Root-to-shoot signaling positively mediates source-sink relation in late growth stages in diploid and tetraploid wheat.

Non-hydraulic root source signaling (nHRS) is a unique positive response to soil drying in the regulation of plant growth and development. However, it is unclear how the nHRS mediates the tradeoff between source and sink at the late growth stages and its adaptive mechanisms in primitive wheat. To address this issue, a root-splitting design was made by inserting solid partition in the middle of the pot culture to induce the occurrence of nHRS using four wheat cultivars (MO1 and MO4, diploid; DM22 and DM31, tetraploid) as materials. Three water treatments were designed as 1) both halves watered (CK), 2) holistic root system watered then droughted (FS), 3) one-half of the root system watered and half droughted (PS). FS and PS were designed to compare the role of the full root system and split root system to induce nHRS. Leaves samples were collected during booting and anthesis to compare the role of nHRS at both growth stages. The data indicated that under PS treatment, ABA concentration was significantly higher than FS and CK, demonstrating the induction of nHRS in split root design and nHRS decreased cytokinin (ZR) levels, particularly in the PS treatment. Soluble sugar and proline accumulation were higher in the anthesis stage as compared to the booting stage. POD activity was higher at anthesis, while CAT was higher at the booting stage. Increased ABA (nHRS) correlated with source-sink relationships and metabolic rate (i.e., leaf) connecting other stress signals. Biomass density showed superior resource acquisition and utilization capabilities in both FS and PS treatment as compared to CK in all plants. Our findings indicate that nHRS-induced alterations in phytohormones and their effect on source-sink relations were allied with the growth stages in primitive wheat.

Response of source-sink relationship to progressive water deficit in the domestication of dryland wheat.

It is crucial to clarify the physiological responses of wheat (T. aestivum) plants to source-sink manipulation and assimilation transportation under drought stress during domestication of dryland wheat. In this research, a two-year field experiment was conducted using nine wheat cultivars in a semiarid site of northwest China. The source-sink manipulation treatments including defoliation of flag leaves and 50% removal of ears were applied at the anthesis stage under two levels of drought stress conditions i.e. progressive water supply (PWS) and rainfed drought treatment (RDT). Our results indicated that drought stress reduced the dry weight of leaves, sheaths and stems, as well as caused a significant yield reduction. High ploidy wheat exhibits a greater capacity to sustain higher grain yields when subjected to drought stress, primarily due to its stronger buffer capacity between source supply and sink demand. All wheat species with different ploidy levels had a certain degree of source limitation and sink restriction. During the domestication of wheat, the type of source and sink might be ploidy-dependent with progressive water deficit, but similar interactive relationships. The source-sink ratio of tetraploid species was the largest, while that of hexaploid species was the lowest.

Density- and moisture-dependent effects of arbuscular mycorrhizal fungus on drought acclimation in wheat.

Arbuscular mycorrhizal fungus (AMF) is widely viewed as an ecosystem engineer to help plants adapt to adverse environments. However, a majority of the previous studies regarding AMF's eco-physiological effects are mutually inconsistent. To clarify this fundamental issue, we conducted an experiment focused on wheat (Triticum aestivum L.) plants with or without AMF (Funneliformis mosseae) inoculation. Two water regimes (80% and 40% field water capacity, FWC80 (CK) and FWC40 (drought stress) and four planting densities (6 or 12 plants per pot as low densities, 24 or 48 plants per pot as high densities) were designed. AMF inoculation did not show significant effects on shoot biomass, grain yield, and water use efficiency (WUE) under the low densities, regardless of water regimes. However, under the high densities, AMF inoculation significantly decreased shoot biomass, grain yield and WUE in FWC80, while it significantly increased these parameters in FWC40, showing density and/or moisture-dependent effects of AMF on wheat performance. In FWC40, the relationships between reproductive biomass (y-axis) vs. vegetative biomass (x-axis) (R-V), and between grain biomass (y-axis, sink) vs. leaf biomass (x-axis, source) fell into a typical allometric pattern (α > 1, P < 0.001), and the AMF inoculation significantly increased the values of α. Yet in FWC80, they were in an isometric pattern (α ≈ 1, P < 0.001) and AMF addition had no significant effects on α. Similarly, AMF did not significantly change the isometric relationship between leaf biomass (i.e., metabolic rate) and shoot biomass (body size) in FWC80, while it significantly decreased the α of allometric relationship between both of them in FWC40 (α > 1, P < 0.001). We therefore, sketched a generalized model of R-V and sink-source relationships as affected by AMF, in which AMF inoculation might enhance the capabilities of sink acquisition and utilization under drought stress, while having no significant effect under the well watered conditions. Our findings demonstrate dual density- and moisture-dependent effects of AMF on plant development and provide new insights into current ecological applications of AMF as an ecosystem engineer.

Dual plastic film and straw mulching boosts wheat productivity and soil quality under the El Nino in semiarid Kenya.

