Evaluation of laboratory and environmental exposure systems for protein modification upon gas pollutants and environmental factors.

Chemical modifications of proteins induced by ambient ozone (O3) and nitrogen oxides (NOx) are of public health concerns due to their potential to trigger respiratory diseases. The laboratory and environmental exposure systems have been widely used to investigate their relevant mechanism in the atmosphere. Using bovine serum albumin (BSA) as a model protein, we evaluated the two systems and aimed to reduce the uncertainties of both the reactants and products in the corresponding kinetic study. In the laboratory simulation system, the generated gaseous pollutants showed negligible losses. Ten layers of BSA were coated on the flow tube with protein extraction recovery of 87.4%. For environmental exposure experiment, quartz fiber filter was selected as the upper filter with low gaseous O3 (8.0%) and NO2 (1.7%) losses, and cellulose acetate filter was appropriate for the lower filter with protein extraction efficiency of 95.2%. The protein degradation process was observed without the exposure to atmospheric oxidants and contributed to the loss of protein monomer mass fractions, while environmental factors (e.g., molecular oxygen and ultraviolet) may cause greater protein monomer losses. Based on the evaluation, the study exemplarily applied the two systems to protein modification and both showed that O3 promotes the protein oligomerization and nitration, while increased temperature can accelerate the oligomerization and increased relative humidity can inhibit the nitration in the environmental exposure samples. The developed laboratory and environmental systems are suitable for studying protein modifications formed under different atmospheric conditions. A combination of the two will further reveal the actual mechanism of protein modifications.

Screening of Sugarcane Proteins Associated with Defense against Leifsonia xyli subsp. xyli, Agent of Ratoon Stunting Disease.

Sugarcane is the most important sugar crop and one of the leading energy-producing crops in the world. Ratoon stunting disease (RSD), caused by the bacterium Leifsonia xyli subsp. xyli, poses a huge threat to ratoon crops, causing a significant yield loss in sugarcane. Breeding resistant varieties is considered the most effective and fundamental approach to control RSD in sugarcane. The exploration of resistance genes forms the foundation for breeding resistant varieties through molecular technology. The pglA gene is a pathogenicity gene in L. xyli subsp. xyli, encoding an endopolygalacturonase. In this study, the pglA gene from L. xyli subsp. xyli and related microorganisms was analyzed. Then, a non-toxic, non-autoactivating pglA bait was successfully expressed in yeast cells. Simultaneously the yeast two-hybrid library was generated using RNA from the L. xyli subsp. xyli-infected sugarcane. Screening the library with the pglA bait uncovered proteins that interacted with pglA, primarily associated with ABA pathways and the plant immune system, suggesting that sugarcane employs these pathways to respond to L. xyli subsp. xyli, triggering pathogenicity or resistance. The expression of genes encoding these proteins was also investigated in L. xyli subsp. xyli-infected sugarcane, suggesting multiple layers of regulatory mechanisms in the interaction between sugarcane and L. xyli subsp. xyli. This work promotes the understanding of plant-pathogen interaction and provides target proteins/genes for molecular breeding to improve sugarcane resistance to L. xyli subsp. xyli.

Differential Gene Expression Analysis of SoCBL Family Calcineurin B-like Proteins: Potential Involvement in Sugarcane Cold Stress.

Sugarcan e is a major crop for sugar and biofuel production and is cultivated in tropical and subtropical areas worldwide. Sugarcane growth is constrained because of winter's low-temperature stress, and cold resistance is an important limitation in sugarcane growth enhancement. Therefore, in this study, we identified a gene involved in the low-temperature stress response of sugarcane. Calcineurin B-like (CBL) protein is a calcium signal receptor involved in the cold stress response. Five sugarcane CBL genes were cloned, sequenced, and named SoCBL1, SoCBL3, SoCBL5, SoCBL6, and SoCBL9. The protein sequences of these genes were analyzed. The calculated molecular weight of these proteins was 24.5, 25.9, 25.2, 25.6, and 26.3 kD, respectively. Subcellular localization analysis revealed that SoCBL1, SoCBL3, SoCBL6, and SoCBL9 were situated in the cytoplasm, while SoCBL5 was present in mitochondria. Secondary structure analysis showed that these five CBL proteins had similar secondary structures. Conserved domain analysis displayed that each sugarcane CBL protein contained three conserved EF domains. According to the self-expanding values of the phylogenetic tree, the CBL gene family was divided into four groups. The CBL1 and CBL9 genes were classified into one group, illustrating that these two genes might possess a similar function. The expression analysis of the SoCBL gene under low temperatures showed that SoCBL3 and SoCBL5 were affected significantly, while SoCBL1 and SoCBL9 were less affected. These results demonstrate that the CBL genes in sugarcane have similar characteristics and present differences in genetic diversity and gene expression response to low temperatures. Therefore, these genes might be novel candidates for fighting cold stress in sugarcane.

