The interrelationships between rhizobacteria and arbuscular mycorrhizal fungi and their importance in the integrated management of nematodes and soilborne plant pathogens

A total of 62 bacterial isolates were isolated from surface sterilized AMF spores, which were previously extracted from tomato fields in Nakhon Ratchasima Province of Thailand. These spore-associated bacteria were tested for their antagonistic potential against the root-knot nematode Meloidogyne incognita and the soilborne plant pathogens Fusarium oxysporum, Pythium aphanidermatum, Pythium ultimum and Rhizoctonia solani. A high percentage of the bacterial isolates (14,5%) reduced nematode penetration of tomato roots in repeated experiments. Two of these antagonistic bacteria were further tested in a long-term experiment, either alone or in combination with Glomus intraradices. Single inoculations resulted in low or even no biological control, but both dual inoculations reduced gall and eggmass production. Twelve bacteria (19,4%) inhibited fungal growth of at least one pathogen in vitro and six isolates showed antagonistic potential against all pathogens tested. The seven isolates that inhibited growth of Fusarium oxyporum in vitro were tested in vivo against the same pathogen. Three of these seven bacteria reduced the reisolation rate of the pathogen and therefore inhibited fungal spread in the tomato stem. The PHPR Rhizobium etli G12, inducing resistance against M. incognita, was found to promote establishment of G. intraradices on three different tomato cultivars. The bacterium appears to accelerate AMF colonization of the root, and therefore should be regarded a Mycorrhiza helper bacterium (MHB). In in vitro studies, R. etli stimulated AMF sporulation and hyphal branching, the latter of which is an important prerequisite for penetration of the host roots. This direct effect of the bacterium on fungal morphology is one explanation for the increased mycorrhiza establishment, but a plant-mediated effect can not be excluded. The combination of G. intraradices with R. etli enhanced biocontrol of M. incognita on tomato, in comparison to single inoculations. The better mycorrhization of the young transplants and the combination of different modes of action could be the explanations of the increased antagonistic potential.Die Wechselbeziehungen zwischen Rhizosphärenbakterien und arbuskulären Mykorrhizapilzen und ihre Bedeutung in der integrierten Bekämpfung von Nematoden und bodenbürtigen pilzlichen Schaderregern Insgesamt 62 Bakterienisolate wurden von oberflächensterilisierten Mykorrhizasporen isoliert, die zuvor aus Tomatenfeldern in der Nakhon Ratchasima Province in Thailand extrahiert wurden. Diese sporenassoziierten Bakterien wurden auf ihr antagonistisches Potential gegenüber dem Wurzelgallennematoden Meloidogyne incognita und den bodenbürtigen Schaderregern Fusarium oxysporum, Pythium aphanidermatum, Pythium ultimum und Rhizoctonia solani untersucht. Ein hoher Prozentsatz (14,5%) der Bakterienisolate reduzierte wiederholt die Eindringung des Nematoden in die Tomatenwurzel. Zwei dieser Isolate wurden in einem Langzeitexperiment erneut getestet, entweder allein oder in Kombination mit Glomus intraradices. Die Einzelinokulationen führten zu keinem oder nur geringem Bekämpfungserfolg. Demgegenüber führte die Kombination der Mikroorganismen in beiden Fällen zu einer signifikanten Reduzierung der Gallen- und Eiermassenbildung. Zwölf der sporenassoziierten Bakterien (19,4%) hemmten das pilzliche Wachstum zu mindest eines Phytopathogens in vitro und sechs Bakterienisolate zeigten antagonistisches Potential gegen alle getesteten pilzlichen Schaderreger. Sieben Isolate, die das Wachstum von Fusarium oxysporum in vitro gehemmt hatten, wurden gegen das gleiche Phytopathogen in vivo getestet. Drei dieser Bakterien reduzierten die Rückisolationsrate des Pathogens und hemmten daher die Ausbreitung des Pilzes im Tomatenspross. Das Bakterium Rhizobium etli G12, welches Resistenz gegen M. incognita induziert, förderte die Etablierung von G. intraradices an vier verschiedenen Tomatensorten. Durch das Bakterium scheint die Pflanzenwurzel schneller mit Mykorrhiza kolonisiert zu werden und daher sollte es als Mykorrhiza förderndes Bakterium betrachtet werden. In in vitro Studien stimulierte R. etli die Sporulation des AMP und die Anzahl der Hyphenverzweigungen. Dieser direkte Effekt des Bakteriums auf die Pilzmorphologie ist eine Erklärung für die geförderte Etablierung des AMP, da eine erhöhte Hyphenverzweigung die Präinfektionsphase des Pilzes einleitet. Es kann aber nicht ausgeschlossen werden, dass Effekte die über die Pflanze vermittelt werden eine Rolle in der Mykorrhizaförderung spielen. Die Kombination von G. intraradices mit R. etli erhöhte den Bekämpfungserfolg von M. incognita an Tomate, gegenüber den Einzelinokulationen. Die bessere Mykorrhizierung der Jungpflanzen und die Kombination verschiedener Wirkungsmechanismen könnte eine Erklärung für das erhöhte antagonistische Potential sein

