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Histamine is an important monoamine neurotransmitter that regulates multiple physiological activities in both vertebrates and invertebrates. Clearance and recycling of histamine are critical for sustaining histaminergic transmission. However, unlike other monoamine neurotransmitters, a histamine-specific transporter capable of clearing histamine from the synaptic cleft has not been identified. Here, through an in vitro histamine uptake screening, we identified an epithelial glia–expressing transporter, HisT ( His tamine T ransporter), that specifically transports histamine into cells. HisT misexpression in both pre- and postsynaptic neurons revealed a critical in vivo role for HisT in histamine transport and synaptic transmission. Last, we generated null hist alleles and demonstrated key physiological roles of HisT in maintaining histamine pools and sustaining visual transmission when the de novo synthesis of histamine synthesis was reduced. Our work identifies the first transporter that specifically recycles histamine and further indicates that the histamine clearance pathway may involve both the uptake-1 and uptake-2 transport systems.

Strawberry is economically important. Anthracnose caused by Colletotrichum spp. has been a serious threat to this crop globally. To detect and distinguish latent Colletotrichum spp. infection on asymptomatic plants at an affordable cost is crucial for this disease control and the sustainability of strawberry industry. Loop-mediated isothermal amplification (LAMP) assay is superior for the higher sensitiveness, efficiency, and lower cost than other methods for pathogen diagnosis. In this study, six previously reported barcodes were evaluated against DNA templates from strawberry fungal pathogens including six Colletotrichum species and five beyond this genus, and further verified in 40 Colletotrichum isolates. Based on the discernibility revealed, a LAMP assay was developed for the diagnosis of Colletotrichum spp. by designing six primers recognizing the conserved regions in β-tubulin 2 gene from 13 Colletotrichum species of C. gloeosporioides and C. acutatum complexes. The specificity and accuracy of LAMP assay was tested against six Colletotrichum species of two complexes, with a detection sensitivity of 100 pg/μL genomic DNA. Current LAMP assay beginning with a 10 min plant lysis enabled a direct and quick diagnosis of Colletotrichum spp. in strawberry within one hour. Followed by PCR using primers specific to ApMat, Marker 2, and Marker 1, this assay could specifically differentiate Colletotrichum species, at least for the dominant species C. fructicola and C. siamense in China, realizing a diagnosis of latent infection at a species level. Current LAMP-PCR combined protocol allows for a sensitive and efficient detection and differentiation of latent Colletotrichum infection on strawberry, which will be useful for disease management and monitoring pathogen population.

Neurotransmitters are generated by de novo synthesis and are essential for sustained, high-frequency synaptic transmission. Histamine, a monoamine neurotransmitter, is synthesized through decarboxylation of histidine by histidine decarboxylase (Hdc). However, little is known about how histidine is presented to Hdc as a precursor. Here, we identified a specific histidine transporter, TADR (torn and diminished rhabdomeres), which is required for visual transmission in

In this study, we propose a parallel processing method for analyzing video-image radiation-response signals and suppressing radiation noise. We studied the linear-representation law of various image-information components on the radiation dose rate. Subsequently, the simulation images were used to examine the response-signal extract and radiation-noise suppression. The results indicate that the majority of response signals in the global image comprise forward superposition. The peak signal-to-noise ratio of the red channel was significantly improved when the noise signal-substitution algorithm and median filter were applied successively. Real-time radiation dose-rate measurements and clear images under irradiation can be obtained simultaneously.

