Apple consumption affects cecal health by regulating 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12(S)-HETE) levels through modifying the microbiota in rats.

Apples are rich in many nutrients and functional components. However, the mechanism of the effect of fresh apple consumption on rats remains unclear. In the present study, fresh apples (10 g kg-1) were added to the diet of Wistar rats, and changes in the microbiota and metabolite content of the cecum were analyzed after 28 days of feeding, and changes in the 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12(S)-HETE) content and indicators related to inflammation, oxidative stress, and apoptosis were detected. Subsequently, a fecal microbiota transplantation (FMT) protocol was designed and carried out to verify the relationship between the microbiota and 12(S)-HETE, the cecal structure, and inflammatory factors. The results show that apple consumption significantly reduced the serum levels of alanine aminotransferase (ALT) and immunoglobulin G (IgG), altered the cecal histomorphology, and significantly upregulated the gene expression of claudin-1 and zonula occludens-1 (ZO-1), which encode tight junction proteins. Apple consumption also changed the structure of the cecal microbiota, increasing the abundance of some species (such as Shuttleworthia) and decreasing the abundance of others (such as Alphaproteobacteria). Metabolomic screening identified 64 significantly different metabolites. The FMT results showed that apple consumption reduced 12(S)-HETE metabolite levels in the cecal contents, improved the intestinal structure, and reduced the levels of proinflammatory factor expression by altering the cecal microbiota. In conclusion, this study provides further insight into the effects of apples on animals using rats as experimental animals. It provides basic data for future exploration of the mechanisms of the effect of apple consumption on humans.

Morphological and molecular characterization of the new aethaloid species Didymium yulii.

Five specimens, initially presumed to be Fuligo septica or Mucilago crustacea, were collected from Jilin Province and the Inner Mongolia Autonomous Region in China, but all five turned out to represent a new aethaloid species, Didymium yulii. This new species is characterized by pseudocapillitia without capillitia and an aethalioid fruiting body, features that are morphologically distinct from those of any other species of Didymium. To assess the phylogenetic relationships between D. yulii and other members of Didymium and in the Didymiaceae, sequences from two nonoverlapping targeted portions of nuc 18S rDNA (~450 bp and ~1050 bp) and translation elongation factor 1-alpha (tef1) were obtained and analyzed. The results indicate that D. yulii forms a single clade separate from other species of Didymium and the clade that contains M. crustacea, which strongly supports the identification of the five specimens as a new species.

Mechanism and Regulation of Silique Dehiscence, Which Affects Oil Seed Production.

Silique dehiscence is an important physiological process during natural growth that enables mature seeds to be released from plants, which then undergo reproduction and ensure the survival of future generations. In agricultural production, the time and degree of silique dehiscence affect the harvest time and processing of crops. Premature silique dehiscence leads to seeds being shed before harvest, resulting in substantial reductions to yields. Conversely, late silique dehiscence is not conducive to harvesting, and grain weight and oil content will be reduced due to the respiratory needs of seeds. In this paper, the mechanisms and regulation of silique dehiscence, and its application in agricultural production is reviewed.

Genome-wide identification of the NPR1-like gene family in Brassica napus and functional characterization of BnaNPR1 in resistance to Sclerotinia sclerotiorum.

KEY MESSAGE: The BnaNPR1-like gene family was identified in B. napus, and it was revealed that repression of BnaNPR1 significantly reduces resistance toS. sclerotiorum, intensifies ROS accumulation, and changes the expression of genes associated with SA and JA/ET signaling in response to this pathogen. The NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) and related NPR1-like genes play an important role in regulating plant defense. Oilseed rape (Brassica napus L.) is an important oilseed crop; however, little is known about the B. napus (Bna) NPR1-like gene family. Here, a total of 19 BnaNPR1-like genes were identified in the B. napus genome, and then named according to their respective best match in Arabidopsis thaliana (At), which led to the determination of B. napus homologs of every AtNPR1-like gene. Analysis of important protein domains and functional motifs indicated the conservation and variation among these homologs. Phylogenetic analysis of these BnaNPR1-like proteins and their Arabidopsis homologs revealed six distinct sub-clades, consequently indicating that their name classification totally conformed to their phylogenetic relationships. Further, B. napus transcriptomic data showed that the expression of three BnaNPR1s was significantly down-regulated in response to infection with Sclerotinia sclerotiorum, the most important pathogen of this crop, whereas BnaNPR2/3/4/5/6s did not show the expression differences in general. Further, we generated B. napus BnaNPR1-RNAi lines to interpret the effect of the down-regulated expression of BnaNPR1s on resistance to S. sclerotiorum. The results showed that BnaNPR1-RNAi significantly decreased this resistance. Further experiments revealed that BnaNPR1-RNAi intensified ROS production and changed defense responses in the interaction of plants with this pathogen. These results indicated that S. sclerotiorum might use BnaNPR1 to regulate specific physiological processes of B. napus, such as ROS production and SA defense response, for the infection.

