Artemisia annua L. is an aromatic-antibacterial herb that destroys malarial parasites, lowers fever, and checks bleeding, and from which the secondary compound of interest is artemisinin. It has become increasingly popular as an effective and safe alternative therapy against malaria, and its derivatives are effective against multidrug resistant Plasmodium falciparum strains. Nitrogen is required by the plants in the largest quantity and is most limiting where biomass production is desired. On the other hand, gibberellic acid plays an important role in flowering, growth, and development and also in other physiological and biochemical processes. The feasibility of foliar GA3 (75 mg·L−1) alone or with varying levels of soil applied nitrogen (40, 80, and 120 mg·kg−1 soil) was tested on A. annua in the present study. The application of GA3 proved effective in alleviating the growth, photosynthesis, and enzyme activities of A. annua. However, N levels combined with GA3 showed better responses, and further improvement in these parameters was observed. Furthermore, the most important task we were interested in was to increase the artemisinin content and its yield on a per plant basis. The N combination (80 mg·kg−1 soil) together with GA3 augmented the content (21.8% more) and yield (55.8% more); this is true for both the treated plants, which were more than the control.
The purpose of this study was to assess the synergistic effects of exogenously applied proline and glycinebetaine (betaine) in antioxidant defense and methylglyoxal (MG) detoxification system in mung bean seedlings subjected to salt stress (200 mmol·L−1 NaCl, 48 h). Seven-day-old mung bean seedlings were exposed to salt stress after pre-treatment with proline or betaine. Salt stress caused a sharp increase in reduced glutathione (GSH) and oxidized glutathione (GSSG) content in leaves, while the GSH/GSSG ratio and ascorbate (AsA) content decreased significantly. The glutathione reductase (GR), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glyoxalase II (Gly II) activities were increased in response to salt stress, while the monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glyoxalase I (Gly I) activities sharply decreased with an associated increase in hydrogen peroxide (H2O2) and lipid peroxidation level (MDA). Proline or betaine pre-treatment had little influence on nonenzymatic and enzymatic components as compared to those of the untreated control. However, proline or betaine pre-treated salt-stressed seedlings showed an increase in AsA, GSH content, GSH/GSSG ratio and maintained higher activities of APX, DHAR, GR, GST, GPX, CAT, Gly I and Gly II involved in ROS and MG detoxification system as compared to those of the untreated control and mostly also salt-stressed plants with a simultaneous decrease in GSSG content, H2O2 and MDA level. These results together with our previous results suggest that coordinate induction of antioxidant defense and glyoxalase system by proline and betaine rendered the plants tolerant to salinity-induced oxidative stress in a synergistic fashion.
Cultivar mixtures have been suggested as ways to increase crop productivity. This field study was conducted to investigate the competition among five cultivated varieties of wheat (Triticum aestivum L.) for the traits like plant height, flag leaf area, fertile tillers per plant, spike length, spikelets per spike, spike density, grain weight per spike, and seed index in relation to competition with yield per plant. It was observed that cultivar mixtures ought to be more productive than corresponding pure stands. Four binary combinations of Seher2006-Kohistan97, Farid2006-SH2002, SH2002-Shahkar95, and SH2002-Kohistan97 were superior in performance, showing land equivalent ratio (LER) values greater than one for plant height, fertile tillers per plant, spike density, grain weight per spike, and grain yield per plant. It was observed that the performance of binary mixtures was mainly due to the increased average performance in spike density, grain weight per spike, and grain yield per plant. The competitive ability of wheat varieties in mixtures was independent of each other for the respective traits, which lead to cumulative effects for the increased performance within the associates in mixtures.
The objective was to study the technology for the separation and purification of oligomeric proanthocyanidins from Rhodiola rosea and establish the best operating conditions. First, the oligomeric proanthocyanidins was extracted by ethyl acetate from rough-extracted R. rosea liquid using an optimized technique. Its purification was achieved by macroporous resins. Five kinds of macroporous adsorbent resins were compared for the adsorption and desorption performance of procyanidins, the concentration and pH value of both the extracted sample and the eluant were investigated. According to the results, the optimized conditions were as follows: four times of extraction at 25 min each time was effective, the best volume ratio was 1.5:1 (ethyl acetate: extracted solution); AB-8 resin was the best choice; the concentration of the extracted sample was 4.0 g/L, and the pH was 4.5; the ratio of the diameter to height of the chromatography column was 1:40 (cm); 50% ethanol was used as the eluant at pH 5; and finally, the purity of procyanidins reached 88. 3%.
