Multivariate analysis compares and evaluates drought and flooding tolerances of maize germplasm.

Drought and flooding are the two most important environmental factors limiting maize (Zea mays L.) production globally. This study aimed to investigate the physiological mechanisms and accurate evaluation indicators and methods of maize germplasm involved in drought and flooding stresses. The twice replicated pot experiments with 60 varieties, combined with the field validation experiment with 3 varieties, were conducted under well-watered, drought, and flooding conditions. Most varieties exhibited stronger tolerance to drought than flooding due to higher antioxidant enzyme activities, osmotic adjustment substances, and lower reactive oxygen species. In contrast, flooding stress resulted in higher levels of reactive oxygen species (particularly O2-), ascorbate peroxidase, catalase, peroxidase, and soluble sugars but lower levels of superoxide dismutase, proline, and soluble protein compared with well-watered conditions. Superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, proline, soluble sugars, and protein contents, in addition to plant height, leaf area/plant, and stem diameter, were accurate and representative indicators for evaluating maize tolerance to drought and flooding stresses and could determine a relatively high mean forecast accuracy of 100.0% for the comprehensive evaluation value. A total of 4 principal components were extracted, in which different principal components played a vital role in resisting different water stresses. Finally, the accuracy of the 3 varieties screened by multivariate analysis was verified in the field. This study provides insights into the different physiological mechanisms and accurate evaluation methods of maize germplasm involved in drought and flooding stresses, which could be valuable for further research and breeding.

[Effects of Human Immunodeficiency Virus-positive Mothers Receiving Antiretroviral Therapy to Prevent Mother-to-child Transmission on the Growth and Development of 18-month-old Children in Lingshan County of Guangxi].

Objective To evaluate the effects of antiretroviral therapy(ART)for the prevention of mother-to-child transmission(PMTCT)of acquired immune deficiency syndrome(AIDS)on the growth and development of 18-month-old children born by human immunodeficiency virus(HIV)-positive pregnant women in Lingshan County,Guangxi Zhuang Autonomous Region,and provide scientific evidence for improving the ART medication plan for PMTCT.Methods Lingshan County,ranking the first in the HIV-epidemic counties of Guangxi,was selected as the research site.According to the design of retrospective case-control study,we assigned all the subjects into the case group and the control group:(1)The case group included the HIV-positive pregnant women who had received ART for PMTCT and their HIV-negative infants in Lingshan County from 2010 to 2017.The historical cards and PMTCT data of them were collected from the national PMTCT database.(2)The control group included the healthy pregnant women and their healthy babies born in the Lingshan Maternity and Infant Hospital in 2017,and the children's growth and development data were collected.The stunted growth in children was defined as at least one of the three main indicators of body height,body weight,and head circumference below the normal range.Results The number of HIV-positive mothers and their infants in the case group was 391 and 368,respectively,and 87.21%(341/391)and 95.38%(351/368)of mothers and infants respectively received ART medication.The HIV positive rate,mortality rate,and mother-to-child transmission rate of 18-month-old children were 1.36%(5/368),4.35%(16/368),and 2.01%(5/249),respectively.The incidence of stunted growth of 18-month-old children in the case group and the control group was 42.12%(155/368)and 23.06%(101/438),respectively,with significant difference(χ2=33.520,P<0.001).Conclusion After HIV-positive mothers in Lingshan County of Guangxi received ART for PMTCT,the incidence of growth stunting in 18-month-old children increased.

Acetylated Rhamnose Triterpenoid Saponins from Glechoma longituba Analyzed by LC-Q-TOFMS.

The aim of the present work is to isolate a series of triterpene derivatives with rhamnosyl linking acetyl groups from Glechoma longituba according to the structural characteristics of previously described triterpene saponins. The extract ion chromatography spectrum of the crude extract of G. longituba was detected and analyzed by HPLC-HR-ESI-MS to determine possible components, and these metabolites were traced and separated by combining high-resolution mass spectrometry and predicted liquid chromatography retention time. Three 11α, 12α-epoxypentacyclic oleanolic acid triterpene saponins (glechomanosides H-J) and one ursane triterpene aldehyde saponin with a C-28 aldehyde group were isolated from G. longituba. The structure of these compounds was confirmed by NMR and compared with those of previously characterized compounds. The strategy described in this report enables a rapid, reliable, and complete analysis of glycoside compounds containing different numbers of acetyl groups at different positions on the sugar.

[Compositions and metabolic footprints of soil nematode communities under different alfalfa-crop planting patterns in semi-arid region of the Loess Plateau, Northwest China.] / 黄土高原半干旱区不同苜蓿-作物种植方式下土壤线虫群落组成及代谢足迹.

