Zanthoxylum bungeanum root-rot associated shifts in microbiomes of root endosphere, rhizosphere, and soil.

Root-rot disease has lead to serious reduction in yields and jeopardized the survival of the economically and ecologically important Zanthoxylum bungeanum trees cultured in Sichuan Province. In order to investigate the interaction between the microbiome and the root-rot disease, a metagenomic analysis was performed to characterize the microbial communities and functions in Z. bungeanum root endosphere, rhizosphere and bulk soil with/without root-rot disease. Soil physicochemical properties, microbial population size and enzyme activities were also analyzed for finding their interactions with the root-rot disease. As results, lower total nitrogen (TN) and available phosphorus (AP) contents but higher pH in rhizosphere and bulk soil, as well as lower substrate-induced respiration (SIR) and higher protease activity in bulk soil of diseased trees were found, in comparison with that of healthy trees. Microbial diversity and community composition were changed by root-rot disease in the endosphere, but not in rhizosphere and bulk soils. The endophytic microbiome of diseased trees presented higher Proteobacteria abundance and lower abundances of Bacteroidetes, Firmicutes and dominant fungal phyla. The relative abundances of nitrogen cycle- and carbon cycle-related genes in endophytic microbiomes were different between the diseased and healthy trees. Based on ANOSIM and PCoA, functional profiles (KEGG and CAZy) of microbiomes in rhizosphere and bulk soil shifted significantly between the diseased and healthy trees. In addition, soil pH, TN, AP, SIR, invertase and protease were estimated as the main factors influencing the shifts of taxonomic and functional groups in microbiomes of rhizosphere and bulk soil. Conclusively, the imbalance of root and soil microbial function groups might lead to shifts in the root endosphere-rhizosphere microenvironment, which in turn resulted in Z. bungeanum root-rot.

Efficacy and safety of CT perfusion-guided patient selection for intra-arterial thrombolysis of anterior circulation ischemic stroke beyond the time window / 中华神经医学杂志

Objective To observe the safety and efficacy ofintra-arterial thrombolysis guided by CT perfusion in patients with anterior circulation ischemic stroke presenting with symptoms longer than 6 h.Methods The clinical data of patients with anterior circulation ischemic stroke presenting with symptoms longer than 6 h (n=36) and shorter than or equal to 6 h (n=30),performed intra-arterial thrombolysis in our hospitals from July 2003 to December 2012,were retrospectively evaluated.Patients of the former group were evaluated the ischemic penumbra and core region of infarction and the mismatch between the two regions based on CT perfusion.The clinical features,clinical outcomes and complications were compared between the two groups.Results As compared with those in patients of symptoms shorter than or equal to 6 h,the early neurological improvement rate (13.3％ vs.22.2％) and long-term neurological improvement rate (86.7％ vs.77.7％),recanalization rate (80.0％ vs.88.9％) and 3-month mortality (6.7％ vs.16.7％) of patients of symptoms longer than were not significantly different (P=0.665,P=0.665,P=0.639 and P=0.607).Conclusions To patients with anterior circulation ischemic stroke presenting with symptoms longer than 6 h,the neurological function at 3-month significantly improves after intra-arterial thrombolysis guided by CT perfusion.Although the incidence of symptomatic intracranial hemorrhage increases,the mortality rate does not significantly increase.