The external morphology of the compound eye of the winged female and male Solenopsis invicta Buren and its microstructure in light and dark adaptations were observed using scanning electron microscopy and optical microscopy. The results indicated that the compound eye located on the lateral side of its head, is the a shape of a half ellipsoid and composed of approximately 510 ommatidia in the female, and a near hemisphere with about 805 ommatidia in the male. The ommatidium was made of a corneal lens, crystalline cone, 8 to 9 retinula cells and basement membrane. The cornea was a colorless, transparent and double convex lens. The crystalline cone, with an inverted cone shape, was approximately 14.50 m long, formed by four equal parts, and surrounded by many pigment granules. The rhabdom beneath the crystalline cone, was about 75.00 m long, with a thicker middle part and thinner ends. More pigment granules were scattered in the distal and proximal ends and less in the middle, and the basement membrane was on the most bottom area of the ommatidium. The primary pigment cells moved horizontally along the crystalline cone from its distal to proximal end during dark adaptation or moved reversely during light adaptation. There was no significant difference between the pigment granule distribution and the structure of the crystalline cone between female and male ommatidium under the same light or dark adaptation. It is concluded that the fire ant compound eye is an apposition eye, whose light-tuning mechanism is accomplished by the change of crystalline cone and the movement of the pigment cells.
Intracellular signal transduction pathways including MAPK, Ca2+, and cAMP signal transduction pathways play important roles in regulating growth, development, and pathogenesis of phytopathogenic fungi. Protein kinase A (PKA) is a key enzyme in cAMP signaling pathway. The transcription level of the gene encoding catalytic subunit of PKA in Setosphaeria turcica under different culture conditions was analyzed by the semiquantitative RT-PCR method. The expression level of PKA-c gene was the lowest on the medium containing sucrose and starch as the carbon source, and it was distinctly inhibited by Cu2+, but it was independent of nitrogen source. After the addition of different concentrations of sorbitol, it showed the positive correlation between the inhibition affection and concentrations. However, the highest expression was observed in response to NaCl (0.9 mol/L). This research enriched the biological information resource of filamentous fungi and laid a foundation for the functional analysis about signal transduction pathway in phytopathogenic fungi.
The effects of incorporation SA into KNO3 priming solution on the germination and emergence of eggplant seeds at 15°C were investigated. Seeds were primed into 3% KNO3 containing 0.05, 0.1, 0.5, or 1 mM salicylic acid (SA) for 6 days, respectively. After the priming, seeds were either immediately used for germination and emergence test at 15°C or stored at 4°C for 1 month and then for the germination test. The primed eggplant seeds in general improved the final germination percentage (FGP), germination rate (G50), and germination synchrony (E10–90) at 15°C compared with non-priming seeds. Priming seeds in 3% KNO3 solution supplement with 0.1 mM SA resulted in the best priming effect compared with other priming treatments and non-priming treatment, and all of the beneficial priming effects were still retained after stored at 4°C for 30 days. These results indicated that priming seeds in 3% KNO3 solution containing 0.1 mM SA could be used as an effective method to improve low-temperature performance of eggplant seeds and subsequent seedling growth.
A full length cDNA encoding HMGR (designated as GuHMGR) was isolated from liquorice (Glycyrrhiza uralensis) based on degenerated PCR and genome walking. The full length cDNA of GuHMGR was 2330 bp with a 1518-bp open reading frame (ORF) encoding a 505-aa polypeptide. Bioinformatics analysis indicated that there were two trans-membrane domains in GuHMGR. A molecular model of tertiary structure showed that GuHMGR is a novel HMGR with a similar spatial structure to other plant HMGRs. The deduced polypeptide of GuHMGR has an isoelectric point (pI) of 6.41 and a calculated molecular weight of about 54.7 kDa. Sequence comparison and phylogenetic tree analysis showed that GuHMGR had the highest homology with HMGRs from Pisum sativum and Medicago truncatula, indicating that GuHMGR belongs to the plant HMGR group. Expression analysis showed the similar amount of transcript level of GuHMGR in roots and leaves, suggesting that this gene was expressed constitutively in plants. Therefore, this novel HMGR gene would possibly provide a new strategy for studying the glycyrrhizin metabolism at the molecular level in the future.
