Although bacterial communities play important roles in the suppression of pathogenic diseases and crop production, little is known about the bacterial communities associated with bacterial wilt. ...Based on 16S rRNA gene sequencing, statistical analyses of microbial communities in disease-suppressive and disease-conducive soils from three districts during the vegetation period of tobacco showed that Proteobacteria was the dominant phylum, followed by Acidobacteria. Only samples from September were significantly correlated to disease factors. Fifteen indicators from taxa found in September (1 class, 2 orders, 3 families and 9 genera) were identified in the screen as being associated with disease suppression, and 10 of those were verified for potential disease suppression in March. Kaistobacter appeared to be the genus with the most potential for disease suppression. Elucidating microbially mediated natural disease suppression is fundamental to understanding microecosystem responses to sustainable farming and provides a possible approach for modeling disease-suppressive indicators. Here, using cluster analysis, MRPP testing, LEfSe and specific filters for a Venn diagram, we provide insight into identifying possible indicators of disease suppression of tobacco bacterial wilt.
Abstract
Single crystals which exhibit mechanical flexibility are promising materials for advanced technological applications. Before such materials can be used, a detailed understanding of the ...mechanisms of bending is needed. Using single crystal X-ray diffraction and microfocus Raman spectroscopy, we study in atomic detail the high-pressure response of the plastically flexible coordination polymer Zn(μ-Cl)
2
(3,5-dichloropyridine)
2
n
(
1
). Contradictory to three-point bending, quasi-hydrostatic compression of (
1
) is completely reversible, even following compression to over 9 GPa. A structural phase transition is observed at
ca
. 5 GPa. DFT calculations show this transition to result from the pressure-induced softening of low-frequency vibrations. This phase transition is not observed during three-point-bending. Microfocus synchrotron X-ray diffraction revealed that bending yields significant mosaicity, as opposed to compression. Hence, our studies indicate of overall disparate mechanical responses of bulk flexibility and quasi-hydrostatic compression within the same crystal lattice. We suspect this to be a general feature of plastically bendable materials.
Cervical cancer (CC) is the one of most common malignant gynecological tumors, which is characterized with the high mortality and recurrence rate. Previous studies have elucidated the oncogenic role ...of small nucleolar RNA host gene 6 (SNHG6) in some types of human cancers, whereas it is unclear whether it functions as an oncogene in CC. This study was aimed at unveiling the role of SNHG6 in CC.
qRT-PCR analysis was implemented to evaluate the expression levels of SNHG6, miR-485-3p and STYX in CC cells. RNA pull down assay and luciferase reporter assay were conducted to verify the interaction between miR-485-3p and SNHG6 or STYX. Functional assays, such as colony formation assay, JC-1 assay and TUNEL assay were applied to detect the biological behaviors of CC cells. The resistance of CC cells to radiation was evaluated by colony formation assay.
SNHG6 was expressed at a high level in CC cells. Silenced SNHG6 suppressed cell proliferation but promoted cell apoptosis. Additionally, silenced SNHG6 could sensitize CC cells to radiation treatment. miR-485-3p could bind to both SNHG6 and STYX. Knockdown of miR-485-3p or overexpression of STYX could abolish the effects of SNHG6 silencing on CC cell growth.
LncRNA SNHG6 enhances the radioresistance of CC cells and promotes CC cell growth by sponging miR-485-3p to release STYX.
Long-term monoculture cropping is usually accompanied by soil acidification and microbial community shifts. Soil aluminum ions are dissolved under acidic condition (pH < 5.0), and the resulting ...aluminum bioavailability can cause toxic effects in plants. In this study, we investigated the bacterial community compositions and aluminum toxicity in fields monocultured with ginger for 35 years, 15 years, and 1 year. Within these fields are ginger plants without and with ginger bacterial wilt disease. The results confirmed that the degree of aluminum toxicity in the diseased soil was more severe than that in the healthy soil. Continuous cropping can significantly increase the bacterial diversity and change the bacterial community composition of ginger rhizosphere soil. The relative abundance of plant growth-promoting rhizobacteria (PGPRs) was increased in the soils used for the continuous cropping of ginger. Additionally, aluminum toxicity had a significant positive correlation with
, and
in healthy soils. Based on these results, aluminum stress may stimulate the increase of PGPRs (
, and
), thereby alleviating ginger aluminum toxicity and bacterial wilt in extremely acidic soil (pH < 4.5).
