Department of Food Science and Technology, Faculty of Science, National University of Singapore, Singapore, Singapore.
Environ Microbiol Rep. 2023 Jun;15(3):229-238. doi: 10.1111/1758-2229.13154. Epub 2023 Mar 14.
Bacillus subtilis (BS) is a well-known beneficial microorganism for plants but is not competitive in the plant rhizosphere microbiome. We report the selective support of Brassica rapa subsp. Chinensis (Xiao Bai Cai) juice (XBCJ) on BS both in hydroponic nutrient solution and the plant rhizosphere of lettuce. After 2 weeks of being inoculated in the lettuce rhizosphere, the Bacillus population was enumerated at 3.30 ± 0.07 log CFU/unit in the BS group and at 5.20 ± 0.39 log CFU/unit in the BS + XBCJ group (p < 0.05). Accordingly, lettuce crops from the BS + XBCJ group were significantly higher than the control group for all of the tested biomass-related parameters (p < 0.05). The treatment did not significantly affect the texture, colour, moisture contents, total phenolic contents, or antioxidant activities of the lettuce crops (p > 0.05). Non-target ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) suggested that phenolic compounds could be the key class of phytochemicals being responsible for the selectivity. High-throughput RNA-based 16S rRNA gene sequencing and analysis were performed to depict the influence of BS and XBCJ over the global microbiome compositions of plant rhizosphere.
枯草芽孢杆菌（BS）是一种广为人知的植物有益微生物，但在植物根际微生物组中不具竞争力。我们报告了 Brassica rapa subsp. Chinensis（小油菜）汁（XBCJ）对 BS 的选择性支持，无论是在水培营养液中还是在生菜的植物根际中。在生菜根际接种 2 周后，BS 组的芽孢杆菌种群数量为 3.30±0.07 log CFU/单位，BS+XBCJ 组的芽孢杆菌种群数量为 5.20±0.39 log CFU/单位（p<0.05）。相应地，BS+XBCJ 组的生菜作物在所有测试的生物量相关参数方面均显著高于对照组（p<0.05）。该处理对生菜作物的质地、颜色、水分含量、总酚含量或抗氧化活性没有显著影响（p>0.05）。非靶向超高效液相色谱-四极杆飞行时间质谱（UPLC-Q-TOF-MS）表明，酚类化合物可能是负责这种选择性的关键类植物化学物质。进行了高通量基于 RNA 的 16S rRNA 基因测序和分析，以描绘 BS 和 XBCJ 对植物根际全球微生物组组成的影响。
