Purification,characterization and comparison of glutathione S-transferases from black-grass (Alopecurus myosuroides Huds) biotypes     

John P H Reade  Andrew H Cobb 《Pest management science》1999,55(10):993-999

In the UK biotypes of black-grass (Alopecurus myosuroides Huds) showing resistance to both chlorotoluron (CTU) and aryloxyphenoxypropionate graminicides are increasingly being observed. Although the precise mechanisms involved in this resistance have yet to be identified, increased herbicide metabolism has been implicated as being involved in at least some cases of resistance. Glutathione S-transferases (GSTs) are a group of enzymes which have been demonstrated to metabolise herbicides in some plants, and the resistant black-grass biotype Peldon contains approximately double the GST activity towards 1-chloro-2,4-dinitrobenzene (CDNB) of susceptible biotypes. To investigate further the possible role of GSTs in herbicide resistance in black-grass, a purification procedure has been developed for these enzymes. A 27.5 kDa polypeptide possessing GST activity was purified from the susceptible biotype Herbiseed. Purification of GSTs from the resistant biotype Peldon also identified this polypeptide along with an additional 30 kDa polypeptide. An in-vitro kinetic study of both crude and purified GST extracts, and western blot analysis using antisera raised against the 27.5 kDa polypeptide, suggest that the 30 kDa polypeptide may possess GST activity, and is not a precursor of the 27.5 kDa polypeptide. These results are discussed and compared to GST profiles for other weeds and crops demonstrating herbicide resistance or tolerance. © 1999 Society of Chemical Industry  相似文献   

Impact of Distillery Effluent on Soil Carbon and Nitrogen Dynamics in a Vertisol of Central India     

AK Biswas  Pankaj Sharma  KM Hati  S Ramana  AB Singh 《Communications in Soil Science and Plant Analysis》2018,49(17):2189-2196

Distilleries produce a huge quantity of effluents, popularly known as spent wash (SW), which when bio-methanated produce post-methanation effluents (PME). A field experiment on soybean–wheat system was conducted for five consecutive years in a Vertisol of central India to evaluate the effect of distillery effluent (DE) on soil carbon and nitrogen dynamics. Ten treatment combinations consisting of control, 100% NPK + Farmyard Manure (FYM), and graded level of SW and PME were applied. Total carbon content of soil increased significantly with applications of FYM and DE. SW was found superior in enhancing carbon content of soil in comparison to PME. Farmyard Manure contributed more carbon toward the recalcitrant pool, whereas DE contributed more carbon toward the active and slow pool. Nitrogen (N) availability was significantly improved with the application of DE. Balanced application of DE may act as amendment for increasing C and N stocks in Vertisol.  相似文献   

Aboveground biomass and nitrogen in four short-rotation woody crop species growing with different water and nutrient availabilities     

William R. Cobb  Rodney E. Will  Richard F. Daniels  Marshall A. Jacobson 《Forest Ecology and Management》2008,255(12):4032-4039

We quantified the effect of water and nutrient availability on aboveground biomass and nitrogen accumulation and partitioning in four species from the southeastern United States, loblolly pine (Pinus taeda), slash pine (Pinus elliottii), sweetgum (Liquidambar styraciflua), and sycamore (Platanus occidentalis). The 6-year-old stands received five levels of resource input (control, irrigation with 3.05 cm water week⁻¹, irrigation + 57 kg N ha⁻¹ year⁻¹, irrigation + 85 kg N ha⁻¹ year⁻¹, and irrigation + 114 kg N ha⁻¹ year⁻¹). Irrigation significantly increased foliage, stem, and branch biomass for sweetgum and sycamore, culminating in 103% and 238% increases in total aboveground biomass. Fertilization significantly increased aboveground components for all species resulting in 49, 58, 281, and 132% increases in total aboveground biomass for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Standing total aboveground biomass of the fertilized treatments reached 79, 59, 48, and 54 Mg ha⁻¹ for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Fertilization increased foliar nitrogen concentration for loblolly pine, sweetgum, and sycamore foliage. Irrigation increased total stand nitrogen content by 6, 14, 93, and 161% for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Fertilization increased total nitrogen content by 62, 53, 172, and 69% with maximum nitrogen contents of 267, 212, 237, and 203 kg ha⁻¹ for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Growth efficiency (stem growth per unit of leaf biomass) and nitrogen use efficiency (stem growth per unit of foliar nitrogen content) increased for the sycamore and sweetgum, but not the loblolly or slash pine.  相似文献   

