Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Ocean Eco-Environmental Engineering, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China.
Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Ocean Eco-Environmental Engineering, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China; Guangdong Provincial Observation and Research Station for Coastal Upwelling Ecosystem, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Shantou, 515041, China.
Mar Environ Res. 2024 Jan;193:106260. doi: 10.1016/j.marenvres.2023.106260. Epub 2023 Nov 24.
Plant growth-promoting rhizobacteria (PGPR) inoculation is a crucial strategy for maintaining the sustainability of agriculture and presents a promising solution for seagrass ecological restoration in the face of disturbances. However, the possible roles and functions of PGPRs in the seagrass rhizosphere remain unclear. Here, we isolated rhizosphere bacterial strains from both reef and coastal regions and screened two PGPR isolates regarding their in vivo functional traits. Subsequently, we conducted microcosm experiments to elucidate how PGPR inoculation affected seagrass photosynthesis and shape within each rhizosphere microbiome. Both screened PGPR strains, Raoultella terrigena NXT28 and Bacillus aryabhattai XT37, excelled at expressing a specific subset of plant-beneficial functions and increased the photosynthetic rates of the seagrass host. PGPR inoculation not only decreased the abundance of sulfur-cycling bacteria, it also improved the abundance of putative iron-cycling bacteria in the seagrass rhizosphere. Strain XT37 successfully colonized the seagrass rhizosphere and displayed a leading role in microbial network structure. As a nitrogen-fixing bacteria, NXT28 showed potential to change the microbial nitrogen cycle with denitrification in the rhizosphere and alter dissimilatory and assimilatory nitrate reduction in bulk sediment. These findings have implications for the development of eco-friendly strategies aimed at exploiting microbial communities to confer sulfide tolerance in coastal seagrass ecosystem.
植物促生根际细菌（PGPR）接种是维持农业可持续性的关键策略，也是应对干扰进行海草生态恢复的有前途的解决方案。然而，PGPR 在海草根际中的可能作用和功能仍不清楚。在这里，我们从珊瑚礁和沿海地区分离了根际细菌菌株，并筛选了两种 PGPR 分离株，以研究其体内功能特性。随后，我们进行了微宇宙实验，以阐明 PGPR 接种如何影响每个根际微生物组中海草的光合作用和形态。两种筛选出的 PGPR 菌株，即 Raoultella terrigena NXT28 和 Bacillus aryabhattai XT37，在表达特定的植物有益功能方面表现出色，并提高了海草宿主的光合作用速率。PGPR 接种不仅降低了硫循环细菌的丰度，还改善了海草根际中潜在的铁循环细菌的丰度。菌株 XT37 成功定殖于海草根际，并在微生物网络结构中发挥主导作用。作为一种固氮细菌，NXT28 具有通过根际反硝化作用改变微生物氮循环的潜力，并改变底泥中异化和同化硝酸盐还原。这些发现对于开发旨在利用微生物群落赋予沿海海草生态系统硫化物耐受性的环保策略具有重要意义。
