Functional groups on wheat (Triticum aestivum) root surface affect aluminium transverse accumulation.

Plant root growth is inhibited markedly by aluminium (Al) even at micromolar concentration and Al is mainly accumulated in plant roots outer layer cell walls. But the underlying reason for this asymmetric transverse distribution is unknown. In this study, two wheat (Triticum aestivum L.) genotypes ET8 and ES8 differing in Al resistance were investigated by hydroculture. The Al-tolerant ET8 expressed a higher root elongation rate (RER) than Al-sensitive ES8 under Al stress. Morphological examination showed symptoms such as root surface ruptures were observed in ET8 and ES8, with ES8 being more obvious. The cation exchange capacity (CEC) values of root tips of ES8 under different Al concentrations are higher than those of ET8. The sensitive genotype ES8 accumulated more Al than ET8 in plant apical root tips as well as cell walls. Under 48 h Al exposure, the root cell wall pectin concentration was increased with a higher magnitude in ES8 than in ET8. The functional groups on ET8 and ES8 roots outer layer and inner cells were investigated by Fourier transform infrared spectrometry (FTIR) under Al stress. The FTIR spectra of selected examined areas showed that the characteristic absorption peaks were located at 1692, 2920, and 3380 cm-1. The outer layer cells had stronger peaks than inner cells at wavenumber 1680-1740 cm-1, indicating root outer layer cells contain more carboxyls in both ET8 and ES8. The results demonstrate that Al transverse distribution on plants apical root cross section is likely influenced by functional groups such as negatively charged carboxylic acid.

Electrical properties of plant root cell plasma membrane influence the alleviation of Al and Cu phytotoxicity by Ca and Mg cations.

Although it is known that cations such as calcium (Ca) and magnesium (Mg) can alleviate metal toxicity in plants, much uncertainty remains regarding the mechanisms by which this alleviation occurs. In this study, three plant species, cowpea (Vigna unguiculata. cv. White Caloona), soybean (Glycine max. cv. Bunya), and wheat (Triticum. cv. Axe), were used to examine growth in nutrient solutions containing a series of cations (Ca and Mg) and toxicants (Al and Cu). The addition of Ca and Mg increased Al3+ activities that induced 50% plant root elongation rate decline (EC50) from 4.0, 4.2, 0.34 to 31, 22, 9.4 for cowpea, soybean, wheat respectively. However, when expressed as the Al3+ activity at the root-cell plasma membrane (PM) surface, the addition of Ca and Mg increased Al sensitivity. In regression models, plant root elongation rate (RER) had higher R2 values with Al3+ activity at the PM than with Al3+ activity in the bulk solutions (0.60, 0.58, 0.93 for cowpea, soybean, wheat respectively). For Cu, the addition of Ca and Mg alleviated its phytotoxicity when expressed as the Cu2+ activity in the bulk-phase solutions for both cowpea and wheat. However, in soybean, the addition of Mg did not alter Cu toxicity when expressed as the Cu2+ bulk activity. Generally, the metal activity at the outer PM surface of the root cells is a better predictor for their phytotoxicity than the activity in bulk solution (R2=0.80, 0.80, 0.87 for cowpea, soybean, wheat respectively). These results supported the concept that the strength of alleviation of Ca and Mg cations depends on both the plant species and the toxicants that they alleviate. The different mechanisms should be fully considered in relevant assessments of trace metal toxicity in plants.

Understanding the delayed expression of Al resistance in signal grass (Urochloa decumbens).

BACKGROUND AND AIMS: Signal grass (Urochloa decumbens) is a widely used pasture grass in tropical and sub-tropical areas due to its high aluminiun (Al) resistance. However, the underlying mechanisms conferring this resistance are not clearly understood. METHODS: The Al concentrations of bulk root tissues and the intracellular compartment were examined, including the impact of a metabolic inhibitor, carbonyl cyanide m-chlorophenyl hydrazone (CCCP). Next, we examined changes in the properties of signal grass root tissues following exposure to toxic levels of Al, including the cell wall cation exchange capacity (CEC), degree of methylation and concentrations of cell wall fractions. KEY RESULTS: Although signal grass was highly resistant to Al, there was a delay of 24-48 h before the expression of this resistance. We found that this delay in the expression of Al resistance was not related to the total Al concentration in the bulk apical root tissues, nor was it related to changes in the Al bound to the cell wall. We also examined changes in other properties of the cell wall, including the CEC, degree of methylation and changes in the concentration of pectin, hemicellulose and cellulose. We noted that concentrations of intracellular Al decreased by approx. 50 % at the same time that the root elongation rate improved after 24-48 h. Using CCCP as a metabolic inhibitor, we found that the intracellular Al concentration increased approx. 14-fold and that the CCCP prevented the subsequent decrease in intracellular Al. CONCLUSIONS: Our results indicate that the delayed expression of Al resistance was not associated with the Al concentration in the bulk apical root tissues or bound to the cell wall, nor was it associated with changes in other properties of the cell wall. Rather, signal grass has an energy-dependent Al exclusion mechanism, and this mechanism requires 24-48 h to exclude Al from the intracellular compartment.

