Assembly patterns and key taxa of bacterial communities in the rhizosphere soil of moso bamboo (Phyllostachys pubescens) under different Cd and Pb pollution.

Moso bamboo is excellent candidate for cadmium (Cd)/lead (Pb) phytoremediation, while rhizosphere microbiome has significant impact on phytoremediation efficiency of host plant. However, little is known about the rhizosphere bacterial communities of moso bamboo in Cd/Pb contaminated soils. Therefore, this study investigated the assembly patterns and key taxa of rhizosphere bacterial communities of moso bamboo in Cd/Pb polluted and unpolluted soils, by field sampling, chemical analysis, and 16S rRNA gene sequencing. The results indicated α-diversity between Cd/Pb polluted and unpolluted soils showed a similar pattern (p > 0.05), while ß-diversity was significantly different (p < 0.05). The relative abundance analysis indicated α-proteobacteria (37%) and actinobacteria (31%) were dominant in Cd/Pb polluted soils, while γ-proteobacteria (40%) and α-proteobacteria (22%) were dominant in unpolluted soils. Co-occurrence network analysis indicated microbial networks were less complex and more negative in polluted soils than in unpolluted soils. Mantel analysis indicated soil available phosphorus, organic matter, and available Pb were the most important environmental factors affecting microbial community structure. Correlation analysis showed 11 bacterial genera were significantly positively related to Cd/Pb. Overall, this study identified the bacterial community composition of bamboo rhizosphere in responding to Cd/Pb contamination and provides a theoretical basis for microbe-assistant phytoremediation in the future.

To date, little is known about the bacterial communities in the rhizosphere of moso bamboo under Cd and Pb multiple stresses. This study investigated the assembly patterns and key taxa of rhizospheric bacterial communities of moso bamboo in Cd/Pb polluted and unpolluted soils. It was found that the bacterial community structure in bamboo rhizosphere is easily influenced by soil chemical environment, such as fertilities and heavy metals. The key bacterial taxa identified here could be target microbe in future microbe-assistant phytoremediation.

Observation and quantification of the pseudogap in unitary Fermi gases.

The microscopic origin of high-temperature superconductivity in cuprates remains unknown. It is widely believed that substantial progress could be achieved by better understanding of the pseudogap phase, a normal non-superconducting state of cuprates1,2. In particular, a central issue is whether the pseudogap could originate from strong pairing fluctuations3. Unitary Fermi gases4,5, in which the pseudogap-if it exists-necessarily arises from many-body pairing, offer ideal quantum simulators to address this question. Here we report the observation of a pair-fluctuation-driven pseudogap in homogeneous unitary Fermi gases of lithium-6 atoms, by precisely measuring the fermion spectral function through momentum-resolved microwave spectroscopy and without spurious effects from final-state interactions. The temperature dependence of the pairing gap, inverse pair lifetime and single-particle scattering rate are quantitatively determined by analysing the spectra. We find a large pseudogap above the superfluid transition temperature. The inverse pair lifetime exhibits a thermally activated exponential behaviour, uncovering the microscopic virtual pair breaking and recombination mechanism. The obtained large, temperature-independent single-particle scattering rate is comparable with that set by the Planckian limit6. Our findings quantitatively characterize the pseudogap in strongly interacting Fermi gases and they lend support for the role of preformed pairing as a precursor to superfluidity.