The miRNAs and their targets in cucumber shoot apexes in response to temperature and photoperiod environments

The cucumber is one of the most important vegetables worldwide and is used as a research model for study of phloem transport, sex determination and temperature-photoperiod physiology. The shoot apex is the most important plant tissue in which the cell fate and organ meristems have been determined. In this study, a series of whole-genome small RNA, degradome and transcriptome analyses were performed on cucumber shoot apical tissues treated with high vs. low temperature and a long vs. short photoperiod. small RNAs and mRNAs were pyrosequenced from the shoot apical tissues of cucumber plants grown in four differential temperature-photoperiod treatments (16 h light at 28 °C /8 h dark at 25 °C, HL; 8 h light at 28 °C /16 h dark at 25 °C, HS; 16 h light at 20 °C /8 h dark at 15 °C, LL; 8 h light at 20 °C /16 h dark at 15 °C, LS). The 16 h/8 h and 8-h/16 h of light/dark photoperiods simulated long- and short-day seasons.Three replicates were perfermed on each treatment.

黄瓜是全球最重要的蔬菜作物之一，同时也是韧皮部运输、性别决定及温光生理（temperature-photoperiod physiology）研究的经典模式植物材料。
茎尖（shoot apex）是植物核心组织之一，细胞命运与器官分生组织的特化过程均在此完成。
本研究针对经高低温、长短光周期处理的黄瓜茎尖组织，开展了全基因组水平的小RNA（small RNA）、降解组（degradome）与转录组（transcriptome）联合分析。
研究人员对种植于四种差异化温光处理条件下的黄瓜茎尖组织中的小RNA与mRNA进行了焦磷酸测序（pyrosequencing）。四种温光处理具体为：HL组：28℃光照16h/25℃黑暗8h；HS组：28℃光照8h/25℃黑暗16h；LL组：20℃光照16h/15℃黑暗8h；LS组：20℃光照8h/15℃黑暗16h。
其中16h光照/8h黑暗与8h光照/16h黑暗的光周期分别模拟了长日照与短日照的季节环境。
每组处理均设置三次生物学重复。