Examining a synchrotron-based approach for in situ analyses of Al speciation in plant roots.

Aluminium (Al) K- and L-edge X-ray absorption near-edge structure (XANES) has been used to examine Al speciation in minerals but it remains unclear whether it is suitable for in situ analyses of Al speciation within plants. The XANES analyses for nine standard compounds and root tissues from soybean (Glycine max), buckwheat (Fagopyrum tataricum), and Arabidopsis (Arabidopsis thaliana) were conducted in situ. It was found that K-edge XANES is suitable for differentiating between tetrahedral coordination (peak of 1566 eV) and octahedral coordination (peak of 1568 to 1571 eV) Al, but not suitable for separating Al binding to some of the common physiologically relevant compounds in plant tissues. The Al L-edge XANES, which is more sensitive to changes in the chemical environment, was then examined. However, the poorer detection limit for analyses prevented differentiation of the Al forms in the plant tissues because of their comparatively low Al concentration. Where forms of Al differ markedly, K-edge analyses are likely to be of value for the examination of Al speciation in plant tissues. However, the apparent inability of Al K-edge XANES to differentiate between some of the physiologically relevant forms of Al may potentially limit its application within plant tissues, as does the poorer sensitivity at the L-edge.

Defining appropriate methods for studying toxicities of trace metals in nutrient solutions.

The use of inappropriate experimental conditions for examining trace metal phytotoxicity results in data of questionable value. The present study aimed to identify suitable parameters for study of phytotoxic metals in nutrient solutions. First, the literature was reviewed to determine the concentration of six metals (Cd, Cu, Hg, Ni, Pb, and Zn) from solution of contaminated soils. Next, the effects of pH, P, Cl, NO3, and four Fe-chelators were investigated by using thermodynamic modelling and by examining changes in root elongation rate of soybean (Glycine max cv. Bunya). The literature review identified that the solution concentrations of metals in soils were low, ranging from (µM) 0.069-11Cd, 0.19-15.8 Cu, 0.000027-0.000079 Hg, 1.0-8.7 Ni, 0.004-0.55 Pb, and 0.4-36.3 Zn. For studies in nutrient solution, pH should generally be low given its effects on solubility and speciation, as should the P concentration due to the formation of insoluble phosphate salts. The concentrations of Cl, NO3, and various chelators also influence metal toxicity through alteration of metal speciation. The nutrient solutions used to study metal toxicity should consider environmentally-relevant conditions especially for metal concentrations, with concentrations of other components added at levels that do not substantially alter metal toxicity.

Factors associated with trait anger level of juvenile offenders in Hubei province: A binary logistic regression analysis.

The risk factors of high trait anger of juvenile offenders were explored through questionnaire study in a youth correctional facility of Hubei province, China. A total of 1090 juvenile offenders in Hubei province were investigated by self-compiled social-demographic questionnaire, Childhood Trauma Questionnaire (CTQ), and State-Trait Anger Expression Inventory-II (STAXI-II). The risk factors were analyzed by chi-square tests, correlation analysis, and binary logistic regression analysis with SPSS 19.0. A total of 1082 copies of valid questionnaires were collected. High trait anger group (n=316) was defined as those who scored in the upper 27th percentile of STAXI-II trait anger scale (TAS), and the rest were defined as low trait anger group (n=766). The risk factors associated with high level of trait anger included: childhood emotional abuse, childhood sexual abuse, step family, frequent drug abuse, and frequent internet using (P<0.05 or P<0.01). Birth sequence, number of sibling, ranking in the family, identity of the main care-taker, the education level of care-taker, educational style of care-taker, family income, relationship between parents, social atmosphere of local area, frequent drinking, and frequent smoking did not predict to high level of trait anger (P>0.05). It was suggested that traumatic experience in childhood and unhealthy life style may significantly increase the level of trait anger in adulthood. The risk factors of high trait anger and their effects should be taken into consideration seriously.

