The nitrogen availability interferes with mycorrhiza-induced resistance against Botrytis cinerea in Tomato

Mycorrhizal plants are generally quite efficient in coping with environmental challenges. It has been shown that the symbiosis with arbuscular mycorrhizal fungi (AMF) can confer resistance against root and foliar pathogens, although the molecular mechanisms underlying such mycorrhiza-induced resistance (MIR) are poorly understood. Tomato plants colonized with the AMF Rhizophagus irregularis display enhanced resistance against the necrotrophic foliar pathogen Botrytis cinerea. Leaves from arbuscular mycorrhizal (AM) plants develop smaller necrotic lesions, mirrored also by a reduced levels of fungal biomass. A plethora of metabolic changes takes place in AMF colonized plants upon infection. Certain changes located in the oxylipin pathway indicate that several intermediaries are over-accumulated in the AM upon infection. AM plants react by accumulating higher levels of the vitamins folic acid and riboflavin, indolic derivatives and phenolic compounds such as ferulic acid and chlorogenic acid. Transcriptional analysis support the key role played by the LOX pathway in the shoots associated with MIR against B. cinerea. Interestingly, plants that have suffered a short period of nitrogen starvation appear to react by reprogramming their metabolic and genetic responses by prioritizing abiotic stress tolerance. Consequently, plants subjected to a transient nitrogen depletion become more susceptible to B. cinerea. Under these experimental conditions, MIR is severely affected although still functional. Many metabolic and transcriptional responses which are accumulated or activated by MIR such NRT2 transcript induction and OPDA and most Trp and indolic derivatives accumulation during MIR were repressed or reduced when tomato plants were depleted of N for 48 h prior infection. These results highlight the beneficial roles of AMF in crop protection by promoting induced resistance not only under optimal nutritional conditions but also buffering the susceptibility triggered by transient N depletion

Overexpression. of dehydrin tas14 gene improves the osmotic stress imposed by drought and salinity in tomato

[EN] One strategy to increase the level of drought and salinity tolerance is the transfer of genes codifying different types of proteins functionally related to macromolecules protection, such as group 2 of late embryogenesis abundant (LEA) proteins or dehydrins. The TAS14 dehydrin was isolated and characterized in tomato and its expression was induced by osmotic stress (NaCl and mannitol) and abscisic acid (ABA) [Godoy et al., Plant Mol Biol 1994;26:1921-1934], yet its function in drought and salinity tolerance of tomato remains elusive. In this study, transgenic tomato plants overexpressing tas14 gene under the control of the 35SCaMV promoter were generated to assess the function of tas14 gene in drought and salinity tolerance. The plants overexpressing tas14 gene achieved improved long-term drought and salinity tolerance without affecting plant growth under non-stress conditions. A mechanism of osmotic stress tolerance via osmotic potential reduction and solutes accumulation, such as sugars and K+ is operating in tas14 overexpressing plants in drought conditions. A similar mechanism of osmotic stress tolerance was observed under salinity. Moreover, the overexpression of tas14 gene increased Na+ accumulation only in adult leaves, whereas in young leaves, the accumulated solutes were K+ and sugars, suggesting that plants overexpressing tas14 gene are able to distribute the Na+ accumulation between young and adult leaves over a prolonged period in stressful conditions. Measurement of ABA showed that the action mechanism of tas14 gene is associated with an earlier and greater accumulation of ABA in leaves during short-term periods. A good feature for the application of this gene in improving drought and salt stress tolerance is the fact that its constitutive expression does not affect plant growth under non-stress conditions, and tolerance induced by overexpression of tas14 gene was observed at the different stress degrees applied to the long term. (C) 2011 Elsevier GmbH. All rights reserved.This work was supported by the Spanish Ministry of Science and Innovation through grant AGL2009-13388-C03 and by the Council of Science and Technology from the Region of Murcia (Spain) (Fundacion SENECA) through grant 04553/GERM/06.Muñoz Mayor, A.; Pineda Chaza, BJ.; García Abellán, JO.; Antón Martínez, MT.; García Sogo, B.; Sánchez Bel, P.; Flores, FB.... (2012). Overexpression. of dehydrin tas14 gene improves the osmotic stress imposed by drought and salinity in tomato. Journal of Plant Physiology. 169(5):459-468. https://doi.org/10.1016/j.jplph.2011.11.018S459468169

Deciphering of benzothiadiazole (BTH)-induced response of tomato (Solanum lycopersicum L.) and its effect on early response to virus infection through the multi-omics approach

