结球甘蓝根肿菌鉴定和种质抗性评价

采集湖北省长阳县火烧坪乡根肿病重发区的病土和病根,通过病原菌形态和PCR鉴定,确定是芸薹根肿菌,然后利用欧洲ECD鉴别系统确定生理小种为ECD17/31/13,此病原菌致病力极强。采用田间苗期人工接种鉴定,与田间成株期自然诱发鉴定相结合,对88份甘蓝种质进行抗性评价和筛选,结果表明:苗期获得1份高抗,7份抗病,17份耐病材料;成株期获得4份高抗,4份抗病,15份耐病材料。2个时期88份材料群体抗性鉴定级别基本一致,93.18%材料成株期病指比苗期高。CR21在2个时期均为高抗,抗性最强,表现稳定;CR55在苗期发病最严重,病指达到76.19,成株期为74.10;CR54在成株期发病最严重,病指达到81.54,苗期为75.97,2个时期发病率均达到100%。根肿病菌的鉴定和致病力的确定,及甘蓝种质抗性评价为抗病品种选育和抗病机理的研究奠定基础。     

Molecular and genetic evidence for a tetrapolar mating system in Sparassis latifolia

Sparassis latifolia is a valuable edible fungus cultivated in East Asia that is rich in β-glucans. Understanding the mating system and sexual life cycle is important not only for breeding programs to improve strains but also for studies on speciation and population structures. In the present study, mating experiments using monokaryons derived from two different parental strains were performed. Chi-squared test indicated satisfied Mendel segregation, which supported a tetrapolar mating system. A search in the genome for homologs to the well-defined homeodomain and pheromone/receptors, as well as frequently found flanking genes, resulted in the identification of known mating-type loci previously identified in tetrapolar basidiomycetes, each represented by two idiomorphic alleles on separate contigs. Deficiency of the β-flanking protein in S. latifolia and S. crispa around the MAT-A locus may be explained by the locus being rich in transposable elements adjacent to HD genes. Monokaryotic mycelia are characterized by a slower growth rate and a relative lack of aerial mycelia compared with the parental strain. Chlamydospores can be produced in both monokaryotic and dikaryotic mycelial stages. We provide genetic and molecular evidence for the mating system of S. latifolia, a finding that will be helpful for the cross-breeding of this mushroom.     

‘Aching to be a boy’: A preliminary analysis of gender assignment of intersex persons in India in a culture of son preference

Intersexuality, particularly in the global South, remains an under-researched field of study. In my in-progress doctoral research project, I explore the cultural, social, and medical discourses that influence how key stakeholders such as healthcare providers make decisions about the sex and gender assignment of the intersex child in India. In this paper I interrogate some of these ideas around gender assignment of intersex people in India, paying particular attention to the context of son preference. I am interested in exploring how decisions of gender assignment by medical professionals are guided by ideas of son preference. Focusing on four qualitative, semi-structured, in-depth interviews across two cities with medical doctors from different specializations, this paper is a preliminary attempt to examine some of the factors that guide medical professionals in making decisions about gender assignment of intersex children and explore the dynamics of the decision-making process. Specifically, I explore the factors that inform doctors’ decision-making and locate these decision-making processes within the broader socio-cultural context of India.     

Exposure of Agaricus bisporus to Trichoderma aggressivum f. europaeum leads to growth inhibition and induction of an oxidative stress response

Green mould disease of mushroom, Agaricus bisporus,is caused by Trichodermaspecies and can result in substantial crop losses.Label free proteomic analysis of changes in the abundance of A. bisporusproteins following exposure to T. aggressivumsupernatantin vitroindicated increased abundance of proteins associated with an oxidative stress response (zinc ion binding (+6.6 fold); peroxidase activity (5.3-fold); carboxylic ester hydrolase (+2.4 fold); dipeptidase (+3.2 fold); [2Fe-2S] cluster assembly (+3.3 fold)). Proteins that decreased in relative abundance were associated with growth: structural constituent of ribosome, translation (-12 fold), deadenylation-dependent decapping of nuclear-transcribed mRNA (-3.4 fold), and small GTPase mediated signal transduction (-2.6 fold). In vivoanalysis revealed that 10^-4 T. aggressivuminoculum decreased the mushroom yield by 29% to 56% and 10^-3 T. aggressivuminoculum decreased the mushroom yield by 68% to 100%. Proteins that increased in abundance in A. bisporusin vivofollowing exposure to T. aggressivumindicated an oxidative stress response and included proteins with pyruvate kinase activity (+2.6 fold) and hydrolase activity (+2.1 fold)). The results indicate that exposure of A. bisporusmycelium to T. aggressivum in vitroand in vivoresulted in an oxidative stress response and reduction in growth.     

