海洋学领域国际期刊Frontiers in Marine Science最近在线发表了对沿海和内陆芦苇种群分化的研究成果，该研究工作由山东大学自然资源部渤海生态预警与保护修复重点实验室，北京自然博物馆和青岛农业大学园林与林学院的研究人员共同完成。文章研究以黄河三角洲（滨海湿地）与马踏湖湿地（内陆湿地）的芦苇为研究对象，比较了同质种植园中在两种盐度和两种受控 DNA 甲基化水平下生长的滨海和内陆芦苇种群的差异，探究了DNA甲基化变异在芦苇种群对盐分的生理生态响应中的作用。研究发现内陆种群在淡水生境中的优势及局域适应。同时表型可塑性可以增加芦苇种群适应盐环境的能力。DNA去甲基化增强了内陆种群的耐盐性。

附论文信息和摘要：

Role of DNA methylation in ecophysiological responses to salinity in natural populations of

Phragmites australis from coastal and inland habitats

Huijia Song1,2, Xiao Guo 3*, Lele Liu1, Zhenwei Xu1, Ning Wang1, Xiao Liu1, Ning Du1 and Weihua Guo1*

1Key Laboratory of Ecological Prewarning, Protection and Restoration of Bohai Sea, Ministry of Natural Resources, School of Life Sciences, Shandong University, Qingdao, China, 2Beijing Museum of Natural History, Beijing Academy of Science and Technology, Beijing, China, 3College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, China

There are different environmental pressures in coastal and inland wetlands resulting in phenotypic variation among plant populations, which might be related to epigenetic modifications. Phragmites australis is a widespread plant in coastal and inland wetlands, and the phenotype of the population is selected by salinity, but the reasons for the population differences in salt tolerance and phenotype are unclear. We investigated coastal and inland P. australis populations grown under two salinities and two manipulated DNA methylation levels in common gardens. The plants were sprayed with 5-azacytidine (DNA demethylation agent) regularly, and the physiological and morphological traits of reeds were measured. Plant height, density, and basal stem of reeds from different sources were significantly different and correlated with soil conductivity of sampling sites (P < 0.05). Salinity significantly decreased the biomass (37.04%, P < 0.05) and plant height (24.68%, P < 0.05) of inland reeds but had no significant effect on coastal populations (13.48%). P.australis responds to salt stress through phenotypic plasticity, and inland wetland populations exhibit local adaptation to freshwater. Increased salt tolerance in inland populations following DNA demethylation, particularly biomass, plant height, and basal stems (increased 23.62%; 13.08%; 5.35%, respectively), could provide more opportunities in adverse environments. This study will provide important insights into the highly adaptive mechanisms of the large non-model plant.

KEYWORDS: DNA methylation, Phragmites australis, phenotypic plasticity, physiological traits, salt tolerance