The effect of soil environmental factors on the yield and quality of Pueraria lobata.

Pueraria lobata is a typical medicinal and edible plant with great market value and demand, thus exploring the relationship between soil environmental factors and the yield and quality of Pueraria lobata is of great significance for its high-value cultivation. In this study, using the Guige 1 variety (Pueraria montana var. Thomsonii) selected by our research group as the material to compare the effects of five soil types, endophytes in three parts of Pueraria lobata and two fertilizers on its yield and quality. The results showed that the comprehensive evaluation effect of five soil types on the yield and quality of Guige 1 was as follow: red-yellow mixed soil (RYMS) > black loam soil (BLS) > sandy loam soil (SLS) > sandy loam soil waterlogging (SLSW) > yellow soil compaction soil (YSCS); the descending order of endophyte types and quantities is in BLS > RYMS > SLS > YSC > SLSW; applying General Compound Fertilizers (GCF) in RYMS is more suitable for the rapid expansion of Guige 1 than Organic-Slow-Release-Fertilizers (OSRF). The high potassium content in RYMS and high effective phosphorus content in BLS are positively correlated with the content of starch and isoflavone in Pueraria lobata. The conclusion is that the high potassium and available phosphorus content in RYMS and BLS, as well as the rich types and quantities of endophytic bacteria, are positively correlated with the yield and quality of Pueraria lobata. The research results have important guiding significance for the high-value cultivation of Pueraria lobata.

[Preparation of Mixed Metal Oxide/Carbon Composites and Its Adsorption Performance for Pb(â ¡)].

Layered double hydroxides, which can be synthesized from metal ions and their analogs, have abundant interlayer ions, surface functional groups, and adsorption characteristics that have been extensively studied. But the adsorption-desorption process may cause secondary pollution of the environment. In this study, the layered double hydroxides that adsorbed Congo red were converted into mixed metal oxide/carbon composites by a calcining carbonization method, and its adsorption performance for heavy metal ions Pb(Ⅱ) in aqueous solution was studied in detail. The results show that the prepared mixed metal oxide/carbon composites have a faster adsorption rate and higher adsorption capacity for Pb(Ⅱ). The adsorption capacity reached more than 150 mg·g-1 in 30 min, and increased with the content of Mg2+ introduced into the layered double metal hydroxide, reaching a maximum of 368 mg·g-1. The removal mechanism of Pb(Ⅱ) by mixed metal oxide/carbon composites was caused by the formation of insoluble Pb3(CO3) 2(OH) 2 on the surface. This research lays the foundation for the application of mixed metal oxide/carbon composites in the remediation of lead-containing soils.

Genome-wide identification and evolutionary analysis of RLKs involved in the response to aluminium stress in peanut.

BACKGROUND: As an important cash crop, the yield of peanut is influenced by soil acidification and pathogen infection. Receptor-like protein kinases play important roles in plant growth, development and stress responses. However, little is known about the number, location, structure, molecular phylogeny, and expression of RLKs in peanut, and no comprehensive analysis of RLKs in the Al stress response in peanuts have been reported. RESULTS: A total of 1311 AhRLKs were identified from the peanut genome. The AhLRR-RLKs and AhLecRLKs were further divided into 24 and 35 subfamilies, respectively. The AhRLKs were randomly distributed across all 20 chromosomes in the peanut. Among these AhRLKs, 9.53% and 61.78% originated from tandem duplications and segmental duplications, respectively. The ka/ks ratios of 96.97% (96/99) of tandem duplication gene pairs and 98.78% (646/654) of segmental duplication gene pairs were less than 1. Among the tested tandem duplication clusters, there were 28 gene conversion events. Moreover, all total of 90 Al-responsive AhRLKs were identified by mining transcriptome data, and they were divided into 7 groups. Most of the Al-responsive AhRLKs that clustered together had similar motifs and evolutionarily conserved structures. The gene expression patterns of these genes in different tissues were further analysed, and tissue-specifically expressed genes, including 14 root-specific Al-responsive AhRLKs were found. In addition, all 90 Al-responsive AhRLKs which were distributed unevenly in the subfamilies of AhRLKs, showed different expression patterns between the two peanut varieties (Al-sensitive and Al-tolerant) under Al stress. CONCLUSIONS: In this study, we analysed the RLK gene family in the peanut genome. Segmental duplication events were the main driving force for AhRLK evolution, and most AhRLKs subject to purifying selection. A total of 90 genes were identified as Al-responsive AhRLKs, and the classification, conserved motifs, structures, tissue expression patterns and predicted functions of Al-responsive AhRLKs were further analysed and discussed, revealing their putative roles. This study provides a better understanding of the structures and functions of AhRLKs and Al-responsive AhRLKs.