High salt stress in the upper part of floating mats of Ulva prolifera,a species that causes green tides,enhances non‐photochemical quenching

Salt stress is a major abiotic stress factor that can induce many adverse effects on photosynthetic organisms. Plants and algae have developed several mechanisms that help them respond to adverse environments. Non‐photochemical quenching (NPQ) is one of these mechanisms. The thalli of algae in the intertidal zone that are attached to rocks can be subjected to salt stress for a short period of time due to the rise and fall of the tide. Ulva prolifera causes green tides and can form floating mats when green tides occur and the upper part of the thalli is subjected to high salt stress for a long period of time. In this study, we compared the Ulva prolifera photosynthetic activities and NPQ kinetics when it is subjected to different salinities over various periods of time. Thalli exposed to a salinity of 90 for 4 d showed enhanced NPQ, and photosynthetic activities decreased from 60 min after exposure up to 4 d. This indicated that the induction of NPQ in Ulva prolifera under salt stress was closely related to the stressing extent and stressing time. The enhanced NPQ in the treated samples exposed for 4 d may explain why the upper layer of the floating mats formed by Ulva prolifera thalli were able to survive in the harsh environment. Further inhibitor experiments demonstrated that the enhanced NPQ was xanthophyll cycle and transthylakoid proton gradient‐dependent. However, photosystem II subunit S and light‐harvesting complex stress‐related protein didn't over accumulate and may not be responsible for the enhanced NPQ.     

Assessment of local influence for the analysis of agreement

The concordance correlation coefficient (CCC) and the probability of agreement (PA) are two frequently used measures for evaluating the degree of agreement between measurements generated by two different methods. In this paper, we consider the CCC and the PA using the bivariate normal distribution for modeling the observations obtained by two measurement methods. The main aim of this paper is to develop diagnostic tools for the detection of those observations that are influential on the maximum likelihood estimators of the CCC and the PA using the local influence methodology but not based on the likelihood displacement. Thus, we derive first‐ and second‐order measures considering the case‐weight perturbation scheme. The proposed methodology is illustrated through a Monte Carlo simulation study and using a dataset from a clinical study on transient sleep disorder. Empirical results suggest that under certain circumstances first‐order local influence measures may be more powerful than second‐order measures for the detection of influential observations.     

Salinity-Induced Attenuation in Secondary Metabolites Profile and Herbicidal Potential of Brassica nigra L. on Anagallis arvensis L.

Studies on plant defense mechanisms in stressful conditions predict that plant cope up with increasing stress for survival. Under environmental stress plants interact with problems like competition and survival under resource constraints or utilization of these resources in production of secondary compounds. In this experiment, we examined the costs of defense by evaluating variation in production of secondary compounds of Brassica nigra grown in the saline (B1?=?100 mM NaCl and B2?=?150 mM NaCl) and control (C?=?0 mM) soils and impact of its extracts on weed Anagallis arvensis L. The main allelopathic compounds in Brassica were determined using gas chromatography–mass spectroscopy (GC–MS). The results indicated that A. arvensis was adversely affected by the aqueous extracts of B. nigra. These observations might be related to extracts induced oxidative stress indicated by superoxide (O₂^?) production through nitroblue tetrazolium, cell integrity by Evans blue staining, malondialdehyde estimation by Schiff reagent, lipid peroxidation, lignin deposition, and antioxidant enzyme activities assay. We observed that soil salinity reduced the phytotoxicity of aqueous extract and decreased its potential. The presence of different bioactive compounds improved the natural herbicidal properties of B. nigra and it can be used in various medicinal and agricultural practices.

