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Pedro Soler-Lloréns Yolanda Gil-Ramírez Ana Zabalza-Baranguá Maite Iriarte Raquel Conde-álvarez Amaia Zú?iga-Ripa Beatriz San Román Michel S Zygmunt Nieves Vizcaíno Axel Cloeckaert María-Jesús Grilló Ignacio Moriyón Ignacio López-Go?i 《Veterinary research》2014,45(1):72
Brucella spp. are Gram-negative bacteria that behave as facultative intracellular parasites of a variety of mammals. This genus includes smooth (S) and rough (R) species that carry S and R lipopolysaccharides (LPS), respectively. S-LPS is a virulence factor, and mutants affected in the S-LPS O-polysaccharide (R mutants), core oligosaccharide or both show attenuation. However, B. ovis is naturally R and is virulent in sheep. We studied the role of B. ovis LPS in virulence by mutating the orthologues of wadA, wadB and wadC, three genes known to encode LPS core glycosyltransferases in S brucellae. When mapped with antibodies to outer membrane proteins (Omps) and R-LPS, wadB and wadC mutants displayed defects in LPS structure and outer membrane topology but inactivation of wadA had little or no effect. Consistent with these observations, the wadB and wadC but not the wadA mutants were attenuated in mice. When tested as vaccines, the wadB and wadC mutants protected mice against B. ovis challenge. The results demonstrate that the LPS core is a structure essential for survival in vivo not only of S brucellae but also of a naturally R Brucella pathogenic species, and they confirm our previous hypothesis that the Brucella LPS core is a target for vaccine development. Since vaccine B. melitensis Rev 1 is S and thus interferes in serological testing for S brucellae, wadB mutant represents a candidate vaccine to be evaluated against B. ovis infection of sheep suitable for areas free of B. melitensis. 相似文献
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Amaia Mena-Petite Alberto Muñoz-Rueda Maite Lacuesta 《European Journal of Forest Research》2005,124(2):73-82
The capacity of radiata pine seedlings to overcome planting shock in wet and dry conditions and their dependence on previous history was analysed by studying post-planting resumption of gas exchange and photochemical reactions, and survival 2 months later. Even under well-irrigated soil conditions, seedlings showed the effects of stress: gas exchange was reduced, but a clear difference between soil-plugged (PR) seedlings and bare-root (BR) seedlings was observed. Drought enhanced the severity of photosynthesis deprivation. Photochemical reactions, analysed by chlorophyll a fluorescence parameters, were not affected by planting shock in conditions of available soil water, but altered dramatically when drought stress was raised, suggesting structural damage of photosynthetic machinery. Despite the dramatic sensitivity of radiata pine to water availability, rewatering produced remarkable recovery, indicating good photosynthetic components repair capacity, which depended, however, on stock quality at the moment of planting. The ability of radiata pine to cope with drought in terms of post-planting performance depended on both storage conditions and water availability at the planting site. These findings provide information for tree physiologists and foresters as to how the management of radiata pine seedlings before planting can affect post-planting performance potential under wet or dry environmental conditions. 相似文献
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Alejandro Martínez-Bilbao Amaya Ortiz-Barredo Emilio Montesinos Jesús Murillo 《Euphytica》2012,188(2):273-283
Host resistance is a key method for the integrated management of apple scab caused by Venturia inaequalis, which is one of the most important diseases of apple. Artificial inoculation of 92 cider apple cultivars with a mixed inoculum of V. inaequalis identified 19 weakly resistant and 19 resistant cultivars. Twelve of these resistant cultivars were previously classified as having low susceptibility to fire blight, and four of them showed complete or weak resistance to races (1), (1, 6) and (6, 7, 13) of V. inaequalis. The analysis of a selection of 72 cultivars for 6 years under field conditions identified 14 cultivars that were classified as resistant to apple scab under high disease pressure involving one to six Mills periods of severe risk of infection each year. Eight out of these 14 cultivars previously showed high levels of resistance to fire blight, which would allow the incorporation of genetic resistance in the integrated production of cider apples in Spain through their use in breeding programs. 相似文献
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Xabier Simón Martínez-Goñi Anabel Robredo Usue Pérez-López Alberto Muñoz-Rueda Amaia Mena-Petite 《Journal of Agronomy and Crop Science》2023,209(2):217-227