Soil nematode communities play an important role in ecosystem material cycling and energy flow. In this study, soil samples were collected from three rotation systems in southern Ningxia mountainous region, including alfalfa continuous cropping (A-A), alfalfa-corn rotation (A-C), alfalfa-potato rotation (A-P). Soil physicochemical properties, nematode community composition and their metabolic footprints were measured. Compared with the A-A plot, the concentrations of soil organic carbon (SOC) and total nitrogen (TN) were significantly increased by 4.6% and 7.4% for SOC, 4.0% and 5.2% for TN in the A-C and A-P plots, respectively. Soil microbial biomass carbon and nitrogen were significantly higher in the A-C and A-P plots when compared with the A-A plot. The total abundance of soil nematodes in the A-C and A-P plots was higher by 49.5% and 93.7% than that in the A-A plot, respectively, with the dominant trophic group being changed to omnivores-predators from plant parasite. Compared to the A-A plot, the plant parasite index (PPI) was decreased significantly in the A-C and A-P plots, indicating that the harm of plant-parasites was reduced in soil food web. The nematode channel ratio (NCR) in the A-C and A-P plots were higher than that in the A-A plot, indicating that the role of bacterial decomposition was enhanced in soil organic matter decomposition. The maturity index (MI), the total nematode metabolic footprint, enrichment footprint, structure footprint in the A-C and A-P plots were all significantly higher than those in the A-A plot, suggesting that the structure and function of soil food web were more mature and stable, and the productivity and metabolic activity of nematodes were significantly enhanced. In general, the alfalfa-crop rotations improved soil nutrient status and reduced the disturbance degree of soil food web. Furthermore, soil ecosystem developed in the stable and healthy direction, which would be beneficial to the sustainable development of agriculture.

[Characteristics of soil microbial and nematode communities under artificial Medicago sativa grasslands with different cultivation years in semi-arid region of Loess Plateau, Northwest China]. / 黄土高原半干旱区不同种植年限紫花苜蓿人工草地土壤微生物和线虫群落特征.

The establishment of Medicago sativa artificial grasslands is an important practice of grassland vegetation restoration in the Loess Plateau. Understanding community characteristics of soil microbes and nematodes can provide important information for evaluating and controlling ecolo-gical and environmental effects of vegetation restoration. In this study, we used M. sativa artificial grasslands with four different cultivation years (1, 2, 6 and 12 years) in southern Ningxia mountainous region, with a farmland and a natural grassland as control, to explore changing trends of the two biological communities during artificial grassland restoration in semi-arid region of the Loess Plateau. The results showed that: 1) After the conversion of farmland to M. sativa grassland, Chao1, ACE and Shannon diversity indices of soil bacterial community increased firstly and then decreased, which reached the maximum after six years of M. sativa grassland establishment. For soil fungal community, Shannon diversity index was lower in 6 and 12 year-old M. sativa grasslands than in the other two artificial grasslands, and the community composition differed across restoration years. 2) With the increases of restoration years, the abundance of soil nematodes showed a similar changing trend with Shannon diversity index of bacterial community. The composition of nematode community did not greatly differ between the 6-year-old M. sativa grassland and farmland, while that in 12-year-old artificial grassland was more similar to that in natural grassland. The proportion of bacterivorous and plant-feeding nematodes, as well as plant parasitic index and nematode channel index of nematode community,were increased, while the proportion of fungivores and omnivores-predators and maturity index were decreased. 3) During the restoration, changes in soil organic carbon, total nitrogen and available phosphorus greatly affected soil microbial community, which could further influence soil nematode community. There were significant correlations between dominant microbial phyla and trophic groups of soil nematodes, implying the possible effects of soil microbes on nematode community. In M. sativa artificial grassland with different establishment years, changes in plant biomass and diversity might significantly affect soil nematode and microbial communities through affecting their food conditions.

Transcriptomic and proteomic response of Manihot esculenta to Tetranychus urticae infestation at different densities.