Exploration of silicon functions to integrate with biotic stress tolerance and crop improvement.

In the era of climate change, due to increased incidences of a wide range of various environmental stresses, especially biotic and abiotic stresses around the globe, the performance of plants can be affected by these stresses. After oxygen, silicon (Si) is the second most abundant element in the earth's crust. It is not considered as an important element, but can be thought of as a multi-beneficial quasi-essential element for plants. This review on silicon presents an overview of the versatile role of this element in a variety of plants. Plants absorb silicon through roots from the rhizospheric soil in the form of silicic or monosilicic acid. Silicon plays a key metabolic function in living organisms due to its relative abundance in the atmosphere. Plants with higher content of silicon in shoot or root are very few prone to attack by pests, and exhibit increased stress resistance. However, the more remarkable impact of silicon is the decrease in the number of seed intensities/soil-borne and foliar diseases of major plant varieties that are infected by biotrophic, hemi-biotrophic and necrotrophic pathogens. The amelioration in disease symptoms are due to the effect of silicon on a some factors involved in providing host resistance namely, duration of incubation, size, shape and number of lesions. The formation of a mechanical barrier beneath the cuticle and in the cell walls by the polymerization of silicon was first proposed as to how this element decreases plant disease severity. The current understanding of how this element enhances resistance in plants subjected to biotic stress, the exact functions and mechanisms by which it modulates plant biology by potentiating the host defence mechanism needs to be studied using genomics, metabolomics and proteomics. The role of silicon in helping the plants in adaption to biotic stress has been discussed which will help to plan in a systematic way the development of more sustainable agriculture for food security and safety in the future.

Exploration of silicon functions to integrate with biotic stress tolerance and crop improvement

In the era of climate change, due to increased incidences of a wide range of various environmental stresses, especially biotic and abiotic stresses around the globe, the performance of plants can be affected by these stresses. After oxygen, silicon (Si) is the second most abundant element in the earth's crust. It is not considered as an important element, but can be thought of as a multi-beneficial quasi-essential element for plants. This review on silicon presents an overview of the versatile role of this element in a variety of plants. Plants absorb silicon through roots from the rhizospheric soil in the form of silicic or monosilicic acid. Silicon plays a key metabolic function in living organisms due to its relative abundance in the atmosphere. Plants with higher content of silicon in shoot or root are very few prone to attack by pests, and exhibit increased stress resistance. However, the more remarkable impact of silicon is the decrease in the number of seed intensities/soil-borne and foliar diseases of major plant varieties that are infected by biotrophic, hemi-biotrophic and necrotrophic pathogens. The amelioration in disease symptoms are due to the effect of silicon on a some factors involved in providing host resistance namely, duration of incubation, size, shape and number of lesions. The formation of a mechanical barrier beneath the cuticle and in the cell walls by the polymerization of silicon was first proposed as to how this element decreases plant disease severity. The current understanding of how this element enhances resistance in plants subjected to biotic stress, the exact functions and mechanisms by which it modulates plant biology by potentiating the host defence mechanism needs to be studied using genomics, metabolomics and proteomics. The role of silicon in helping the plants in adaption to biotic stress has been discussed which will help to plan in a systematic way the development of more sustainable agriculture for food security and safety in the future.

Long Non-coding RNA THRIL Mediates Cell Growth and Inflammatory Response of Fibroblast-Like Synoviocytes by Activating PI3K/AKT Signals in Rheumatoid Arthritis.

The present study explored the possible functions and the underlying mechanism of tumor necrosis factor-α (TNF-α) and heterogeneous nuclear ribonucleoprotein L (hnRNPL)-related immunoregulatory lncRNA plasmacytoma variant translocation 1 (THRIL) in rheumatoid arthritis (RA). Serum samples were collected from patients with RA. Primary fibroblast-like synoviocytes (FLSs) were separated from synovial tissues and cultured for subsequent cell experiments by transfecting different vectors. The qRT-PCR analysis was employed for evaluating the levels of THRIL in the serum. Enzyme-linked immunosorbent assay (ELISA) analysis was employed to detect the levels of inflammatory cytokines. MTT assay and Annexin V-FITC/PI apoptosis assay were used to evaluate the cell viability and apoptosis, respectively. Besides, the levels of the apoptotic proteins and the pathway-related proteins were measured by western blotting. Pearson's correlation analysis was used to assess the correlation between THRIL and clinical parameters. THRIL was overexpressed in the blood of patients with RA as compared with healthy participants (p < 0.05). The THRIL levels in the RA blood sample were positively associated with TNF-α levels, DAS 28, and ESR (p < 0.001). TNF-α treatment significantly inhibited cell viability and enhanced cell apoptosis. Furthermore, it elevated the levels of IL-1ß and MMP-3 (p < 0.05), whereas the suppression of THRIL reversed these effects in TNF-α-treated RA-FLSs (p < 0.05). Moreover, the reduced THRIL remarkably reduced the expression of p-PI3K and p-AKT (p < 0.05) in TNF-α-treated RA-FLSs. The present study revealed that THRIL could regulate cell growth and inflammatory response of FLSs by activating the PI3K/AKT signaling pathway, subsequently playing important roles in promoting the occurrence and development of RA.

