145 research outputs found
ttl mutants are impaired in cellulose biosynthesis under osmotic stress
As sessile organisms, plants require mechanisms to sense and respond to the challenging environment, that encompass both biotic and abiotic factors that results in differential development. In these conditions is essential to balance growth and stress responses. As cell walls shape plant growth, this differential growth response cause alterations to the plant cell wall and cellulose is a major component. Therefore, understanding the mechanisms that regulate cellulose biosynthesis is essential to develop strategies to improve plant production. Previous studies have shown that the GSK3 kinase BIN2 modulate cellulose biosynthesis through phosphorylating cellulose synthases and that the expression of cellulose synthases are regulated by Brassinosteroids. Our previous work reveals that the tetratricopeptide-repeat thioreoxin-like (TTL) TTL1, TTL3, and TTL4 genes, in addition to their reported role in abiotic stress tolerance, are positive regulators of BR signaling. We observe association of TTL3 with most core components in traducing BR signalling, such as LRR-RLK BRI1, BIN2 and the transcription factor BES1 that positively regulate cellulose biosynthesis. We show that ttl mutants are affected in cellulose biosynthesis, particularly in osmotic stress conditions. Furthermore, TTL3 associates with LRR-RLKs that have been shown to be important for cellulose biosynthesis such as FEI1 in the FEI1/FEI2/SOS5 pathway. We aim to investigate the mechanisms by which TTL proteins regulate cellulose biosynthesis using a combination of genetics, biochemical, and molecular and cell biology approaches.
This work was supported by grants from: (1) Ministerio de Ciencia e Innovación BIO2014-55380-R, BIO2014-56153-REDT; (2) Ministerio de Economía, Industria y Competitividad (BES-2015-071256); (3) Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.This work was supported by grants from: (1) Ministerio de Ciencia e Innovación BIO2014-55380-R, BIO2014-56153-REDT; (2) Ministerio de Economía, Industria y Competitividad (BES-2015-071256); (3) Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Efficacy of the treatment of plantar warts using 1064 nm laser and cooling
Cutaneous plantar warts may be treated using several optional methods, with the use of laser surgery having increased in the last few years. This work examined the efficacy of laser treatment combined with simple cooling to reduce pain. The cure rate was approximately 84%. There were no significant differences in the efficacy of treatment for different viral genotypes. The laser parameters were 500 msec pulses, 30 W of power, and a fluence of 212 J/cm2 delivered in up to four sessions. Successful treatment was achieved after an average of 3.6 sessions
Unraveling the mechanism of TTL genes in cellulose biosynthesis
As sessile organisms, plants require mechanisms to sense and respond to the challenging environment, that encompass both biotic and abiotic factors that results in differential development. In these conditions is essential to balance growth and stress responses. As cell walls shape plant growth, this differential growth response cause alterations to the plant cell wall where cellulose is the major component. Therefore, understanding the mechanisms that regulate cellulose biosynthesis is essential to develop strategies to improve plant production. In Arabidopsis, the TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) gene family is composed by four members (TTL1 to TTL4) and mutations in TTL1, TTL3, and TTL4 genes cause reduced growth under salt and osmotic stress due to defects in plant cell wall integrity. We observe association of TTL3 with most core components in traducing BR signalling, such as LRR-RLK BRI1 or GSK3 BIN2 that modulate cellulose biosynthesis through phosphorylating cellulose synthases. Here, we show that ttl mutants present defects in the plant cell wall, particularly in Isoxaben, salt or sucrose stress. Spinning disk microscopy in etiolated hypocotyls reveals that, TTL proteins are responsible for the cellulose synthase complex (CSC) stability in plasma membrane (PM) upon sucrose stress. Moreover, TTL3 associates with LRR-RLKs that have been shown to be important for cellulose biosynthesis such as FEI1 in the FEI1/FEI2/SOS5 pathway. We aim to investigate the mechanisms by which TTL proteins regulate CesA stability in PM under stress, using a combination of genetics, biochemical, and molecular and cell biology approaches.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
