背景回顾：Mangroves are adapted to harsh environments, such as high UV light, low nutrition, and fluctuating salinity in coastal zones. 

提出问题：However, little is known about the transcriptomic and epigenomic basis of the resilience of mangroves due to limited available genome resources.

主要研究：We performed a de novo genome assembly and in natura epigenome analyses of the mangrove Bruguiera gymnorhiza, one of the dominant mangrove species. We also performed the first genome-guided transcriptome assembly for mangrove species. 

结果1-组装、注释：The 309 Mb of the genome is predicted to encode 34,403 genes and has a repeat content of 48%.

结果2-与环境相关的转录变化：Depending on its growing environment, the natural B. gymnorhiza population showed drastic morphological changes associated with expression changes in thousands of genes. 

结果3-高盐诱导的DNA甲基化：Moreover, high-salinity environments induced genome-wide DNA hypermethylation of transposable elements (TEs) in the B. gymnorhiza. DNA hypermethylation was concurrent with the transcriptional regulation of chromatin modifier genes, suggesting robust epigenome regulation of TEs in the B. gymnorhiza genome under high-salinity environments. 

结论：The genome and epigenome data in this study provide novel insights into the epigenome regulation of mangroves and a better understanding of the adaptation of plants to fluctuating, harsh natural environments.

 摘 要 

红树林适应于沿海地区的强紫外、低营养以及波动盐度等恶劣环境。然而，由于可用基因组资源的限制，我们对于红树林适应力的转录组学和表观基因组基础知之甚少。本文中，作者对红树林中的一种主要红树林植物木榄（Bruguiera gymnorhiza）进行了从头基因组组装和自然表观基因组分析。作者还进行了红树林物种的第一次以基因组为参考的转录组组装。木榄的基因组大小约为309MB，共编码34403个基因，重复序列含量为48%。根据其生长环境的不同，天然的木榄表现出形态的剧烈变化，并且与数千个基因的表达变化相关。此外，高盐环境诱导木榄全基因范围上转座子（TEs）的DNA超甲基化。DNA超甲基化与染色质修饰基因的转录调控同时发生，这表明在高盐环境下木榄基因组中TEs具有强大的表观基因组调控。本文的研究结果为红树林的表观基因组调控提供了新的见解，并为植物适应波动、恶劣的自然环境提供了更好的理解。