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C. Rusterucci Z. Zhao K. Haines D. Mellersh M. Neumann R.K. Cameron 《Physiological and Molecular Plant Pathology》2005,66(6):120
As plants mature it has been observed that some become more resistant to normally virulent pathogens. The ability to manifest the Age-Related Resistance (ARR) response in Arabidopsis to Pseudomonas syringae pathovars tomato (Pst) coincided with the transition to flowering in plants both delayed and accelerated in the transition to flowering. ARR was also associated with a change in PR-1 gene expression, such that young plants expressed PR-1 abundantly at 3 days post inoculation (dpi) while mature plants expressed much less. The Arabidopsis ARR response requires SA accumulation via isochorismate synthase (ICS1) [24]. ICS1 was expressed one dpi with virulent and avirulent Pst in both young and mature plants. The ARR response was also effective versus avirulent Pst providing an additional 4-fold limitation in bacterial growth. Arabidopsis ARR was found to be ineffective against two necrotrophs, Erwinia carotovora subspecies carotovora (bacterium) and Botrytis cinerea (fungus) and one obligate biotroph, Erysiphe cichoracearum (fungus). However, mature wild type, SA-deficient sid2 and NahG plants supported little growth of the obligate biotrophic oomycete, Peronospora parasitica. Therefore ARR to P. parasitica appears to be SA-independent, however the level of ARR resistance was somewhat reduced in these mutants in some experiments. Thus, there may be numerous defence pathways that contribute to adult plant resistance in Arabidopsis. 相似文献
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Gould D Pettitt L McLaughlin B Holmes N Forman O Thomas A Ahonen S Lohi H O'Leary C Sargan D Mellersh C 《Veterinary ophthalmology》2011,14(6):378-384
Primary lens luxation (PLL) is a well-recognized, painful and potentially blinding inherited ocular condition in dogs. We screened PLL-affected dogs of 30 different breeds, to identify those which carried a previously described c.1473+1 G>A mutation in ADAMTS17 that is associated with PLL in Miniature Bull terriers, Lancashire Heelers, and Jack Russell terriers. This ADAMTS17 mutation was identified in PLL-affected dogs from 14 additional breeds. PLL-affected dogs from some breeds (most notably the Shar pei and the Brittany spaniel) did not carry the G1473+1A ADAMTS17 mutation, indicating they must suffer from a genetically distinct form of the condition. We also estimated the frequency of this ADAMTS17 mutation in some of the breeds. Our findings indicate the mutation segregates in a large number of different breeds of dog, many of which are terriers or breeds with terrier co-ancestry, but some of which have more diverse origins. Our results also indicate that the mutation is present at high frequency within most of the breeds in which it segregates. In the miniature bull terrier breed estimates of mutation frequency ranged from 0.27 to 0.39, corresponding to 7.3-15.2% PLL-affected dogs in this breed. We also identified an increased risk of PLL associated with heterozygosity at ADAMTS17, suggesting that carriers carry a low risk of developing PLL. 相似文献
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Charlton BR Walker RL Kinde BH Bauer CR Channing-Santiago SE Farver TB 《Avian diseases》2005,49(3):418-422
The California Egg Quality Assurance Program uses the delayed secondary enrichment culture method for detecting Salmonella Enteritidis in environmental drag swabs obtained from commercial layer complexes. The turnaround time for this method is variable and is dependent on the prevalence of Salmonella, level of the Salmonella identification, and capabilities of the performing laboratory. On a sample basis, a range of 4 to 8 days is required to identify a Salmonella sp. to the serogroup level. Additional time is required to serotype group D Salmonella isolates. A Salmonella Enteritidis-specific polymerase chain reaction (PCR) assay was developed for use on drag swabs and chick box papers, and had a turnaround time of 3-4 days. The delayed secondary enrichment culture method and the Salmonella Enteritidis-specific PCR assay were compared on 942 drag swab and 85 chick box paper samples submitted from 217 and 22 premises, respectively, as part of the California Egg Quality Assurance Program. The PCR assay identified 43 positive Salmonella Enteritidis samples from 22 premises, whereas the culture method identified 24 group D Salmonella-positive samples from 16 premises. There was a significant difference (P = 0.001) in the proportion of positive samples as determined by the two assays. Complete serotyping of the group D Salmonella-positive cultures confirmed Salmonella Enteritidis in all but one sample that was identified as Salmonella Jamaica and was negative by the PCR assay. 相似文献
