Nitrogen-mediated volatilisation of defensive metabolites in tomato confers resistance to herbivores.

Plants synthesise a vast array of volatile organic compounds (VOCs), which serve as chemical defence and communication agents in their interactions with insect herbivores. Although nitrogen (N) is a critical resource in the production of plant metabolites, its regulatory effects on defensive VOCs remain largely unknown. Here, we investigated the effect of N content in tomato (Solanum lycopersicum) on the tobacco cutworm (Spodoptera litura), a notorious agricultural pest, using biochemical and molecular experiments in combination with insect behavioural and performance analyses. We observed that on tomato leaves with different N contents, S. litura showed distinct feeding preference and growth and developmental performance. Particularly, metabolomics profiling revealed that limited N availability conferred resistance upon tomato plants to S. litura is likely associated with the biosynthesis and emission of the volatile metabolite α-humulene as a repellent. Moreover, exogenous application of α-humulene on tomato leaves elicited a significant repellent response against herbivores. Thus, our findings unravel the key factors involved in N-mediated plant defence against insect herbivores and pave the way for innovation of N management to improve the plant defence responses to facilitate pest control strategies within agroecosystems.

Spatio-temporal analysis of socio-economic characteristics for pulmonary tuberculosis in Sichuan province of China, 2006-2015.

BACKGROUND: The disease burden caused by pulmonary tuberculosis (TB) in Sichuan province still persisted at a high level, and large spatial variances were presented across regional distribution disparities. The socio-economic factors were suspected to affect the population of TB notification, we aimed to describe TB case notification rate (CNR) and identify which factors influence TB epidemic are necessary for the prevention and control of the disease in Sichuan province. METHODS: A retrospective cross-sectional study and an ecological spatial analysis was conducted to quantify the presence and location of spatial clusters of TB by the Moran's I index and examined these patterns with socio-economic risk factors by hierarchical Bayesian spatio-temporal model. RESULTS: A total of 630,009 pulmonary TB cases were notified from 2006 to 2015 in 181 counties of Sichuan province. The CNR decreased year by year since 2007, from 88.70 to 61.37 per 100,000 persons. The spatial heterogeneities of CNR were observed during the study periods. Global Moran's I index varied from 0.23 to 0.44 with all P-value < 0.001. The Bayesian spatio-temporal model with parametric spatio-temporal interactions was chosen as the best model according to the minimum of Deviance Information Criterion (DIC)(19,379.01), and in which the quadratic form of time was taken. The proportion of age group and education year were all associated with CNR after adjusting the spatial effect, temporal effect and spatio-temporal interactions. TB CNR increased by 10.2% [95% credible interval (CI): 6.7-13.7%] for every 1-standard-deviation increase in proportion of age group and decreased by 23% (95% CI: 13.7-32.7%) for every 1-standard-deviation increase in education year. CONCLUSIONS: There were spatial clusters of TB notification rate in Sichuan province from 2006 to 2015, and heavy TB burden was mainly attributed to aging and low socioeconomic status including poor education. Thus, it is more important to pay more attention to the elderly population and improve socioeconomic status including promoting education level in Sichuan province to reduce the TB burden.

[Constitutive characteristics and change trend of gynecological malignant tumors in 8009 hospitalized patients in Guangxi Zhuang Autonomous Region].

OBJECTIVE: To investigate the constitutive characteristics and the change trend of gynecologic malignant tumors in hospitalized patients in Guangxi Zhuang Autonomous Region over the recent 20 years. METHODS: Clinical data of 8009 in-patients who suffered from gynecologic malignant tumors in 23 hospitals from 1985 to 2004 in Guangxi Zhuang Autonomous Region were analyzed, with respect to the tumor types and change trend. RESULTS: (1) The leading 4 types of malignant tumors were cervical cancers, ovarian cancers, endometrial cancers, and malignant trophoblastic tumors according to the constitutive ratios of the tumors. The constitutive ratio of cervical cancer patients rose year by year, from 17.48% during the 1985-1989 period to 49.25% during the 2000-2004 period (P < 0.01). While the constitutive ratio of malignant trophoblastic tumors dropped year by year. The changes of ovarian cancer, endometrial cancer, vulvar and vaginal carcinomas, and sarcoma of the uterus were not obvious (P > 0.05). (2) The occurring age of cervical cancers became younger obviously, from > or = 60 years old dropped to < 40 years old. (3) Cervical cancers were found mainly in urban residents in the former 10 years, the constitutive ratio being 67.1%; while in the latter 10 years it gradually shifted to rural residents, accounting for 52.6% of the total gynecological tumors. (4) Patients were usually at stages II, III, IV when they visited a doctor for their diseases. Especially for ovarian cancer, malignant trophoblastic tumors, sarcoma of the uterus, these patients were in the intermediate or advanced stage when they were diagnosed, mainly because of lack of obvious symptoms. The constitutive ratio of these advanced patients was over 60%. CONCLUSIONS: We should strengthen the screening program of cervical cancer, and pay more attention to prevention and control of other gynecological reproductive organ tumors at the same time. On the other hand, we should explore better tumor markers, new methods of diagnosis and treatment to improve early diagnosis and treatment of gynecologic malignant tumors.