| 摘要: |
| 探究植物叶表面颗粒物及微生物群落的分布特征，对深入了解植物叶片与环境互作机制及城市公园绿植选择具有重要意义。本研究选择青岛市中山公园冬青、女贞和樱花3种植物作为供试树种，利用环境扫描电镜观察植物叶片微观结构，采用16S rRNA高通量测序分析叶际细菌群落多样性与丰富度，通过组间差异对比分析不同季节不同植物的叶际细菌群落差异。结果显示：3种植物叶片对大气颗粒物的滞纳能力为冬青＞女贞＞樱花，总体趋势表现为灌木＞乔木，常绿植物＞落叶植物，且受季节变化、植物叶片生长情况与颗粒物累积等因素的影响，叶面颗粒物滞留量表现为春季显著低于其他季节；扫描电镜观察到植物叶片表面存在不同类型的真菌且存在明显季节变化，其中春夏季节植物叶表面存在孢子较多，而秋冬季节主要为丝状真菌，这与青岛秋冬季节出现灰霾天气导致空气气溶胶中真菌含量大相关；高通量测序发现3种植物的叶际微生物群落结构存在明显差异，叶际细菌丰富度为冬青＞女贞＞樱花，且夏季叶际细菌群落丰富度最低，但相对丰度最高的优势菌门均为Proteobacteria和Cyanobacteria，主要优势菌属为norank_f__norank_o__Chloroplast、Sphingomonas、Acinetobacter和Hymenobacter，预示环境因素对叶际微生物群落结构具有重要影响。本研究证明不同植物叶面颗粒物形态存在明显时空变化规律，冬青和女贞叶片滞尘能力强，可作为城市绿化植物的优选；植物类型是影响叶表面颗粒物及微生物群落分布特征的根本因素，而季节变化和位置是影响植物叶面微观特征的重要因素。 |
| 关键词: 颗粒物 群落结构 高通量测序 环境扫描电镜 |
| DOI：10.7515/JEE222063 |
| CSTR：32259.14.JEE222063 |
| 分类号: |
| 基金项目:山东省自然科学基金项目（ZR2020QC027） |
| 英文基金项目:Shandong Provincial Natural Science Foundation (ZR2020QC027) |
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| Characteristics of particles on leaf surface and phyllosphere bacterial community of three plant species in urban parks of Qingdao |
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XU Ailing, JIANG Min, BAI Pingping, SONG Qi, LI Huijuan, SONG Zhiwen
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1. School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, China
2. Operation and Maintenance Center of Water Transfer Project in Shandong Province, Qingdao 266111, China
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| Abstract: |
| Background, aim, and scope Atmospheric particles are a major pollutant in urban air, leading to hazy weather and posing health risks. Leaves play a crucial role in the deposition of atmospheric particles. Phyllosphere microorganisms, residing on the leaf surfaces, are unique particles with essential functions, such as promoting plant growth and degrading environmental pollutants. Therefore, understanding the characteristics of particles on leaf surfaces and the phyllosphere bacterial community is vital for studying plant-environment interactions and selecting suitable green plant species for urban parks. Materials and methods In this study, we focused on three plant species (holly, ligustrum, and cherry) in the urban parks of Qingdao. Environmental scanning electron microscopy was used to observe the microstructure of the leaf surface, and the 16S rRNA Illumina high-throughput sequencing was performed to analyze the diversity of phyllosphere bacterial community. Results The dust retention ability of the three plant species was ranked as holly＞ligustrum＞cherry, with lower particle quantities on leaf surfaces during spring compared to other seasons. Seasonal variations were observed for fungi on leaf surfaces, with an abundance of spores in spring and summer, and filamentous fungi dominating in autumn and winter. There were significant differences in phyllosphere bacterial community of three plant species. The richness of phyllosphere bacteria was holly＞ligustrum＞cherry, and it was lowest in summer. However, the Proteobacteria and Cyanobacteria were the dominant phyla, the dominant species were norank_f__norank_o__Chloroplast, Sphingomonas, Acinetobacter, Hymenobacter. Discussion The micromorphological characteristics of leaves surface are affected by season, leaf age and the accumulation of particles. The ability of the dust retention was shrubs＞trees, evergreen plants＞deciduous plants. It is because the leaves of the shrubs are close to the ground, and the leaves are affected by the dust on the ground easily. On the contrary, the trunks of the trees are tall, and the particles on the leaves are blown away by the wind easily and settle on the surface leaves of the shrubs. The accumulation of particles on the leaves of evergreen plants was large because the leaves were exposed to the air for a long time. The leaves of deciduous plants wither in winter, and the particles on the leaves were transferred to the soil with the old leaves, which it had less particles on the leaves surface. The distribution characteristics of phyllosphere microorganisms were related to urban air quality and air microbial community composition. For example, the leaves surface was mainly filamentous fungi in autumn and winter, which was consistent with the large content of fungi in the air aerosol in Qingdao in autumn and winter. In addition, the phyllosphere of the same plant had a specific microbial community, and the relationship between the abundance of phyllosphere bacteria and quantity of particles on leaf surface in different seasons was opposite. It indicated that there was not significant effect of leaves particles retention on the relative richness of phyllosphere bacterial community. The plant type was the main factor affecting the distribution of phyllosphere microbial community. Conclusions There were obvious temporal and spatial changes in the morphology of particles on leaf surface in different plants. The holly and ligustrum had higher dust retention capacity, which might be the optimal greening plants in urban. Furthermore, the plant species were the fundamental factors affected the distribution of particles and phyllosphere bacteria, while the season and location were important factors. Recommendations and perspectives To investigate the micromorphological characteristics of leaves truly and effectively have great significance for elucidating the relationship between leaf micromorphological characteristics and the growth of host plants. This study can lay a theoretical foundation for improving urban air quality and optimizing the selection of urban greening plants. |
| Key words: particles phyllosphere microorganism high-throughput sequencing environmental scanning
electron microscope |
