• Mangroves are adapted to harsh environments, such as high ultraviolet (UV) light, low nutrition, and fluctuating salinity in coastal zones. However, little is known about the transcriptomic and epigenomic basis of the resilience of mangroves due to limited available genome resources.
• 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.
• The 309 Mb of the genome is predicted to encode 34 403 genes and has a repeat content of 48%. Depending on its growing environment, the natural B. gymnorhiza population showed drastic morphological changes associated with expression changes in thousands of genes. 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.
• 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.

中文翻译：

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从头基因组组装和自然表观基因组学揭示红树林 Bruguiera gymnorhiza 中盐度诱导的 DNA 甲基化

• 红树林适应恶劣的环境，例如高紫外线 (UV) 光、低营养和沿海地区波动的盐度。然而，由于可用的基因组资源有限，人们对红树林恢复力的转录组学和表观基因组学基础知之甚少。
• 我们对主要红树林物种之一的红树林Bruguiera gymnorhiza进行了从头基因组组装和自然表观基因组分析。我们还为红树林物种进行了第一个基因组引导的转录组组装。
• 预计 309 Mb 的基因组编码 34 403 个基因，重复含量为 48%。根据其生长环境，天然B . 裸子根种群表现出与数千个基因表达变化相关的剧烈形态学变化。此外，高盐度环境诱导B中转座因子 (TE) 的全基因组 DNA 超甲基化。裸子根。DNA 高甲基化与染色质修饰基因的转录调节同时进行，表明B中 TE 的表观基因组调节非常稳健。高盐度环境下的裸子根基因组。
• 本研究中的基因组和表观基因组数据提供了对红树林表观基因组调控的新见解，并更好地了解植物对波动、恶劣的自然环境的适应性。