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Reactive oxygen species (ROS) homeostasis is critical for both physiological processes and stress responses of plants. NADPH oxidases (NOXs) are the key producers of ROS in plants. However, their functions in ROS homeostasis and plant growth regulation in wheat ( Triticum aestivum ) are little investigated. Here, we cloned and characterized a NOX isoform TaNOX7 in wheat. Overexpression of TaNOX7 in rice led to enhanced root length, ROS production, drought tolerance as well as bigger panicles and higher yield but shorter growth period duration. Further results indicate that TaCDPK13, a member of calcium-dependent protein kinases (CDPKs), can directly interact with TaNOX7 and enhance ROS production in plants. These results demonstrate that TaNOX7 plays crucial roles in wheat development, fertility, and drought tolerance via interaction with TaCDPK13, which may act as an upstream regulator of TaNOX7 to regulate ROS production in wheat.

Benapenem is a novel carbapenem. The objective of this study was to determine the pharmacokinetic (PK)/pharmacodynamic (PD) cutoff values and evaluate the optimal administration regimens of benapenem for the treatment of bacterial infections via PK/PD modeling and simulation. Ertapenem was used as a control. Infected mice received an intravenous (i.v.) injection of benapenem or ertapenem of 14.6, 58.4, or 233.6 mg/kg of body weight, and the PK/PD profiles were evaluated. The MICs were determined by using a 2-fold agar dilution method. Mathematical models were developed to characterize the pharmacokinetic profile of benapenem in humans and mice. Monte Carlo simulations were employed to determine the cutoff values and the appropriate benapenem dosing regimens for the treatment of infections caused by clinical isolates of Enterobacteriaceae Two 2-compartment models were developed to describe the PK profiles of benapenem in humans and mice. A two-site binding model was applied to fit the protein binding in mouse plasma. Through correlation analysis, the percentage of the time that the free drug concentration remains above the MIC (% fT >MIC ) was determined to be the indicator of efficacy. Results from the simulation showed that the probability of target attainment (PTA) against the tested isolates was over 90% with the dosing regimens studied. The PK/PD cutoff value of benapenem was 1 mg/liter at a % fT >MIC of 60% when given at a dose of 1,000 mg/day by i.v. drip for 0.5 h. The established model provides a better understanding of the pharmacological properties of benapenem for the treatment of Enterobacteriaceae infections. The proposed PK/PD cutoff value suggests that benapenem is a promising antibacterial against the Enterobacteriaceae The cutoff value of 1 mg/liter may be a useful guide for the clinical use of benapenem and for surveillance for benapenem resistance., (Copyright © 2020 Ji et al.)

The objective of this trial was to investigate the safety, tolerability, and pharmacokinetics (PK) of benapenem administered by single or multiple intravenous infusions in healthy Chinese volunteers. The trial was divided into 3 parts. In part A, 94 subjects were enrolled in a double-blind, placebo-controlled, sequential-ascending-single-dose study. The subjects were randomly assigned to groups receiving placebo or benapenem for injection at doses of 62.5, 125, 250, 500, 1,000, 2,000, or 3,000 mg. The effects of intravenous infusion time on the subjects of 250-, 500-, and 1,000-mg groups were explored. In part B, 12 subjects were enrolled in a single-dose PK study under fasting conditions and received 250, 500, or 1,000 mg of benapenem for injection. In part C, 36 subjects were given 250, 500, and 1,000 mg of benapenem for injection once daily for 7 consecutive days. The results showed that benapenem for injection was well tolerated during the studies. The major observed adverse events were mild, and all were resolved spontaneously without any medical intervention. Benapenem was mainly excreted through the kidneys in the form of parent molecule and metabolites. The PK and safety profiles of benapenem in healthy Chinese volunteers support its once-daily dosing in future clinical investigations. (Part A, part B, and part C have been registered at ClinicalTrials.gov under identifiers NCT03588156, NCT03578588, and NCT03570970, respectively.)., (Copyright © 2019 American Society for Microbiology.)

Mizolastine is a selective histamine H1 receptor antagonist for chronic urticaria or allergic rhinitis. We investigated whether the variant genotypes of metabolic enzymes UGT1A1, CYP3A5 and transporter ABCB1 influence pharmacokinetic phenotype of substrate mizolastine in Chinese volunteers. Genotyping of single nucleotide polymorphisms in UGT1A1*6 (G211A), CYP3A5*3 (A6986G) and ABCB1 (C3435T) was determined by the pyrosequencing method. After a single oral dose of 10 mg mizolastine, the plasma concentrations were measured using validated high-performance liquid chromatography in 24 Chinese healthy volunteers. The results showed that the distributions of wild-type homozygotes and variant allele carriers (the sum of variant heterozygotes and variant homozygotes) were as follows: 17 cases (70.8%) versus seven cases (29.2%) in UGT1A1*6 genotypes, five cases (20.8%) versus 19 cases (79.2%) in CYP3A5*3 genotypes and seven cases (29.2%) versus 17 cases (70.8%) in ABCB1 3435T genotypes, respectively. There were no significant differences in pharmacokinetic parameters of mizolastine between the variant allele UGT1A1*6, CYP3A5*3 and ABCB1 3435T carriers and the wild-type homozygotes, and the ratios were as follows: C max was 101.03%, 86.02% and 105.78%; T max was 162.35%, 98.98% and 144.90%; AUC 0-28 was 113.04%, 77.35% and 112.71%; and t 1/2 was 95.77%, 72.40% and 100.97%, respectively. In conclusion, these results suggested that the UGT1A1, CYP3A5 and ABCB1 genetic polymorphisms might be not contributed to the interindividual variation of mizolastine pharmacokinetic phenotype in the Chinese population., (© 2018 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)

