57 research outputs found
Does abscisic acid affect strigolactone biosynthesis?
Strigolactones are considered a novel class of plant hormones that, in addition to their endogenous signalling function, are exuded into the rhizosphere acting as a signal to stimulate hyphal branching of arbuscular mycorrhizal (AM) fungi and germination of root parasitic plant seeds. Considering the importance of the strigolactones and their biosynthetic origin (from carotenoids), we investigated the relationship with the plant hormone abscisic acid (ABA).
Strigolactone production and ABA content in the presence of specific inhibitors of oxidative carotenoid cleavage enzymes and in several tomato ABA-deficient mutants were analysed by LC-MS/MS. In addition, the expression of two genes involved in strigolactone biosynthesis was studied.
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The carotenoid cleavage dioxygenase (CCD) inhibitor D2 reduced strigolactone but not ABA content of roots. However, in abamineSG-treated plants, an inhibitor of 9-cis-epoxycarotenoid dioxygenase (NCED), and the ABA mutants notabilis, sitiens and flacca, ABA and strigolactones were greatly reduced. The reduction in strigolactone production correlated with the downregulation of LeCCD7 and LeCCD8 genes in all three mutants.
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The results show a correlation between ABA levels and strigolactone production, and suggest a role for ABA in the regulation of strigolactone biosynthesis
Phosphorus availability drives mycorrhiza induced resistance in tomato
Arbuscular mycorrhizal (AM) symbiosis can provide multiple benefits to the host
plant, including improved nutrition and protection against biotic stress. Mycorrhiza
induced resistance (MIR) against pathogens and insect herbivores has been
reported in different plant systems, but nutrient availability may influence the
outcome of the interaction. Phosphorus (P) is a key nutrient for plants and insects,
but also a regulatory factor for AM establishment and functioning. However, little is
known about how AM symbiosis and P interact to regulate plant resistance to
pests. Here, using the tomato-Funneliformis mosseae mycorrhizal system, we
analyzed the effect of moderate differences in P fertilization on plant and pest
performance, and on MIR against biotic stressors including the fungal pathogen
Botrytis cinerea and the insect herbivore Spodoperta exigua. P fertilization
impacted plant nutritional value, plant defenses, disease development and
caterpillar survival, but these effects were modulated by the mycorrhizal status
of the plant. Enhanced resistance of F. mosseae-inoculated plants against B.
cinerea and S. exigua depended on P availability, as no protection was observed
under the most P-limiting conditions. MIR was not directly explained by changes in
the plant nutritional status nor to basal differences in defense-related
phytohormones. Analysis of early plant defense responses to the damage
associated molecules oligogalacturonides showed primed transcriptional
activation of plant defenses occurring at intermediate P levels, but not under
severe P limitation. The results show that P influences mycorrhizal priming of plant
defenses and the resulting induced-resistance is dependent on P availability, and
suggest that mycorrhiza fine-tunes the plant growth vs defense prioritization
depending on P availability. Our results highlight how MIR is context dependent,
thus unravel molecular mechanism based on plant defence in will contribute to
improve the efficacy of mycorrhizal inoculants in crop protection
The local skin celular immune response determines the clinical outcome of sarcoptic mange in Iberian ibex (Capra pirenaica)
13 páginas, 8 figuras, 7 tablas.This project was funded by the Consejería de Medio Ambiente de
la Junta de Andalucía (project 173/2009/M/00;03/15/M/00;
861_11_M_00 and 2016/00014/M) and the Spanish Ministerio de
Economía y Competitividad (projects CGL2012-40043-C02-01,
CGL2012-40043-C02-02, and CGL2016-80543-P). The authors’
research activities are partially supported by the Plan Andaluz de
Investigación (RNM-118 group). MV is supported by a FI-GENCAT
Fellowship (2020_FI_B2_00049, which is cofinanced by the Agència
de Gestió d’Ajuts Universitaris i de Recerca and the European Social
Fund). GM is a Serra Húnter Fellow.Peer reviewe
Diseases of Iberian ibex (Capra pyrenaica)
36 páginas, 7 figuras, 4 tablas.Iberian ibex (Caprapyrenaica) is an ecologically and economically relevant medium-sized emblematic mountain ungulate. Diseases participate in the population dynamics of the species as a regulating agent, but can also threaten the conservation and viability of vulnerable population units. Moreover, Iberian ibex can also be a carrier or even a reservoir of pathogens shared with domestic animals and/or humans, being therefore a concern for livestock and public health. The objective of this review is to compile the currently available knowledge on (1) diseases of Iberian ibex, presented according to their relevance on the health and demography of free-ranging populations; (2) diseases subjected to heath surveillance plans; (3) other dis-eases reported in the species; and (4) diseases with particular relevance in captive Iberian ibex populations. The systematic review of all the information on diseases affecting the species unveils unpublished reports, scientific communications in meetings, and scientific articles, allowing the first comprehensive compilation of Iberian ibex diseases. This review identi-fies the gaps in knowledge regarding pathogenesis, immune response, diagnostic methods, treatment, and management of diseases in Iberian ibex, providing a base for future research. Moreover, this challenges wildlife and livestock disease and wildlife population managers to assess the priorities and policies currently implemented in Iberian ibex health surveillance and monitoring and disease management.Open Access Funding provided by Universitat Autonoma de Barcelona. Part of the authors benefitted of the support of the Consejería de Medio Ambiente of the Junta de Andalucía (Spain) to the group RNN 118 through the grants 173/2009/M/00; 03/15/M/00; 861_11_M_00, 2016/00014/M. This review benefitted from funding of the Spanish Ministerio de Economía y Competitividad through the grants CGL2012-40043-C02-01, CGL2012-40043-C02-02, and CGL2016-80543-P. Marta Valldeperes was supported by the pre-doctoral grant 2020_FI_B2_00049, funded by the Agència de Gestió d'Ajuts Universitaris i de Recerca of the Generalitat de Catalunya (Spain) and the European Social Fund.Peer reviewe