Background and aims One of the preventive methods used to limit the losses caused by viruses is the application of synthetic immunity inducers, such as benzo(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH). This study aimed at explaining how the BTH treatment affects the defence and developmental processes in tomato plants (Solanum lycopersicum L.) as well as plant response to virus infection. Method The comparative multi-omics analyses concerning tomato plants treated with BTH were performed, including transcriptomics (RNA-Seq), proteomics (Liquid Chromatography-Mass Spectrometry), and metabolomics (targeted hormonal analysis). To confirm the priming effect of BTH on tomato resistance, the plants were infected with tomato mosaic virus (ToMV) seven days post-BTH treatment. Results The combined functional analysis indicated the high impact of BTH on the plant's developmental processes and activation of the immune response early after the treatment. In the presented experimental model, the increased level of WRKY TRANSCRIPTION FACTORS, ARGONAUTE 2A, thiamine and glutathione metabolism, cell wall reorganization, and detoxification processes, as well as accumulation of three phytohormones: abscisic acid, jasmonic acid-isoleucine (JA-Ile), and indole-3-carboxylic acid (I3CA), were observed upon BTH application. Conclusion The immune response activated by BTH was related to increased expression of genes associated with the cellular detoxification process, systemic acquired resistance, and induced systemic resistance as well as post-transcriptional gene silencing. Increased levels of I3CA and JA-Ile might explain the BTH's effectiveness in the induction of the plant defence against a broad spectrum of pathogens. For the first time, the BTH involvement in the induction of the thiamine metabolism was revealed in tomatoes

The SafeBoosC phase II clinical trial: an analysis of the interventions related with the oximeter readings

BACKGROUND The SafeBoosC phase II randomised clinical trial recently demonstrated the benefits of a combination of cerebral regional tissue oxygen saturation (rStO2) by near-infrared spectroscopy (NIRS) and a treatment guideline to reduce the oxygen imbalance in extremely preterm infants. AIMS To analyse rStO2-alarm-related clinical decisions and their heterogeneity in the NIRS experimental group (NIRS monitoring visible) and their impact on rStO2 and SpO2. METHODS Continuous data from NIRS devices and the alarms (area under the curve of the rStO2 out of range had accumulated 0.2%h during 10 min), clinical data at discrete time points and interventions prompted by the alarms were recorded. RESULTS Sixty-seven infants had data that fulfilled the requirements for this analysis. 1107 alarm episodes were analysed. The alarm triggered a treatment guideline intervention in 25% of the cases; the type of intervention chosen varied among clinical sites. More than 55% of alarms were not followed by an intervention ('No action'); additionally, in 5% of alarms the rStO2 value apparently was considered non-reliable and the sensor was repositioned. The percentage of unresolved alarms at 30 min after 'No action' almost doubled the treatment guideline intervention (p<0.001). Changes in peripheral oxygen saturation (SpO2), were observed only after treatment guideline interventions. CONCLUSIONS This study shows that 25% of rStO2 alarms were followed by a clinical intervention determined by the treatment guideline. However, the rStO2 and SpO2 returned to normal ranges after the intervention, supporting the notion that decisions taken by the clinicians were appropriate. TRIAL REGISTRATION NUMBER ClinicalTrial.gov NCT01590316

Dietary patterns and their relationship with the perceptions of healthy eating in European adolescents : the HELENA study

Objective: The aim of this study was to identify dietary patterns (DPs) in European adolescents and to examine the association between perceptions of healthy eating and the obtained DPs. Method: A multinational cross-sectional study was carried out in adolescents aged 12.5 to 17.5?years and 2,027 (44.9% males) were considered for analysis. A self-reported questionnaire with information on food choices and preferences, including perceptions of healthy eating, and two 24-hour dietary recalls were used. Principal component analysis was used to obtain sex-specific DPs, and linear analyses of covariance were used to compare DPs according to perceptions of healthy eating. Results: Three and four DPs for boys and girls were obtained. In boys and girls, there were significant associations between some perceptions about healthy food and the Breakfast-DP (p?<?0.05). In boys, Breakfast-DP and Healthy Beverage-DP were associated with the perception of the own diet as healthy (p?<?0.05). Healthy Beverage-DP was associated with those disliking fruits and vegetables (p?<?0.05). Girls considering the own diet as healthy were associated with Mediterranean-DP, Breakfast-DP, and Unhealthy Beverage and Meat-DP (p?<?0.05). The perception of snacking as a necessary part of a healthy diet was associated with Breakfast-DP in both genders (p?<?0.05). Conclusions: In European adolescents, perceptions of healthy eating were mainly associated with a DP characterized by foods consumed at breakfast. Future studies should further explore these findings in order to implement health promotion programs to improve healthy eating habits in adolescents