Apriona germari is a destructive stem-boring pest. To date, the control of the pest is still based largely on the chemical insecticides. To meet the needs of people’s high pesticide efficacy and environment safety, the alternative management strategy must be proposed. Beauveria bassiana is one of the most widely studied and used entomopathogenic fungi. The potential of Beauveria bassiana used to control Apriona germari was here evaluated. The result showed that the infective rate of B. bassiana to adults was 20%, with no pathogenicity to eggs. But it showed a high pathogenicity to larvae. The laboratory bioassays showed that the mortality, when concentration was 1 × 108 conidia/mL, was 96.47% ten days after inoculation. LT50 of B. beauveria to Apriona germari larvae was 4.53 d at the concentration of 1 × 108 conidia/mL; LC50 was 6.76 × 105 conidia/mL. The infecting experiments in field showed that, 20 days after control, the mortality was 68.4%. The present results suggested that B. bassiana has an excellent potential for biological control of A. germari larvae.
Seed priming technique has been known to improve germination and seedling emergence under different environment stresses. The objective of this study was to evaluate the effectiveness of seed priming in improving the seed germination and seedling vigor of Agropyron elongatum and Bromus inermis in response to five concentrations of the allelopathic extract of Thymus kotschyanus (0, 5%, 25%, 50% and 75%) under laboratory conditions. Pretreatments included gibberellic acid (250, 500 and 1000 ppm), potassium nitrate (0.1%, 0.2% and 0.3%) and salicylic acid (100, 200 and 300 mg/L). This experiment was carried out as a factorial experiment based on a completely randomized design with four replications. The results showed that seed germination, germination speed and seedling vigor were significantly decreased (P < 0.01) by increasing extract concentrations of Thymus kotschyanus allelopathic compounds in unprimed seed (control) compared with primed seeds. Seed priming enhanced germination percentage, germination speed and initial growth. Overall, the results of this study showed that the response of both species to pretreatment of seeds was positive. Therefore, pretreatments of seeds with the aforementioned chemical stimulators before planting can significantly reduce the negative effect of allelopathic compounds in Thymus kotschyanus during the germination stage and contribute to plant establishment by increasing germination speed and growth of embryos.
To clone the antibiotic biosynthesis gene cluster of Streptomyces roseoflavus Men-myco-93-63, we constructed a Fosmid genomic library. The genomic DNA of the strain Men-myco-93-63 was isolated by the modified CTAB procedure, and the size of most genomic DNA fragments was larger than 150 kb. Then, a Fosmid genomic library containing more than 6000 clones was constructed. The average size of the inserted DNA in recombinant plasmids was 38.1 kb, and the probability of harboring any gene in the genome of the strain Men-myco-93-63 was 99.99%. The library coverage was at least a 10-fold genome equivalent. Therefore, the constructed Fosmid library meets the requirements as a standard genomic library
The aim of this paper was to study the biochemical changes in fermented scallop flour paste (SFP) during different fermentation periods. SFP was prepared with scallop muscles, flour koji, salt, rice koji, and neutral protease at 40°C for 12 days. Biochemical changes during fermentation were investigated. By reducing sugar content, formaldehyde nitrogen content, total acid content, and free amino acids (FAAs), the concentration of SFP was increased but water activity was decreased. Most FAAs were increased, and the amounts of glutamic acid, glycine, alanine, and leucine were high. Some amino acid concentrations were higher than their taste threshold, such as the glutamate of umami, the glycine and alanine of sweet and umami, and the arginine and lysine of bitter and sweet. They contributed significantly to the characteristic taste of SFP. Therefore, SFP is a potential seasoning agent with nutritional properties and good taste.
