Chen Bowei, Zhang Tianxu, Guo Yile, Cao Lesheng, Zhang Xu, Ali Shahid, Ma Renyi, Xie Linan, Wang Jiang, Zinta Gaurav, Sun Shanwen, Liu Guifeng, Zhang Qingzhu
Institute of Carbon Neutrality, Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Ecology, Northeast Forestry University, Harbin, China.
Heilongjiang Maoershan Forest Ecosystem National Observation and Research Station, School of Ecology, Northeast Forestry University, Harbin, China.
Mol Ecol. 2025 Aug;34(16):e70031. doi: 10.1111/mec.70031. Epub 2025 Jul 21.
Epigenetics has been proposed to be an important mechanism that enables plant species to respond and adapt to environmental and climatic fluctuations and is sometimes entirely uncoupled from genetic variation. Nevertheless, the extent of this uncoupling and the contribution of epigenetics to plant responses to global climate change have not been well studied, particularly in forest trees. Here, we generated a high-quality genome assembly for Betula platyphylla, a key pioneer species in temperate and boreal forest ecosystems, one of the most sensitive areas to global warming. Extensive multi-omics sequencing of naturally white birch across the 48 provenances captured their full scope of temperate/boreal forests in Northeast China. Using a genome-wide association study (GWAS), it was shown that over 55% of differentially methylated regions (DMRs) were spontaneous, independent of genetic factors. More than 30% of the spontaneous DMRs were significantly associated with gene expression, that is, potential epialleles, which are primarily involved in metabolism and responses to abiotic stresses; and 1819 of these epialleles were significantly associated with bio-climatic variables (i.e., climatic epialleles, cEpialleles). Integrating these cEpialleles into a gradient modelling framework revealed that the natural populations of Asian white birch at high altitude/latitude might be most vulnerable to future climates. Our findings highlight the importance of integrating epigenomic and climatic data sets to forecast the adaptive capacity of a key forest species to rapid climate change.
表观遗传学被认为是一种重要机制，使植物物种能够响应并适应环境和气候波动，而且有时与遗传变异完全无关。然而，这种不相关性的程度以及表观遗传学对植物应对全球气候变化的贡献尚未得到充分研究，尤其是在森林树木中。在此，我们为白桦（Betula platyphylla）生成了高质量的基因组组装，白桦是温带和寒温带森林生态系统中的关键先锋物种，而温带和寒温带森林生态系统是对全球变暖最敏感的地区之一。对来自中国东北48个种源的天然白桦进行了广泛的多组学测序，涵盖了该地区温带/寒温带森林的全貌。通过全基因组关联研究（GWAS）表明，超过55%的差异甲基化区域（DMR）是自发的，与遗传因素无关。超过30%的自发DMR与基因表达显著相关，即潜在的表观等位基因，主要参与代谢和对非生物胁迫的响应；其中1819个表观等位基因与生物气候变量显著相关（即气候表观等位基因，cEpialleles）。将这些cEpialleles整合到梯度建模框架中发现，高海拔/高纬度地区的亚洲白桦自然种群可能最易受到未来气候的影响。我们的研究结果凸显了整合表观基因组和气候数据集以预测关键森林物种对快速气候变化的适应能力的重要性。