Understanding plant response and resilience to drought under a high CO2 environment will be crucial to ensure crop production in the future. Sorghum bicolor is a C4 plant that resists drought better than other crops, which could make it a good alternative to be grown under future climatic conditions. Here, we analyse the physiological response of sorghum under 350 ppm CO2 (aCO2) or 700 ppm CO2 (eCO2) with drought (D) or without drought (WW) for 9, 13 and 16 days; as well as its resilience under long (R1: 9D + 7R) or short (R2: 13D + 3R) recovery treatments. Sorghum showed elevated rates of gs under aCO2 and WW, which resulted in a significant decrease in Ψw, gs, E, ΦPSII, Fv’/Fm′ when exposed to drought. Consequently, A was greatly decreased. When re-watered, both re-watering treatments prioritized A recovery by restoring photosynthetic machinery under aCO2, whereas under eCO2 plants required little recovery since plant were hardly affected by drought. However, sorghum growth rate for aboveground organs did not reach control values, indicating a slower long-term recovery. Overall, these results provide information about the resilience of sorghum and its utility as a suitable candidate for the drought episodes of the future. 相似文献
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Organic carbon storage in soils of the Basque Country (Spain): the effect of climate,vegetation type and edaphic variables 总被引:8,自引:0,他引:8
This study was performed to identify the environmental factors that control soil organic carbon (SOC) accumulation in the Basque Country (Northern Spain) and to evaluate the impact of land use change on SOC budget in this territory. A total of 30 samples of the organomineral horizon were taken under representative vegetation types including native forest, coniferous plantations, scrub, pasture and cultures. The edaphic variables measured were organic C content, pH, total N, available P, exchangeable H+ and Al3+, cation exchange capacity (CEC), texture, and carbonates. The substitution of the original forest with a pasture led to a significant increase in organic C content of the topsoil in all cases studied. Temperature was the main climatic factor affecting the organic C levels in soil, being the two variables negatively correlated. The CEC and texture were other key factors controlling the organic C content, which increased with CEC and decreased with total sand. Average organic C content of the organomineral horizon did not differ significantly (P <0.05) with base content of original substrate nor climate type, but it was more sensitive to climate change in the Atlantic soils than in the Mediterranean ones, where edaphic variables such as CEC and texture were important in regulating C sequestration. 相似文献
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José Miguel Olano Nere Amaia Laskurain Adrián Escudero Marcelino De La Cruz 《Annals of Forest Science》2009,66(1):105-105
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Erwinia amylovora, the causal agent of fire blight, is genetically very homogeneous, and current methodologies provide insufficient or contradictory information about the probable dispersal routes of the pathogen. With the final aim to obtain specific and reliable molecular markers for different lineages of the pathogen, we studied the molecular basis of rep-polymerase chain reaction (PCR) polymorphism using seven different arbitrary primers to fingerprint 93 E. amylovora strains from different countries, including Spain. Polymorphism was very low, and was displayed by only 11 E. amylovora strains, which produced 22 polymorphic bands. Five of 11 polymorphic bands cloned contained DNA that was present in more than 85% of the strains, whereas six bands were due to DNA present exclusively in the strains producing the rep-PCR polymorphism. Also, five of the polymorphic bands were due to the possession of either the ubiquitous plasmid pEA29, of plasmid pEU30, which was exclusively found in strains from North America, or of a 35-kb cryptic plasmid, present only in 28 strains from Northern Spain. We designed primer pairs from several cloned polymorphic bands that allowed the specific identification of the strains producing the polymorphism. Our results indicate that rep-PCR is not adequate for constructing genealogies of E. amylovora, although the strategy illustrated here, as well as the designed primers, can be used effectively in epidemiological studies with this pathogen. 相似文献
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Luna Ramos Lourdes Solé Benet Albert Lázaro Suau Roberto Arzadun Larrucea Amaia Hens del Campo Luis Urdiales Matilla Antonio 《Journal of Soils and Sediments》2021,21(5):1989-1997
Journal of Soils and Sediments - Many industries and agriculture generate huge amounts of wastes either mineral, organic or both, with environmental impact. Some of these residues have the... 相似文献