Transcriptome analysis reveals significant difference in gene expression and pathways between two peanut cultivars under Al stress.

Aluminum (Al) toxicity is an important factor in limiting peanut growth on acidic soil. The molecular mechanisms underlying peanut responses to Al stress are largely unknown. In this study, we performed transcriptome analysis of the root tips (0-1 cm) of peanut cultivar ZH2 (Al-sensitive) and 99-1507 (Al-tolerant) respectively. Root tips of peanuts that treated with 100 µM Al for 8 h and 24 h were analyzed by RNA-Seq, and a total of 8,587 differentially expressed genes (DEGs) were identified. GO and KEGG pathway analysis excavated a group of important Al-responsive genes related to organic acid transport, metal cation transport, transcription regulation and programmed cell death (PCD). These homologs were promising targets to modulate Al tolerance in peanuts. It was found that the rapid transcriptomic response to Al stress in 99-1507 helped to activate effective Al tolerance mechanisms. Protein and protein interaction analysis indicated that MAPK signal transduction played important roles in the early response to Al stress in peanuts. Moreover, weighted correlation network analysis (WGCNA) identified a predicted EIL (EIN3-like) gene with greatly increased expression as an Al-associated gene, and revealed a link between ethylene signaling transduction and Al resistance related genes in peanut, which suggested the enhanced signal transduction mediated the rapid transcriptomic responses. Our results revealed key pathways and genes associated with Al stress, and improved the understanding of Al response in peanut.

Remarkable active-site dependent H2O promoting effect in CO oxidation.

The interfacial sites of supported metal catalysts are often critical in determining their performance. Single-atom catalysts (SACs), with every atom contacted to the support, can maximize the number of interfacial sites. However, it is still an open question whether the single-atom sites possess similar catalytic properties to those of the interfacial sites of nanocatalysts. Herein, we report an active-site dependent catalytic performance on supported gold single atoms and nanoparticles (NPs), where CO oxidation on the single-atom sites is dramatically promoted by the presence of H2O whereas on NPs' interfacial sites the promoting effect is much weaker. The remarkable H2O promoting effect makes the Au SAC two orders of magnitude more active than the commercial three-way catalyst. Theoretical studies reveal that the dramatic promoting effect of water on SACs originates from their unique local atomic structure and electronic properties that facilitate an efficient reaction channel of CO + OH.

Mechanisms by which fibroblast growth factor 20 improves motor performance in a mouse model of Parkinson's disease.

Genome-wide studies have reported that Parkinson's disease is associated with abnormal expression of various growth factors. In this study, male C57BL/6 mice aged 10 weeks were used to establish Parkinson's disease models using an intraperitoneal injection of 60 mg/kg 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. 28 days later, 10 or 100 ng fibroblast growth factor 20 was injected intracerebroventricularly. The electrophysiological changes in the mouse hippocampus were recorded using a full-cell patch clamp. Expression of Kv4.2 in the substantia nigra was analyzed using a western blot assay. Serum malondialdehyde levels were analyzed by enzyme-linked immunosorbent assay. The motor coordination of mice was evaluated using the rotarod test. The results showed that fibroblast growth factor 20 decreased A-type potassium current in neurons of the substantia nigra, increased long-term potentiation amplitude in the hippocampus, and downregulated Kv4.2 expression. A high dose of fibroblast growth factor 20 reduced serum malondialdehyde levels and enhanced the motor coordination of mice. These findings confirm that fibroblast growth factor 20 has a therapeutic effect on the toxicity induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, and its mechanism of action is associated with the inhibition of A-type K+ currents and Kv4.2 expression. All animal procedures were approved by the Animal Care and Use Committee of Qilu Hospital of Shandong University, China in 2017 (approval No. KYLL-2017-0012).

