Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
State Key Laboratory of Agrobiotechnology, School of Life Sciences, Chinese University of Hong Kong, Hong Kong, China.
Genes (Basel). 2020 Mar 18;11(3):324. doi: 10.3390/genes11030324.
Litchi is an important subtropical fruit tree that requires an appropriately low temperature to trigger floral initiation. Our previous studies have shown that reactive oxygen species (ROS) are involved in litchi flowering. To identify oxidative stress-induced flowering related genes in leaves, 'Nuomici' potted trees were grown at medium low-temperature conditions (18/13 °C for day/night, medium-temperature). The trees were treated with the ROS generator methyl viologen dichloride hydrate (MV) as the MV-generated ROS treatment (MM, medium-temperature plus MV) and water as the control treatment (M, medium-temperature plus water). Sixteen RNA-sequencing libraries were constructed, and each library generated more than 5,000,000 clean reads. A total of 517 differentially expressed genes (DEGs) were obtained. Among those DEGs, plant hormone biosynthesis and signal transduction genes, ROS-specific transcription factors, such as AP2/ERF and WRKY genes, stress response genes, and flowering-related genes () and () were significantly enriched. Then, as a confirmatory experiment, the potted trees were uniformly sprayed with MV, N,N'-dimethylthiourea (DMTU, ROS scavenger) plus MV, and water at medium-temperature. The results showed that the MV-generated ROS promoted flowering and changed related gene expression, but these effects were repressed by DMTU treatment. The results of our studies indicate that ROS could promote flowering and partly bypass chilling for litchi flowering.
荔枝是一种重要的亚热带果树，需要适当的低温来触发开花。我们之前的研究表明，活性氧（ROS）参与了荔枝开花。为了鉴定叶片中与氧化应激诱导开花相关的基因，将‘糯米糍’盆栽树在中低温条件下（18/13°C 日/夜，中温）生长。将这些树用 ROS 发生器甲紫氯化二水合物（MV）处理作为 MV 产生的 ROS 处理（MM，中温加 MV），用水处理作为对照处理（M，中温加水）。构建了 16 个 RNA-seq 文库，每个文库生成超过 500 万条清洁reads。共获得 517 个差异表达基因（DEGs）。在这些 DEGs 中，植物激素生物合成和信号转导基因、ROS 特异性转录因子（如 AP2/ERF 和 WRKY 基因）、应激反应基因和开花相关基因（）和（）显著富集。然后，作为验证实验，将盆栽树在中温下均匀喷洒 MV、N,N'-二甲基硫脲（DMTU，ROS 清除剂）加 MV 和水。结果表明，MV 产生的 ROS 促进了开花，并改变了相关基因的表达，但这些效应被 DMTU 处理抑制。我们的研究结果表明，ROS 可以促进开花，并在一定程度上绕过荔枝开花所需的低温。
