Tissue-specific transcriptome profiling of the citrus fruit epidermis and subepidermis using laser capture microdissection.
Tissue-specific transcriptome profiling of the citrus fruit epidermis and subepidermis using laser capture microdissection.
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DOI：
10.1093/jxb/erq153
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发表时间：
2010-07
影响因子：
6.9
通讯作者：
Rose JK
中科院分区：
文献类型：
--
作者：
Matas AJ;Agustí J;Tadeo FR;Talón M;Rose JK
大多数与果实膨大和成熟相关并控制果实膨大和成熟的生物化学和调控途径的研究都是基于均质化的大块组织，而没有考虑到从其中提取分析物（无论是转录物、蛋白质还是代谢物）的不同细胞类型的多样性。因此，可能有价值的空间信息丢失，并且仅在某些细胞类型中表达的较低丰度细胞组分可能被稀释到检测水平以下。本研究采用激光显微切割（LMD）技术分离绿色、膨大的柑橘果实表皮和亚表皮细胞，并利用20 k柑橘cDNA微阵列和实时荧光定量PCR技术比较了它们的转录组。结果显示，两种细胞类型之间的基因表达谱存在显著差异，揭示了可能与其各自的细胞器组成和细胞壁特化相关的特定代谢途径。显微镜检查提供了组织特化的额外证据，这可能与细胞器和代谢物积累存在明显差异的转录谱相关。表皮下优势基因主要参与光合作用和能量相关过程，以及细胞壁的生物合成和重组。与此相反，大多数表皮优势基因与角质层的生物合成、类黄酮和防御反应有关。此外，表皮转录谱显示出高比例的基因，没有已知的功能，支持原来的假设，在组织/细胞特异性水平的分析可以促进基因的发现，并导致更好地了解每个组织的水果生理学的专门贡献。
Most studies of the biochemical and regulatory pathways that are associated with, and control, fruit expansion and ripening are based on homogenized bulk tissues, and do not take into consideration the multiplicity of different cell types from which the analytes, be they transcripts, proteins or metabolites, are extracted. Consequently, potentially valuable spatial information is lost and the lower abundance cellular components that are expressed only in certain cell types can be diluted below the level of detection. In this study, laser microdissection (LMD) was used to isolate epidermal and subepidermal cells from green, expanding Citrus clementina fruit and their transcriptomes were compared using a 20k citrus cDNA microarray and quantitative real-time PCR. The results show striking differences in gene expression profiles between the two cell types, revealing specific metabolic pathways that can be related to their respective organelle composition and cell wall specialization. Microscopy provided additional evidence of tissue specialization that could be associated with the transcript profiles with distinct differences in organelle and metabolite accumulation. Subepidermis predominant genes are primarily involved in photosynthesis- and energy-related processes, as well as cell wall biosynthesis and restructuring. By contrast, the most epidermis predominant genes are related to the biosynthesis of the cuticle, flavonoids, and defence responses. Furthermore, the epidermis transcript profile showed a high proportion of genes with no known function, supporting the original hypothesis that analysis at the tissue/cell specific levels can promote gene discovery and lead to a better understanding of the specialized contribution of each tissue to fruit physiology.