Phytoene synthase (Psy), a critical enzyme in the carotenoid biosynthetic pathway, demonstrated high association with the yellow pigment (YP) content in wheat grain. Characterization of Psy genes and the development of functional markers for them are of importance for marker-assisted selection in wheat breeding. In this study, the full-length genomic DNA sequence of a Psy gene (Psy-A1) located on chromosome 7A, was characterized by in silico cloning and experimental validation. The cloned Psy-A1 comprises six exons and five introns, 4,175 bp in total, and an ORF of 1,284 bp. A co-dominant marker, YP7A, was developed based on polymorphisms of two haplotypes of Psy-A1, yielding 194 and 231-bp fragments in cultivars with high and low YP content, respectively. The marker YP7A was mapped on chromosome 7AL using an RIL population from cross PH82-2/Neixing 188, and a set of Chinese Spring nullisomic-tetrasomic lines and ditelosomic line 7AS. Psy-A1, co-segregating with the STS marker YP7A, was linked to SSR marker Xwmc809 on chromosome 7AL with a genetic distance of 5.8 cM, and explained 20-28% of the phenotypic variance for YP content across three environments. A total of 217 Chinese wheat cultivars and advanced lines were used to validate the association between the polymorphic band pattern and grain YP content. The results showed that the functional marker YP7A was closely related to grain YP content and, therefore, could be used in wheat breeding programs targeting of YP content for various wheat-based products.

A ratio of 75/25 NH4+ -N/NO3- -N increased dry weight, N accumulation and grain yield of 'Nanguang' by 30, 36 and 21 %, respectively, but no effect was found in 'Elio' when compared with those of 100/0 NH4+ -N/NO3- -N. Uptake experiments with 15N-NH4+ showed that NO3- increased NH4+ uptake efficiency in 'Nanguang' by increasing Vmax (14 %), but there was no effect on Km. This indicated that partial replacement of NH4+ by NO3- could increase the number of the ammonium transporters but did not affect the affinity of the transporters for NH4+. Real-time PCR showed that expression of OsAMT1s in 'Nanguang' was improved by PNN, while that in 'Elio' did not change, which is in accordance with the differing responses of these two cultivars to PNN. Conclusions Increased NUE by PNN can be attributed to improved N uptake. The rice cultivar with a higher NUE has a more positive response to PNN than that with a low NUE, suggesting that there might be a relationship between PNN and NUE.

Two main antifungal metabolites resistomycin and tetracenomycin D were isolated and purified from a termite-associated Streptomyces canus BYB02 by column chromatography. The structures of isolated compounds were determined on the basis of extensive spectroscopic analysis. Resistomycin possessed strong activities against mycelial growth of Valsa mali (IC(50) = 1.1 μg/mL) and Magnaporthe grisea (IC(50) = 3.8 μg/mL), which were comparable to those of referenced cycloheximide, with IC(50) values of 2.3 and 0.3 μg/mL, respectively. A further spore germination test showed that resistomycin exhibited potent reduction in spore germination for M. grisea , with an IC(50) value of 5.55 μg/mL. Finally, the in vivo antifungal activity experiment showed that resistomycin possessed significant preventive efficacy against rice blast, which was more potent than that of referenced carbendazim, with control efficacies of 66.8 and 58.7%, respectively. The present results suggest that resistomycin has potential to be used as a fungicide.

A comparative slaughter trial was conducted to estimate the trace element concentrations and distributions in the main body tissues and the net requirements for maintenance and growth of Dorper × Hu crossbred lambs. Thirty-five lambs of each gender (19.2 ± 0.36 kg initial BW) were used. Seven lambs of each gender were randomly chosen and slaughtered at approximately 20 kg BW as the baseline group for measuring initial body composition. Another 7 lambs of each gender were also randomly chosen and offered a pelleted mixed diet for ad libitum intake and slaughtered at approximately 28 kg BW. The remaining 21 sheep of each gender were randomly divided into 3 groups with 7 sheep each and assigned to ad libitum or 40 or 70% of ad libitum intake of a pelleted mixed diet (42:58 concentrate:roughage, DM basis). The 3 groups of each gender were slaughtered when the sheep fed ad libitum reached approximately 35 kg BW. Empty body (head + feet, hide, viscera + blood, and carcass) trace element contents were determined after slaughter. The results showed that the trace elements were mainly distributed in viscera (blood included), except for Zn, which was mainly distributed in the muscle and bone tissues. The net requirements were calculated using the comparative slaughter technique. For males and females, the daily net trace element requirements for maintenance were 356.1 and 164.1 μg Fe, 4.3 and 3.4 μg Mn, 42.0 and 29.8 μg Cu, and 83.5 and 102.0 μg Zn per kilogram empty body weight (EBW), respectively. Net requirements for growth decreased from 65.67 to 57.27 mg Fe, 0.35 to 0.25 mg Mn, and 3.45 to 2.82 mg Cu and increased from 26.36 to 26.65 mg Zn per kilogram EBW gain (EBWG) for males. Net requirements for growth decreased from 30.66 to 22.14 mg Fe, 0.43 to 0.32 mg Mn, 2.86 to 2.18 mg Cu, and 27.71 to 25.83 mg Zn per kilogram EBWG for females from 20 to 35 kg BW. This study indicated that the net trace element requirements for Dorper × Hu crossbred lambs may be different from those of purebred or other genotypes, and more data are needed for sheep in general.