Modulating the vitamin D receptor (VDR) is an effective way to treat for cancer. We previously reported a potent non-secosteroidal VDR modulator (sw-22) with modest anti-tumor activity, which could be due to its undesirable physicochemical and pharmacokinetic properties. In this study, we investigated the structure-activity and structure-property relationships around the 2'-hydroxyl group of sw-22 to improve the physicochemical properties, pharmacokinetic properties and anti-tumor activity. Compounds 19a and 27b, the potent non-secosteroidal VDR modulators, were identified as the most effective molecules in inhibiting the proliferation of three cancer cell lines, particularly breast cancer cells, with a low IC 50 via the distribution of cell cycle and induction of apoptosis by stimulating the expression of p21, p27 and Bax. Further investigation revealed that 19a and 27b possessed favorable rat microsomal metabolic stability (2.22 and 2.3 times, respectively, more stable than sw-22), solubility (43.9 and 50.2 times, respectively, more soluble than sw-22) and in vivo pharmacokinetic properties. In addition, 19a and 27b showed excellent in vivo anti-tumor activity without cause hypercalcemia, which is the main side effect of marketed VDR modulators. In summary, the favorable physicochemical properties, pharmacokinetic properties and anti-tumor activity of 19a and 27b highlight their potential therapeutic applications in cancer treatment., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Stripe rust caused by Puccinia striiformis f. sp. tritici ( Pst ) is a devastating foliar disease that affects common wheat and barley throughout the world. The reasonable deployment of adult plant resistance (APR) wheat varieties is one of the best methods for controlling this disease. Wheat landraces are valuable resources for identifying the genes/QTLs responsible for disease resistance. Humai 15 is a Chinese spring wheat landrace and it has exhibited adequate levels of APR to the prevalent Pst races in field environments for many years. In this study, a population of 177 recombinant inbred lines (RILs) was derived from Humai 15 × Mingxian 169. After screening based on a 90K chip array using 45 RILs and Kompetitive Allelic Specific PCR marker genotyping for the population of RILs, a major effect QTL in Humai 15 was located on the centromere of chromosome 2B, where it accounted for up to 47.2% of the phenotypic variation. Two other minor QTL genes from Humai 15 were located on chromosome arms 3BS and 4BL. The Yr18 gene was identified on chromosome arm 7DS in Mingxian 169.

Panax ginseng is a slow-growing perennial plant. Panax ginseng extract has numerous biological activities, including antitumor, anti-inflammatory and antistress activities. Panax ginseng extract also has a cognition-enhancing effect in rats with alcohol-induced memory impairment. In this study, we partially occluded the bilateral carotid arteries in the rat to induce chronic cerebral hypoperfusion, a well-known model of vascular dementia. The rats were then intragastrically administered 50 or 100 mg/kg Panax ginseng extract. Morris water maze and balance beam tests were used to evaluate memory deficits and motor function, respectively. Protein quantity was used to evaluate cholinergic neurons. Immunofluorescence staining was used to assess the number of glial fibrillary acidic protein-positive cells. Western blot assay was used to evaluate protein levels of vascular endothelial growth factor, basic fibroblast growth factor, Bcl-2 and Bax. Treatment with Panax ginseng extract for 8 weeks significantly improved behavioral function and increased neuronal density and VEGF and bFGF protein expression in the hippocampal CA3 area. Furthermore, Panax ginseng extract reduced the number of glial fibrillary acidic protein-immunoreactive cells, and it decreased apoptosis by upregulating Bcl-2 and downregulating Bax protein expression. The effect of Panax ginseng extract was dose-dependent and similar to that of nimodipine, a commonly used drug for the treatment of vascular dementia. These findings suggest that Panax ginseng extract is neuroprotective against vascular dementia induced by chronic cerebral hypoperfusion, and therefore might have therapeutic potential for preventing and treating the disease., Competing Interests: None declared

Chronic pancreatitis (CP) is a serious disease that characterized by the progressive replacement of functional pancreas tissue by fibrotic tissue. Vitamin D receptor (VDR) plays a critical role in the development of CP, since it inhibits excessive deposition of extracellular matrix (ECM) in activated pancreatic stellate cells (PSCs). Herein, a novel series of non-secosteriodal VDR ligands were designed and synthesized, and their VDR affinity and anti-fibrosis activity were evaluated. The identification of the potent compound 9c was found over structural optimization, which inhibited ECM deposition and fibrotic gene expression in the western blot and qPCR assays, respectively. Further investigation revealed that compound 9c inhibited pancreatic fibrosis in vivo without increase on serum calcium, which could cause hypercalcemia. These results provide novel insight in possible drug discovery for the treatment of CP using non-secosteroidal VDR modulators., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

In order to identify the antagonistic substances produced by Bacillus subtilis E1R-J as candidate of biocontrol agents for controlling Apple Valsa Canker, hydrochloric acid precipitation, reverse phase chromatography, gel filtration, and ion exchange chromatography were used. The purified fraction EP-2 showed a single band in native-polyacrylamide gel electrophoresis (native-PAGE) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Fraction EP-2 was eluted from native-PAGE and showed a clear inhibition zone against V. mali 03-8. These results prove that EP-2 is one of the most important antifungal substances produced by B. subtilis E1R-J in fermentation broth. SDS-PAGE and Nano-LC-ESI-MS/MS analysis results demonstrated that EP-2 was likely an antifungal peptide (trA0A086WXP9), with a relative molecular mass of 12.44 kDa and isoelectric point of 9.94. The examination of antagonistic mechanism under SEM and TEM showed that EP-2 appeared to inhibit Valsa mali 03-8 by causing hyphal swelling, distortion, abnormality and protoplasts extravasation. Inhibition spectrum results showed that antifungal protein EP-2 had significantly inhibition on sixteen kinds of plant pathogenic fungi. The stability test results showed that protein EP-2 was stable with antifungal activity at temperatures as high as 100 °C for 30 min and in pH values ranging from 1.0 to 8.0, or incubated with each 5 mM Cu(2+), Zn(2+), Mg(2+), or K(+). However, the antifungal activity was negatively affected by Proteinase K treatment.

