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Plant rhizosphere microbes are closely related to plant growth, whereas how the rhizosphere microbial community affects root development remains poorly understood. In this study, 16S rRNA gene high-throughput sequencing technology was used to detect the bacterial community of tobacco rhizosphere, and to explore the association mechanism between different developmental conditions of tobacco roots and differences in rhizosphere microbial community. The results showed that the species richness and diversity of rhizosphere bacteria in the well-developed root system (WDR) were higher than those in the undeveloped root system (UDR), with the genera Gallionella and Luteimona significantly increased, while the genera Edaphobaculum, PLTA13 and Rhodobacter significantly increased. Abundance significantly reduced (P<0.05). The molecular ecological network of UDR is more complex, and the interaction between species is strong, especially the cooperative behavior. The number of key nodes in the WDR network is more, and its carbon cycle related network modules increase. In addition, the WDR rhizosphere bacterial community assembly tends to be more developmentally aggregated, and environmental filtering plays a more important role in it. Overall, the results of this study emphasize that the structural composition, network changes and community assembly of the rhizosphere microbial community play an important role in the development of plant roots, and provide a theoretical basis for regulating the rhizosphere microbial community to promote plant root growth. [ABSTRACT FROM AUTHOR]

Objective: To investigate the outcomes, survival status, and the prognostic factors of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) patients., Methods: A retrospective study was carried out to analyze the clinical data of 61 EBV-HLH cases, from January 2008 to July 2014. Prognostic factors were analyzed through COX model (single factor and multiple factors)., Results: A total of 246 patients with HLH were diagnosed, among which 102 cases were with EBV infection (including 61 EBV-HLH, 36 lymphoma associated HLH, 5 primary HLH. Among the 61 cases, 40 were male and 21 were female, with a ration of 1.9:1. The median age was 28 years (range, 12-78). 1, 3, 6 and 12-month overall survival rates of 61 EBV-HLH were 65.6%, 47.5%, 32.4%, and 25.0%, respectively. The median follow-up time was 3 (0.5-28) months. 12 patients didn't use etoposide within 4 weeks after diagnosis, while HLH-94 protocol was used in 33 patients and HLH-2004 protocol was used in 16 patients. Response rates of theses three groups were 33.3%, 51.5%, and 43.8%, respectively (P=0.401). There was statistically difference between the group without etoposide and the HLH-94/ HLH-2004 group in the overall survival rate (P=0.033). Serum albumin level (P=0.033) and whether EBV could became negative (P=0.010) were independent predictors for EBV-HLH., Conclusion: EBV-HLH patients have severe clinical feature and poor prognosis. Early application of immune chemotherapy based on etoposide can improve survival. Serum albumin level and whether EBV can become negative are independent prognostic factors for survival.