The timing of floral transition is tightly controlled by a combination of endogenous and environmental signals. One early flowering mutant plant was screened from Arabidopsis library of T-DNA insertion to accelerate flowering under short-day condition, and a related-gene EFS1 (AT4G36680.1) was isolated and identified as a novel flowering-time gene of Arabidopsis in our preliminary studies. To investigate the function and the specific mechanism of EFS1 in the flower process control, the RNAi expression vector containing EFS1 gene-specific sequences in the sense and antisense orientations was constructed and transferred into Arabidopsis by using the floral-dip method, with 11 transgenic plants obtained through hygromycin B screening and PCR assays. The results showed that the expression level of EFS1 in transgenic lines was significantly lower than that in wild type and efs1 mutant. The flowering time of the efs1 mutant and RNAi transgenic plants was much earlier than that of wild-type plants. This result further verified that the EFS1 gene played an important role in flowering, and its specific mechanisms need further study. These work provided a foundation to further regulatory mechanisms of EFS1 in the control of floral transition.
MiRNAs belong to one type of noncoding RNAs involved in developmental regulation, genome maintenance, and defense in eukaryotes. In plants, the miRNAs are involved in many molecular interactions, including interfere with expression of mRNAs encoding factors that control developmental processes, stem cell maintenances, auxin responses, and other developmental and physiologic processes. In this paper, the molecular characterization and the functions of miRNAs on mediation of target gene silencing in plants have been overviewed. Further studies on the miRNAs will be helpful for elucidation of the molecular mechanism of post- transcriptional gene silencing in plants.
An enhancin-like gene was cloned from Bacillus thuringiensis ( Bt ) strain GS8 isolated from soil samples in china. The sequence analysis revealed that an open reading frame (ORF) of 2202 nucleotides encoding a protein containing 733 amino acids with a molecular mass of 84 kDa. The enhancin-like protein showed 100% identity to Bel protein (FJ644935) and 23%–41% identity to viral enhancin proteins; in the 252 to 261 amino-acid sequence of enhancin-like protein, a conserved metal binding motif (HEIAH) similar to that in the reported bacterial enhancin-like proteins was found (HEXXH in viral enhancin protein), which indicated that the enhancin-like protein belongs to metalloprotease. The purified enhancin-like protein was fed together with Cry9Ea to Spodopera exigua and Trichoplusia ni larvae, but no significant increase in toxicity was observed.
Two generations of Clostera anachoreta (Fabricius) larvae were fed continuously with leaves of selected clones of transgenic (Bt + API) triploid Chinese white poplar in order to evaluate additive insect-resistant effects of transgenic triploid Chinese white poplar. When the two generations were subcultured with the high and medium level insect-resistant transgenic poplar, the high and medium level insect-resistant transgenic poplar manifested its obvious additive resistance to C. anachoreta (Fabricius), with higher mortality of the second generation C. anachoreta (Fabricius) larvae and longer larvae growth period of the second generation than those of the first generation. Furthermore, the weight of pupa and the fecundity of the second generation were lower than those of the first generation. However, there was no significant difference between both generations when subcultured with low level insect-resistant transgenic poplar. These results implied that the population of C. anachoreta (Fabricius) would decline gradually to under the economic threshold even when planting the medium level insect-resistant transgenic poplars in the environment.
Cotton growers face a problem of low cotton yield in late planting (after sunflower and maize). The objective of our study was to determine the effects of planting date, plant spacing (plant density), and genotypes on seed cotton yield and its components, ginning outturn (GOT%), and fiber quality traits (fiber length and fiber fineness). Five planting dates (May 1, May 15, May 30, June 15, and June 30), three plant spacings (15, 30, and 45 cm), and three cotton genotypes (CRS-6070, CRS-738, and CIM-496) were evaluated for seed cotton yield with its components and fiber quality traits. The results showed that monopodial branches/plant, sympodial branches/plant, number of bolls/plant, and seed cotton yield differed significantly among different planting dates, plant spacing, and genotypes. While the boll weight was significantly different among genotypes only. GOT%, fiber length, and fiber fineness were different significantly among planting time and cotton genotypes, which were not significantly affected by plant spacing. Cotton grown in early planting dates had higher seed cotton yield (4874 and 4653 kg/hm2) at the highest plant spacing (45 cm). While late sown cotton (June 15 onward) gave higher seed cotton yields (2068 and 1889 kg/hm2) at the lowest plant spacing (15 cm). GOT%, fiber length, and fiber fineness improved significantly in late planting and not affected from plant spacing. From our present study, it is concluded that high seed cotton yield can be achieved at high plant spacing in early planting while at low plant spacing in late planting.