Tetranychus urticae (Acari: Tetranychidae) is an extremely serious cassava (Manihot esculenta) pest. Building a genomic resource to investigate the molecular mechanisms of cassava responses to T. urticae is vital for characterizing cassava resistance to mites. Based on the tolerance of cassava varieties to mite infestation (focusing on mite development rate, fecundity and physiology), cassava variety SC8 was selected to analyze transcriptomic and proteomic changes after 5 days of T. urticae feeding. Transcriptomic analysis revealed 698 and 2140 genes with significant expression changes under low and high mite infestation, respectively. More defense-related genes were found in the enrichment pathways at high mite density than at low density. In addition, iTRAQ-labeled proteomic analysis revealed 191 proteins with significant expression changes under low mite infestation. Differentially expressed genes and proteins were mainly found in the following defense-related pathways: flavonoid biosynthesis, phenylpropanoid biosynthesis, and glutathione metabolism under low-density mite feeding and plant hormone signal transduction and plant-pathogen interaction pathways under high-density mite feeding. The plant hormone signal transduction network, involving ethylene, jasmonic acid, and salicylic acid transduction pathways, was explored in relation to the M. esculenta response to T. urticae. Correlation analysis of the transcriptome and proteome generated a Pearson correlation coefficients of R = 0.2953 (P < 0.01), which might have been due to post-transcriptional or post-translational regulation resulting in many genes being inconsistently expressed at both the transcript and protein levels. In summary, the M. esculenta transcriptome and proteome changed in response to T. urticae, providing insight into the general activation of plant defense pathways in response to mite infestation.

[Comparative study on oral candidal infection in individuals with diabetes mellitus and impaired glucose regulation].

OBJECTIVE: To investigate the positive rate, infection rate and bearing rate of salivary candida in patients with type 2 diabetes mellitus (DM), individuals with impaired glucose regulation (IGR) and individuals with normal glucose tolerance (NGT) and their predisposing factors. METHODS: Questionnaire was given to 145 patients with DM, 142 individuals with IGR and 149 NGT individuals. Oral examination was carried out, and fasting plasma glucose (FPG) level and plasma glucose level of 2 hours post glucose-load (PG2h), resting salivary flow, salivary pH value were tested. Salivary candida was cultured. RESULTS: In DM, IGR and NGT groups, the positive rates of salivary candida were 21.4% (31/145), 7.0% (10/142), 4.7% (7/149) respectively, the infection rates were 7.6% (11/145), 1.4% (2/142), 1.3% (2/149) respectively, and the bearing rates of salivary candida were 13.8% (20/145), 5.6% (8/142), 3.4% (5/149) respectively. The candida positive rate, candida infection rate in DM group were higher than those of IGR and NGT groups respectively (P < 0.05). There were no significant differences in the candida positive rate, infection rate and bearing rate between IGR and NGT groups (P > 0.05). Resting salivary flow in DM [(1.30 ± 1.20) ml/10 min] and IGR [(1.40 ± 1.17) ml/10 min]groups were lower than that in NGT group [(1.93 ± 1.66) ml/10 min], salivary pH values in DM (7.11 ± 0.56) and IGR (7.05 ± 0.48) groups were lower than that in NGT group (7.38 ± 0.48) (P < 0.05), while FPG value in DM [(7.68 ± 2.75) mmol/L] and IGR [(5.67 ± 0.73) mmol/L] groups were respectively higher tham that in NGT group [(4.99 ± 0.44) mmol/L], P < 0.05. The infection rate of salivary candida was influenced to some degree by age, FPG level and bearing denture (OR value = 1.106, 1.258, 3.166). CONCLUSIONS: The patients with DM were more subjected to bearing or infection of candida than individuals with IGR and NGT. To control the plasma glucose level will help to decrease the positive rate and infection rate of oral candida.

Changes in the proportions of CD4(+)T cell subsets defined by CD127 and CD25 expression during HBV infection.

CD4(+)T cell counts are closely related to the progression of HBV infection. Here, we investigated how the proportions of three CD4(+)T cell subsets - CD127(-)CD25(-), CD127(+)CD25(low/-) and CD127(low)CD25(high) - changed during HBV infection, as is little known. Compared with healthy controls, the proportions of CD127(-)CD25(-) in chronic hepatitis B (CHB) patients and HBV carriers significantly increased, while that of CD127(+)CD25(low/-) significantly decreased. The proportion of CD127(low)CD25(high) in CHB patients was significantly higher than those in HBV carriers or healthy controls. Compared with HBV-DNA negative group, the proportion of CD127(-)CD25(-) in positive group significantly decreased and that of CD127(+)CD25(low/-) significantly increased. In the follow-up study for CHB patients treated with interferon-α2b for 12 weeks or 24 weeks, the proportions of CD127(-)CD25(-) significantly decreased, while that of CD127(low/-)CD25(high) significantly increased. The results suggested that specific changes in the fraction of CD4(+)T cell subsets expressing CD127 and/or CD25 were associated with hepatitis B progression.

[Effects of inoculating arbuscular mycorrhizal fungi on Artemisia annua growth and its officinal components].