This work was supported by grants from: (1) Ministerio de Ciencia e Innovación BIO2014-55380-R, BIO2014-56153-REDT; (2) Ministerio de Economía, Industria y Competitividad (BES-2015-071256
Efectos de la salinidad en el desarrollo vegetativo e intercambio gaseoso de Fragaria x ananassa y Fragaria chiloensis
81 p.La frutilla comercial (Fragaria x ananassa) es un híbrido entre Fragaria chiloensis y Fragaria virginiana. La frutilla comercial es muy sensible a salinidad por NaCl. Se ha visto que algunos genotipos de F. chiloensis son capaces de crecer en zonas costeras y suelo pobres en nutrientes, lo que sugiere una mayor tolerancia a estreses bióticos que la frutilla comercial. Esta importante característica podría ser de gran valor para el mejoramiento genético de la frutilla comercial. Este estudio se desarrolló para evaluar la tolerancia a la salinidad de dos accesiones de F. chiloensis (‘Bau’ y ‘Cucao’) y un cultivar de F. x ananassa (‘Camarosa’). Las plantas fueron sometidas a tres niveles salinos 0, 30 y 60 mM de NaCl. El peso fresco de hojas, corona y raíces, peso seco de hojas, corona y raíces, diámetro de corona, área foliar de la planta, número de hojas, tasa fotosintética (A), contenido de CO2 interno (Ci), la eficiencia instantánea en el uso del agua (WUEi), el contenido de clorofila a, b y total y el contenido de antocianos decrecieron con el incremento salino en la solución. La accesión ‘Cucao’ mostró menor sensibilidad a NaCl que ‘Camarosa’ y ‘Bau’, lo que se reflejó en menores disminuciones del área foliar de la planta, diámetro de corona, peso seco de hojas y raíces, peso fresco de hojas y raíces, número de hojas, contenido de clorofila total y antocianos. F. x ananassa ‘Camarosa’ y F. chiloensis accesión ‘Bau’ mostraron similar grado de sensibilidad a la salinidad. Los resultados sugieren que el genotipo ‘Cucao’ podría ser utilizado en programas de mejoramiento genético para disminuir la sensibilidad de la frutilla comercial al estrés salino./ABSTRACT: Commercial strawberry (Fragaria x ananassa) is a hybrid of Fragaria chiloensis and Fragaria virginiana. This species is sensitive to salt stress. It has been shown that some genotypes of F. chiloensis are able to grow in coastal areas and nutrient-poor soils, suggesting a higher tolerance to biotic stresses than commercial strawberry. This important feature may be of great value for breeding of commercial strawberry. This study was conducted to evaluate the salinity tolerance of two accessions of F. chiloensis (‘Bau’ and ‘Cucao’) and one cultivar of F. x ananassa (‘Camarosa’). The plants were cultivated under three levels of NaCl: 0, 30 and 60 mM. The fresh weight of leaves, crown and roots, dry weight of leaves, crown and roots, crown diameter, leaf area of the plant, number of leaves, photosynthetic rate (A), content of internal CO2 (Ci), instantaneous water use efficiency (WUEi), chlorophyll content and anthocyanin content decreased with the increase of salt content in the irrigation solution. The accession ‘Cucao’ showed lower sensitivity to salt stress than ‘Camarosa’ and ‘Bau’, which was reflected in smaller reductions in leaf area per plant, crown diameter, dry and fresh weights of leaf and roots, number of leaves, content of total chlorophyll and anthocyanins. F. x ananassa ‘Camarosa’ and F. chiloensis accession ‘Bau’ showed similar degree of sensitivity to salinity. The results suggest that the genotype ‘Cucao’ could be used in breeding programs to reduce the sensitivity of the commercial strawberry to salt stress
Presentación
La Historia de la Lengua ha visto modificados sus parámetros de estudio, pues el modelo textual eminentemente literario se ha ampliado con aquellas aportaciones procedentes de la ciencia y de la técnica. (...