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OBJECTIVES: (1) To review the signalment, clinical, and histological features of canine limbal melanoma; (2) to perform pedigree analysis on breeds predisposed to limbal melanoma to establish if common ancestry exists; and (3) to investigate if any ancestral relationship exists between canine limbal melanoma and canine anterior uveal melanoma (CAUM). DESIGN: Retrospective study. ANIMALS STUDIED: Thirty dogs with limbal melanoma. METHODS: Medical records of patients were reviewed. Follow-up information was obtained by re-examination of patients or telecommunications with the referring veterinary surgeons or the owners. Pedigrees were analyzed for common ancestry amongst affected dogs. RESULTS The mean age (+/- SD) at diagnosis was 6.2 (+/- 2.75) years with a range from 1 to 11 years. There was a bimodal distribution of ages with a peak at 3-4 years and a peak at 7-10 years. There was no eye predilection or predisposition for sex or coat color. Twenty-five (83%) of the limbal melanomas occurred within a dorsal arc from the dorsomedial to the ventrolateral limbus. Golden retrievers were four times more common in the melanoma group compared to the Animal Health Trust population (P < 0.0001). Labrador retrievers were three times more common in the melanoma group (P=0.01). Pedigree analysis on eight Golden retrievers [limbal melanoma (n=5), CAUM (n=2) and diffuse ocular melanosis (n=1)], revealed a pattern of inter-relatedness consistent with the condition(s) being caused, at least in part, by a genetic mutation(s). A similar level of inter relatedness was evident in six Labrador retrievers (limbal melanoma (n=2) and CAUM (n=4)). In 5/22 cases (23%), histological features suggestive of malignancy were present including intratumor necrosis in 4/22 cases (18%) and cellular atypia in 1/22 cases (5%). CONCLUSIONS: In Golden and Labrador retrievers there is evidence that limbal melanomas, CAUM and ocular melanosis are at least in part heritable and that the same genetic mutation(s) may be causally associated with melanocytic disease at different ocular sites. The same genetic mutation(s) may be present in these two breeds. Histology should be performed on all cases to identify those with greater malignant potential. 相似文献
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Yield and nitrogen use efficiency of wheat increased with root length and biomass due to nitrogen,phosphorus, and potassium interactions 
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下载免费PDF全文 Elliott G. Duncan Cathryn A. O'Sullivan Margaret M. Roper Jairo Palta Kelley Whisson Mark B. Peoples 《植物养料与土壤学杂志》2018,181(3):364-373
Balanced applications of nitrogen (N), phosphorus (P), and potassium (K) are known to increase grain yield of wheat but the impact of the interactions among N, P, and K on root growth and nitrogen use efficiency (NUE) have not been proven. The aim of this study was to investigate the effect of balanced applications of N, P, and K on the rooting patterns and NUE of wheat. Two glasshouse experiments were conducted. A rhizobox study was used to assess the impact of interactions among N, P, and K fertilisers on total root length, biomass, specific root length, root length density, N use efficiency (NUE), and N uptake efficiency of the shoots (NUpEshoot) and N nutrition index. In a separate pot study, plants were grown to maturity to confirm the effect of the observed changes in root growth on NUE, NUpEgrain, and grain/biomass yield. In the rhizobox experiment when plants were supplied with N+P+K, total root biomass increased approximately six‐fold relative to plants grown with N alone or with no fertiliser. Plants exposed to N+P+K had NUpEshoot and NUE values that were five and ten times higher, respectively, than plants that received just fertiliser N. Plants supplied with N+P or N+P+K had N nutrition indices close to one (N‐adequate), while plants that only received N had an index of 0.62 (N‐deficient). The pot study confirmed that the changes in root length and biomass in plants exposed to N+P+K resulted in significant increases in NUE, NUpEgrain, shoot biomass, and grain yield at maturity. Interactions among fertiliser N, P, and K played a critical role in influencing root biomass and length, which was associated with increases in NUE, NUpEshoot and NUpEgrain. 相似文献
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Charlotte E. Matthews Christopher E. Moorman Cathryn H. Greenberg Thomas A. Waldrop 《Forest Ecology and Management》2009