In the proceeding of screening new bioactive natural products, the ethyl acetate extract of the fermentation broth of Fusarium proliferatum ZS07, a fungus residing in the gut of long-horned grasshoppers (Tettigonia chinensis), was found possessing selective phytotoxic activity against the radicle growth of Amaranthus retroflexus L. Bioactivity-guided fractionation lead to the isolation of six fungal metabolites 1-6, including a new polyketide derivate O-methylated SMA93 (2) and five known compounds SMA93 (1), rhodolamprometrin (3), radicinin (4), dehydroallogibberic acid (5), and 3-methyl-6,8-dihydroxyisocoumarin (6). Their structures were identified on the basis of spectroscopic analysis and by comparison of the corresponding data to those reported in the literature previously. Phytotoxic effects of the four isolated compounds 1-4 on the radicle growth of A. retroflexus L. seeds were investigated under laboratory conditions, and compounds 2 and 4 showed good phytotoxic activity in the concentration of 100 μg/mL, with the inhibition rates of 83.0 and 65.2%, respectively. Furthermore, the antibacterial activity of compounds 1-5 were evaluated against selected bacteria. Compounds 1-3 were found to possess potent antibacterial activity against Bacillus subtilis (ATCC 6633), with the minimum inhibitory concentration (MIC) values of 3.13-12.50 μg/mL, while Escherichia coli (ATCC 8739) and Salmonella typhimurium [CMCC(B) 50115] were not susceptible. These results suggest that the new polyketide derivate 2 and known compounds 1, 3, and 4 have potential to be used as biocontrol agents in agriculture.

No abstract

fungal bioremediation is a promising approach to remove heavy-metal from contaminated water. present study examined the ability of an earthworm gut fungus Trichoderma brevicompactum QYCD-6 to tolerate and remove both individual and multi-metals. the minimum inhibitory concentration (MIC) of heavy metals [Cu(II), Cr(VI), Cd(II) and Zn(II)] against the fungus was ranged 150-200 mg L −1 on composite medium, and MIC of Pb(II) was the highest with 1600 mg L −1 on potato dextrose (pD) medium. The Pb(II) presented the highest metal removal rate (97.5%) which mostly dependent on bioaccumulation with 80.0%, and synchronized with max biomass (6.13 g L −1) in PD medium. However, on the composite medium, the highest removal rate was observed for Cu(II) (64.5%). Cellular changes in fungus were reflected by TEM analysis. FTIR and solid-state NMR analyses indicated the involvement of different functional groups (amino, carbonyl, hydroxyl, et al.) in metallic biosorption. these results established that the earthworm-associated T. brevicompactum QYCD-6 was a promising fungus for the remediation of heavy-metal wastewater. Environmental pollution by heavy metals (such as Cr(VI), Cu(II), Cd(II), Pb(II) and Zn(II)), is widespread owing to urbanization, industrialization and agricultural practices 1,2. As multi-metals are non-biodegradable, they are constantly present in the environment and bio-accumulate in the tissues of plants, animals and humans, resulting in bio-magnification in the food chain. Biomagnified heavy metals lead to health disorders, such as osteomalacia, birth defects, and health hazards to the liver, kidneys, nervous and gastrointestinal systems 3,4. Toxic heavy metals are traditionally treated by physicochemical techniques, such as precipitation, membrane filtration, adsorption, and chemical oxidation-reduction 5. However, these methods are generally costly and ineffective when the metallic concentrations are low 1. The use of microorganisms to bioremediate is a cheaper and environmental friendly alternative approach to remove heavy metals from environment 6-8. Earthworms have the ability to accumulate heavy metals, including Cu, Cd, Pb and Zn 9. In general, metallic accumulation by earthworm occurs through two pathways, which include absorption following dermal contact and adsorption through the intestinal tissues 10-12. It has been reported that the gut microbiota of other animals were found to exhibit strong metals tolerance and binding abilities 13,14. So, it could be hypothesized that the intestinal microorganisms of earthworms have the ability of heavy metal tolerance and removal. In the course of our ongoing efforts to screen potential strain for metal removal from the gut microbiota of earthworm, we found that intestinal fungus Trichoderma brevicompactum QYCD-6 of Pheretima tschiliensis exhibited good potential for heavy metal tolerance. Here, we reported the details of the ability and mechanisms of tolerance and removal of the individual heavy metal as well as multiple metals by T. brevicompactum QYCD-6. T...

The phylogenetic diversity of fungi isolated from the Odontotermes formosanus was investigated by dilution-plate method, combined with morphological characteristics and 5.8S rDNA sequencing. Thirty-nine fungi were isolated and purified from O. formosanus, which were belonging to two phyla and four classes (Sordariomycetes, Dothideomycetes, Eurotiomycetes, Agaricomycetes). Furthermore, nine bacterial 16S rRNA sequences were obtained from total fungal genomic DNA. All bacterial symbionts were segmented into four genera: Bacillus, Methylobacterium, Paenibacillus, and Trabulsiella. The antimicrobial activities of all endophytic fungi extracts were tested by using the filter paper method against Escherichia coli (ATCC 8739), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538), and Canidia albicans (ATCC 10231). The results exhibited that 25 extracts (64%) exhibited antibacterial activity against at least one of the tested bacterial strains. Furthermore, the secondary metabolites 1 [5-hydroxyramulosin (1a):biatriosporin M (1b) = 2:1] from the Pleosporales sp. BYCDW4 exhibited potent antimicrobial activities against E. coli, C. albicans, B. subtilis, and S. aureus with the inhibition zone diameter (IZD) of 13.67, 14.33, 12.17, and 11.33 mm, respectively, which were comparable with those of the positive control. 1-(2,5-Dihydroxyphenyl)-3-hydroxybutan-1-one (2) from the Microdiplodia sp. BYCDW8 showed medium inhibitory activities against B. subtilis and S. aureus, with the IZD range of 8.32-9.13 mm. In conclusion, the study showed the diversity of insect symbionts could be expected to develop the resource of new species and antibiotics.