Relationships among KRAS mutation status, expression of RAS pathway signaling molecules, and clinicopathological features and prognosis of patients with colorectal cancer.

BACKGROUND: The RAS/RAF/MEK/ERK and PI3K/AKT/mTOR signaling pathways all belong to mitogen-activated protein kinase (MAPK) signaling pathways, Mutations in any one of the upstream genes (such as the RAS gene or the BRAF gene) may be transmitted to the protein through transcription or translation, resulting in abnormal activation of the signaling pathway. This study investigated the relationship between the KRAS gene mutation and the clinicopathological features and prognosis of colorectal cancer (CRC), and the effect of KRAS mutations on its associated proteins in CRC, with an aim to clarify the cause of tumor progression and drug resistance caused by mutation of the KRAS gene. AIM: To investigate the KRAS gene and RAS pathway signaling molecules in CRC and to analyze their relationship with clinicopathological features and prognosis. METHODS: Colorectal cancer tissue specimens from 196 patients were analyzed for KRAS mutations using quantitative polymerase chain reaction and for KRAS, BRAF, MEK, and ERK protein expression levels using immunohistochemistry of tumor microarrays. To analyze differences of RAS pathway signaling molecule expression levels in different KRAS gene status, the relationships between these parameters and clinicopathological features, 4-year progression-free survival, and overall survival were analyzed by independent sample t test, Kaplan-Meier plots, and the log-rank test. Predictors of overall and disease-free survival were assessed using a Cox proportional hazards model. RESULTS: Of the 196 patients, 62 (32%) carried mutations in codon 12 (53/62) or codon 13 (9/62) in exon 2 of the KRAS gene. KRAS, BRAF, ERK, and MEK protein expression was detected in 71.4%, 78.8%, 64.3%, and 50.8% of CRC tissues, respectively. There were no significant differences between KRAS mutation status and KRAS, BRAF, MEK, or ERK protein levels. Positive expression of KRAS and ERK was associated with poor tumor differentiation, and KRAS expression was also associated with age < 56 years. MEK expression was significantly associated with distant metastasis (P < 0.05). The 4-year progression-free survival rate, but not overall survival rate, was significantly higher in patients with KRAS-negative tumors than in those with KRAS-positive tumors (P < 0.05), whereas BRAF, MEK, and ERK expression was unrelated to survival. Multivariate analysis showed that only the expression of KRAS protein was a risk factor for tumor recurrence (P < 0.05). No other clinicopathological factors correlated with KRAS, BRAF, MEK, or ERK expression. CONCLUSION: KRAS gene mutations do not affect downstream protein expression in CRC. KRAS protein is associated with poor tumor differentiation, older age, and a risk of tumor recurrence.

Non defect-stabilized thermally stable single-atom catalyst.

Surface-supported isolated atoms in single-atom catalysts (SACs) are usually stabilized by diverse defects. The fabrication of high-metal-loading and thermally stable SACs remains a formidable challenge due to the difficulty of creating high densities of underpinning stable defects. Here we report that isolated Pt atoms can be stabilized through a strong covalent metal-support interaction (CMSI) that is not associated with support defects, yielding a high-loading and thermally stable SAC by trapping either the already deposited Pt atoms or the PtO2 units vaporized from nanoparticles during high-temperature calcination. Experimental and computational modeling studies reveal that iron oxide reducibility is crucial to anchor isolated Pt atoms. The resulting high concentrations of single atoms enable specific activities far exceeding those of conventional nanoparticle catalysts. This non defect-stabilization strategy can be extended to non-reducible supports by simply doping with iron oxide, thus paving a new way for constructing high-loading SACs for diverse industrially important catalytic reactions.