Robust extraction of baseline signal of atmospheric trace species using local regression

The identification of atmospheric trace species measurements that are representative of well-mixed background air masses is required for monitoring atmospheric composition change at background sites. We present a statistical method based on robust local regression that is well suited for the selection of background measurements and the estimation of associated baseline curves. The bootstrap technique is applied to calculate the uncertainty in the resulting baseline curve. The non-parametric nature of the proposed approach makes it more flexible than other commonly used statistical data filtering methods. Application to carbon monoxide (CO) measured from 1996 to 2009 at the high-alpine site Jungfraujoch (Switzerland, 3580m asl.), and to measurements of 1,1-difluoroethane (HFC-152a) from Jungfraujoch (2000 to 2009) and Mace Head (Ireland, 1995 to 2009) demonstrates the feasibility and usefulness of the proposed approach. The determined average annual change of CO at Jungfraujoch for the 1996 to 2009 period as estimated from filtered annual mean CO concentrations is -2.2 1.1 ppb/yr. For comparison, the linear trend of unfiltered CO measurements at Jungfraujoch for this time period is -2.9 1.3 ppb/yr

Abrupt reversal in emissions and atmospheric abundance of HCFC-133a (CF3CH2Cl)

Hydrochlorofluorocarbon HCFC-133a (CF3CH2Cl) is an anthropogenic compound whose consumption for emissive use is restricted under the Montreal Protocol. A recent study showed rapidly increasing atmospheric abundances and emissions. We report that, following this rise, the at- mospheric abundance and emissions have declined sharply in the past three years. We find a Northern Hemisphere HCFC-133a increase from 0.13 ppt (dry air mole fraction in parts-per-trillion) in 2000 to 0.50 ppt in 2012–mid-2013 followed by an abrupt reversal to 0.44 ppt by early 2015. Global emissions derived from these observations peaked at 3.1 kt in 2011, followed by a rapid decline of 0.5 kt yr−2 to 1.5 kt yr−1 in 2014. Sporadic HCFC-133a pollution events are detected in Europe from our high-resolution HCFC-133a records at three European stations, and in Asia from sam- ples collected in Taiwan. European emissions are estimated to be <0.1 kt yr−1 although emission hotspots were identi- fied in France

Na(+)-D-glucose cotransporter SGLT1 is pivotal for intestinal glucose absorption and glucose-dependent incretin secretion.

To clarify the physiological role of Na(+)-D-glucose cotransporter SGLT1 in small intestine and kidney, Sglt1(-/-) mice were generated and characterized phenotypically. After gavage of d-glucose, small intestinal glucose absorption across the brush-border membrane (BBM) via SGLT1 and GLUT2 were analyzed. Glucose-induced secretion of insulinotropic hormone (GIP) and glucagon-like peptide 1 (GLP-1) in wild-type and Sglt1(-/-) mice were compared. The impact of SGLT1 on renal glucose handling was investigated by micropuncture studies. It was observed that Sglt1(-/-) mice developed a glucose-galactose malabsorption syndrome but thrive normally when fed a glucose-galactose-free diet. In wild-type mice, passage of D-glucose across the intestinal BBM was predominantly mediated by SGLT1, independent the glucose load. High glucose concentrations increased the amounts of SGLT1 and GLUT2 in the BBM, and SGLT1 was required for upregulation of GLUT2. SGLT1 was located in luminal membranes of cells immunopositive for GIP and GLP-1, and Sglt1(-/-) mice exhibited reduced glucose-triggered GIP and GLP-1 levels. In the kidney, SGLT1 reabsorbed ∼3% of the filtered glucose under normoglycemic conditions. The data indicate that SGLT1 is 1) pivotal for intestinal mass absorption of d-glucose, 2) triggers the glucose-induced secretion of GIP and GLP-1, and 3) triggers the upregulation of GLUT2