An antifungal protein exhibiting a high activity against Sclerotinia sclerotiorum in vivo was purified by ammonium sulfate precipitation, hydrophobic chromatography, and gel filtration chromatography from the culture filtrate of the endophytic Bacillus subtilis strain Em7. The protein was characterized as a β-1,3-1,4-glucanase according to amino acid analysis, and showed excellent properties in thermal stability and acid resistance. At the same time, the antifungal protein was cloned and heterologously expressed in Escherichia coli BL21. The recombinant protein was purified and showed similar enzymatic properties to the native protein, exhibiting strong inhibitory activity against S. sclerotiorum. This shows that the β-1,3-1,4-glucanase may play a very important role in B. subtilis Em7 biocontrol function. In addition, many physiochemical properties of the native and purified recombinant protein were compared, including the effect of pH, temperature, metal cations, substrate specificity, and kinetic parameters. All parameters were similar between the native and recombinant purified protein, indicating that the purified recombinant protein has potential for industrial applications.

Puccinia striiformis f. sp. tritici (Pst) is the obligate biotrophic fungus responsible for stripe rust wheat. In this study, we developed and characterized 20 polymorphic microsatellite markers from the genomic sequence of an isolate of Chinese Pst race CY32. Polymorphism at each simple sequence repeat (SSR) locus was determined using 32 Pst isolates from 7 countries. The number of alleles varied from 2 to 7 across isolates, and the observed and expected heterozygosities ranged from 0.33 to 0.97 (mean 0.62) and 0.23 to 0.73 (mean 0.51), respectively. As expected the genomic SSR markers were more polymorphic than the expressed sequence tag (EST)-SSR markers developed previously. These markers will be more useful for population genetics and molecular genetics studies in Pst.

Stripe rust, caused by Puccinia striiformis f. tritici, is one of the most destructive diseases of wheat in the world. The Sichuan Basin is one of the most important regions of wheat production and stripe rust epidemics in China. Stripe rust resistance gene Yr26 (the same gene as Yr24) has been widely used in wheat breeding programs and in many cultivars grown in this region since the gene was discovered in the early 1990s. Virulence to Yr26 has increased in frequency since its first detection in 2008. The objective of this study was to assess the vulnerability of the wheat cultivars and breeding lines in the Sichuan Basin to Yr26-virulent races. In total, 85 wheat accessions were tested with Yr26-avirulent races CYR32, CYR33, and Su11-4 and two Yr26-virulent races, V26/CM42 and V26/Gui22. DNA markers for Yr26 were used to determine the presence and absence of Yr26 in the wheat accessions. Of the 85 wheat accessions, only 5 were resistant and 19 susceptible to all races tested, and the remaining 61 were resistant to at least one or more races tested in seedling stage. In all, 65 (76.5%) accessions were susceptible to the emerging Yr26-virulent race V26/Gui22. In field tests, susceptible accessions increased from 31.8% in a nursery inoculated with predominant and Yr26-avirulent races to 61.2% in the nursery inoculated with the predominant races mixed with V26/Gui22. Based on the results of the molecular marker and race tests, 33 (38.8%) accessions were determined to have Yr26, showing that the Yr26 virulence is a major threat to wheat production in the Sichuan Basin and potentially in other regions of China.

The PstICL1 gene, which encodes isocitrate lyase, a key enzyme in the glyoxylate cycle, was cloned and characterized in the biotrophic wheat pathogen Puccinia striiformis f. sp. tritici (Pst). Expression analyses of PstICL1 exhibited high levels of transcripts in ungerminated urediniospores, which showed low isocitrate lyase enzyme activity. In planta, PstICL1 expression was continuously down-regulated upon germination. During the later stages of the infection of wheat, the level of PstICL1 expression was extremely low. The function of PstICL1 was identified via mutant complementation. The expression of PstICL1 in Saccharomyces cerevisiae can complement the defects of the △ICL mutant. Using 3-nitropropionate, we observed that inactivation of isocitrate lyase greatly reduced the germination rate of urediniospores, indicating that PstICL1 plays a key role during Pst germination. Furthermore, analysis of lipid bodies revealed that lipid components continuously enter the germ tube from the urediniospore cell during germ tube elongation. Moreover, during this period, the lipid contents continuously decreased, and the total carbohydrates markedly increased, demonstrating that the lipids are being converted into carbohydrates. These results suggest that PstICL1 is required for Pst germination.