Complete chloroplast genome sequence of Pueraria thomsonii, an important traditional Chinese medicine plant.

Pueraria thomsonii is a leguminous plant with high root yield and starch content. It is also a medicinal material in the Chinese pharmacopeia. However, the raw materials of P. thomsonii are often confused with some non-medicinal Pueraria plants. To enrich the genetic resources of P. thomsonii and guide its molecular identification, the complete chloroplast genome was sequenced and reported. The total genome of P. thomsonii is 153,434 bp in length. consisting of two inverted repeat regions (IRS, 25,640 bp each) separated by a large single-copy (LSC, 84,155 bp) and a small single-copy region (SSC, 17,999 bp). The overall GC content is 35.41%. It contains 130 genes, including 85 protein coding genes, 8 rRNA genes and 37 tRNA genes. Phylogenetic analysis showed that P. thomsonii could be distinguished from other plants and closely related to the legume Pachyrhizus erosus. This study enriches the genetic information of P. thomsonii and contributes to the screening of excellent germplasm.

Effect of Group Density on the Physiology and Aggressive Behavior of Male Brandt's Voles (Lasiopodomys brandtii).

Xin Dai, Ling-Yu Zhou, Jie-Xia Cao, Yan-Qi Zhang, Feng-Ping Yang, Ai-Qin Wang, Wan-Hong Wei, and Sheng-Mei Yang (2018) Population density is well known to influence animal physiology and behavior. How population density affects the aggressive behavior of the Brandt's vole (Lasiopodomys brandtii) is, however, little known. The aim of this study was to investigate the effect of group density on physiologic responses and aggressive behavior of male Brandt's voles and their potential underlying neuro-mechanism. The results show that increasing group density led to elevated serum corticosterone levels and increased spleen weight; it also induced more male-male aggressive behavior. By contrast, it had a negative effect on body growth and the weight of testis and epididymis. Aging also increased male-male aggressive behavior. Higher density reduced mRNA levels of tryptophan hydroxylase 2 (TPH2), 5-hydroxytryptamine receptor 1A (5HT1A), and 5-hydroxytryptamine receptor 1B (5HT1B) in the amygdala and the dorsal raphe nucleus (DRN). Our results demonstrate that higher population density can intensify stress reactions and male-male aggressive behavior in Brandt's voles at the price of inhibiting body growth and reproduction. Serotonergic systems in the amygdala and the DRN may take part in the control of aggressive behavior among male voles. Our results provide novel insights into the neuro-mechanism underlying the influence of population density on aggressive behavior in Brandt's vole, and imply that aggressive behavior may play an important role in the population fluctuation of the animal.

DNA methylation assay for colorectal carcinoma.

Colorectal carcinoma (CRC) is a common cause of morbidity and mortality worldwide. Two pathogenic pathways are involved in the development of adenoma to CRC. The first pathway involvesAPC/ß-catenin characterized by chromosomal instability resulting in the accumulation of mutations. The second pathway is characterized by lesions inDNA mismatch repair genes. Aberrant DNA methylation in selected gene promoters has emerged as a new epigenetic pathway in CRC development. CRC screening is the most efficient strategy to reduce death. Specific DNA methylation events occur in multistep carcinogenesis. Epigenetic gene silencing is a causative factor of CRC development. DNA methylations have been extensively examined in stool from CRC and precursor lesions. Many methylated genes have been described in CRC and adenoma, although no definite DNA methylation biomarkers panel has been established. Multiple DNA methylation biomarkers, including secreted frizzled-related protein 2, secreted frizzled-related protein 1, tissue factor pathway inhibitor 2, vimentin, and methylguanine DNA methyltransferase, have been further investigated, and observations have revealed that DNA methylation biomarkers exhibit with high sensitivity and specificity. These markers may also be used to diagnose CRC and adenoma in early stages. Real time polymerase chain reaction (qPCR) is sensitive, scalable, specific, reliable, time saving, and cost effective. Stool exfoliated markers provide advantages, including sensitivity and specificity. A stool qPCR methylation test may also be an enhanced tool for CRC and adenoma screening.