     

Novel enhancer and promoter elements indispensable for the tissue-specific expression of the sericin-1 gene of the silkworm Bombyx mori

Sericins are glue proteins produced specifically in the middle silk gland (MSG) of the silkworm Bombyx mori, while the silk fiber protein, fibroin, is produced in the posterior silk gland (PSG). These silk proteins are expected to be useful biomaterials in medical technology as well as biotechnology. In this study, we analyzed promoter elements of the sericin-1 gene (ser1) in vivo by introducing reporter constructs into silk glands via gene gun technology. The region from −1602 to +47 was sufficient to induce MSG-specific expression. The 5′ deletion mutants showed a three-step decrease in promoter activity with the key sequences located between −1362 and −1250, −201 and −116, and −115 and −37. We detected a tissue- and stage-specific factor complex (MSG-intermolt-specific complex: MIC) bound to the sequence elements around the −1350, −320, −180, and −70 regions. A mutation in the −70 region, which inhibits MIC-binding, diminished almost all promoter activity, while another mutation that did not inhibit MIC-binding showed no effect on promoter activity. The results suggest that the binding of MIC to the above elements is intrinsic for the spatiotemporal specificity of ser1 in vivo.     

Metformin induces S‐adenosylmethionine restriction to extend the Caenorhabditis elegans healthspan through H3K4me3 modifiers

Metformin, a widely prescribed first‐line drug for the treatment of type II diabetes mellitus, has been shown to extend lifespan and delay the onset of age‐related diseases. The precisely mechanisms by which these effects are realized remain elusive. We find that metformin exposure is restricted to adults, which is sufficient to extend lifespan. However, limiting metformin exposure to the larvae has no significant effect on Caenorhabditis elegans longevity. Here, we show that after metformin treatment, the level of S‐adenosylmethionine (SAM) is reduced in adults but not in the larvae. Potential mechanisms by which reduced SAM might increase lifespan include altering the histone methylation. However, the molecular connections between metformin, SAM limitation, methyltransferases, and healthspan‐associated phenotypes are unclear. Through genetic screening of C. elegans, we find that metformin promotes the healthspan through an H3K4 methyltransferase/demethylase complex to downregulate the targets, including mTOR and S6 kinase. Thus, our studies provide molecular links between meformin, SAM limitation, histone methylation, and healthspan and elucidate the mode action of metformin‐regulated healthspan extension will boost its therapeutic application in the treatment of human aging and age‐related diseases.     

Reduced fire blight susceptibility in apple cultivars using a high‐efficiency CRISPR/Cas9‐FLP/FRT‐based gene editing system

The bacterium Erwinia amylovora, the causal agent of fire blight disease in apple, triggers its infection through the DspA/E effector which interacts with the apple susceptibility protein MdDIPM4. In this work, MdDIPM4 knockout has been produced in two Malus × domestica susceptible cultivars using the CRISPR/Cas9 system delivered via Agrobacterium tumefaciens. Fifty‐seven transgenic lines were screened to identify CRISPR/Cas9‐induced mutations. An editing efficiency of 75% was obtained. Seven edited lines with a loss‐of‐function mutation were inoculated with the pathogen. Highly significant reduction in susceptibility was observed compared to control plants. Sequencing of five potential off‐target sites revealed no mutation event. Moreover, our construct contained a heat‐shock inducible FLP/FRT recombination system designed specifically to remove the T‐DNA harbouring the expression cassettes for CRISPR/Cas9, the marker gene and the FLP itself. Six plant lines with reduced susceptibility to the pathogen were heat‐treated and screened by real‐time PCR to quantify the exogenous DNA elimination. The T‐DNA removal was further validated by sequencing in one plant line. To our knowledge, this work demonstrates for the first time the development and application of a CRISPR/Cas9‐FLP/FRT gene editing system for the production of edited apple plants carrying a minimal trace of exogenous DNA.     

Mechanism underlying the response of fungi and their Fusarium symbiotic networks to the rotations of soybean and corn

Fusarium oxysporum and Fusarium solani are the main soybean root rot pathogens in northern China. We investigated the distribution and driving factors of Fusarium under different cropping systems to evaluate and regulate soil health. The factors affecting Fusarium in soybean cropping systems were assessed using high-throughput sequencing of ITS1 to identify soil microbial population diversity, and then the soil physicochemical properties were assessed to determine the levels of various elements present in the environment. According to the results, the abundance of Fusarium was obviously reduced in the corn–soybean rotation and uncultivated soil systems. The relative abundance of Fusarium in the soil and the abundance and diversity of fungal communities were significantly positively associated with the abundance of Ascomycota. Additionally, the relative abundance of Fusarium was significantly positively correlated with the zinc (Zn) content. When the Zn content was high, the abundance of Fusarium increased, and the correlations with Chaetomium, Cryptococcus, Penicillium and Trichoderma significantly decreased. Soybean yield was significantly negatively correlated with fungal community abundance and diversity. Based on our results, the uncultivated soil and corn–soybean rotation cropping systems improved the organizational structure of the soil fungal community and were conducive to the health and production of soybean.     

