Center for Ecological Research, Kyoto University, Otsu, Japan.
Faculty of Life Sciences, Ritsumeikan University, Kusatsu, Japan.
Sci Rep. 2020 Aug 6;10(1):13291. doi: 10.1038/s41598-020-69941-9.
The rhizome is a plant organ that develops from a shoot apical meristem but penetrates into belowground environments. To characterize the gene expression profile of rhizomes, we compared the rhizome transcriptome with those of the leaves, shoots and roots of a rhizomatous Brassicaceae plant, Cardamine leucantha. Overall, rhizome transcriptomes were characterized by the absence of genes that show rhizome-specific expression and expression profiles intermediate between those of shoots and roots. Our results suggest that both endogenous developmental factors and external environmental factors are important for controlling the rhizome transcriptome. Genes that showed relatively high expression in the rhizome compared to shoots and roots included those related to belowground defense, control of reactive oxygen species and cell elongation under dark conditions. A comparison of transcriptomes further allowed us to identify the presence of an ER body, a defense-related belowground organelle, in epidermal cells of the C. leucantha rhizome, which is the first report of ER bodies in rhizome tissue.
根茎是一种植物器官，由茎尖分生组织发育而来，但会穿透到地下环境中。为了描述根茎的基因表达谱，我们将其与一种根茎十字花科植物——碎米荠（Cardamine leucantha）的叶片、茎和根的转录组进行了比较。总的来说，根茎转录组的特征是缺乏表现出根茎特异性表达的基因，其表达谱介于茎和根之间。我们的结果表明，内源性发育因子和外部环境因素对于控制根茎转录组都很重要。与茎和根相比，在根茎中表达较高的基因包括与地下防御、活性氧控制以及黑暗条件下细胞伸长相关的基因。转录组的比较还使我们能够鉴定出 ER 体的存在，这是一种与防御相关的地下细胞器，存在于碎米荠根茎的表皮细胞中，这是 ER 体在根茎组织中的首次报道。