The extreme climate events such as El Nino seriously threaten crop production and agro-ecological sustainability because of the aggravated environmental stresses worldwide, particularly in sub-Saharan Africa. To address this issue, we investigated the effects of dual plastic film and straw mulching in ridge-furrow (RF) system on wheat productivity, soil carbon and nitrogen stocks in a semiarid area in Kenya from 2015 to 2017. The experimental site represents a typical semiarid continental monsoon climate, and soil type is chromic vertisols. Field experiment with randomized block design consisted of six RF treatments as follows: 1) dual black plastic film and straw mulching (RFbS), 2) dual transparent plastic film and straw mulching (RFtS), 3) sole black plastic film mulching (RFb), 4) sole transparent plastic mulching RF (RFt), 5) sole straw mulching (RFS) and 6) no mulching (CK). The results indicated that seasonal dynamics of rainfall and air temperature fit in with the weather type of El Nino over four growing seasons. RFbS, RFtS, RFb and RFt significantly increased soil water storage (SWS), topsoil temperature, aboveground biomass, grain yield and water use efficiency across four growing seasons (p < 0.05) as compared with CK. Among all the treatments, RFbS and RFtS achieved the greatest SWS, AgB, grain yield and WUE, owing to improved soil hydro-thermal status in both treatments. Critically, RFbS and RFtS significantly improved soil organic carbon and total nitrogen, soil bulk density and the C:N ratio following four growing seasons, comparing with other treatments (p < 0.05). Besides, RFbS and RFtS gave the highest economic returns among all treatments. For the first time, we found that dual plastic film and straw mulching could serve as a sustainable land management to boost wheat productivity and improve soil quality under El Nino in semiarid areas of SSA.

Association of IL-6 -174G>C (rs1800795) polymorphism with cervical cancer susceptibility.

Interleukin-6 (IL-6) is a multifunctional cytokine that has been implicated in the etiology of cancer. Several case-control studies have been conducted to assess the association of IL-6 -174G>C (rs1800795) polymorphism with the risk of cervical cancer, yet with conflicting conclusions. To derive a more precise estimation of the relationship, we performed this meta-analysis updated to June 2018. A total of seven original publications were identified covering IL-6 -174G>C (rs1800795) polymorphism. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the relationship strengths. Statistically significant relationship was observed between IL-6 -174G>C polymorphism and cervical cancer risk (OR = 0.61, 95% CI: 0.40-0.94 for GG vs. CC, and OR = 0.77, 95% CI: 0.64-0.93 for G vs. C). Moreover, the significant association was found among Asians (OR = 0.46, 95% CI: 0.29-0.75 for GG vs. CC, and OR = 0.70, 95% CI: 0.57-0.89 for G vs. C); hospital-based subgroup (OR = 0.53, 95% CI: 0.38-0.72 for GG vs. CC, and OR = 0.73, 95% CI: 0.61-0.87 for G vs. C); and Hardy-Weinberg equilibrium ≤0.05 (OR = 0.56, 95% CI: 0.37-0.86 for GG vs. GC, and OR = 0.66, 95% CI: 0.47-0.93 for G vs. C). This meta-analysis showed the evidence that the IL-6 -174G>C polymorphism was a low-penetrance susceptibility variant for cervical cancer. Further large-scale case-control studies are needed to confirm these results.

XRCC1 polymorphisms and cervical cancer risk: an updated meta-analysis.

X-ray repair cross complementing 1 (XRCC1) plays a key role in DNA repair, genetic instability and tumorigenesis. A series of epidemiological studies have examined associations between XRCC1 polymorphisms and cervical cancer risk, but the findings remain inconclusive. We searched three electronic databases (MEDLINE, EMBASE and CNKI) for studies on the association between XRCC1 polymorphisms and cervical cancer risk published before June 2013. Pooled odds ratio (OR) and 95 % confidence interval (CI) were calculated to estimate risk associations. A total of 28 case-control studies from 15 publications with 5,890 cervical cancer cases and 7,626 controls were identified. There was a significant association between rs25487 and cervical cancer risk in Asian populations (Dominant model: OR = 1.25, 95 % CI =1.04-1.50, P = 0.051 for heterogeneity test). After excluding three studies deviated from Hardy-Weinberg equilibrium, we observed a significant association of rs1799782 with cervical cancer risk in all populations and in Asian populations (Recessive model: OR = 1.62 and 1.72, 95 % CI = 1.22-2.14 and 1.29-2.30, P = 0.090 and 0.266 for heterogeneity test, respectively). However, there was no significant association between rs25489 and cervical cancer risk. These findings were further confirmed by false-positive report probability analysis. No publication bias was found by using the funnel plot and Egger's test. This meta-analysis provides strongly statistical evidence for the association between rs1799782 and cervical cancer risk, as well as its association with rs25487 only in Asian populations. However, single large, well-designed prospective studies are needed to confirm these findings.

[Pathological study on effects of preservative-free 1% lidocaine on lens epithelial cells of patients with age-related cataract].