Polyglutamine diseases are neurodegenerative diseases caused by the expansion of polyglutamine (polyQ) tracts within different proteins. Although multiple pathways have been found to modulate aggregation of the expanded polyQ proteins, the mechanisms by which polyQ tracts induced neuronal cell death remain unknown. We conducted a genome-wide genetic screen to identify genes that suppress polyQ-induced neurodegeneration when mutated. Loss of the scaffold protein RACK1 alleviated cell death associated with the expression of polyQ tracts alone, as well as in models of Machado-Joseph disease (MJD) and Huntington’s disease (HD), without affecting proteostasis of polyQ proteins. A genome-wide RNAi screen for modifiers of this rack1 suppression phenotype revealed that knockdown of the E3 ubiquitin ligase, POE (Purity of essence), further suppressed polyQ-induced cell death, resulting in nearly wild-type looking eyes. Biochemical analyses demonstrated that RACK1 interacts with POE and ERK to promote ERK degradation. These results suggest that RACK1 plays a key role in polyQ pathogenesis by promoting POE-dependent degradation of ERK, and implicate RACK1/POE/ERK as potent drug targets for treatment of polyQ diseases., Author summary Polyglutamine (polyQ) diseases are neurodegenerative diseases caused by the expansion of glutamine repeats in specific proteins. After >100 years of effort trying to decipher the pathogenesis of polyQ diseases, the mechanisms by which these mutant proteins induced neuronal death are still unknown. Here, we performed a genome-wide genetic screen in Drosophila for mutations that alleviate polyQ cytotoxicity. We found that a mutation in the gene rack1, which encodes a scaffold protein, suppressed polyQ-induced neurodegeneration when polyQ tracts were expresses, and in models of HD and MJD. Importantly, this effect was seen without clearance of the polyQ proteins. Further, we found that RACK1 binds both the E3 ubiquitin ligase POE and ERK, thereby promoting ERK degradation. These data suggest that the RACK1/POE/ERK pathway is involved in pathogenesis of polyQ diseases, and identify RACK1/POE/ERK as potential therapeutic targets for treating polyQ diseases.

Systemic fungicides and antifungals are used as frontline treatments for fungal diseases in plants and humans. It is generally accepted that fungicides will bring significant negative side-effects to the environment and result in fungicide resistance in the pathogenic fungi. Although previous research has focused on fungicide application rates and fungal resistance for a long time, little attention has been paid to fungicide residues after treatment, especially their potential role in fungal growth and sporulation. Here we investigated the effect of fungicides at sublethal concentrations on fungal sporulation. The results showed that two kinds of 14α-demethylase inhibitors (DMIs) fungicides increased the number of isolates of Colletotrichum spp. to sporulate on PDA. Both on PDA medium and plant tissue, low concentration of DMI fungicides could promote spore production of Colletotrichum spp., whereas pyraclostrobin, a quinone outside inhibitor (QoIs), had no significant effects on sporulation of Colletotrichum spp. Transcriptomic analysis suggested that the DMIs fungicide stress signal may be transmitted to the central regulatory pathway through the FluG-mediated signalling pathway, and further confirmed the morphological effect of DMI fungicide on promoting sporulation of Colletotrichum. To our knowledge, this is the first study to provide insights into the reproductive response of fungi in response to fungicide stress. Our findings indicate that fungicides have two-way effects on the growth and reproduction of pathogenic fungi and provide a new basis for the scientific and rational use of fungicides.

The ascomycete fungus Colletotrichum gloeosporioides is a devastating plant pathogen with a wide host range and worldwide distribution. Carbendazim has been widely used to control anthracnose caused by the C. gloeosporioides complex in China for more than 30 years and resistance to carbendazim has been reported in China. A total of 125 Colletotrichum isolates of strawberry and yam were collected from different geographical regions in Hubei Province, China. Approximately 52.8% of Colletotrichum spp. isolates showed resistance to carbendazim. The isolates tested in this study belong to four species, and the frequencies of resistant isolates differed across Colletotrichum species. Resistant isolates were found in C. siamense and C. fructicola. In contrast, all isolates of C. gloeosporioides and C. aenigma were sensitive to carbendazim. Highly carbendazim-resistant isolates harbored the E198A mutation in the β-tubulin 2 (TUB2) gene, whereas moderately carbendazim-resistant isolates harbored the F200Y mutation in the TUB2 gene. Carbendazim-sensitive Colletotrichum isolates in this study were not genetically similar enough to form a separate cluster from resistant isolates. The result of this study emphasizes the importance of knowing which Colletotrichum sp. is present, when strategies for disease control are made.