Key Message: We report a new stripe rust resistance gene on chromosome 7AS in wheat and molecular markers useful for transferring it to other wheat genotypes. Several new races of the stripe rust pathogen have established throughout the wheat growing regions of China in recent years. These new races are virulent to most of the designated seedling resistance genes limiting the resistance sources. It is necessary to identify new genes for diversification and for pyramiding different resistance genes in order to achieve more durable resistance. We report here the identification of a new resistance gene, designated as Yr61, in Chinese wheat cultivar Pindong 34. A mapping population of 208 F2 plants and 128 derived F2:3 lines in a cross between Mingxian 169 and Pindong 34 was evaluated for seedling stripe rust response. A genetic map consisting of eight resistance gene analog polymorphism (RGAP), two sequence-tagged site (STS) and four simple sequence repeat (SSR) markers was constructed. Yr61 was located on the short arm of chromosome 7A and flanked by RGAP markers Xwgp5467 and Xwgp5765 about 1.9 and 3.9 cM in distance, which were successfully converted into STS markers STS5467 and STS5765b, respectively. The flanking STS markers could be used for marker-assisted selection of Yr61 in breeding programs.

MicroRNAs (miRNAs) play critical roles in post-transcriptional regulation and act as important endogenous regulators to various stresses. Cold, wounding and high-salinity are three common environmental stress stimuli influencing crops growth and development. In this study, we identified 31 known miRNAs and 3 novel miRNAs in wheat. Moreover, 19 stress-regulated miRNAs using RT-qPCR data in which the effects of three stresses were surveyed from the known miRNAs. Among them, 16, 12 and 8 miRNAs were regulated under cold, wounding and high-salinity treatments, respectively. Of which 4 miRNAs were highly responsive to cold stress in wheat by northern blot, and 6 wounding-regulated and 3 high-salinity-regulated miRNAs were detected. Meanwhile, miR159, miR393 and miR398 were responsive to multiple stress stimuli. Besides, 2 novel miRNAs were regulated by cold stress. While, the analyses of targets suggested miR159, miR398 and miR6001 could responses to stress conditions in regulation pathways. Taken together, the results of this study suggest that wheat miRNAs may play important roles in response to abiotic stress., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Key Message: This manuscript reports a new gene for non-race-specific resistance to stripe rust and molecular markers for incorporating it into wheat cultivars for control of the disease with durable resistance. Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive wheat diseases worldwide. The spring wheat germplasm 'PI 178759' originating from Iraq showed effective resistance to stripe rust in field evaluations over 8 years in Washington state, USA. To map the resistance gene(s), PI 178759 was crossed with 'Avocet Susceptible', and the parents and 176 F2:3 lines were phenotyped in the fields under natural infection and in a greenhouse with selected races of P. striiformis f. sp. tritici. PI 178759 was identified to have high-temperature adult-plant (HTAP) resistance. Resistance gene analog polymorphism and simple sequence repeat techniques were used to identify molecular markers linked to the resistance gene and a chromosome region was mapped using a quantitative trait locus approach. One major gene was mapped to the long arm of chromosome 7B. Flanked by Xwgp5175 and Xbarc32 in a 2.1 cM region, the gene explained 31.8 and 54.7 % of the phenotypic variation in rAUDPC and IT, respectively. Based on genetic distances among markers and allelism tests, the HTAP resistance gene in PI 178759 is different from the previously reported Yr39, Yr52, YrZH84, and YrC591, also located on chromosome 7BL, and is therefore designated as Yr59. The gene and its flanking markers should be useful for developing wheat cultivars with durable resistance.

The fungus Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust, is an obligate biotrophic basidiomycete. Many studies have found that myosins play important roles during fungal growth and propagation. However, there are few reports on the myosins of Pst. In this study, we cloned and obtained the myosin light chain gene PsMLC1 from Pst and characterized its expression. Furthermore, the function of PsMLC1 was identified by mutant complementation. As a result, we found that expression of PsMLC1 in Schizosaccharomyces pombe mostly complemented the defects of the cdc4 mutant, indicating that PsMLC1 belongs to the myosin light chain family member. Expression studies showed that the transcript levels of PsMLC1 little changed before 24 h post inoculation then was suddenly down-regulated during Pst infection of wheat. By using ML-7, we observed that inactivity of PsMLC1 greatly reduced the germination rate of urediniospores. These results suggest that PsMLC1 is essential for the early stages of Pst infection of wheat but unnecessary for the later stages of infection. This work elucidates the function of the myosins in Pst and may provide some theoretical basis for controlling strip rust.

MicroRNAs (miRNAs) play critical roles in post-transcriptional gene regulation and act as important endogenous regulators to various stressors. Ultraviolet-B (UV-B) radiation is a major factor influencing crop growth and development. In this study, we isolated a novel wheat miRNA, named Tae-miR6000, and confirmed its expression diversity after UV-B treatments. Additionally, using the Northern blotting technique, we found that six miRNAs were highly responsive to UV-B stress in wheat. Of these six miRNAs, miR159, miR167a, and miR171 were significantly upregulated, and the remaining three miRNAs were downregulated, at different time points after UV-B treatment. This result indicates that miRNAs may be involved in the regulation of targets after induction by UV-B stress. Furthermore, promoter analysis of the UV-B-responsive miRNA genes revealed some light-relevant cis-elements, such as the I-box and G-box. Taken together, the results of this study suggest that wheat miRNAs play important roles in the response to UV-B stress.