Isolation and Characterization of the Novel Phages vB_VpS_BA3 and vB_VpS_CA8 for Lysing Vibrio parahaemolyticus.

Accumulating evidence has indicated that the multiple drug resistant Vibrio parahaemolyticus may pose a serious threat to public health and economic concerns for humans globally. Here, two lytic bacteriophages, namely vB_VpS_BA3 and vB_VpS_CA8, were isolated from sewage collected in Guangzhou, China. Electron microscopy studies revealed both virions taxonomically belonged to the Siphoviridae family with icosahedral head and a long non-contractile tail. The double-stranded DNA genome of phage BA3 was composed of 58648 bp with a GC content of 46.30% while phage CA8 was 58480 bp with an average GC content of 46.42%. In total, 85 putative open reading frames (ORFs) were predicted in the phage BA3 genome while 84 were predicted in that of CA8. The ORFs were associated with phage structure, packing, host lysis, DNA metabolism, and additional functions. Furthermore, average nucleotide identity analysis, comparative genomic features and phylogenetic analysis revealed that BA3 and CA8 represented different isolates but novel members of the family, Siphoviridae. Regarding the host range of the 61 V. parahaemolyticus isolates, BA3 and CA8 had an infectivity of 8.2 and 36.1%, respectively. Furthermore, ∼100 plaque-forming units (pfu)/cell for phage BA3 and ∼180 pfu/cell for phage CA8 were determined to be the viral load under laboratory growth conditions. Accordingly, the phage-killing assay in vitro revealed that phage CA8 achieved approximately 3.65 log unit reductions. The present results indicate that CA8 is potentially applicable for biological control of multidrug resistant V. parahaemolyticus.

Genome characterization of the novel lytic Vibrio parahaemolyticus phage vB_VpP_BA6.

A lytic bacteriophage, designated Vibrio phage vB_VpP_BA6, was isolated from sewage collected in Guangzhou, China. The double-stranded DNA genome of phage BA6 is composed of 50,520 bp with a G+C content of 41.77%. It possesses 64 open reading frames relating to phage structure, packaging, host lysis, DNA metabolism, and additional functions. Three tRNAs genes (encoding Pro, Ile and Trp) were detected. Comparison of its genomic features and phylogenetic analysis revealed that phage BA6 is a novel member of the family Podoviridae. This phage may represent a potential therapeutic agent against multidrug-resistant Vibrio parahaemolyticus.

Genome sequencing and characterization of three Bacillus cereus-specific phages, DK1, DK2, and DK3.

In the study, three Bacillus cereus-specific phages, named DK1, DK2 and DK3, belonging to the family Podoviridae, were isolated from Pearl River water and sludge in Guangzhou, China. The genomes of DK1, DK2 and DK3 were 27,180 bp, 26,357 bp, and 26,865 bp in length and contained 49, 45 and 46 open reading frames, respectively. Among the three phages, DK2 shared the highest genome sequence similarity (96% identity) with DK3. Genes encoding rRNA, tRNA, virulence factors and antibiotic resistance were absent in these phage genomes. In addition, comparative genomic and phylogenetic analysis revealed that they were novel phages of B. cereus. Each genome encoded a putative endolysin that might be of value for the control of the foodborne pathogen B. cereus.

Morphological and Physiological Responses of Sugarcane to Leifsonia xyli subsp. xyli Infection.