Effect of photoperiod and 6-methoxybenzoxazolinone (6-MBOA) on the reproduction of male Brandt's voles (Lasiopodomys brandtii).

Plant secondary metabolite 6-methoxybenzoxazolinone (6-MBOA) has been suggested to stimulate animal reproduction. 6-MBOA is detected in Leymus chinensis, a main diet of Brandt's vole (Lasiopodomys brandtii). We have previously reported a stimulatory effect of 6-MBOA on reproduction of male Brandt's voles under a short-day photoperiod. The goal of this study was to investigate the effect of 6-MBOA on reproductive physiology of male Brandt's voles under a long-day photoperiod and examine if 6-MBOA under this photoperiodic regime altered the reproductive status of male Brandt's voles differently than the short-day photoperiod. Under the long-day photoperiod, a high dose of 6-MBOA decreased KiSS-1 mRNA in the arcuate nucleus (ARC), and we also saw a decrease in circulating levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T). Steroidogenic acute regulatory protein (StAR) and cytochrome P45011a1 (CYP11a1) in the testes, and relative testis weight also decreased with 6-MBOA administration. Compared to the short-day photoperiod, animals under the long-day photoperiod exhibited increased body weight as well as all other reproductive parameters. Our results showed that 6-MBOA inhibited the reproduction of male Brandt's vole under a long-day photoperiod, a stark contrast from its stimulatory effects under a short-day photoperiod. The paradoxical effects of 6-MBOA suggest it may act as a partial agonist of melatonin. These results provide insight into the complex interactions between environmental factors such as photoperiod and diet in the control of Brandt's vole reproduction.

[Effects and Mechanisms of In-situ Cement Solidification/Stabilization on a Pb-, Zn-, and Cd-Contaminated Site at Baiyin, China].

In order to evaluate the effects and mechanism of in-situ cement solidification/stabilization (S/S) on heavy metal contaminated soils, leaching tests, speciation analysis, and microscopic analysis were conducted after cement treatment of a Pb, Zn, and Cd contaminated site in Baiyin, China. The leaching test results showed that cement could effectively stabilize Cd and Zn, which could reduce 99.5%-100% and 96.6%-98.8% of H2SO4-HNO3 extractable Cd and Zn, respectively. However, the leaching concentration of Pb was 2.6-5.8 times higher than that before 5% cement treatment. After adding 8% cement, H2SO4-HNO3 extractable Cd and Zn were reduced by 99.6%-100% and 94.4%-97.9% respectively. Similarly, the leaching concentration of Pb was 1.9-12.5 times higher than that before 8% cement treatment. The results of sequential extraction test proposed by the European Community Bureau of Reference (BCR) showed that cement could transform acid extractable Cd and Zn to residual form and transform reducible fractions of Pb to oxidizable and residual form, increasing the stability of heavy metals in soil. The microscopic analysis results showed that Pb2+, Zn2+, and Cd2+ could participate in the process of cement hydration and form silicate minerals and hydroxides. In conclusion, cement could be an effective S/S agent to remediate heavy metal contaminated soils, and site characteristics and environmental conditions should also be considered during the construction process.

Nitric Oxide Inhibits Al-Induced Programmed Cell Death in Root Tips of Peanut (Arachis hypogaea L.) by Affecting Physiological Properties of Antioxidants Systems and Cell Wall.