Factors Associated with Trait Anger Level of Juvenile Offenders in Hubei Province: A Binary Logistic Regression Analysis / 华中科技大学学报（医学）（英德文版）

The risk factors of high trait anger of juvenile offenders were explored through question naire study in a youth correctional facility of Hubei province,China.A total of 1090 juvenile offenders in Hubei province were investigated by self-compiled social-demographic questionnaire,Childhood Trauma Questionnaire (CTQ),and State-Trait Anger Expression Inventory-Ⅱ (STAXI-Ⅱ).The risk factors were analyzed by chi-square tests,correlation analysis,and binary logistic regression analysis with SPSS 19.0.A total of 1082 copies of valid questionnaires were collected.High trait anger group (n=316) was defined as those who scored in the upper 27th percentile of STAXI-Ⅱ trait anger scale (TAS),and the rest were defined as low trait anger group (n=766).The risk factors associated with high level of trait anger included:childhood emotional abuse,childhood sexual abuse,step family,frequent drug abuse,and frequent internet using (P＜0.05 or P＜0.01).Birth sequence,number of sibling,ranking in the family,identity of the main care-taker,the education level of care-taker,educational style of care-taker,family income,relationship between parents,social atmosphere of local area,frequent drinking,and frequent smoking did not predict to high level of trait anger (P＞0.05).It was suggested that traumatic experience in childhood and unhealthy life style may significantly increase the level of trait anger in adulthood.The risk factors of high trait anger and their effects should be taken into consideration seriously.

Association of ß-adrenergic receptor genes polymorphisms with incidence of subsequent cardiovascular events in Han Chinese patients with coronary artery disease.

BACKGROUND: Sequence variants in the ß-adrenergic receptor (ADRB) genes have a close relationship with the development of coronary artery disease (CAD) and the patient's prognosis. However, there is a lack of data on the role of the variants in ADRBs genes in Han Chinese patients with CAD. We aimed to investigate the association of genetic variants in the ADRB1 and ADRB2 genes with the incidence of major adverse cardiac event (MACE) in Han Chinese patients with CAD. METHODS: A total of 545 Han Chinese patients with CAD undergoing percutaneous coronary intervention (PCI) were recruited to the study and followed for one year. Three variant sites in ADRB1 (rs1801253) and ADRB2 (rs1042713 and rs1042714) were genotyped. The effect of the ADRB1 and ADRB2 genotypes on MACE within one year was assessed. RESULTS: There were 47 cases of MACE during follow-up. There was no significant difference in the incidence of MACE among patients carrying different genotypes of the three variants in ADRB1 and ADRB2 (Log-rank, all P > 0.05). Cox regression analysis showed no association between three variants in ADRB1 and ADRB2 genes and the incidence of MACE during one-year follow-up, the adjusted hazard ratios (95% confidence interval) for rs1801253, rs1042713 and rs1042714 were 1.05 (0.54-2.02), 1.24 (0.58-2.64) and 1.66 (0.81-3.42), respectively. CONCLUSION: Our data did not support a relationship between the three polymorphisms of ADRB1 (rs1801253) and ADRB2 (rs1042713 and rs1042714) genes and risk of subsequent cardiovascular events after PCI in Han Chinese patients with CAD.

Baseline LDL-C and Lp(a) elevations portend a high risk of coronary revascularization in patients after stent placement.