Our previous study identified a hypovirulent strain QT5-19 of Botrytis cinerea, the causal agent of the plant gray mold disease, and found that QT5-19 can produce volatile organic compounds (VOCs) with high antifungal activity and high control efficacy against B. cinerea. However, impact of the QT5-19 VOCs on plant growth remains unknown. This study was conducted to investigate the impact of the QT5-19 VOCs on tomato growth, and to elucidate the mechanisms for the plant growth-promoting (PGP) activity of the QT5-19 VOCs. Results showed that compared to the control treatment, the QT5-19 VOCs significantly (P < 0.05) promoted tomato growth, and the PGP activity of the QT5-19 VOCs acted in dose- and time-dependent manners. Results also showed that the values of photosynthetic assimilation, stomatal conductance and transpiration, water use efficiency and chlorophyll content in the treatments of the QT5-19 VOCs were significantly (P < 0.05) higher than the corresponding values in the control treatment. The QT5-19 VOCs up-regulated expression of the genes for expansins (EXP2, EXP9 and EXP18), IAA (SlIAA1, SlIAA3 and SlIAA9), cytokinins (SlCKX1) and gibberellins in leaves and/or roots, whereas down-regulated expression of the gene ACO1 for ethylene in both organs. Moreover, enhanced accumulation of auxins and decreased accumulation of ethylene were observed in tomato roots in the treatment of the QT5-19 VOCs, compared to the control treatment. These results suggest that the QT5-19 VOCs probably promote tomato growth through improving photosynthesis and biosynthesis of expansins and IAA, and reducing ethylene biosynthesis. This study suggests that QT5-19 is a versatile biocontrol control agent.

The PacC/Rim101 pH-responsive transcription factor is an important pathogenicity element for many plant-pathogenic fungi. In this study, we investigated the roles of a PacC homologue, CmpacC, in the mycoparasitic fungus Coniothyrium minitans. CmpacC was confirmed to have the transcriptional activation activity by the transcriptional activation test in Saccharomyces cerevisiae. Disruption of CmpacC resulted in impaired fungal responses to ambient pH. Compared to the wild-type, the CmpacC-disruption mutant ΔCmpacC-29 was significantly suppressed for activities of chitinase and β-1,3-glucanase at pH 5 and 7, consistent with reduced expression levels of Cmch1 and Cmg1 coding for the two enzymes respectively. However, the mutant displayed acidity-mimicking phenotypes such as improved oxalate degradation and increased antifungal activity at pH 6 or higher. Improved efficacy in oxalate degradation by ΔCmpacC-29 was consistent with the enhanced expression level of Cmoxdc1 coding for oxalate decarboxylase. CmpacC transcriptional activation of Cmch1 and Cmg1 and repression of Cmoxdc1 were verified by the presence of the PacC/Rim101 consensus binding-motifs in gene promoter regions and by the promoter DNA-binding assays. This study suggests that CmpacC plays an activator role in regulation of C. minitans mycoparasitism, whereas plays a repressor role in regulation of oxalate degradation and possibly antifungal activity of C. minitans.

In this paper, a new Improved Hybrid Gravitational Search Algorithm (IHGSA) is proposed. First, the influence of the learning factor on global exploration and the local exploitation of the algorithm is analyzed, and the parameter adjustment mechanism which can balance the two search capabilities is designed reasonably. Secondly, the PSO is embedded into the Gravitational Search Algorithm (GSA), and an Improved Hybrid Gravitational Search Algorithm (IHGSA) is proposed. Finally, 21 benchmark test functions are programmed and calculated in comparison with the results of the Gravity Search Algorithm (GSA). The numerical results show that the new algorithm balanced the global exploration and local exploitation. The IHGSA are also better than the Gravity Search Algorithm (GSA) in convergence rate and convergence accuracy.