BnaMPK6 is a determinant of quantitative disease resistance against Sclerotinia sclerotiorum in oilseed rape.

Sclerotinia sclerotiorum causes a devastating disease in oilseed rape (Brassica napus), resulting in major economic losses. Resistance response of B. napus against S. sclerotiorum exhibits a typical quantitative disease resistance (QDR) characteristic, but the molecular determinants of this QDR are largely unknown. In this study, we isolated a B. napus mitogen-activated protein kinase gene, BnaMPK6, and found that BnaMPK6 expression is highly responsive to infection by S. sclerotiorum and treatment with salicylic acid (SA) or jasmonic acid (JA). Moreover, overexpression (OE) of BnaMPK6 significantly enhances resistance to S. sclerotiorum, whereas RNAi in BnaMPK6 significantly reduces this resistance. These results showed that BnaMPK6 plays an important role in defense to S. sclerotiorum. Furthermore, expression of defense genes associated with SA-, JA- and ethylene (ET)-mediated signaling was investigated in BnaMPK6-RNAi, WT and BnaMPK6-OE plants after S. sclerotiorum infection, and consequently, it was indicated that the activation of ET signaling by BnaMPK6 may play a role in the defense. Further, four BnaMPK6-encoding homologous loci were mapped in the B. napus genome. Using the allele analysis and expression analysis on the four loci, we demonstrated that the locus BnaA03.MPK6 makes an important contribution to QDR against S. sclerotiorum. Our data indicated that BnaMPK6 is a previously unknown determinant of QDR against S. sclerotiorum in B. napus.

BnaMPK3 Is a Key Regulator of Defense Responses to the Devastating Plant Pathogen Sclerotinia sclerotiorum in Oilseed Rape.

The disease caused by Sclerotinia sclerotiorum has traditionally been difficult to control, resulting in tremendous economic losses in oilseed rape (Brassica napus). Identification of important genes in the defense responses is critical for molecular breeding, an important strategy for controlling the disease. Here, we report that a B. napus mitogen-activated protein kinase gene, BnaMPK3, plays an important role in the defense against S. sclerotiorum in oilseed rape. BnaMPK3 is highly expressed in the stems, flowers and leaves, and its product is localized in the nucleus. Furthermore, BnaMPK3 is highly responsive to infection by S. sclerotiorum and treatment with jasmonic acid (JA) or the biosynthesis precursor of ethylene (ET), but not to treatment with salicylic acid (SA) or abscisic acid. Moreover, overexpression (OE) of BnaMPK3 in B. napus and Nicotiana benthamiana results in significantly enhanced resistance to S. sclerotiorum, whereas resistance is diminished in RNAi transgenic plants. After S. sclerotiorum infection, defense responses associated with ET, JA, and SA signaling are intensified in the BnaMPK3-OE plants but weakened in the BnaMPK3-RNAi plants when compared to those in the wild type plants; by contrast the level of both H2O2 accumulation and cell death exhibits a reverse pattern. The candidate gene association analyses show that the BnaMPK3-encoding BnaA06g18440D locus is a cause of variation in the resistance to S. sclerotiorum in natural B. napus population. These results suggest that BnaMPK3 is a key regulator of multiple defense responses to S. sclerotiorum, which may guide the resistance improvement of oilseed rape and related economic crops.

Study Physicochemical Characteristics of Spring Honeys from Yunnan with the Application of HPLC-RI and FAAS.

Many special honeys are produced in Yunnan province due to abundant nectar plants and minerals resources provided by the unique natural environment in this area. In this work, the physicochemical property of three honeys (Viciacracca honey, Hevea brasiliensis honey and Punica granatum honey) from Yunnan was studied. The results showed that in different honeys the moisture content, electrical conductivity and dynamic viscosity were different. The sugar contents of each honey were determined with HPLC-RI. The results showed that P. granatum honey had the most abundant glucose [35.62 g·(100 g)-1], and H. brasiliensis honey had the most abundant fructose [41.03 g·(100 g)-1]. Thirteen different mineral elements in three honey species were determined with FAAS. It was found that the mineral level was from 167.24 mg·kg-1 in P. granatum honey to 437.34 mg·kg-1 in H. brasiliensis. Based on the mineral content the three honey species were classified following the principal component analysis (PCA) method. The result showed that Cu, Zn and Na could act as the elemental markers for V. cracca honey, while Mg, K, Ca, As and Cd act as the elemental markers for H. brasiliensis honey, and Fe, Mn, Ni, and Cr act as the elemental markers for P. granatum honey. This study reported the physicochemical property of three special Yunnan honeys, which could help the further study and utilization of these honeys.