The production and germination of asexual spores in a diverse group of fungi play a crucial role in their infection cycles. These processes are regulated by a set of genes, namely, conidiation-related genes, involved in the production, morphological characteristics, and differentiation of conidia. In this study, we identified and characterized the PsCon1 gene, which is the first conidiation-related gene identified in Puccinia striiformis f. sp. tritici (Pst). Sequence analysis revealed that PsCON1 has two conserved conidiation-specific protein 6 domains. Single nucleotide polymorphisms and insertion/deletion variations were detected in the coding region of PsCon1 among five Pst races. Quantitative RT-PCR assays revealed that PsCon1 was expressed at the highest level in resting urediospores of Pst, and gradually decreased after germination and infection. However, at 312 hpi, at the stage of forming large amounts of urediospores on leaves, the amount of PsCon1 mRNA was sharply increased but only 0.1-fold that of resting urediospores. Subcellular localization assays indicated PsCon1 heterologously expressed in Fusarium graminearum was located in the cytoplasm of conidia. The results suggest that PsCon1 may play a role in formation or survival of Pst urediospores., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Wheat stripe rust (yellow rust [Yr]), caused by Puccinia striiformis f. sp. tritici, is an economically important disease of wheat worldwide. Virulence information on P. striiformis f. sp. tritici populations is important to implement effective disease control with resistant cultivars. In total, 235 P. striiformis f. sp. tritici isolates from Algeria, Australia, Canada, Chile, China, Hungary, Kenya, Nepal, Pakistan, Russia, Spain, Turkey, and Uzbekistan were tested on 20 single Yr-gene lines and the 20 wheat genotypes that are used to differentiate P. striiformis f. sp. tritici races in the United States. The 235 isolates were identified as 129 virulence patterns on the single-gene lines and 169 virulence patterns on the U.S. differentials. Virulences to YrA, Yr2, Yr6, Yr7, Yr8, Yr9, Yr17, Yr25, YrUkn, Yr28, Yr31, YrExp2, Lemhi (Yr21), Paha (YrPa1, YrPa2, YrPa3), Druchamp (Yr3a, YrD, YrDru), Produra (YrPr1, YrPr2), Stephens (Yr3a, YrS, YrSte), Lee (Yr7, Yr22, Yr23), Fielder (Yr6, Yr20), Tyee (YrTye), Tres (YrTr1, YrTr2), Express (YrExp1, YrExp2), Clement (Yr9, YrCle), and Compair (Yr8, Yr19) were detected in all countries. At least 80% of the isolates were virulent on YrA, Yr2, Yr6, Yr7, Yr8, Yr17, YrUkn, Yr31, YrExp2, Yr21, Stephens (Yr3a, YrS, YrSte), Lee (Yr7, Yr22, Yr23), and Fielder (Yr6, Yr20). Virulences to Yr1, Yr9, Yr25, Yr27, Yr28, Heines VII (Yr2, YrHVII), Paha (YrPa1, YrPa2, YrPa3), Druchamp (Yr3a, YrD, YrDru), Produra (YrPr1, YrPr2), Yamhill (Yr2, Yr4a, YrYam), Tyee (YrTye), Tres (YrTr1, YrTr2), Hyak (Yr17, YrTye), Express (YrExp1, YrExp2), Clement (Yr9, YrCle), and Compair (Yr8, Yr19) were moderately frequent (>20 to <80%). Virulence to Yr10, Yr24, Yr32, YrSP, and Moro (Yr10, YrMor) was low (≤20%). Virulence to Moro was absent in Algeria, Australia, Canada, Kenya, Russia, Spain, Turkey, and China, but 5% of the Chinese isolates were virulent to Yr10. None of the isolates from Algeria, Canada, China, Kenya, Russia, and Spain was virulent to Yr24; none of the isolates from Algeria, Australia, Canada, Nepal, Russia, and Spain was virulent to Yr32; none of the isolates from Australia, Canada, Chile, Hungary, Kenya, Kenya, Nepal, Pakistan, Russia, and Spain was virulent to YrSP; and none of the isolates from any country was virulent to Yr5 and Yr15. Although the frequencies of virulence factors were different, most of the P. striiformis f. sp. tritici isolates from these countries shared common virulence factors. The virulences and their frequencies and distributions should be useful in breeding stripe-rust-resistant wheat cultivars and understanding the pathogen migration and evolution.

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most damaging diseases of wheat worldwide. It is essential to identify new genes for effective resistance against the disease. Durum wheat PI 480148, originally from Ethiopia, was resistant in all seedling tests with several predominant Pst races in the US under controlled greenhouse conditions and at multiple locations subject to natural infection for several years. To map the resistance gene(s) and to transfer it to common wheat, a cross was made between PI 480148 and susceptible common wheat genotype Avocet S (AvS). Resistant F(3) plants with 42 chromosomes were selected cytologically and by testing with Pst race PST-100. A total of 157 F(4) plants from a single F(3) plant with 2n = 42 tested with PST-100 segregated in a 3 resistant: 1 susceptible ratio, indicating that a single dominant gene from PI 480148 conferred resistance. Using the F(3:4) population and the resistance gene-analog polymorphism (RGAP) and simple sequence repeat (SSR) markers, the gene was mapped to the long arm of chromosome 2B. SSR marker Xwmc441 and RGAP marker XLRRrev/NLRRrev ( 350 ) flanked the resistance gene by 5.6 and 2.7 cM, respectively. The effective resistance of the gene to an Australian Pst isolate virulent to Yr5, which is also located on 2BL and confers resistance to all US Pst races, together with an allelism test of the two genes, indicated that the gene from PI 480148 is different from Yr5 and should be a new and useful gene for resistance to stripe rust. Resistant common wheat lines with plant types similar to AvS were selected for use in breeding programs.