OBJECTIVE: To assess whether preservative-free 1% lidocaine is capable of destroying the LECs in age-related cataract (ARC) in order to provide scientific basis for pursuing safe and effective drugs to eliminate LECs in cataract surgery. METHODS: Lens anterior capsule (LAC) specimens were collected from 75 patients (82 eyes) with age-related cataract (ARC), including forty males (44 eyes) and thirty-five females (38 eyes). The age range was 41 - 85 years, the mean age was 67.97 years. There were 34 cortical cataracts, 22 nuclear cataracts and 26 subcapsular cataracts. Capsule specimens were divided into 4 groups: balanced salt solution (BSS) group I and group II (exposed to BSS for 1 minute), lidocaine group (exposed to preservative-free 1% lidocaine for 1 minute) and the control group. Specimens were stained with trypan blue and alizarin red. Photomicrographs of each capsule were taken to observe the viability of LECs and to count the number of necrosis LECs. The pathologic changes of LECs were evaluated by histological methods (11 LAC, 22 pieces) as well as transmission and scanning electron microscopes (5 LAC, 10 pieces). In the control and BSS group I (23 LAC), one half of each capsule specimen was used for the control group and the other half was used for BSS group I. In lidocaine group and BSS group II (43 LAC), one half of each capsule specimen was used for lidocaine group and the other half was used for BSS group II. RESULTS: The rate of necrosis LECs of the anterior capsules in the control group and BSS group I was (56.19 +/- 2.71)% and (57.23 +/- 1.98)%, respectively. The rate of necrosis LECs of the capsules in lidocaine group and BSS group II was (99.86 +/- 8.22)% and (57.64 +/- 7.00)%, respectively. Matching t-test showed that the rate of necrosis LECs in lidocaine group was greater than that in the BSS group II (t = 27.6781, P = 0.0000). There was no significant difference in the number of necrosis LECs between the control group and BSS group I (t = 2.0693, P = 0.0505). There was also no significant difference between males and females; between different cataract, types and between varying age groups (P > 0.05). After irrigated with lidocaine, LECs showed vacuoles and detached from the capsule, and many cavities appeared between the LECs and the capsule. The capsules of BSS and control group showed a normal layer of LECs attached to the capsule. Under transmission and scanning electron microscopes, in lidocaine group, the junction between the LECs and between the cells and the capsule were destroyed; many cells detached from the capsule and the rest arranged loosely. Some LECs dented and many vacuoles emerged, resulting in destruction of the cellular structures. CONCLUSION: Preservative-free 1% lidocaine may loose the junction between LECs and between the cells and the capsule, and also destroy cellular structures, resulting in degeneration and necrosis of the LECs.

[Histopathological study of the effect of preservative-free 1% lidocaine on rabbit lens epithelial cells].

OBJECTIVE: To assess whether preservative-free 1% lidocaine is capable of loosing the junction between the rabbit lens epithelial cells (LECs) and between the cells and capsules and is capable of destroying the LECs, in order to provide scientific basis for pursuing safe and effective drugs to eliminate LECs in cataract surgery and to prevent capsular pacification. METHODS: Lens capsule specimens were collected from 29 rabbits (58 eyes) and divided into 3 groups: balanced salt solution (BSS) group (exposed to BSS for 1 minute), lidocaine group (exposed to preservative-free 1% lidocaine for 1 minute) and the control group. Specimens were stained with trypan blue and alizarin red. Photomicrographs of each capsule were taken to observe the viability of LECs and count the number of dead LECs. The histopathologic changes of LECs treated with lidocaine were evaluated by histological method and transmission electron microscope. RESULTS: The rate of dead LECs of the anterior and the equatorial lens capsules in control group was (1.51 +/- 0.39)%, and (1.52 +/- 0.32)%, respectively. The rate of dead LECs of the anterior and the equatorial lens capsules irrigated with BSS was (1.78 +/- 0.50)% and (1.77 +/- 0.47)%. The rate of dead LECs of the anterior and the equatorial lens capsules irrigated with preservative-free 1% lidocaine was (13.01 +/- 4.67)% and (9.59 +/- 3.35)%, respectively. The nested design ANOVA showed that the rate of dead LECs in the lidocaine group was greater than that in the control group or BSS group (P < 0.05), There was no significant difference in the number of dead cells between the anterior lens capsules and the equatorial lens capsules. After irrigated with lidocaine, cavities appeared ibetween the LECs and the capsule, cells detached from the capsule and showed vacuoles. The capsules of control group and BSS group showed a normal layer of LECs attached to the capsule. Under transmission electron microscope, in the lidocaine group, the junction between LECs and between the cell and the capsule were destroyed, many cells detached from the capsule and the rest arranged loosely. Some LECs dentes, and many vacuoles emerged, resulting in destruction of the cellular frame. CONCLUSION: Preservative-free 1% lidocaine may loose the junction between the LECs and between the cells and capsules, resulting in degeneration and death of the LECs.