氧化石墨烯对黑麦草种子内生真菌群落结构和多样性的影响

为了探究氧化石墨烯(GO)对黑麦草种子内生真菌群落结构和多样性的影响,将黑麦草种子在0.4%、0.8%和1.2%水平的GO溶液中胁迫4 d,采用高通量测序技术,分析GO胁迫下黑麦草种子内生真菌群落组成和多样性的变化。结果显示,4个样本所有样品共分离获得303种真菌,归属于10门39纲84目160科240属。在门分类水平上,子囊菌门(Ascomycota)和担子菌门(Basidiomycota)是主要的内生真菌类群;在属分类水平上,各处理的共有优势菌属为链格孢属(Alternaria)。不同GO处理黑麦草种子内生真菌群落结构存在差异,随着GO浓度的增加,子囊菌门的丰度出现下降,0.8%和1.2%GO处理较对照分别显著降低了19%和20%(P<0.05);所有GO处理的担子菌门丰度均显著高于对照(P<0.05);1.2%处理链格孢属的丰度较对照显著降低了37.36%。与对照相比,1.2%GO 处理内生真菌的丰富度和多样性显著增加,ACE、Chao1和Shannon指数分别增加了123.5%、127.4%和117.5%(P<0.05)。主坐标分析(PCoA)分析表明,1.2%GO处理内生真菌群落结构与其他处理有较大差异;线性判别分析(LEfSe)分析发现, 各处理差异指示种明显不同。可见,GO改变了黑麦草种子内生真菌群落的组成和多样性,尤其是高浓度处理(1.2%)。研究可为碳纳米材料暴露对共生物种的潜在影响研究提供参考。

Effects of graphene oxide on the structure and diversity of endophytic fungal community in the seeds of Lolium perenne L.

With the rapid development of nanotechnology, graphene oxide (GO) has increasingly been produced and widely applied in many fields, resulting in its environmental release and exposure to plants. Endophytic fungi can colonize the internal tissue of the plant without causing harm on their host, forming a mutually beneficial symbiotic relationship with the host plant. To date, the impacts of GO exposure on the fungal endophytic community in terrestrial plants have been rarely reported. In the present study, ryegrass (Lolium perenne L.) seeds were exposed to varying concentrations of GO solution (0.4%, 0.8%, and 1.2%) for a duration of 4 days to assess the impact of GO on the composition and diversity of endophytic fungi within ryegrass seeds. A high-throughput sequencing technique was utilized to analyze the alterations in the endophytic fungal community as affected by GO. Our results revealed the presence of 303 fungal species across all samples, categorized into 10 phyla, 39 classes, 84 orders, 160 families, and 240 genera. Predominantly, Ascomycota and Basidiomycota were identified as the dominant fungal phyla, with Pleosporales and Alternaria being the common dominant fungal order and genus, respectively. Importantly, the fungal endophytes within ryegrass seeds demonstrated sensitivity to GO exposure, particularly with the 1.2% GO treatment. As the concentration of GO increased, the abundance of Ascomycota exhibited a significant reduction of 19% and 20% for the 0.8% and 1.2% GO treatments, respectively, in comparison to the control (P<0.05). On the other hand, the abundance of Basidiomycota was significantly higher in all GO treatments compared to the control (P<0.05). Specifically, in the case of the 1.2% GO treatment, the abundance of Pleosporales and Alternaria notably decreased by 44.48% and 37.36%, respectively, compared to the control. Furthermore, exposure to GO altered the richness and diversity of the fungal endophytic communities in ryegrass seeds. The presence of GO at 1.2% resulted in significant increases (P<0.05) of 123.5%, 127.4%, and 117.5% in ACE, Chao1, and Shannon indices, respectively, relative to the control. Hierarchically clustered heatmap of fungal distribution at the genus level and Principal Coordinate Analysis (PCoA) highlighted significant disparities in the community structure of endophytic fungi between the 1.2% GO and the other three treatments. Additionally, LEfSe analysis revealed noteworthy distinctions in indicator taxa among the different treatments. Our findings underscore the influence of GO on altering the composition and diversity of endophytic fungal communities within ryegrass seeds, particularly evident in high-concentration treatments (1.2%). This study serves as a valuable reference for assessing the potential impact of carbon nanomaterial exposure on cohabiting species.