The effects of global warming have warmed the climate of the Qinghai-Tibetan Plateau (QTP) leading to changes in plant growth and soil nutrients in the alpine meadows. However, few studies have ...addressed the effects of warming on plant allometric growth and soil stoichiometry in these meadows on a long-term scale. Therefore, the effects of soil stoichiometry on plant allometric growth remain unclear under long-term warming in the alpine meadows. This study adopted infrared radiators to conduct an 8-year warming experiment in a permafrost region on the QTP starting in 2010, and surveyed growth indices of the plant community during the growing season. Soil organic carbon (C), total nitrogen (N), and total phosphorus (P) in an alpine meadow were measured. We initially learned that the aboveground part of the alpine meadow vegetation in the warming treatment changed from an isometric to an allometric growth pattern while the allometric growth pattern of the belowground part was further strengthened. Second, the contents of soil C, N, and P decreased at the 0-20 cm depth and increased at the 20-30 cm depth in warming. The ratios of soil C:N, C:P, and N:P showed increasing trends at different soil depths with artificial warming, and their amplitudes increased with soil depths. Warming promoted the migration of soil stoichiometric characteristics of C, N, and P to deep soil. Finally, the correlations of plant growth with soil stoichiometric characteristics were weakened by warming, demonstrating that the downward migration of soil stoichiometric characteristics to deep soil in warming had effects on the growth of vegetation in the alpine meadow. It concludes that the change in soil stoichiometric characteristics with soil depths promotes plant allometric growth in the alpine meadow under climate warming.
In the carbon neutrality strategy, understanding the effects of green finance on green technology innovation is conductive to promoting the green transformation of the economy. Based on the ...micro-level and provincial panel data of Shanghai and Shenzhen A-share listed companies from 2012 to 2019, this study explored the impact of green financial development on the enterprises’ green technology innovation. Both mediating effect and moderating effect models were employed to determine the impact of green finance on green technological innovation. It was found that green finance significantly improved the enterprises’ green technology innovation, despite sufficient incentives for “quantity” and relatively insufficient motivation for “quality”. The mechanistic tests demonstrated that the green finance could encourage enterprises to improve green technology innovation by alleviating corporate financing constraints. The green innovation effect of green finance was gradually increased when the regional intellectual property protection was improved. The heterogeneity test indicated that the incentive effect of green financial development on green technology innovation was more evident in state-owned enterprises, enterprises with good internal control quality, and enterprises in the growth period. If only enterprises in the recession stage received green financial support, a “green innovation bubble” might occur. The research conclusions enrich the theories on the driving factors of enterprise green innovation and provide empirical evidence for enhancing the competitiveness of enterprise green innovation and achieving carbon neutrality.
The near-surface soil freeze state is affected by global warming, and its changes have profound effects on landscapes, ecosystems and hydrological processes. On the basis of daily soil freeze ...observational data at 476 meteorological stations over 50 freezing years from September 1, 1961 to August 31, 2011, the spatial distributions and temporal variations of the near-surface soil freeze state were estimated using five freeze variables (first date, last date, maximum seasonally frozen depth, duration and actual number of freeze days) across China, which was divided into three regions (eastern China, northwestern China and the Qinghai-Tibetan Plateau (QTP)). The near-surface soil freeze state varied greatly across China. The QTP has an earlier freeze, later thaw, longer freeze days and deeper seasonally frozen depth than the other two regions. The spatial distributions of the near-surface soil freeze state can be explained largely by altitude in northwestern China and on the QTP, whereas they can be explained by latitude in eastern China. The near-surface soil freeze state has changed significantly over 50 freezing years. On average across China over the study period, the first date of freezing was delayed by approximately 10 ± 1 days with a rate of 0.20 ± 0.02 days/year, the last date advanced by approximately 18 ± 2 days with a rate of 0.36 ± 0.04 days/year, the duration and the number of freeze days decreased by 28 ± 2 and 23 ± 2 days with rates of 0.56 ± 0.04 and 0.45 ± 0.04 days/year, respectively, and the maximum seasonally frozen depth decreased by 20 ± 3 cm with a rate of 0.41 ± 0.06 cm/year. The change in the freeze variables is relatively large in high-latitude and high-altitude regions.
•The near-surface soil freeze state varies greatly and can be explained largely by altitude or latitude.•The soil freeze state on the QTP is obviously different from the other two regions.•The change of the freeze variables is relatively large in high-latitude and high-altitude regions.