A pot experiment was conducted to study the effects of inoculating arbuscular mycorrhizal (AM) fungi on the growth, nutrient uptake, and officinal components of Artemisia annua. Inoculation with AM fungi Glomus mosseae and G. versiforme improved the uptake of nitrogen, phosphorus, and potassium by A. annua, and increased the leaf chlorophyll content, net photosynthetic rate, stomatal conductance, and transpiration rate as well as the stem diameter and aboveground biomass of A. annua, with greater effects of inoculating G. mosseae than G. versiforme. After the colonization of G. mosseae and G. versiforme, the artemisinin content in A. annua stem, branch, and leaf was increased by 32.8%, 15.2%, and 19.6%, and 26.5%, 10.1%, and 14.9%, and the volatile oil content in leaf was increased by 45.0% and 25. 0%, respectively, compared with the control. Furthermore, mycorrhizal colonization led to changes in volatile components.

Induction of DIMBOA accumulation and systemic defense responses as a mechanism of enhanced resistance of mycorrhizal corn (Zea mays L.) to sheath blight.

Arbuscular mycorrhizas are the most important symbioses in terrestrial ecosystems and they enhance the plant defense against numerous soil-borne pathogenic fungi and nematodes. Two corn (Zea mays) varieties, Gaoyou-115 that is susceptible to sheath blight disease caused by Rhizoctonia solani and Yuenong-9 that is resistant, were used for mycorrhizal inoculation in this study. Pre-inoculation of susceptible Gaoyou-115 with arbuscular mycorrhizal fungus (AMF) Glomus mosseae significantly reduced the disease incidence and disease severity of sheath blight of corn. HPLC analysis showed that AMF inoculation led to significant increase in 2,4-dihydroxy-7-methoxy-2 H-1,4-benzoxazin-3(4 H)-one (DIMBOA) accumulation in the roots of both corn varieties and in leaves of resistant Yuenong-9. R. solani inoculation alone did not result in accumulation of DIMBOA in both roots and leaves of the two corn varieties. Our previous study showed that DIMBOA strongly inhibited mycelial growth of R. solani in vitro. Real-time PCR analysis showed that mycorrhizal inoculation itself did not affect the transcripts of most genes tested. However, pre-inoculation with G. mosseae induced strong responses of three defense-related genes PR2a, PAL, and AOS, as well as BX9, one of the key genes in DIMBOA biosynthesis pathway, in the leaves of corn plants of both Yuenong-9 and Gaoyou-115 after the pathogen attack. Induction of defense responses in pre-inoculated plants was much higher and quicker than that in non-inoculated plants upon R. solani infection. These results indicate that induction of accumulation of DIMBOA, an important phytoalexin in corn, and systemic defense responses by AMF, plays a vital role in enhanced disease resistance of mycorrhizal plants of corn against sheath blight. This study also suggests that priming is an important mechanism in mycorrhiza-induced resistance.

Optimizing DC vaccination by combination with oncolytic adenovirus coexpressing IL-12 and GM-CSF.

Dendritic cell (DC)-based vaccination is a promising strategy for cancer immunotherapy. However, clinical trials have indicated that immunosuppressive microenvironments induced by tumors profoundly suppress antitumor immunity and inhibit vaccine efficacy, resulting in insufficient reduction of tumor burdens. To overcome these obstacles and enhance the efficiency of DC vaccination, we generated interleukin (IL)-12- and granulocyte-macrophage colony-stimulating factor (GM-CSF)-coexpressing oncolytic adenovirus (Ad-ΔB7/IL12/GMCSF) as suitable therapeutic adjuvant to eliminate immune suppression and promote DC function. By treating tumors with Ad-ΔB7/IL12/GMCSF prior to DC vaccination, DCs elicited greater antitumor effects than in response to either treatment alone. DC migration to draining lymph nodes (DLNs) dramatically increased in mice treated with the combination therapy. This result was associated with upregulation of CC-chemokine ligand 21 (CCL21(+)) lymphatics in tumors treated with Ad-ΔB7/IL12/GMCSF. Moreover, the proportion of CD4(+)CD25(+) T-cells and vascular endothelial growth factor (VEGF) expression was decreased in mice treated with the combination therapy. Furthermore, combination therapy using immature DCs also showed effective antitumor effects when combined with Ad-ΔB7/IL12/GMCSF. The combination therapy had a remarkable therapeutic efficacy on large tumors. Taken together, oncolytic adenovirus coexpressing IL-12 and GM-CSF in combination with DC vaccination has synergistic antitumor effects and can act as a potent adjuvant for promoting and optimizing DC vaccination.