[Melissopalynology and trophic niche of Apis cerana ceraca and Apis mellifera ligustica in Yunnan Province of Southwest China].

In 2010 and 2011, the honey samples of Apis cerana cerana and A. mellifera ligustica were collected from Kunming and Mengzi of Yunnan Province, respectively, aimed to analyze the melissopalynology and tropic niche of the two bee species. The absolute pollen concentration of the honey of A. cerana cerana was 1.55 x 10(4) ind x g(-1), being significantly higher than that (1.01 x 10(4) ind x g(-1)) of A. mellifera ligustica, and the number of nectar plant species collected by A. cerana cerana was 12.9, also significantly higher than that (7.7) collected by A. mellifera ligustica, indicating that A. cerana cerana could utilize more nectar plants, while A. mellifera ligustica had stronger selectivity to the nectar plants. The trophic niche breadth of A. cerana cerana was 0.35, which was significantly higher than that (0.23) of A. mellifera ligustica. The trophic niche overlap index between the two bee species was 0.71, and the interspecific competition index was 0.93, suggesting that the food competition between A. cerana cerana and A. mellifera ligustica was fierce.

MAPKs regulate root growth by influencing auxin signaling and cell cycle-related gene expression in cadmium-stressed rice.

This work aims to analyze the relationship between root growth, mitogen-activated protein kinase (MAPK), auxin signaling, and cell cycle-related gene expression in cadmium (Cd)-stressed rice. The role of MAPKs in auxin signal modification and cell cycle-related gene expression during root growth was investigated by disrupting MAPK signaling using the MAPKK inhibitor PD98059 (PD). Treatment with Cd caused a significant accumulation of Cd in the roots. A Cd-specific probe showed that Cd is mainly localized in the meristematic zone and vascular tissues. Perturbation of MAPK signaling using PD significantly suppressed root system growth under Cd stress. The transcription of six MAPK genes was inhibited by Cd compared to the control. Detection using DR5-GUS transgenic rice showed that the intensity and distribution pattern of GUS staining was similar in roots treated with PD or Cd, whereas in Cd plus PD-treated roots, the GUS staining pattern was similar to that of the control, which indicates a close association of MAPK signaling with auxin homeostasis under control and Cd stress conditions. The expression of most key genes of auxin signaling, including OsYUCCA, OsPIN, OsARF, and OsIAA, and of most cell cycle-related genes, was negatively regulated by MAPKs under Cd stress. These results suggest that the MAPK pathway plays specific roles in auxin signal transduction and in the control of the cell cycle in response to Cd stress. Altogether, MAPKs take part in the regulation of root growth via auxin signal variation and the modified expression of cell cycle-related genes in Cd-stressed rice. A working model for the function of MAPKs in rice root systems grown under Cd stress is proposed.

Hydrogen peroxide-mediated growth of the root system occurs via auxin signaling modification and variations in the expression of cell-cycle genes in rice seedlings exposed to cadmium stress.

The link between root growth, H2O2, auxin signaling, and the cell cycle in cadmium (Cd)-stressed rice (Oryza sativa L. cv. Zhonghua No. 11) was analyzed in this study. Exposure to Cd induced a significant accumulation of Cd, but caused a decrease in zinc (Zn) content which resulted from the decreased expression of OsHMA9 and OsZIP. Analysis using a Cd-specific probe showed that Cd was mainly localized in the meristematic zone and vascular tissues. Formation and elongation of the root system were significantly promoted by 3-amino-1,2,4-triazole (AT), but were markedly inhibited by N,N'-dimethylthiourea (DMTU) under Cd stress. The effect of H2O2 on Cd-stressed root growth was further confirmed by examining a gain-of-function rice mutant (carrying catalase1 and glutathione-S-transferase) in the presence or absence of diphenylene iodonium. DR5-GUS staining revealed close associations between H2O2 and the concentration and distribution of auxin. H2O2 affected the expression of key genes, including OsYUCCA, OsPIN, OsARF, and OsIAA, in the auxin signaling pathway in Cd-treated plants. These results suggest that H2O2 functions upstream of the auxin signaling pathway. Furthermore, H2O2 modified the expression of cell-cycle genes in Cd-treated roots. The effects of H2O2 on root system growth are therefore linked to auxin signal modification and to variations in the expression of cell-cycle genes in Cd-stressed rice. A working model for the effects of H2O2 on Cd-stressed root system growth is thus proposed and discussed in this paper.