The recycling of neurotransmitters is essential for sustained synaptic transmission. In Drosophila, histamine recycling is required for visual synaptic transmission. Synaptic histamine is rapidly taken up by laminar glia, and is converted to carcinine. After delivered back to photoreceptors, carcinine is hydrolyzed to release histamine and β-alanine. This histamine is repackaged into synaptic vesicles, but it is unclear how the β-alanine is returned to the laminar glial cells. Here, we identified a new β-alanine transporter, which we named BalaT (Beta-alanine Transporter). Null balat mutants exhibited lower levels of β-alanine, as well as less β-alanine accumulation in the retina. Moreover, BalaT is expressed and required in retinal pigment cells for maintaining visual synaptic transmission and phototaxis behavior. These results provide the first genetic evidence that retinal pigment cells play a critical role in visual neurotransmission, and suggest that a BalaT-dependent β-alanine trafficking pathway is required for histamine homeostasis and visual neurotransmission. DOI: http://dx.doi.org/10.7554/eLife.29146.001, eLife digest Neurons transmit information around the body in the form of electrical signals, but these signals cannot cross the gaps between neurons. To send a message to its neighbor, a neuron releases a molecule known as a neurotransmitter into the gap between the cells. The neurotransmitter binds to proteins on the recipient neuron and triggers new electrical signals inside that cell. When the message has been received, the neurotransmitter molecules are returned to the first neuron so that they can be reused. This recycling is particularly important in the visual system, where neurons communicate via rapid-fire signaling. In fruit flies, for example, light-sensitive neurons in the eye known as photoreceptors release a neurotransmitter called histamine when they detect light. Supporting cells called laminar glia take up any leftover histamine and combine it with another molecule known as β-alanine to form a larger molecule. The photoreceptors absorb this larger molecule and break it back down into histamine and β-alanine. However, it is not clear how the β-alanine returns to the glia to allow this cycle to continue. Many molecules rely on so-called “transporter” proteins to help them move into or out of cells. To identify transporters that might help to move β-alanine, Han, Xiong et al. prepared a list of fruit fly genes that encode transporter proteins found inside the insect’s head. Testing the resulting proteins in a cultured cell system revealed that one of them was able to transport β-alanine. This protein, named BalaT, is found in another type of support cell called retinal pigment cells. Mutant flies that cannot produce BalaT are blind because their photoreceptors have problems in transmitting information to other neurons. Han, Xiong et al. propose that BalaT transports β-alanine from photoreceptors to retinal pigment cells, which then pass β-alanine on to the laminar glia. Follow-up studies are required to find out exactly how the laminar glia take up histamine. DOI: http://dx.doi.org/10.7554/eLife.29146.002

Coniothyrium minitans (Cm) is a mycoparasite of the phytopathogenic fungus Sclerotinia sclerotiorum (Ss). Ss produces a virulence factor oxalic acid (OA) which is toxic to plants and also to Cm, and Cm detoxifies OA by degradation. In this study, two oxalate decarboxylase genes, Cmoxdc1 and Cmoxdc2, were cloned from Cm strain Chy-1. OA and low pH induced expression of Cmoxdc1, but not Cmoxdc2. Cmoxdc1 was partially responsible for OA degradation, whereas Cmoxdc2 had no effect on OA degradation. Disruption of Cmoxdc1 in Cm reduced its ability to infect Ss in dual cultures where OA accumulated. Compared with Chy-1, the Cmoxdc1-disrupted mutants had reduced expression levels of two mycoparasitism-related genes chitinase (Cmch1) and β-1,3-glucanase (Cmg1), and had no detectable activity of extracellular proteases in the presence of OA. On the other hand, the cultural filtrates of the Cmoxdc1-disrupted mutants in OA-amended media showed enhanced antifungal activity, possibly because of increased production of antifungal substances under acidic pH condition resulted from reduced Cmoxdc1-mediated OA degradation. This study provides direct genetic evidence of OA degradation regulating mycoparasitism and antibiosis of Cm against Ss, and sheds light on the sophisticated strategies of Cm in interacting with metabolically active mycelia and dormant sclerotia of Ss.

NiO nanospheres have been synthesized by using magnetic stirring and ultrasound methods. The structure and morphology of synthesized samples were characterized by X-ray diffraction, scanning electron microscopy and high resolution transmission electron microscopy. The results show the NiO nanospheres prepared by the ultrasonic method are far less than that prepared by the stirring method. Moreover, in the presence of surfactant, the average diameter of NiO nanospheres prepared by the ultrasonic method is only 1–3 nm. The capacitance of NiO electrodes was investigated with cyclic voltammetry. The NiO prepared by the ultrasonic method exhibited higher specific capacitance of ~260 F g −1 at 1 A g −1 current density.

Coniothyrium minitans is a mycoparasite and a promising biocontrol agent of Sclerotinia sclerotiorum, an omniovorous plant pathogenic fungus. Our previous studies indicate that mycoparasitism and antibiosis of C. minitans are greatly affected by ambient pH, implying that a pH-regulatory system may exist in C. minitans. In this study, we cloned a putative pH-responsive transcription factor gene, cmpacC, from strain Chy-1 of C. minitans. The full-length DNA sequence of cmpacC (GenBank Acc. No. FJ176399) has one open reading frame (ORF) and two introns. cmpacC putatively encodes a polypeptide with 596 amino acid residues (GenBank Acc. No. ACN43303). The sequence of this polypeptide has three conserved zinc finger domains. Meanwhile, a 2,740 bp-long 5′ flanking sequence of cmpacC was obtained. It contains five copies of PacC binding sequences (5′-GCCAAG-3′). Real-time RT-PCR analysis indicated that with the increase of ambient pH from 3 to 8, expression of cmpacC, as well as the chitinase gene (cmch1) and the β-1,3-glucanase gene (cmg1), increased consistently in C. minitans. Cloning of cmpacC from C. minitans suggests that the conserved pH-dependent signaling pathway might exist in C. minitans. It provides a clue for further deciphering of the pH-regulatory mechanism responsible for the pH-associated interaction between C. minitans and S. sclerotiorum.