Classical swine fever in Victorian domestic pigs: evidence of disease freedom     

JC Hunnam  KM Moore  P Daniel  MA Stevenson  SE Salmon 《Australian veterinary journal》2019,97(11):447-451

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Isolation and characterisation of two glucosyltransferases from Glycine max associated with bentazone metabolism     

Jon M. Leah  Timothy L. Worrall  Andrew H. Cobb 《Pest management science》1992,34(1):81-87

Two glucosyltransferases capable of glucosylating the primary major bentazone metabolite, 6-hydroxybentazone, have been isolated from tolerant soybean (Glycine max (L.) Fiskerby V) tissue. A soluble flavonol glucosyltransferase, whose primary substrate was kaempferol, was isolated from 3-week-old light-grown tissue. This enzyme had a relative molecular mass of 44 600, a pH optimum of 6·3 and Michaelis constants for kaempferol and 6-hydroxybentazone of 0·09 and 2·45 mM respectively. A membrane-bound glucosyltransferase whose primary substrate was the intermediate shikimic acid metabolite, p-hydroxyphenylpyruvic acid, was also isolated from 7-day-old etiolated tissue. This enzyme had a relative molecular mass of 53000 (which could be dissociated to approximately 28000), a pH optimum of 7·5 and Michaelis constants for p-hydroxyphenylpyruvic acid and 6-hydroxybentazone of 0·11 and 1·96 mM respectively. These results suggest that 6-hydroxybentazone, and possibly many other hydroxylated pesticides, may be further detoxified by several glucosyltransferases with overlapping specificity whose primary role involves the storage of endogenous metabolites.  相似文献   

Dachshund bitch with severe uterine adhesions and intramural uterine foreign material as an incidental ovariohysterectomy finding          下载免费PDF全文

KM Watson  NU Horadagoda  SA Piripi 《Australian veterinary journal》2016,94(1-2):24-26

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Using policy goals to evaluate red wolf reintroduction in eastern North Carolina     

Christopher Serenari  David T Cobb  Deidre M Peroff 《Human Dimensions of Wildlife》2018,23(4):359-374

Despite being politicized in its early stages, the Red Wolf (Canis rufus) Recovery Program (RWRP) existed for 30 years in eastern North Carolina with little attention paid to finding common ground between policy contestants. We situated our data from 62 key informant interviews within Stone’s (2002) policy goals framework to evaluate red wolf recovery in eastern North Carolina, United States. Four goals underpin U.S. political culture and offer common ground with which to begin negotiation among policy contestants. Our results highlight challenges to achieving one definition prescribing how to treat each policy goal. The future of recovery within the red wolf’s historic range could hinge on decision-makers’ willingness to prioritize policy design over policy tool evaluation, developing a process by which to achieve an agreed-upon set of values underscoring red wolf recovery. This process must reconcile disagreements about what is fair or equitable treatment of landowners and include local-level experiences.  相似文献   

SOME RECENT ASPECTS OF NEMATOLOGY     

Cobb NA 《Science (New York, N.Y.)》1931,73(1880):22-29

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TRANSFERENCE OF NEMATODES (MONONCHS) FROM PLACE TO PLACE FOR ECONOMIC PURPOSES     

Cobb NA 《Science (New York, N.Y.)》1920,51(1330):640-641

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Interglacial hydroclimate in the tropical West Pacific through the Late Pleistocene     

Meckler AN  Clarkson MO  Cobb KM  Sodemann H  Adkins JF 《Science (New York, N.Y.)》2012,336(6086):1301-1304

Records of atmospheric carbon dioxide concentration (P(CO(2))) and Antarctic temperature have revealed an intriguing change in the magnitude of interglacial warmth and P(CO(2)) at around 430,000 years ago (430 ka), but the global climate repercussions of this change remain elusive. Here, we present a stalagmite-based reconstruction of tropical West Pacific hydroclimate from 570 to 210 ka. The results suggest similar regional precipitation amounts across the four interglacials contained in the record, implying that tropical hydroclimate was insensitive to interglacial differences in P(CO(2)) and high-latitude temperature. In contrast, during glacial terminations, drying in the tropical West Pacific accompanied cooling events in northern high latitudes. Therefore, the tropical convective heat engine can either stabilize or amplify global climate change, depending on the nature of the climate forcing.  相似文献