MyD88 Signaling in the CNS Is Required for Development of Fatty Acid-Induced Leptin Resistance and Diet-Induced Obesity

Obesity-associated activation of inflammatory pathways represents a key step in the development of insulin resistance in peripheral organs, partially via activation of TLR4 signaling by fatty acids. Here, we demonstrate that palmitate acting in the central nervous system (CNS) inhibits leptin-induced anorexia and Stat3 activation. To determine the functional significance of TLR signaling in the CNS in the development of leptin resistance and diet-induced obesity in vivo, we have characterized mice deficient for the TLR adaptor molecule MyD88 in the CNS (MyD88^ΔCNS). Compared to control mice, MyD88^ΔCNS mice are protected from high-fat diet (HFD)-induced weight gain, from the development of HFD-induced leptin resistance, and from the induction of leptin resistance by acute central application of palmitate. Moreover, CNS-restricted MyD88 deletion protects from HFD- and icv palmitate-induced impairment of peripheral glucose metabolism. Thus, we define neuronal MyD88-dependent signaling as a key regulator of diet-induced leptin and insulin resistance in vivo.     

Choline-containing compounds quantification by 1H NMR spectroscopy using external reference and noise measurements

Proton magnetic resonance spectroscopy (¹H-MRS) is largely exploited in clinical settings to non-invasively investigate chemical compounds in human tissues. Applications of ¹H-MRS in oncology field are connected to the detection of abnormal levels of choline compounds in more active tumours, providing useful information for cancer diagnosis and treatment monitoring. Since benign lesions may also show presence of a choline peak, implementing absolute evaluation will help differentiating benign from malignant tumours. An external reference procedure was described to provide choline quantification in standard unit of measurements. Spectra were acquired on a 1.5 T scanner using both phantoms and healthy volunteers with a PRESS sequence. The implemented quantification procedure used metabolite and noise measurements on the spectrum to remove large part of scanner settings contributing to metabolites of interest. A standard quantification was also used to compare performances of the noise-based method. In vitro quantification had accuracy and precision in the range (95–99)% and (5–13)%, respectively. When applied to in vivo studies on healthy volunteers, the method provided very close values of choline concentration, more exactly (1.73 ± 0.24) mmol/l. The method proposed can quantify the proper choline content in phantoms as well as in human structures, as brain. The method is ease of use, computational costless and it can be rapidly calibrated and implemented in any centre.     

A Highlights from MBoC Selection: Nucleotide- and Protein-Dependent Functions of Actg1

Cytoplasmic β- and γ-actin proteins are 99% identical but support unique organismal functions. The cytoplasmic actin nucleotide sequences Actb and Actg1, respectively, are more divergent but still 89% similar. Actb^–/– mice are embryonic lethal and Actb^–/– cells fail to proliferate, but editing the Actb gene to express γ-actin (Actb^c–g) resulted in none of the overt phenotypes of the knockout revealing protein-independent functions for Actb. To determine if Actg1 has a protein-independent function, we crossed Actb^c–g and Actg1^–/– mice to generate the bG/0 line, where the only cytoplasmic actin expressed is γ-actin from Actb^c–g. The bG/0 mice were viable but showed a survival defect despite expressing γ-actin protein at levels no different from bG/gG with normal survival. A unique myopathy phenotype was also observed in bG/0 mice. We conclude that impaired survival and myopathy in bG/0 mice are due to loss of Actg1 nucleotide-dependent function(s). On the other hand, the bG/0 genotype rescued functions impaired by Actg1^–/–, including cell proliferation and auditory function, suggesting a role for γ-actin protein in both fibroblasts and hearing. Together, these results identify nucleotide-dependent functions for Actg1 while implicating γ-actin protein in more cell-/tissue-specific functions.