Consumption and processing of allochthonous plant litter by fishes is more common in tropical than temperate streams and rivers. Therefore, aquatic hyphomycetes in water (filtration), leaf litter (bubble chamber incubation), and fecal pellets (direct observation and inoculation to sterile leaf litter) of three dominant fishes belonging to the family Cyprinidae (Aplocheilus lineatus, Puntius filamentosus, and Rasbora daniconius) in two locations of the River Kali of the Western Ghats, India, were evaluated during postmonsoon season. Spores of 14 and 9 species of aquatic hyphomycetes were recovered on filtering water samples of Kaiga stream and Kadra dam with equal number of spores (32 spores · 100 mL−1) and high Shannon diversity in Kaiga stream. In a bubble chamber incubation of leaf litter, 16 and 9 species were recovered from Kaiga stream and Kadra dam with high spore output (1122 versus 324 spores per mg dry mass) and high Shannon diversity in Kaiga stream. Both direct and indirect methods of examination of fecal pellets of fishes revealed more species in Kaiga stream than Kadra dam (4–7 versus 1–4 species). The spore release in leaf litter incubated with fecal pellets ranged from 2.3 to 98 spores·mg−1·d−1 with the highest Aplocheilus lineatus in Kaiga stream; while in Kadra dam, it was from 0.02 to 22.9 spores·mg−1·d−1 with the highest in Puntius filamentosus. The Shannon diversity of aquatic hyphomycetes was high in fecal pellets of Aplocheilus lineatus of Kaiga stream and Rasbora daniconius of Kadra dam. The top-ranked five species of aquatic hyphomycetes differed in water, leaf litter, and fish fecal pellets; however, Triscelophorus konajensis was common for all. All five top-ranked species of aquatic hyphomycetes in feces produced multicelled spores; thus, they were likely to have a better chance of viability through gut passage than single-celled spores. Preferential feeding, fungi in gut and feces, and survival and dissemination of spores by invertebrates and fishes with reference to aquatic hyphomycetes were discussed.
A novel conidium development mutant was obtained by screening the transformants of Botrytis cinerea produced by Agrobacterium tumefaciens mediated method, which lost the ability of producing conidia. The flanking sequence of T-DNA insertion site was acquired by TAIL-PCR technology, and then, the T-DNA insertion in the second exon of BC1G_02800.1 confirmed by BLAST between the flanking sequence and the known sequence in the B. cinerea gene database. The mutant gene was identified as BC1G_02799.1 located in the upstream of BC1G_02800.1 gene by RTPCR. The DNA full-length sequence of BC1G_02799.1 was 1951 bp and contained 1848 bp coding region, which encoded a 615 amino acids putative protein similar to ABC-transporter, and the function of BC1G_02799.1 gene was unknown to date. Phenotype analysis of the mutant found that the mutant strain colony was white, grew slowly, and did not produce conidium and sclerotia on PDA medium but showed a stronger pathogenicity to tomato leaves and successfully increased the enzyme activity related to pathogenicity compared to the wild type strain. The results suggested that the BC1G_02799.1 gene was involved in the conidium development, the sclerotia formation, and pathogenicity in B. cinerea . Our research will facilitate in understanding the molecular mechanism of conidium development, sclerotia formation, and pathogenic in B. cinerea .
Phosphoinositide-specific phospholipase C plays pivotal roles in a host of physiologic processes in both animals and plants. Animal PI-PLC is regulated by heterotrimeric G-protein. Plant PI-PLCs are structurally close to the mammalian PI-PLC-ζ isoform, and it is not testified what regulated this isoform enzyme. In this paper, two isoform genes of LdPLC (Pan, 2005) and three subunits of heterotrimeric G-protein in Arabidopsis were amplified and recombinated with plasmids of a yeast two-hybrid system. Using this system, we provided the evidence that LdPLC1 and Gβ subunit could be able to interact with each other. This result indicated that LdPLC1 might be regulated by G-protein.
