Portulaca umbraticola, an important ephemeral summer bedding plant, may be a model system for studies on flowering behavior under heat stress. Herein, we report the first comprehensive transcriptome analysis of P. umbraticola by RNA-sequencing. We generated 22.15 G bases which were assembled into 68,928 unigenes, and a total of 43,880 coding sequences (CDS) were detected. We also detected 13,603 simple sequence repeats on 10,784 unigenes, and predicted 1,444 transcription factor (TF) coding unigenes. Subsequently, we focused on gene discovery in the areas of flower senescence and opening rhythm. We identified the majority of transcripts involved in ethylene biosynthesis, perception, and signaling pathways, as well as transcripts corresponding to circadian clock components. Expression profiles of the ethylene biosynthesis and signaling pathway genes in two cultivars with different flower longevity showed a clear correlation with previously observed endogenous ethylene production. PuACS1 and PuACO2 transcripts showed higher expression, and peaked earlier in a short lived cultivar than in a long lived cultivar. Expression analysis of the core clock component genes showed PuCCA1/PuLHY and PuTOC1 under reciprocal circadian regulation similar to that found in Arabidopsis thaliana, and other plant species. This study provides the first steps in understanding the molecular mechanisms underlying flowering traits in P. umbraticola, and paves the way for future integrated insights into molecular genetics, biotechnology and physiological studies of P. umbraticola.

重要的短暂夏季被褥植物Portulaca umbraticola，可能是研究热胁迫下开花行为的模型系统。在此，我们报告了伞形假单胞菌的第一个综合转录组分析通过RNA测序。我们生成了22.15个G碱基，这些碱基被组装成68,928个单基因，并检测到总共43,880个编码序列（CDS）。我们还检测了10,784个单基因上的13,603个简单序列重复，并预测了1,444个转录因子（TF）编码的单基因。随后，我们专注于花衰老和开放节奏方面的基因发现。我们确定了涉及乙烯生物合成，知觉和信号传导途径的大多数转录物，以及与生物钟组件相对应的转录物。乙烯生物合成和信号通路基因在两个具有不同花寿命的品种中的表达谱显示出与先前观察到的内源性乙烯产生明显的相关性。PuACS1和PuACO2转录本显示较高的表达，并且在长寿品种中比在长寿品种中更早达到高峰。对核心时钟成分基因的表达分析表明，PuCCA1 / PuLHY和PuTOC1在相互的昼夜节律调节下与拟南芥和其他植物中的相似。这项研究为了解伞形假单胞菌开花性状的分子机制提供了第一步，并为将来对伞形假单胞菌的分子遗传学，生物技术和生理学研究提供了全面的见解。