Resurrection plant Ramonda serbica is a suitable model to investigate mechanisms of desiccation tolerance, while variegated Pelargonium zonale has been proven to serve as an excellent model for the metabolite allocation between sink tissue and source tissue within the same organ. However, the genomes of these plants are still not sequenced, limiting their application in molecular studies. To investigate the transcript abundance by next-generation sequencing, high-quality RNA input is required. Leaves of both P. zonale and R. serbica are rich in polyphenols that interfere with high-quality RNA extraction by common protocols. Moreover, low water content and high amount of sugars and other osmoprotectants in desiccated R. serbica leaves present the additional challenge in total RNA extraction. Here, we evaluated and compared several already established TRIzol- and CTAB-based protocols aiming to develop the efficient, simple and low-cost methods for the extraction of the satisfactory yield RNA of great purity and integrity, required for the construction of high-quality cDNA libraries. Our results show that the CTAB-based protocol (i.e. CTAB 1b) enabled the extraction of high-quality RNA from photosynthetically active and non-photosynthetically active leaf sectors of P. zonale, with high RIN values. On the other hand, TRIzol-based protocol provided a high RNA yield with low contamination and high RNA integrity even in desiccated leaves of R. serbica. We envisage that the proposed protocol would be suitable for the RNA extractions from other desiccated organs (e.g. seeds, grains, pollen grains).

复活植物Ramonda serbica是研究干燥耐性机制的合适模型，而杂色天竺葵已被证明是同一器官内汇聚组织和源组织之间代谢物分配的极好模型。但是，这些植物的基因组仍未测序，限制了它们在分子研究中的应用。要通过下一代测序研究转录本的丰度，需要高质量的RNA输入。两个叶片P. zonale和R. serbica富含与由公共协议高质量RNA提取干扰多酚。此外，干燥后水分含量低，糖和其他渗透保护剂的含量高R. serbica叶子对总RNA提取提出了额外的挑战。在这里，我们评估并比较了几种已经建立的基于TRIzol和CTAB的方案，旨在开发高效，简单和低成本的方法，以提取高质量构建所需的高纯度和完整性的满意产量RNA cDNA文库。我们的结果表明，基于CTAB的协议（即CTAB 1b）能够从P的光合活性和非光合活性叶片中提取高质量的RNA 。zonale，具有较高的RIN值。另一方面，基于TRIzol的实验方案即使在塞尔维亚干叶干燥的叶子中也能提供高RNA产量，低污染和高RNA完整性。我们设想，拟议的协议将适用于从其他干燥器官（例如种子，谷物，花粉粒）中提取RNA。