It has been reported that nitric oxide (NO) is a negative regulator of aluminum (Al)-induced programmed cell death (PCD) in peanut root tips. However, the inhibiting mechanism of NO on Al-induced PCD is unclear. In order to investigate the mechanism by which NO inhibits Al-induced PCD, the effects of co-treatment Al with the exogenous NO donor or the NO-specific scavenger on peanut root tips, the physiological properties of antioxidants systems and cell wall (CW) in root tip cells of NO inhibiting Al-induced PCD were studied with two peanut cultivars. The results showed that Al exposure induced endogenous NO accumulation, and endogenous NO burst increased antioxidant enzyme activity in response to Al stress. The addition of NO donor sodium nitroprusside (SNP) relieved Al-induced root elongation inhibition, cell death and Al adsorption in CW, as well as oxidative damage and ROS accumulation. Furthermore, co-treatment with the exogenous NO donor decreased MDA content, LOX activity and pectin methylesterase (PME) activity, increased xyloglucan endotransglucosylase (XET) activity and relative expression of the xyloglucan endotransglucosylase/hydrolase (XTH-32) gene. Taken together, exogenous NO alleviated Al-induced PCD by inhibiting Al adsorption in CW, enhancing antioxidant defense and reducing peroxidation of membrane lipids, alleviating the inhibition of Al on root elongation by maintaining the extensibility of CW, decreasing PME activity, and increasing XET activity and relative XTH-32 expression of CW.

Reproductive responses of male Brandt's voles (Lasiopodomys brandtii) to 6-methoxybenzoxazolinone (6-MBOA) under short photoperiod.

The plant secondary metabolite 6-methoxybenzoxazolinone (6-MBOA) can stimulate and enhance animal reproduction. This compound has been successfully detected in Leymus chinensis, which is the main diet of Brandt's voles. The aim of this study was to investigate the effect of different 6-MBOA doses on the reproductive physiology of male Brandt's voles under a short photoperiod. The results showed that 6-MBOA administration increased relative testis weight, regardless of the dose, but it had little effect on the body mass. Low and middle doses of 6-MBOA increased the concentrations of luteinizing hormone and testosterone in the serum and the mRNA levels of StAR and CYP11a1 in the testes. However, 6-MBOA did not cause any significant increase in the mRNA levels of KiSS-1, GPR54, and GnRH compared to those in the control group. The mRNA level of KiSS-1 in the arcuate nucleus (ARC) was higher than that in the anteroventral periventricular nucleus (AVPV). Collectively, our results demonstrated that the number of KiSS-1-expressing neurons located in the ARC was the highest, and that 6-MBOA, which might modulate the reproductive activity along the hypothalamic-pituitary-gonadal axis, had a dose-dependent stimulatory effect on the reproductive activity of Brandt's voles under a short photoperiod. Our study provided insights into the mechanism of 6-MBOA action and the factors influencing the onset of reproduction in Brandt's voles.

Serum/plasma microRNAs as biomarkers for HBV-related hepatocellular carcinoma in China.

MicroRNAs (miRNAs) are a group of small RNAs with a fundamental role in the regulation of gene expression. These RNAs have been shown to participate in various cellular and physiological processes, including cellular development, apoptosis, proliferation, and differentiation. Aberrant expression of several miRNAs was found to be involved in a large variety of neoplasms, including hepatocellular carcinoma (HCC). Previous studies have shown the existence of a large amount of stable miRNAs in human serum/plasma, which laid the foundation for studying the role of serum/plasma miRNAs in the diagnosis and prognosis of HCC. Here, we review the recent progress in research on serum miRNAs as biomarkers for HCC in Chinese patients.

Aluminum induces rapidly mitochondria-dependent programmed cell death in Al-sensitive peanut root tips.