The increasing atmospheric burden of the greenhouse gas sulfur hexafluoride (SF&lt;sub&gt;6&lt;/sub&gt;)

We report a 40-year history of SF6 atmospheric mole fractions measured at the Advanced Global Atmospheric Gases Experiment (AGAGE) monitoring sites, combined with archived air samples, to determine emission estimates from 1978 to 2018. Previously we reported a global emission rate of 7.3±0.6 Gg yr-1 in 2008 and over the past decade emissions have continued to increase by about 24% to 9.04±0.35 Gg yr-1 in 2018. We show that changing patterns in SF6 consumption from developed (Kyoto Protocol Annex-1) to developing countries (non-Annex-1) and the rapid global expansion of the electric power industry, mainly in Asia, have increased the demand for SF6-insulated switchgear, circuit breakers, and transformers. The large bank of SF6 sequestered in this electrical equipment provides a substantial source of emissions from maintenance, replacement, and continuous leakage. Other emissive sources of SF6 occur from the magnesium, aluminium, and electronics industries as well as more minor industrial applications. More recently, reported emissions, including those from electrical equipment and metal industries, primarily in the Annex-1 countries, have declined steadily through substitution of alternative blanketing gases and technological improvements in less emissive equipment and more efficient industrial practices. Nevertheless, there are still demands for SF6 in Annex-1 countries due to economic growth, as well as continuing emissions from older equipment and additional emissions from newly installed SF6-insulated electrical equipment, although at low emission rates. In addition, in the non-Annex-1 countries, SF6 emissions have increased due to an expansion in the growth of the electrical power, metal, and electronics industries to support their continuing development. There is an annual difference of 2.5-5 Gg yr-1 (1990-2018) between our modelled top-down emissions and the UNFCCC-reported bottom-up emissions (United Nations Framework Convention on Climate Change), which we attempt to reconcile through analysis of the potential contribution of emissions from the various industrial applications which use SF6. We also investigate regional emissions in East Asia (China, S. Korea) and western Europe and their respective contributions to the global atmospheric SF6 inventory. On an average annual basis, our estimated emissions from the whole of China are approximately 10 times greater than emissions from western Europe. In 2018, our modelled Chinese and western European emissions accounted for ∼36% and 3.1 %, respectively, of our global SF6 emissions estimate.NASA (Grant NAG5-12669, NNX07AE89G and NNX11AF17G)NOAA (Contract RA-133R-15-CN-0008

Olfactory Receptors in Non-Chemosensory Organs: The Nervous System in Health and Disease

Olfactory receptors (ORs) and down-stream functional signaling molecules adenylyl cyclase 3 (AC3), olfactory G protein \u3b1 subunit (G\u3b1olf), OR transporters receptor transporter proteins 1 and 2 (RTP1 and RTP2), receptor expression enhancing protein 1 (REEP1), and UDP-glucuronosyltransferases (UGTs) are expressed in neurons of the human and murine central nervous system (CNS). In vitro studies have shown that these receptors react to external stimuli and therefore are equipped to be functional. However, ORs are not directly related to the detection of odors. Several molecules delivered from the blood, cerebrospinal fluid, neighboring local neurons and glial cells, distant cells through the extracellular space, and the cells' own self-regulating internal homeostasis can be postulated as possible ligands. Moreover, a single neuron outside the olfactory epithelium expresses more than one receptor, and the mechanism of transcriptional regulation may be different in olfactory epithelia and brain neurons. OR gene expression is altered in several neurodegenerative diseases including Parkinson's disease (PD), Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and sporadic Creutzfeldt-Jakob disease (sCJD) subtypes MM1 and VV2 with disease-, region- and subtype-specific patterns. Altered gene expression is also observed in the prefrontal cortex in schizophrenia with a major but not total influence of chlorpromazine treatment. Preliminary parallel observations have also shown the presence of taste receptors (TASRs), mainly of the bitter taste family, in the mammalian brain, whose function is not related to taste. TASRs in brain are also abnormally regulated in neurodegenerative diseases. These seminal observations point to the need for further studies on ORs and TASRs chemoreceptors in the mammalian brain