RESULTS: We characterized the leaf microstructures across the ten Ulmus lines. Chun exhibited a highly undulated abaxial surface and dense stomatal distribution. Langya and Xingshan possessed dense abaxial trichomes, while Lieye, Zuiweng, and Daguo had sparsely distributed, short abaxial trichomes. Duomai, Qingyun, and Lang were characterized by sparse stomata and flat abaxial surfaces, whereas Jinye had sparsely distributed but extensive stomata. The mean leaf retention values for total suspended particulate (TSP), PM2.5, PM2.5-10, PM10-100, and PM> 100 were 135.76, 6.60, 20.10, 90.98, and 13.08 µg·cm- 2, respectively. Trichomes substantially contributed to PM2.5 retention, while larger undulations enhanced PM2.5-10 retention, as evidenced by positive correlations between PM2.5 and abaxial trichome density and between PM2.5-10 and the adaxial raw microroughness values. Phyllosphere microbial diversity patterns varied among lines, with bacteria dominated by Sediminibacterium and fungi by Mycosphaerella, Alternaria, and Cladosporium. Redundancy analysis confirmed that dense leaf trichomes facilitated the capture of PM2.5-associated fungi, while bacteria were less impacted by PM and struggled to adhere to leaf microstructures. Long and dense trichomes provided ideal microhabitats for retaining PM-borne microbes, as evidenced by positive feedback loops between PM2.5, trichome characteristics, and the relative abundances of microorganisms like Trichoderma and Aspergillus.
CONCLUSIONS: Based on our findings, a three-factor network profile was constructed, which provides a foundation for further exploration into how different plants retain PM through foliar microstructures, thereby impacting phyllosphere microbial communities.
结果:我们表征了十个Ulmus品系的叶片微观结构。Chun表现出高度起伏的背面和密集的气孔分布。狼牙岛和兴山拥有密集的背轴毛状体,而Lieye,左翁,大果分布稀疏,短的背轴毛状体。Duomai,青云,Lang的特征是气孔稀疏,背面平坦,而金叶的气孔分布稀疏,但气孔广泛。总悬浮颗粒(TSP)的平均叶片保留值,PM2.5、PM2.5-10、PM10-100和PM>100分别为135.76、6.60、20.10、90.98和13.08µg·cm-2。Trichomes大大有助于PM2.5的保留,虽然更大的起伏增强了PM2.5-10的保留,PM2.5与背轴毛状体密度之间以及PM2.5-10与近轴原始微粗糙度值之间呈正相关。毛圈微生物多样性模式因品系而异,细菌以细菌为主,真菌以分枝杆菌为主,Alternaria,和枝孢菌.冗余分析证实,密集的叶毛促进了PM2.5相关真菌的捕获,而细菌受PM的影响较小,难以粘附到叶片微观结构上。长而密集的毛状体提供了保留PM传播微生物的理想微生境,PM2.5、毛状体特征之间的正反馈回路证明了这一点,以及木霉属和曲霉等微生物的相对丰度。
结论:根据我们的发现,构建了一个三因素网络配置文件,这为进一步探索不同植物如何通过叶面微观结构保留PM提供了基础,从而影响叶球微生物群落。