Therapeutic and tumor-specific immunity induced by combination of dendritic cells and oncolytic adenovirus expressing IL-12 and 4-1BBL.

Recently, gene-based cytokine treatment has been actively pursued as a new promising approach in treating cancer. In an effort to augment the efficiency of antitumor effect by cytokine-mediated immunotherapy, we selected both interleukin (IL)-12 and 4-1BB ligand (4-1BBL) as suitable cytokines to fully activate the type-1 immune response. Coexpression of IL-12 and 4-1BBL mediated by oncolytic adenovirus (Ad) greatly enhanced the antitumor effect. Further, synergistic enhancement in interferon (IFN)-gamma levels were seen in mice treated with oncolytic Ad expressing both IL-12 and 4-1BBL. Next, to improve the overall antitumor immune response, we coadministered IL-12- and 4-1BBL-coexpressing oncolytic Ad with dendritic cells (DCs). Combination treatment of IL-12- and 4-1BBL-coexpressing oncolytic Ad and DCs elicited greater antitumor and antimetastatic effects than either treatment alone. Moreover, enhanced type-1 antitumor immune response and higher migratory abilities of DCs in tumors were also observed in the combination arms. The nature of the enhanced antitumor immune response seems to be mediated through the enhanced cytolytic activity of cytotoxic T lymphocytes (CTLs) and IFN-gamma-releasing immune cells. Taken together, these data highlight the potential therapeutic benefit of combining IL-12- and 4-1BBL-coexpressing oncolytic Ad with DCs and warrants further evaluation in the clinic.

Relaxin expression from tumor-targeting adenoviruses and its intratumoral spread, apoptosis induction, and efficacy.

BACKGROUND: The use of oncolytic adenoviruses as cancer gene therapy is limited by their uneven penetration and distribution in tumors. We investigated whether the expression of the cell matrix-degradative protein relaxin by adenovirus could improve adenovirus distribution and penetration in tumors. METHODS: We generated relaxin-expressing, replication-incompetent (dl-lacZ-RLX) and -competent (Ad-deltaE1B-RLX) adenoviruses by inserting a relaxin gene into the E3 adenoviral region. Controls were parental adenoviruses (dl-lacZ and Ad-deltaE1B) and phosphate-buffered saline (PBS) (vehicle). Replication-incompetent viruses, which do not lyse cells, were used to assess transduction efficiency. Viral spread in tumor spheroids, made by dissecting tumor tissue into homogeneous fragments, was assessed by reporter gene (i.e., lacZ) expression. Tumor growth inhibition was assessed by injecting adenoviruses into xenograft tumors in athymic mice (n = 8 or 9). Overall survival was assessed by the Kaplan-Meier method. Extracellular matrix was examined with Masson's trichrome staining. Therapeutic efficacy was evaluated by assessing spontaneous pulmonary metastasis in the B16BL6 melanoma mouse model and growth inhibition of orthotopically implanted hepatoma (n = 4-6). All statistical tests were two-sided. RESULTS: In tumor spheroids and established solid tumors in vivo, transduction with dl-lacZ-RLX, compared with parental virus or vehicle, elicited higher transduction efficiency and viral spread throughout the tumor mass. Infection with Ad-deltaE1B-RLX, compared with parental virus, elicited greater viral persistence and spread, leading to increased survival (e.g., 100%, 95% confidence interval [CI] = 63.1% to 100%, for C33A tumor-bearing mice treated with Ad-deltaE1B-RLX, and 50%, 95% CI = 15.7% to 84.3%, for C33A tumor-bearing mice treated with Ad-deltaE1B). Infection with Ad-deltaE1B-RLX substantially decreased the collagen content of tumor tissue but not of adjacent normal tissue, compared with noninfected tissues. Intratumoral injection of Ad-deltaE1B-RLX inhibited the formation of lung metastases in mice (PBS = 268 mg of metastatic tumor per mouse and Ad-deltaE1B-RLX = 10 mg; difference = 258 mg, 95% CI = 94 to 426; P = .003, Mann-Whitney test). Systemic treatment with Ad-deltaE1B-RLX completely inhibited the growth of Hep1 hepatocellular carcinomas (PBS = 20.2 mg of tumor per mouse and Ad-deltaE1B-RLX = 0 mg; difference = 20.2 mg, 95% CI = 3.7 to 36.7; P = .004, Mann-Whitney test). CONCLUSION: Extracellular matrix degradation by relaxin expressed by adenoviruses increased viral distribution and tumor penetration, inhibited tumor growth and metastasis, and increased survival of mice.