Ivermectin plasma concentration in iberian ibex (capra pyrenaica) following oral administration: a pilot study
7 páginas, 1 tabla, 1 figura.Sarcoptic mange is considered the main driver of demographic declines occurred in the
last decades in Iberian ibex (Capra pyrenaica) populations. Mass treatment campaigns
by administration of in-feed acaricides are used as a measure to mitigate the impact
of mange in the affected populations. However, there are no data on ivermectin (IVM)
pharmacokinetics in this wild caprine, and the treatment through medicated feed is
not endorsed by evidence on its effectiveness. The aim of this study is to determine
the pharmacokinetic profile of IVM in plasma samples of ibexes after the experimental
oral administration of IVM, using high performance liquid chromatography (HPLC) with
automated solid phase extraction and fluorescence detection. A dose of 500 µg of IVM
per body weight was orally administered in a feed bolus to nine healthy adult ibexes
(seven males and two females). Blood samples were collected by jugular venipuncture
into heparin-coated tubes at day 1, 2, 3, 4, 7, 10, 15, and 45 post-administration
(dpa). The highest plasma concentration of IVM (Cmax = 3.4 ng/ml) was detected 24 h
after the oral administration (T1), followed by a rapid decrease during the first week
post-administration. Our results reveal that plasma IVM concentration drops drastically
within 5 days of ingestion, questioning the effectiveness of a single in-feed dose of this
drug to control sarcoptic mange. To the best of our knowledge, this is the first study on
plasma availability of oral IVM in ibexes and in any wild ungulate species.This project was funded by the Consejería de Medio
Ambiente de la Junta de Andalucía (project 173/2009/M/00;
03/15/M/00; 861_11_M_00 and 2016/00014/M), and by
the Spanish Ministerio de Economía y Competitividad
(projects CGL2012-40043-C02-01, CGL2012-40043-C02-
02, and CGL2016-80543-P). The authors’ research activities are
partially supported by the Plan Andaluz de Investigación (RNM 118 group). MV is supported by a FI-GENCAT Fellowship
(2020_FI_B2_00049, co-financiated by Agència de Gestió
d’Ajuts Universitaris i de Recerca and European Social Fund) and ES by the Spanish Ministerio de Ciencia Innovación y
Universidades (MICINN) through a Ramon y Cajal agreement
(RYC-2016-21120). GM is a Serra Húnter Fellow.Peer reviewe
Hormonal and transcriptional profiles highlight common and differential host responses to arbuscular mycorrhizal fungi and the regulation of the oxylipin pathway
Arbuscular mycorrhizal (AM) symbioses are mutualistic associations between soil fungi and most vascular plants. The symbiosis significantly affects the host physiology in terms of nutrition and stress resistance. Despite the lack of host range specificity of the interaction, functional diversity between AM fungal species exists. The interaction is finely regulated according to plant and fungal characters, and plant hormones are believed to orchestrate the modifications in the host plant. Using tomato as a model, an integrative analysis of the host response to different mycorrhizal fungi was performed combining multiple hormone determination and transcriptional profiling. Analysis of ethylene-, abscisic acid-, salicylic acid-, and jasmonate-related compounds evidenced common and divergent responses of tomato roots to Glomus mosseae and Glomus intraradices, two fungi differing in their colonization abilities and impact on the host. Both hormonal and transcriptional analyses revealed, among others, regulation of the oxylipin pathway during the AM symbiosis and point to a key regulatory role for jasmonates. In addition, the results suggest that specific responses to particular fungi underlie the differential impact of individual AM fungi on plant physiology, and particularly on its ability to cope with biotic stresses
How do nitrogen and phosphorus deficiencies affect strigolactone production and exudation?
Plants exude strigolactones (SLs) to attract symbiotic arbuscular mycorrhizal fungi in the rhizosphere. Previous studies have demonstrated that phosphorus (P) deficiency, but not nitrogen (N) deficiency, significantly promotes SL exudation in red clover, while in sorghum not only P deficiency but also N deficiency enhances SL exudation. There are differences between plant species in SL exudation under P- and N-deficient conditions, which may possibly be related to differences between legumes and non-legumes. To investigate this possibility in detail, the effects of N and P deficiencies on SL exudation were examined in Fabaceae (alfalfa and Chinese milk vetch), Asteraceae (marigold and lettuce), Solanaceae (tomato), and Poaceae (wheat) plants. In alfalfa as expected, and unexpectedly in tomato, only P deficiency promoted SL exudation. In contrast, in Chinese milk vetch, a leguminous plant, and in the other non-leguminous plants examined, N deficiency as well as P deficiency enhanced SL exudation. Distinct reductions in shoot P levels were observed in plants grown under N deficiency, except for tomato, in which shoot P level was increased by N starvation, suggesting that the P status of the shoot regulates SL exudation. There seems to be a correlation between shoot P levels and SL exudation across the species/families investigated
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