Exploring different types of resistance genes and deploying diversity resistance genes among different wheat producing regions are important strategy to control stripe rust epidemic in large scale. The resistance spectra of the wheat line Guinong 775 at seedling stage was tested in greenhouse with ten isolates of Puccinia triticina West. f. sp. tritici; and the inheritance of resistance was investigate with F(2:3) and BC(1) populations derived from a cross between Guinong 775 and a susceptible cultivar Avocet (S), inoculated with isolates CYR32 and CH42, which poses a notable threat to current wheat varieties carrying Yr26 resistance gene. The results showed that Guinong 775 was immune or nearly immune to all the tested races; however, the resistant germplasm 92R137, Chuanmai 42, Guinong 22, and Yr24/6*Avocet (S) were susceptible to CH42. The resistance of Guinong 775 was conferred by a single dominant gene to CYR32 and another single dominant gene to CH42, and these genes proved to be different.

The fungus Puccinia striiformis f. sp. tritici, the causal agent of wheat stripe rust, is an obligate biotrophic basidiomycete. Urediniospores are the most common spore type involved in the epidemiology of this disease. Tip growth of germ tubes of germinated urediniospores is a key step during infection of wheat, but few studies have investigated it so far. Recent research has found that actin is closely associated with hyphal tip growth. In this study, we have cloned and obtained the full-length actin cDNA from P. striiformis f. sp. tritici and characterized its expression. Furthermore, actin filament (F-actin) patterns were visualized microscopically during germ tube formation. The most conspicuous actin-containing structures were actin patches. They were mainly concentrated near the hyphal tip and scattered throughout the cortex. By using cytochalasin B, we observed that depolymerization of F-actin greatly reduced the germination rate of urediniospores and disrupted the transport of vesicles to the germ tube tip, indicating that F-actin played a key role in the tip growth of P. striiformis f. sp. tritici. This work helps us to understand the tip growth mechanism of P. striiformis f. sp. tritici, and may provide a theoretical framework for designing novel pesticides.

An endophytic actinomycete strain, designated Hhs.015(T), was isolated from roots of cucumber seedlings. The endophytic isolate was identified by means of a polyphasic taxonomic approach. On the basis of 16S rRNA gene sequence similarities, strain Hhs.015(T) was closely related to members of the genus Saccharothrix. DNA-DNA hybridization with the four closest relatives, Saccharothrix longispora NRRL B-16116(T), Saccharothrix xinjiangensis NRRL B-24321(T), Saccharothrix autraliensis CGMCC 4.1355(T) and Saccharothrix espanaensis CGMCC 4.1714(T), gave similarity values of 33.8, 28.2, 44.1 and 29.5%, respectively, which indicated that strain Hhs.015(T) represents a novel species of the genus Saccharothrix. This is consistent with the morphological, physiological and chemotaxonomic data. As a whole, these results suggest that strain Hhs.015(T) represents a novel Saccharothrix species. The name Saccharothrix yanglingensis sp. nov. is proposed, with the type strain Hhs.015(T) (=CGMCC 4.5627(T) = KCTC 19722(T)).

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a devastating disease of wheat. The use of wheat cultivars resistant to powdery mildew provides an effective, economical, and environmentally friendly method to control the disease. Previously, we identified a dominant resistance gene, temporarily named Pmhym, from the wheat cultivar Hongyoumai. In order to screen differential transcripts related to Pmhym-mediated resistance, four F3 homozygous resistant and four susceptible progenies derived from the Hongyoumai/Yumai13 cross were selected to construct two different pools, respectively, representing an incompatible and compatible interaction with Bgt. Pre-inoculated control and the pathogen-inoculated treatments at 24 h post inoculation (hpi) were used. Three groups of differential genes were categorized from three comparisons as pre- and post-induced, respectively, in two interactions, and post-induced between incompatible and compatible interaction. It was found that salicylic acid (SA), jasmonate (JA), and ethylene (ET) signaling-related genes were differentially expressed, thus suggesting that they are involved in the defensive response against Bgt infection. In compatible interactions, the genes involved in the abscisic acid (ABA) signaling pathway might be inhibitory to the above-mentioned three pathways, resulting in a susceptible reaction. Genes involved in disease/defense, signal transduction, and reactive oxygen species (ROS) metabolism were up-regulated in incompatible interactions, implying a role in resistant response. The results of qRT-PCR analysis on several candidate genes were consistent in their expression patterns as revealed by microarray analysis. The differential expression analyses in the present study are good candidates for further elucidation of wheat defensive response to powdery mildew.

Background: A new fluroquinolone antibacterial agent, antofloxacin hydrochloride, developed in China, is an 8-NH(2) derivant of levofloxacin. The purpose of the study was to evaluate the pharmacokinetic characteristics of single and multiple oral doses of antofloxacin hydrochloride in Chinese healthy male volunteers., Methods: An open-label, non-randomized, single and multiple dose clinical trial was conducted. In single dose study, 12 subjects took 200 mg antofloxacin hydrochloride. In multiple dose study, 12 subjects took antofloxacin hydrochloride 400 mg once on day 1 and 200 mg once daily from day 2 to day 7. HPLC was used to assay the serum and urinary concentrations of antofloxacin., Results: In single dose study, the maximum concentration of drug in serum (C(max)), the time to reach C(max) (T(max)), and the area under the serum concentration-time curve (AUC (0-∞)) of antofloxacin were (1.89 ± 0.65) mg/L, (1.29 ± 0.26) hours, and (25.24 ± 7.26) mg×h(-1)×L(-1), respectively. Accumulating elimination rate of antoflocaxin from urine within 120 hours was 39.1%. In multiple dose study, blood concentration of antofloxiacin achieved stable state on day 2 after dosing. The minimum concentration drug in serum (C(min)), AUCss, mean concentration of drug in serum (C(av)), and degree of fluctuation (DF) were (0.73 ± 0.18) mg/L, (47.59 ± 7.85) mg×h(-1)×L(-1), (1.98 ± 0.33) mg/L, and 1.74 ± 0.60, respectively. On day 7 after dosing, T(max), C(max), and AUC (0-∞) was (1.14 ± 0.50) hours, (2.52 ± 0.38) mg/L, and (48.77 ± 8.44) mg×h(-1)×L(-1), respectively. Accumulating elimination rate of antofloxaxin from urine within 120 hours after the last dosing was 60.06%., Conclusions: The regimen of 400 mg loading dose given on the first treatment day and then 200 mg dose once daily results in satisfactory serum drug concentration.