Antifungal activity (AA) of the mycoparasite Coniothyrium minitans (CM) against Sclerotinia sclerotiorum (SS), designated as AA CM–SS , was detected by measuring the effect of cell-free cultural filtrates of CM on inhibition of growth (IG) of SS on potato dextrose agar. Using this bioassay method, effects of ambient pH and nutritional factors on AA CM–SS in CM cultures grown in various liquid media were investigated. Results showed that production of AA CM–SS by CM was closely related to ambient pH. After incubation for 9–15 days, AA CM–SS was high in modified Czapek–Dox broth (MCD) with IG values being 78–90%, but low in potato dextrose broth (PDB) with IG values being 9–18%. In contrast, pH value was as low as 3.3–3.6 in the MCD cultures, whereas as high as 6.0–7.2 in the PDB cultures. In the pH-buffered experiment, AA CM–SS was detected in MCD cultures of CM buffered at pH 2–8 with the optimum pH being 3–5, under which AA CM–SS in PDB cultures of CM was greatly enhanced with the IG values reaching up to 46–67%. Results also indicated that AA CM–SS in CM cultures can be affected by nutritional factors and their effects were also related to ambient pH. In the basal medium Czapek mineral salts, most carbon and nitrogen sources investigated were favourable to CM to produce AA CM–SS with the IG values being 73–91% and the final pH values being 2.7–4.1. In the other basal medium potato extracts, a few carbon and nitrogen sources were favourable for CM to produce AA CM–SS with the IG values being 40–60% and the final pH values being 2.7–5.5. In the pH-buffered experiments with selected carbon and nitrogen sources, or with mycelial or sclerotial extracts of SS, AA CM–SS was much higher in CM cultures buffered at pH 3 than that buffered at pH 6. Additional experiments showed that AA CM–SS could be induced by the phytotoxin oxalic acid (OA), but not by sodium oxalate, further suggesting the importance of acidic pH in production of AA CM–SS by CM. Meanwhile, leaf blight incidence on Chinese cabbage caused by SS was greatly reduced in the treatment of CM conidia pre-germinated in PDB plus OA (16 mM) than that in the treatment of CM conidia pre-germinated in PDB alone. This study suggests that ambient pH plays an important role in regulation of the antifungal activity of CM against SS.

The PacC/Rim101 pH-responsive transcription factor is an important pathogenicity element for many plant-pathogenic fungi. In this study, we investigated the roles of a PacC homologue, CmpacC, in the mycoparasitic fungus Coniothyrium minitans. CmpacC was confirmed to have the transcriptional activation activity by the transcriptional activation test in Saccharomyces cerevisiae. Disruption of CmpacC resulted in impaired fungal responses to ambient pH. Compared to the wild-type, the CmpacC-disruption mutant ΔCmpacC-29 was significantly suppressed for activities of chitinase and β-1,3-glucanase at pH 5 and 7, consistent with reduced expression levels of Cmch1 and Cmg1 coding for the two enzymes respectively. However, the mutant displayed acidity-mimicking phenotypes such as improved oxalate degradation and increased antifungal activity at pH 6 or higher. Improved efficacy in oxalate degradation by ΔCmpacC-29 was consistent with the enhanced expression level of Cmoxdc1 coding for oxalate decarboxylase. CmpacC transcriptional activation of Cmch1 and Cmg1 and repression of Cmoxdc1 were verified by the presence of the PacC/Rim101 consensus binding-motifs in gene promoter regions and by the promoter DNA-binding assays. This study suggests that CmpacC plays an activator role in regulation of C. minitans mycoparasitism, whereas plays a repressor role in regulation of oxalate degradation and possibly antifungal activity of C. minitans.