Fuel hazards have increased in forests across the United States because of fire exclusion during the 20th century. Treatments used to reduce fuel buildup may affect wildlife, such as shrews, living on the forest floor, especially when treatments are applied repeatedly. From mid-May to mid-August 2006 and 2007, we used drift fences with pitfall traps to capture shrews in western North Carolina in 3 fuel reduction treatment areas [(1) twice-burned (2003 and 2006), (2) mechanical understory cut (2002), and (3) mechanical understory cut (2002) followed by 2 burns (2003 and 2006)] and a control. We captured 77% fewer southeastern shrews (Sorex longirostris) in mechanical + twice-burned treatment areas than in mechanical treatment areas in 2006, but southeastern shrew captures did not differ among treatment areas in 2007. Total shrew captures did not differ among treatment areas in either year. Decreases in leaf litter, duff depth, and canopy cover in mechanical + twice-burned treatment areas may have decreased ground-level moisture, thereby causing short-term declines in southeastern shrew captures. Prescribed fire or mechanical fuel reduction treatments in the southern Appalachian Mountains did not greatly affect shrew populations, though the combination of both treatments may negatively affect some shrew species, at least temporarily. 相似文献
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Karmi N Brown EA Hughes SS McLaughlin B Mellersh CS Biourge V Bannasch DL 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2010,24(6):1337-1342
Background: Hyperuricosuria is a condition that predisposes dogs to urate urolithiasis. A mutation that causes canine hyperuricosuria was previously identified in 3 unrelated dog breeds. The occurrence of the mutation in additional breeds was not determined. Hypothesis/Objectives: Identify additional breeds that have the hyperuricosuria mutation and estimate the mutant allele frequency in those breeds. Animals: Three thousand five hundred and thirty dogs from 127 different breeds were screened for the hyperuricosuria mutation. Methods: DNA samples were genotyped by pyrosequencing and allele‐specific polymerase chain reaction methods. Results: Mutant allele frequencies that range from 0.001 to 0.15 were identified in the American Staffordshire Terrier, Australian Shepherd, German Shepherd Dog, Giant Schnauzer, Parson (Jack) Russell Terrier, Labrador Retriever, Large Munsterlander, Pomeranian, South African Boerboel, and Weimaraner breeds. Conclusions and Clinical Importance: The hyperuricosuria mutation has been identified in several unrelated dog breeds. The mutant allele frequencies vary among breeds and can be used to determine an appropriate breeding plan for each breed. A DNA test is available and may be used by breeders to decrease the mutant allele frequency in breeds that carry the mutation. In addition, veterinarians may use the test as a diagnostic tool to identify the cause of urate urolithiasis. 相似文献
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We compared the effects of three fuel reduction techniques and a control on the relative abundance and richness of reptiles and amphibians using drift fence arrays with pitfall and funnel traps. Three replicate blocks were established at the Green River Game Land, Polk County, North Carolina. Each replicate block contained four experimental units that were each approximately 14 ha in size. Treatments were prescribed burn (B); mechanical understory reduction (M); mechanical + burn (MB); and controls (C). Mechanical treatments were conducted in winter 2001–2002, and prescribed burns in March 2003. Hot fires in MB killed about 25% of the trees, increasing canopy openness relative to controls. Leaf litter depth was reduced in B and MB after burning, but increased in M due to the addition of dead leaves during understory felling. The pre-treatment trapping period was short (15 August–10 October 2001) but established a baseline for post-treatment comparison. Post-treatment (2002–2004), traps were open nearly continuously May–September. We captured a total of 1308 species of 13 amphibians, and 335 reptiles of 13 species. The relative abundance of total salamanders, common salamander species, and total amphibians was not changed by the fuel reduction treatments. Total frogs and toads (anurans) and Bufo americanus were most abundant in B and MB; however, the proximity of breeding sites likely affected our results. Total reptile abundance and Sceloporus undulatus abundance were highest in MB after burning, but differed significantly only from B. Mean lizard abundance in MB was highest in 2004 and higher than in other treatments, but differences were not statistically significant. Our results indicate that a single application of the fuel reduction methods studied will not negatively affect amphibian or reptile abundance or diversity in southern Appalachian upland hardwood forest. Our study further suggests that high-intensity burning with heavy tree-kill, as in MB, can be used as a management tool to increase reptile abundance – particularly lizards – with no negative impact on amphibians, at least in the short-term. 相似文献