BACKGROUND AND AIM: Incidence of coronary restenosis after stent placement is high. Our study was going to investigate whether Lp(a) elevation was potential for predicting coronary restenosis and whether the effects of Lp(a) elevation on coronary restenosis were dependent on LDL-C level. METHODS AND RESULTS: Totally 832 participants eligible for stent placement were enrolled and followed up for monitoring clinical end points. Baseline characteristics were collected. According to the cut point of Lp(a), participants were divided into low Lp(a) group (Lp(a) < 30 mg/dL) and high Lp(a) group (Lp(a) ≥ 30 mg/dL). Furthermore, based on baseline LDL-C level, participants were divided into LDL-C < 1.8 mmol/L and ≥1.8 mmol/L subgroups. Clinical end points including major adverse cardiovascular events (MACE), cardiovascular death, nonfatal myocardial infarction, ischemic stroke, and coronary revascularization (CR) were compared. Patients in high Lp(a) groups more frequently presented with acute coronary syndrome and three vessel stenoses. In subgroup of LDL-C < 1.8 mmol/L, no significant differences of cardiovascular outcomes were found between low and high Lp(a) groups. While in the subgroup of LDL-C ≥ 1.8 mmol/L, incidences of MACE and CR were significantly higher in high Lp(a) group, and odds ratio for CR was 2.05. CONCLUSION: With baseline LDL-C and Lp(a) elevations, incidence of CR is significantly increased after stent placement.

Lack of association between lipoprotein(a) genetic variants and subsequent cardiovascular events in Chinese Han patients with coronary artery disease after percutaneous coronary intervention.

BACKGROUND: Elevated lipoprotein(a) [Lp(a)] levels predict cardiovascular events incidence in patients with coronary artery disease (CAD). Genetic variants in the rs3798220, rs10455872 and rs6415084 single-nucleotide polymorphisms (SNPs) in the Lp(a) gene (LPA) correlate with elevated Lp(a) levels, but whether these SNPs have prognostic value for CAD patients is unknown. The present study evaluated the association of LPA SNPs with incidence of subsequent cardiovascular events in CAD patients after percutaneous coronary intervention (PCI). METHODS: TaqMan SNP genotyping assays were performed to detect the rs6415084, rs3798220 and rs10455872 genotypes in 517 Chinese Han patients with CAD after PCI. We later assessed whether there was an association of these SNPs with incidence of major adverse cardiovascular events (MACE: cardiac death, nonfatal myocardial infarction, ischemic stroke and coronary revascularization). Serum lipid profiles were also determined using biochemical methods. RESULTS: Only the rs6415084 variant allele was associated with higher Lp(a) levels [41.3 (20.8, 74.6) vs. 18.6 (10.3, 40.9) mg/dl, p < 0.001]. During a 2-year follow-up period, 102 patients suffered MACE, and Cox regression analysis demonstrated that elevated Lp(a) (≥30 mg/dl) levels correlated with increased MACE (adjusted HR, 1.69; 95% CI 1.13-2.53), but there was no association between LPA genetic variants (rs6415084 and rs3798220) and MACE incidence (p > 0.05). CONCLUSIONS: Our data did not support a relationship between genetic LPA variants (rs6415084 and rs3798220) and subsequent cardiovascular events after PCI in Chinese Han CAD patients.

Irbesartan and emodin on myocardial remodeling in Goldblatt hypertensive rats.

OBJECTIVE: Interactions between the renin-angiotensin system and transforming growth factor-beta 1 (TGF-ß1) have been well documented. The aim was to explore the effect of irbesartan combining with emodin on myocardial remodeling in Goldblatt (2K-1C) hypertensive rats. METHODS: All 60 Sprague-Dawley rats were randomly divided into 5 groups as follows: the sham-clipped without any drugs; 2K-1C without any drugs; the 2K-1C with irbesartan (50 mg/kg/day); the 2K-1C with emodin (80 mg/Kg/day); and the 2K-1C with irbesartan and emodin together for the last 8 weeks of a 12-week period of study. The outcome measures included left ventricular mass index, TGF-ß1 and angiotensin II in the left ventricle, mRNA expression of TGF-ß1, and connective tissue growth factor (CTGF). RESULTS: Compared with 2K1C group, the 2K1C/irbesartan group and 2K-1C/emodin plus irbesartan group had significantly lower systolic blood pressure and local angiotensin II (P < 0.05). The left ventricular mass index in each of the 3 treatment groups was significantly lower than that in the 2K1C group, especially in the combined group. The mRNA/protein TGF-ß1 and the mRNA CTGF of 2K1C/irbesartan group, 2K1C/emodin group, and 2K-1C/emodin plus irbesartan group were significantly decreased compared with 2K-1C group (P < 0.05). CONCLUSIONS: Irbesartan or emodin or 2 drugs together can inhibit myocardial remodeling in renovascular hypertension rats probably by reducing TGF-ß1 and CTGF expression. The combination of irbesartan and emodin is better than single drug application.