Members of the family of 70-kD heat shock proteins (HSP70 s) play various stress-protective roles in plants. In this study, a wheat HSP70 gene was isolated from a suppression subtractive hybridization (SSH) cDNA library of wheat leaves infected by Puccinia striiformis f. sp. tritici. The gene, that was designated as TaHSC70, was predicted to encode a protein of 690 amino acids, with a molecular mass of 73.54 KDa and a pI of 5.01. Further analysis revealed the presence of a conserved signature that is characteristic for HSP70s and phylogenetic analysis demonstrated that TaHSC70 is a homolog of chloroplast HSP70s. TaHSC70 mRNA was present in leaves of both green and etiolated wheat seedlings and in stems and roots. The transcript level in roots was approximately threefold less than in leaves but light-dark treatment did not charge TaHSC70 expression. Following heat shock of wheat seedlings at 40°C, TaHSC70 expression increased in leaves of etiolated seedlings but remained stable at the same level in green seedlings. In addition, TaHSC70 was differentially expressed during an incompatible and compatible interaction with wheat-stripe rust, and there was a transient increase in expression upon treatment with methyl jasmonate (MeJA) treatment. Salicylic acid (SA), ethylene (ET) and abscisic acid (ABA) treatments had no influence on TaHSC70 expression. These results suggest that TaHSC70 plays a role in stress-related responses, and in defense responses elicited by infection with stripe rust fungus and does so via a JA-dependent signal transduction pathway.

Proteins encoded by the NAC gene family constitute one of the largest plant-specific transcription factors, which have been identified to play many important roles in both abiotic and biotic stress adaptation, as well as in plant development regulation. In the current paper, a full-length cDNA sequence of a novel wheat NAC gene, designated as TaNAC4, was isolated using in silico cloning and the reverse transcription PCR (RT-PCR) methods. TaNAC4 sharing high homology with rice OsNAC4 gene was predicted to encode a protein of 308 amino acid residues, which contained a plant-specific NAC domain in the N-terminus. Transient expression analysis indicated that the deduced TaNAC4 protein was localized in the nucleus of onion epidemical cells. Yeast one-hybrid assay revealed that the C-terminal region of the TaNAC4 protein had transcriptional activity. The expression of TaNAC4 was largely higher in the wheat seedling roots, than that in leaves and stems. TaNAC4 transcript in wheat leaves was induced by the infection of strip rust pathogen, and also by exogenous applied methyl jasmonate (MeJA), ABA and ethylene. However, salicylic acid (SA) had no obvious effect on TaNAC4 expression. Environmental stimuli, including high salinity, wounding, and low-temperature also induced TaNAC4 expression. These results indicate that this novel TaNAC4 gene functions as a transcriptional activator involved in wheat response to biotic and abiotic stresses.

We described twenty polymorphic microsatellite loci derived from the expressed sequence tags of Puccinia striiformis f. sp. tritici, which causes yellow rust disease on wheat. The numbers of alleles range from two to six and eight microsatellite loci show significant similarities to known genes. Observed and expected heterozygosities ranged from 0.12 to 0.78 and from 0.24 to 0.87, respectively., (© 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.)

Stripe rust caused by Puccinia striiformis f. sp. tritici Westend is one of the most important epidemic diseases of wheat in the world. To understand the population evolution of this rust fungus will facilitate the control of this disease and the breeding of rust-resistant wheat. In the past decades, DNA molecular markers have been applied to investigate the population genetics of wheat stripe rust fungus, and rapid progress has brought out in the research of P. striiformis molecular ecology. In this paper, the main research progress in the molecular ecology of stripe rust was reviewed, and the limitations and trends of related research in China were discussed.

The hypersensitive response (HR) is one of the most efficient forms of plant defense against biotrophic pathogens and results in localized cell death and the formation of necrotic lesions. In this study, a novel putative hypersensitive induced reaction (HIR) gene from wheat leaves infected by incompatible stripe rust pathogen CY23, designated as Ta-hir1, was identified by using rapid amplification of cDNA ends (RACE). Ta-hir1 encodes 284 amino acids, with a predicted molecular mass of 31.31 KDa. A phylogenetic analysis showed that Ta-hir1 was highly homologous to Hv-hir1 from barley at both cDNA and deduced amino-acid levels. Amino-acid sequence analysis of the wheat HIR protein indicated the presence of the SPFH (Stomatins, Prohibitins, Flotillins and HflK/C) protein domain typical for stomatins which served as a negative regulator of univalent cation permeability, especially for potassium. The expression profile of the Ta-hir1 transcript detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time polymerase chain reaction (real time-PCR), respectively, showed that the highest expression occurred 48 h post inoculation (hpi), which is consistent with our previous histopathology observations during the stripe rust fungus-wheat incompatible reaction.