BACKGROUND: Although many studies suggested that aluminum (Al) induced programmed cell death (PCD) in plants, the mechanism of Al-induced PCD and its effects in Al tolerance is limited. This study was to investigate the mechanism and type of Al induced PCD and the relationship between PCD and Al tolerance. RESULTS: In this study, two genotypes of peanut 99-1507 (Al tolerant) and ZH2 (Al sensitive) were used to investigate Al-induced PCD. Peanut root growth inhibition induced by AlCl3 was concentration and time-dependent in two peanut varieties. AlCl3 at 100 µM could induce rapidly peanut root tip PCD involved in DNA cleavage, typical apoptotic chromatin condensation staining with DAPI, apoptosis related gene Hrs203j expression and cytochrome C (Cyt c) release from mitochondria to cytosol. Caspase3-like protease was activated by Al; it was higher in ZH2 than in 99-1507. Al increased the opening of mitochondrial permeability transition pore (MPTP), decreased inner membrane potential (ΔΨm) of mitochondria. Compared with the control, Al stress increased O2•- and H2O2 production in mitochondria. Reactive oxygen species (ROS) burst was produced at Al treatment for 4 h. CONCLUSIONS: Al-induced PCD is earlier and faster in Al-sensitive peanut cultivar than in Al-tolerant cultivar. There is a negative relationship between PCD and Al resistance. Mitochondria- dependence PCD was induced by Al and ROS was involved in this process. The mechanism can be explained by the model of acceleration of senescence under Al stress.

Aluminum-induced programmed cell death promoted by AhSAG, a senescence-associated gene in Arachis hypoganea L.

Programmed cell death (PCD) is a foundational cellular process in plant development and elimination of damaged cells under environmental stresses. In this study, Al induced PCD in two peanut (Arachis hypoganea L.) cultivars Zhonghua 2 (Al-sensitive) and 99-1507 (Al-tolerant) using DNA ladder, TUNEL detection and electron microscopy. The concentration of Al-induced PCD was lower in Zhonghua 2 than in 99-1507. AhSAG, a senescence-associated gene was isolated from cDNA library of Al-stressed peanut with PCD. Open reading frame (ORF) of AhSAG was 474bp, encoding a SAG protein composed of 157 amino acids. Compared to the control and the antisense transgenic tobacco plants, the fast development and blossom of the sense transgenic plants happened to promote senescence. The ability of Al tolerance in sense transgenic tobacco was lower than in antisense transgenic tobacco according to root elongation and Al content analysis. The expression of AhSAG-GFP was higher in sense transgenic tobacco than in antisense transgenic tobacco. Altogether, these results indicated that there was a negative relationship between Al-induced PCD and Al-resistance in peanut, and the AhSAG could induce or promote the occurrence of PCD in plants.

One-step in situ fabrication of a granular semi-IPN hydrogel based on chitosan and gelatin for fast and efficient adsorption of Cu2+ ion.

The novel granular semi-IPN hydrogels were in situ prepared in an aqueous solution by the free-radical grafting and crosslinking reactions among chitosan (CTS), acrylic acid (AA), gelatin (GE) and N,N'-methylene-bis-acrylamide. The FTIR spectra and elemental analysis confirmed that the AA monomers were grafted onto CTS backbone, and the GE macromolecular chains interpenetrated through the CTS-g-PAA network. The hydrogels are granular, which are composed of numerous micro-spheres according to the scanning electron microscope observations. The gel strength, adsorption, reuse and recovery properties of the hydrogels for Cu(2+) ion were systematically investigated. The results indicate the hydrogel with 2 wt% GE has the highest adsorption capacity of 261.08 mg/g with the recovery ratio of 95.2%. And the incorporation of 10 wt% GE enhanced the storage modulus by 103.4% (ω=100 rad/s) and 115.1% (ω=0.1 rad/s), and the adsorption rate by 5.67%. Moreover, the adsorption capacity of the hydrogel is still as high as 153.9 mg/g, after five cycles of adsorption-desorption. It was found that the ion-exchange and complexation interactions between the functional groups (-COO(-) and -NH2) of the hydrogels and Cu(2+) ion are the predominant adsorption mechanisms.