on genome transcription and whole‐plant metabolism, physiology and development in switchgrass. P‐limitation reduced overall plant growth, increased root/shoot ratio, increased root branching at moderate P‐stress, and decreased root diameter with increased density and length of root hairs at severe P‐stress. RNA‐seq analysis revealed thousands of genes that were differentially expressed under moderate and severe P‐stress in roots and/or shoots compared to P‐replete plants, with many stress‐induced genes involved in transcriptional and other forms of regulation, primary and secondary metabolism, transport, and other processes involved in P‐acquisition and homeostasis. Amongst the latter were multiple miRNA399 genes and putative targets of these. Metabolite profiling showed that levels of most sugars and sugar alcohols decreased with increasing P stress, while organic and amino acids increased under mild and moderate P‐stress in shoots and roots, although this trend reversed under severe P‐stress, especially in shoots.

中文翻译：

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柳枝to对磷限制的转录，代谢，生理和发育反应。

知道如何柳枝稷（柳枝稷大号。）响应并适应磷（P）的局限性-将有助于优化该物种中磷的获取和利用，以实现可持续的生物量生产。这项综合研究调查了轻度，中度和重度P胁迫对柳枝genome基因组转录和全草代谢，生理和发育的影响。磷限制降低了整体植物的生长，增加了根/枝比率，在中等磷胁迫下增加了根的分支，并且在严重磷胁迫下随着密度和根毛长度的增加而降低了根径。RNA-seq分析揭示了成千上万的基因，在根和/或芽中，在中等和严重的P-胁迫下与P-全营养植物相比差异表达，许多胁迫诱导的基因参与了转录和其他形式的调控，主要和次要新陈代谢，运输，以及P采集和动态平衡中涉及的其他过程。在后者中有多个miRNA399基因和这些基因的推定靶标。代谢物谱分析表明，大多数磷和糖醇的含量随磷胁迫的增加而降低，而在轻度和中度磷胁迫下，茎和根中有机糖和氨基酸的含量增加，尽管这种趋势在严重磷胁迫下逆转，尤其是在芽中。