Ratoon stunt, caused by the bacterium Leifsonia xyli subsp. xyli, is one of the major sugarcane diseases worldwide. The objectives of this study were to determine the variation in morphology and DNA sequence of L. xyli subsp. xyli strains isolated in China, to compare the changes that occurred in vascular ultrastructure and levels of endogenous hormone abscisic acid (ABA), auxins (indoleacetic acid [IAA]), and gibberellic acids (GA3) in sugarcane stalks. Experiments were also conducted with two sugarcane varieties, 'ROC22' and 'Badila', in the greenhouse to understand the cytological and physiological mechanisms of L. xyli subsp. xyli-induced growth stunting. There were three treatments in the experiments: (i) healthy plants (L. xyli subsp. xyli-free plants), (ii) infected plants (L. xyli subsp. xyli-infected seedcanes treated with hot water, and (iii) infected plants (healthy seedcanes dipped in L. xyli subsp. xyli cell culture). The results showed that sequence coverage of a locally isolated strain, LxxGXBZ01, was 99.99%, and the average nucleotide identity between LxxGXBZ01 and the other well-characterized Brazilian isolate LxxCTCB07 was 93.61%. LxxGXBZ01 occurred in different sizes and shapes in xylem vessels of infected plants. In comparison with healthy stalks, the secondary walls of the vessel element in L. xyli subsp. xyli-infected stalks were degraded with uneven wall thickness, deformities, sticky substances, and electron-dense substances accumulated inside the cells. Compared with the healthy and hot-water treatments, the contents of IAA and GA3 were significantly lower, while that of ABA was significantly higher in the L. xyli subsp. xyli-infected stalks. The information obtained in this study will expand our understanding of ratoon stunt etiology and cytological and physiological bases of the disease manifestation.

[Prevalence and risk factors for anxiety among inhabitants in the relief centers after the 5 *12 Sichuan earthquake].

OBJECTIVE: To investigate the prevalence and risk factors for anxiety among inhabitants in the relief centers one month after the 5 * 12 Sichuan earthquake and to formulate intervention strategies. METHODS: A total of 402 tent inhabitants aged > or = 18 years were randomly selected from 13 relief centers of 4 townships in Jiangyou city. Data were collected by Self-rating Anxiety Scale (SAS) and risk factor questionnaires. RESULTS: The prevalence of anxiety among inhabitants in the relief centers was 22.1% (95% CI: 18.2%-26.6% ) (89/402). In single factor analysis, female, aged > or = 40 years, family per-capita monthly income of < 600 Yuan, education level of less than junior high school, inconvenient living conditions, history of chronic diseases, limited living space in tents, shortage of goods, and sex life being interrupted etc might increase anxiety. In multi-factor analysis, female (OR = 2.921), inconvenient living conditions (OR = 2.475), history of chronic diseases (OR = 3.997), and limited living space in tents (OR = 2.982) were the risk factors for anxiety. CONCLUSION: Inhabitants in the relief centers exhibited higher prevalence of anxiety as compared with the general population. Measures to improve the living conditions of the relief centers, including guarantee of water, electricity and material supply, sewage treatment, living space and privacy, and early psychological interventions were recommended for prevention and relief of anxiety.

[Investigation of anxiety among 402 tent inhabitants in Jiangyou city after the 5.12 Sichuan earthquake].

OBJECTIVE: To investigate the prevalence of anxiety among tent inhabitants one month after the 5.12 Sichuan earthquake as to formulating intervention strategies. METHODS: A stratified random sampling method was adopted. Inclusion criteria were: inhabitants, aged above 18 years old, living in tent in 13 relief centers of 4 townships in Jiangyou city; and only one person from each tent/family could be enrolled in this study. A total of 402 subjects were interviewed with Self-rating Anxiety Scale (SAS). SAS scores were compared between different groups and symptomatic differences between anxiety and non-anxiety victims were analyzed by stepwise multiple regression analysis. RESULTS: The prevalence of anxiety among tent inhabitants was 22.1% (89/402). A higher rate of anxiety was observed in senior age group than in younger age group (F = 7.03, P < 0.01). Age with > or = 50 years (42.85 +/- 11.15), 40-49 years (41.57 +/- 10.30), 30-39 years (37.99 +/- 9.66), 18-29 years (36.62 +/- 9.92). Female (43.13 +/- 10.45) had a high rate of anxiety than male (36.80 +/- 9.88) (t = -6.09, P < 0.01). The most common symptoms were anxiety (79.4%, 319/402), fatigue (68.2%, 274/402), phobia (65.7%, 264/402), sleep disorders (65.4%, 263/402), unfortunate feelings (65.2% , 262/402), akathisia (59.7%, 240/402), and fear (58.2%, 234/402). Stepwise multiple regression analysis revealed that insane feelings(t = 5.37, P < 0.01), trembling(t = 5.33, P < 0.01), dyspnea (t = 4.28, P < 0.01), unfortunate feelings (t = 3.87, P < 0.01), headache(t = 3.85, P < 0.01), facial flushing (t = 3.48, P <0.01), fatigue (t = 3.27, P < 0.01), dizziness (t = 2.79, P < 0.01), frequent micturition (t = 2.41, P < 0.05), and akathisia (t = 2.31, P < 0.05) were more frequently experienced in the anxiety victims than non-anxiety victims. CONCLUSION: Tent inhabitants in the post-earthquake relief centers exhibit a higher prevalence of anxiety as compared with the general population. Much attention should be paid to elderly, female, and those who have developed specific symptoms such as insane feelings, trembling, dyspnea, etc. Meanwhile, some intervention measures should be timely taken.