Overexpression of Hsp90 from grass carp (Ctenopharyngodon idella) increases thermal protection against heat stress.

With homologous DNA probes, we had screened a grass carp heat shock protein 90 gene (CiHsp90). The full sequence of CiHsp90 cDNA was 2793 bp, which could code a 798 amino acids peptide. The phylogenetic analysis demonstrated that CiHsp90 shared the high homology with Zebrafish Grp94. Quantitative RT-PCR analysis showed that CiHsp90 was ubiquitously expressed at lower levels in all detected tissues and up-regulated after heat shock at 34 °C or cold stress at 4 °C. To understand the function of CiHsp90 involving in thermal protection, an expression vector containing coding region cDNA was expressed in E. coli BL21 (DE3) plysS. Upon transfer from 37 °C to 42 °C, these cells that accumulated CiHsp90 peptides displayed greater thermoresistance than the control cells. While incubated at 4°C for different periods, it could also improve the cell viability. After transient transfected recombinant plasmid pcDNA3.1/CiHsp90 into mouse myeloma cell line SP2/0, we found that CiHsp90 could contribute to protecting cells against both thermal and cold extremes. On the contrary, the mutant construct ΔN-CiHsp90 (256-798aa) could abolish the protection activity both in prokaryotic cells and eukaryotic cells. Additionally, both CiHsp90 and ΔN-CiHsp90 peptides could reduce the level of citrate synthase aggregation at the high temperature.

Removal of genotoxicity in chlorinated secondary effluent of a domestic wastewater treatment plant during dechlorination.

PURPOSE: Dechlorination with tetravalent sulfur is widely used in wastewater treatment processes after chlorination. Dechlorination can remove certain genotoxic disinfection by-products (DBPs). However, the reactions occurring during dechlorination of chlorinated secondary effluent and their genotoxic chemicals are still very complex, and the related genotoxicity changes remain unknown. Therefore, the effects of dechlorination on genotoxicity in secondary effluent and its fractions and typical genotoxic chemical after chlorination were evaluated. METHODS: The dissolved organic matter in the secondary effluent sample was separated into four fractions with XAD-8 resin. Genotoxicity of secondary effluent and its fractions was evaluated by SOS/umu test, an ISO standard method. The concentration of typical genotoxic chemical named ofloxacin was determined by liquid chromatography with a mass spectrometer and a fluorescence detector. RESULTS: Dechlorination with the addition of Na(2)SO(3) notably decreased the genotoxicity in the chlorinated secondary effluent, especially in the presence of high ammonia nitrogen concentration in the sample before chlorination. The Na(2)SO(3) addition significantly decreased the genotoxicity of the secondary effluent and its genotoxic ofloxacin prior to chlorination. The genotoxicity in the fractions containing hydrophobic acids (HOA) increased after chlorination, while addition of Na(2)SO(3) decreased the genotoxicity induced by chlorination. Tryptophan found in HOA exhibited genotoxicity after chlorination, while dechlorination decreased the genotoxicity in chlorinated tryptophan induced by DBPs. CONCLUSIONS: Dechlorination was found to decrease the genotoxicity of chlorinated secondary effluent. The decrease was associated with the reduction of genotoxicity in genotoxic chemicals in secondary effluent prior to chlorination and DBPs.

Reduced effect of bromide on the genotoxicity in secondary effluent of a municipal wastewater treatment plant during chlorination.

Chlorination of wastewater can form genotoxic, mutagenic, and/or carcinogenic disinfection byproduct (DBPs). In this study, the effect of bromide on genotoxicity in secondary effluent of a municipal wastewater treatment plant during chlorination was evaluated by the SOS/umu test. The presence of bromide notably decreased the genotoxicity in secondary effluent during chlorination, especially under conditions of high ammonia concentration. Bromide significantly decreased the concentration of ofloxacin, a genotoxic chemical in secondary effluent, during chlorination with high concentration of ammonia, while genotoxic DBPs formation of humic acid and aromatic amino acids associated with bromide limitedly contributed to the changes of genotoxicity in secondary effluent under the conditions of this study. By fractionating dissolved organic matter (DOM) in the secondary effluent into different fractions, the fractions containing hydrophilic substances (HIS) and hydrophobic acids (HOA) contributed to the decrease in genotoxicity induced by bromide. Chlorination of HOA without bromide increased genotoxicity, while the addition of bromide decreased genotoxicity.

Improvement in fruiting body yield by introduction of the Ampullaria crossean multi-functional cellulase gene into Volvariella volvacea.