Monitoring the pathogenic fungus of wheat stripe rust, Puccinia striiformis f. sp. tritici, plays a key role in effective control of the disease. In the present study, we developed a specific and sensitive polymerase chain reaction (PCR) assay for detecting the pathogen in wheat (Triticum aestivum) leaves. A pair of primers (PSF and PSR) was designed based on the internal transcribed spacer (ITS) region sequence of P. striiformis f. sp. tritici. PCR products that were amplified with universal primers ITS1 and ITS4 were cloned into pGEM-T Easy vectors and sequenced. The ITS sequence was compared with those of P. striiformis f. sp. tritici, P. triticina, P. graminis f. sp. tritici, Blumeria graminis f. sp. tritici, Fusarium graminearum, Rhizoctonia cerealis, and Bipolaris sorokiniana, which are associated with early symptoms of foliar diseases on wheat. Specificity of the primers was tested in the PCR assays using DNA extracted from all tested P. striiformis f. sp. tritici isolates, other fungal species, and healthy and infected wheat leaves sampled around stripe rust foci in wheat fields, different days after inoculation with P. striiformis f. sp. tritici, as well as asymptomatic wheat leaves sampled around stripe rust foci in the fields. A PCR product of 169 bp was amplified from DNA of all P. striiformis f. sp. tritici isolates. The primers did not amplify DNA from the other tested fungal species. The pathogen was detected from asymptomatic wheat leaves inoculated with P. striiformis f. sp. tritici under greenhouse conditions, as well as leaves sampled around stripe rust foci in wheat fields. Under optimum conditions, the PCR assay was highly sensitive and required only 0.1 pg of the target DNA for a detectable and reliable amplification with the PSF and PSR primers.

An actinomycete strain xjy was isolated from the soil of cotton field in Xinjiang against pathogenic fungus Fulvia fulva. The growth of 23 plant pathogens and 6 bacteria were strongly inhibitded by strain xjy on PDA plate. Antimicrobial spectrum of fermentation filtrate of strain xjy is extensive and selective to different pathogens. The morphology, cultural characteristics, physiological and biochemical properties, chemotaxonomy and 16S rDNA sequences of this strain were studied. The strain showed faint yellow vegetative mycelium, spiral spore-bearing filaments and column spores with smooth surface. No pigment was produced in culture. The cell wall type I and sugar type C showed the strain with streptomyces character. A phylogenetic tree was constructed by comparing with the published 16S rDNA sequences of the related species and showed 99.6% identity of nucleotide sequence of 16S rDNA with Streptomyces lavendulae. From the polyphasic taxonomical view, the strain xjy falls into Streptomyces lavendulae. The optimum fermentation condition of strain xjy for producing the most effective ferment filtrate were cultured in 2% soybean flour, 2% glucose, 0.8% NaCl, 0.2% CaCO3, 0.32% (NH4)2 SO4, the initial pH of 7.0, at 28 degrees C and shaked at 180r/mim for 6d. These results are valuable to strain application, antibiotics purification and its industrialization.

Microbial biocontrol agents (BCAs) are generally used for controlling plant diseases via antagonistic mechanisms including competition, antibiosis, parasitism, and cross-protection. Some BCAs can even promote plant growth, and provide induced systemic resistance (ISR), i. e., induce the plants to have resistance against pathogens including phytopathogenic fungi, bacteria and virus, and in some cases, pest insects and nematodes. ISR is characterized by non-specific, wide spectrum and systemic. It is phenotypically similar to the systemic acquired resistance (SAR) induced by the infection of pathogens, and with the same efficiency but without hypersensitive response (HR) and visible symptoms in plant as SAR, which is helpful to open a new way to develop and improve safer and environmentally friendly strategies for plant protection. In this paper, the research advances on ISR mediated by biocontrol fungi and bacteria, elicitors or determinants, and signaling transduction pathways were summarized, with more emphasis on the biochemical and cytological mechanisms of host plant defense reaction induced by free-living and endophytic BCAs. The potential application of ISR in biocontrol of plant diseases was also discussed.

Rice dwarf virus (RDV) is a member of the genus Phytoreovirus, which is composed of viruses with segmented double-stranded RNA genomes. Proteins that support the intercellular movement of these viruses in the host have not been identified. Microprojectile bombardment was used to determine which open reading frames (ORFs) support intercellular movement of a heterologous virus. A plasmid containing an infectious clone of Potato virus X (PVX) defective in cell-to-cell movement and expressing either beta-glucuronidase or green fluorescent protein (GFP) was used for cobombardment with plasmids containing ORFs from RDV gene segments S1 through S12 onto leaves of Nicotiana benthamiana. Cell-to-cell movement of the movement-defective PVX was restored by cobombardment with a plasmid containing S6. In the absence of S6, no other gene segment supported movement. Identical results were obtained with Nicotiana tabacum, a host that allows fewer viruses to infect and spread within its tissue. S6 supported the cell-to-cell movement of the movement-defective PVX in sink and source leaves of N. benthamiana. A mutant S6 lacking the translation start codon did not complement the cell-to-cell movement of the movement-defective PVX. An S6 protein product (Pns6)-enhanced GFP fusion was observed near or within cell walls of epidermal cells from N. tabacum. By immunocytochemistry, unfused Pns6 was localized to plasmodesmata in rice leaves infected with RDV. S6 thus encodes a protein with characteristics identical to those of other viral proteins required for the cell-to-cell movement of their genome and therefore is likely required for the cell-to-cell movement of RDV.

This investigation was designed as an overall study of breast feeding rates and corresponding influencing factors in urban and rural communities in the People's Republic of China. In all 95,578 infants between 0 and 6 months old who lived within 20 different provinces or autonomous regions were subjects for the study which was conducted from March 1983 to August 1985. The findings revealed that breast feeding rates for urban areas were significantly lower than the rates for the rural areas.