Precipitation and temperature in the Qilian Mountains and the Hexi oasis are changing with climate change. The characteristics and control factors of these changes are not well understood, affecting ...the ability to allocate water resources in this area judiciously. We analyzed the annual and seasonal variability in precipitation and temperature during 1960–2016 using monthly data from 25 national meteorological stations in the Qilian Mountains. Results showed that precipitation increased by 6.2, 4.1, and 8.9 mm/decade for the whole regions (including oasis and mountains), oasis, and mountains, respectively. Variability in summer precipitation made the greatest contribution to the annual change in precipitation. Moreover, the increment in precipitation was amplified with elevation. Enhanced westerly circulation and increased water vapor were the factors responsible for the increased precipitation in the study area. Temperature in the whole regions, oasis, and mountains increased at the rate of 0.32, 0.32, and 0.33 °C/decade, respectively. Changes in temperature were greatest in winter, with 0.47, 0.36 and 0.50 °C/decade in the whole regions, oasis, and mountains, respectively; changes in winter temperature made the greatest contribution to the annual temperature changes. Seasonal differences in carbon dioxide concentration may have caused the seasonal differences in the rate of temperature increase. The annual increase in temperature was mainly due to Siberian High, and Arctic Oscillation, carbon emissions and decreased cloud cover in the study area. The study results will help evaluate climatic hazards and contribute to development of water resources management strategies such as supplementary irrigation.
Bacterial wilt, caused by the plant pathogen
Ralstonia solanacearum
, occurs more severely in acidified soil according to previous reports. However,
R. solanacearum
cannot grow well in acidic ...environments under barren nutrient culture conditions, especially when the pH is lower than 5. With the worsening acidification of farmland, further determination of how
R. solanacearum
adapts to the long-term acidic environment is worthwhile. In this study, experimental evolution was applied to evaluate the adaptability and mechanism of the
R. solanacearum
experimental population responding to long-term acid stress. We chose the CQPS-1 strain as the ancestor, and minimal medium (MM medium) with different pH values as the culture environment to simulate poor soil. After 1500 generations of serial passage experiments in pH 4.9 MM, acid-adapted experimental strains (denoted as C49 strains) were obtained, showing significantly higher growth rates than the growth rates of control experimental strains (serial passage experiment in pH 6.5 MM, denoted as C65 strains). Competition experiments showed that the competitive indices (CIs) of all selected clones from C49 strains were superior to the ancestor in acidic environment competitiveness. Based on the genome variation analysis and functional verification, we confirmed that loss of function in the
phcA
gene was associated with the acid fitness gain of
R. solanacearum
, which meant that the inactivation of the PhcA regulator caused by gene mutation mediated the population expansion of
R. solanacearum
when growing in an acidic stress environment. Moreover, the swimming motility of acid evolution strains and the
phcA
deletion mutant was significantly enhanced compared to CQPS-1. This work provided evidence for understanding the adaptive strategy of
R. solanacearum
to the long-term acidic environment.
Bacterial wilt is accompanied by microbial communities shift and soil acidification. However, the relationship between the changes of bacterial communities and bacterial wilt under the influence of ...different acidification levels has not been fully elucidated. Here, we analyzed the abundance of Ralstonia solanacearum, rhizosphere bacterial communities and carbon metabolism at differently acidic levels (pH 6.45, pH 5.60, pH 5.35, pH 4.90 and pH 4.45) and soil amendment treatment (CaO). The results indicated that both the abundance of R. solanacearum and the incidence of bacterial wilt showed a significant trend of first increasing and then decreasing with the increase of soil pH. The Firmicutes phylum and potentially beneficial genera
,
,
and Pseudomonas were significantly enriched at pH 6.45. The metabolic ability in response to the l-arginine and 4-hydroxybenzoic acid was significantly increased at pH 6.45. After using CaO to increase the pH of diseased soil from 5.45 to 6.05, the abundance of R. solanacearum and the incidence of bacterial wilt were significantly reduced, the Firmicutes and potentially beneficial genera
and Pseudomonas were significantly enriched. Overall, alleviating soil acidification to a slightly acidic level (pH 6.0-6.5) could suppress bacterial wilt by suppressing the growth of R. solanacearum and enriching the rhizosphere potentially beneficial bacteria, and further emphasized the importance of increasing soil pH in biological control of bacterial wilt.
The rhizosphere microbiota and soil acidification have been shown to have impacts on bacterial wilt. However, the influence of different acidification levels on the rhizosphere communities and bacterial wilt has not been fully studied. In this study, the potentially beneficial bacteria (
and Pseudomonas) were significantly enriched in the slightly acidic soil (pH 6.45), leading to the increase of the metabolism of 4-hydroxybenzoic acid and the decrease of pathogenic R. solanacearum, thereby alleviating the occurrence of bacterial wilt. The changes of potentially beneficial bacteria and pathogenic R. solanacearum in strongly acidic soil (pH 5.35) with the highest incidence of bacterial wilt were just the opposite. These findings help clarify the mechanisms by which soil bacteria exert influence on bacterial wilt outbreak under different soil acidification levels.
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