The multi-functional cellulase gene, mfc, from Ampullaria crossean was transformed into Volvariella volvacea by PEG-mediated protoplast transformation to improve the biological efficiency and fruiting body yield. PCR and Southern blotting indicated that mfc was integrated into the genomes of four transformants. In laboratory and large scale cultivation experiments, the average biological efficiency of the transformants was 18.39+/-1.27% and 27.84+/-3.21%, respectively, considerably higher than the corresponding values for untransformed controls of 12.69+/-1.31% and 20.63+/-2.59%. This is the first report of an improvement in biological efficiency and fruiting body yield of V. volvacea through transgenesis.

Different responses of plant growth and antioxidant system to the combination of cadmium and heat stress in transgenic and non-transgenic rice.

A comparative study of just cadmium (Cd) or heat and their combination treatments on some physiological parameters and the antioxidant systems in transgenic rice (Oryza sativa L. cv. Zhonghua No.11) carrying glutathione-S-transferase (GST, EC. 2.5.1.18) and catalase1 (CAT1, EC. 1.11.1.6) and non-transgenics was conducted. The results revealed improved resistance in the transgenics to Cd and the combined Cd and heat stress than non-transgenics. Data showed that the activities of CAT, GST, superoxide dismutase (EC.1.15.1.1) and all components of the ascorbate-glutathione cycle measured in the stressed transgenics shoots are significantly different from those of non-transgenics. Results indicated that co-expression of GST and CAT1 had an important effect on the antioxidant system, in particular, the whole ascorbate-glutathione cycle. The less oxidative damage induced by Cd and the stress combination in the transgenics resulted not only from the GST and CAT1 transgene but also from the coordination of the whole ascorbate-glutathione cycle.

[Transgenic rice breeding for abiotic stress tolerance--present and future].

Environmental stresses and the continuing deterioration of arable land, along with an explosive increase in world population, pose serious threats to global agricultural production and food security. Improving the tolerance of the major crop plants to abiotic stresses has been a main goal in agriculture for a long time. As rice is considered one of the major crops, the development of new cultivars with enhanced abiotic stress-tolerance will undoubtedly have an important effect on global food production. The transgenic approach offers an attractive alternative to conventional techniques for the genetic improvement of rice cultivars. In recent years, an array of stress-related genes has already been transferred to rice to improve its resistance against abiotic stresses. Many transgenic rice plants with enhanced abiotic stress-tolerance have been obtained. This article focuses on the progress in the study of abiotic stress tolerance in transgenic rice breeding.

[Transferring the Suaeda salsa glutathione S-transferase and catalase genes enhances low temperature stress resistance in transgenic rice seedlings].

The GST (glutathione S-transferase) and GST+CAT1 (catalase 1) of Suaeda salsa were introduced into a low temperature-sensitive rice cultivar (Oryza sativa cv. Zhonghua No.11) by Agrobacterium tumefaciens-mediated transformation under the control of cauliflower mosaic virus (CaMV) 35S promoter, and the transformed calli and plantlets were screened on Murashige and Skoog (1962) medium supplemented with hygromycin 25 microg/mL and cefotaxime 300 microg/mL. The putative primary transformants (T(0) generation) were acclimatized at 26 degrees C /22 degrees C in a greenhouse for 7 d, and then transplanted to the field, where they grew up to maturity under outdoor conditions. 25 and 14 independent transgenic lines of T(1) generation carrying the GST and GST+CAT1 genes, respectively, were identified by PCR amplification. Transgene expression was monitored by RNA-blot hybridization using total RNA samples from leaf tissues. To investigate whether expressing the Suaeda salsa GST and GST+CAT1 in transgenic rice increased low temperature stress tolerance, the T(4) 14-day-old transgenic and non-transgenic rice seedlings were transferred to a low temperature (day 7 degrees C/night 4 degrees C) growth chamber for 3-6 d. The experimental data showed that expressing the Suaeda salsa GST and GST+CAT1 enhanced low temperature stress resistance in transgenic rice seedlings. When treated with low temperature, both GST and CAT activity increased in the transformants with the time of temperature treatment. These transgenic rice plant seedlings exhibited a higher level of photosynthetic capacity than those of the non-transgenic control seedlings under low temperature treatment. Whereas, there were lower H(2)O(2) and MDA (malondialdehyde) content, and relative electrolyte leakage through the plasma membrane was also lower in transgenic rice seedlings than in the parent line under low temperature condition. The results also indicated that GST+CAT1 co-expression conferred greater level of low temperature stress tolerance to the transformed rice plants compared to the single GST transformed plants.