Effects of TiO2 nanoparticles on green vegetable(Brassica chinensis L.)growth and soil bacterial community
To understand the mechanisms by which nano TiO2 promotes plant growth and feedback effects on microorganisms and investigate the changes in microbial communities induced by nano TiO2 treatment,a pot experiment was conducted under greenhouse conditions by spraying different concentrations of TiO2 nanoparticles(0,50,100,and 150 mg/L;denoted as CK,L,M,and H,respectively)onto the surfaces of Chinese cabbage leaves.Plant biomass and photosynthetic characteristics of plant leaves were measured.High-throughput sequencing was employed to analyze changes in the diversity and composition of the rhizosphere bacterial community.The results showed that spraying with TiO2 nanoparticles promoted the growth of Chinese cabbage.It notably increased plant biomass,chlorophyll-a and chlorophyll-b content,and the net photosynthetic rate of plant leaves.The most significant increases were observed in the M treatment,with those values 25.51％,20.29％,23.33％,and 30.86％higher than those in CK,respectively.High-throughput sequencing showed no significant changes in the alpha diversity of the rhizosphere bacterial community.However,the composition and structure of the bacterial community were significantly shifted by the M treatment.Specifically,the M treatment significantly increased the relative abundances of Bacillales and Gemmatimonadales,but decreased those of Solibacterales and Desulfuromonadales.Such features led to a profound dissimilarity in bacterial community structure under the M treatment compared to CK.Furthermore,redundancy analysis(RDA)showed positive correlations between the bacterial community and Chinese cabbage biomass,chlorophyll content,and photosynthetic rate in the M treatment.Correlation analysis showed that bacterial lineages such as Chromatiales and Gemmatimonadales were positively correlated with plant growth parameters,Nitrospirales was significantly and negatively correlated with chlorophyll content,and Soilbacterales and Desulfuromonadales were significantly and negatively correlated with plant biomass and net photosynthetic rate.In summary,spraying of an appropriate concentration of TiO2 nanoparticles on plant leaves can stimulate Chinese cabbage growth,increase leaf chlorophyll content,and alter the composition of soil bacterial communities.This study enhances our understanding of the mechanisms within the plant-soil ecosystem following the application of TiO2 nanoparticles and provides a valuable reference for their agricultural use.
TiO2 nanoparticlenet photosynthetic rateplant growthsoil microorganismbacterial community structure
NETL
NSTL
万方数据
