Belle W. Baruch Institute for Marine and Coastal Sciences, University of South Carolina, Columbia, South Carolina, United States of America.
Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America.
PLoS One. 2018 Sep 10;13(9):e0203230. doi: 10.1371/journal.pone.0203230. eCollection 2018.
Spartina alterniflora, marsh grass, is a vegetative apomicticly-reproducing halophyte native to marshes along the east coast of the United States and invasive across the world. S. alterniflora provides many ecosystem services including, but not limited to, water filtration, habitats for invertebrates, and sediment retention. Widespread diebacks of longstanding marsh grass colonies launched extensive investigations into probable mechanisms leading to patchy diebacks. There is still current debate as to the causes of a marsh dieback but environmental stress is acknowledged as a constant. Spatial epigenetic variation could contribute to variation of stress susceptibility, but the scale and structure of epigenetic variation is unknown. The current study investigates patterns of epigenetic variation in a natural population of S. alterniflora. This study examines variation of global DNA methylation within and among clones of the marsh grass Spartina alterniflora using an ELISA-like microplate reaction and observed significant heterogeneity of global DNA methylation within and among clones of S. alterniflora across the North Inlet basin, as well as significant differences of global methylation between adults and sexually produced seedlings. The present study also characterized differences for plants in a section of the population that experienced an acute marsh dieback in the year 2001 and have subsequently recolonized, finding a significant positive correlation between cytosine methylation and time period of colonization. The significant heterogeneity of global DNA methylation both within and among clones observed within this natural population of S. alterniflora and potential impacts from hypersaline environments at North Inlet suggests the need for more in-depth epigenetic studies to fully understand DNA methylation within an ecological context. Future studies should consider the effects of varying saline conditions on both global DNA and gene specific methylation.
互花米草，一种盐沼草，是一种具有营养繁殖能力的美国东海岸原生的、在世界范围内入侵的盐沼植物。互花米草提供了许多生态系统服务，包括但不限于水过滤、无脊椎动物栖息地和沉积物保持。长期存在的互花米草殖民地的广泛衰退引发了广泛的调查，以研究可能导致斑块性衰退的机制。虽然导致互花米草衰退的原因仍存在争议，但环境压力是公认的。空间表观遗传变异可能导致对压力敏感性的变异，但目前还不知道表观遗传变异的规模和结构。本研究调查了自然种群中互花米草的表观遗传变异模式。本研究使用 ELISA 样微孔板反应，研究了盐沼草互花米草克隆内和克隆间的全球 DNA 甲基化变异，观察到北进流域内互花米草克隆内和克隆间的全球 DNA 甲基化存在显著的异质性，以及成年个体和有性繁殖的幼苗之间的全球甲基化存在显著差异。本研究还对 2001 年经历急性互花米草衰退并随后重新殖民的种群部分的植物进行了特征描述，发现胞嘧啶甲基化与殖民时间之间存在显著的正相关。在这个自然互花米草种群中，无论是在克隆内还是克隆间，都观察到了全球 DNA 甲基化的显著异质性，以及北进流域高盐环境的潜在影响，这表明需要进行更深入的表观遗传研究，以在生态背景下全面了解 DNA 甲基化。未来的研究应考虑不同盐度条件对全球 DNA 和基因特异性甲基化的影响。