Adaptative mechanisms of cellulose synthesis under stress conditions
Cellulose is the main structural compound of the plant cell wall and the most abundant biopolymer on
Earth (Bar‐On et al 2018). The essential role of cellulose in plant development and defence highlights the
importance of understanding how its synthesis is regulated and will provide new tools to improve crop
tolerance to biotic and abiotic stresses.
We identified that Tetratricopeptide Thioredoxin‐Like (TTL) proteins function as scaffold components of
brassinosteroid signalling components (Amorim‐Silva et al 2019) and as new components of the
Cellulose Synthase Complex (CSC) and describe its unique dynamic association with the CSC under
cellulose‐deficient conditions (Kesten, García‐Moreno, Amorim‐Silva et al 2022). The TTL‐CESA
interaction at the plasma membrane significantly increased under conditions that cause reduced
cellulose content, such as salt stress and structural alterations of the CSCs. The relocalization of cytosolic
TTLs to the active CSCs allows cellulose synthesis, mediated by a stress‐resilient cortical microtubule
array and the stabilization of the CSCs at the plasma membrane. TTLs carry this out by interacting with
Cellulose Synthase 1 and promoting the polymerization of microtubules, thus maintaining the stability
and integrity of the complex. We propose that TTLs act as bridges connecting stress‐mediated cell wall
modification with the regulation of cellulose biosynthesis.
We are currently investigating novel components involved in TTL function and how this protein family is
regulated. Recently, we have identified the 14‐3‐3 proteins as interactors of TTL3. The 14‐3‐3s are a
family of proteins conserved in eukaryotes that target a wide number of proteins (Huang et al 2022). An
Arabidopsis line overexpressing 14‐3‐3λ present phenotypes under stress consistent with defects in
cellulose biosynthesis. This study will elucidate a possible role of 14‐3‐3 proteins in TTL regulation and
cellulose biosynthesis.This work was funded by the Spanish Ministry for Science and Innovation (MCIN/AEI/10.1 0 9/ 011000110 ) and the Andalusian Research Plan cofinanced by the European
Union(PAI I 2020-PY20_0008 and UMA20- E ERJA-02 ) to M.A.B.; V.A.-S. was supported by an Emerging Investigator research project (UMA20- E ERJA-007) and cofinanced by the
“Programa Operativo E ER 201 -2020” and by the “Consejeria de Economia y Conocimiento de la Junta de Andalucia”. R.P.M. was supported by the Andalusian PRE OC_01
fellowship. A.M. was supported by Shanghai Center for Plant Stress Biology.
Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Root and Aboveground Traits Expressed by Landraces and Interspecific Hybrid of Alfalfa (\u3cem\u3eMedicago sativa\u3c/em\u3e. Hybr. (Alborea)) with Putative Drought Tolerance in Mediterranean Environments
Alfalfa’s drought tolerance has not been a major breeding target until recently, and the extent of genetic variation for this trait and its contributing mechanisms have not been thoroughly elucidated. Eight populations, including four landraces (Alta Sierra, Aragon, APG6567, APG44669), two Australian cultivars (Venus and Genesis), and two interspecific hybrids (AF3448 and AF3347) of alfalfa were selected based on their outstanding breeding values for dry matter production and plant persistence in Mediterranean drought-prone environments. The objective of this work was to evaluate the below and above ground phenotypic expression of these drought-tolerant alfalfa accessions, in order to identify morpho- physiological mechanisms conferring to alfalfa greater agronomical performance in drought-prone environments. Individual plants of each population were established on mesocosms of PVC tubes 11 cm in diameter and 100 cm in depth. Plants were grown at two water regimes: with water deficit (WD) and well- watered (WW). Both trials were organized in a complete block design with four replicates. Plant height, stem elongation rate, shoot dry matter, chlorophyll content, stomatal conductance, canopy temperature, leaf area, specific leaf area, crown diameter, relative length density, and root dry matter at 0-30, 30-60 y 60-100 cm were determined. The water regime affected significantly the phenotypic expression of all above and belowground morpho-physiological traits evaluated (P \u3c 0.05), which resulted in a 40% reduction in shoot dry matter and plant height in WD relative to WW. Alfalfa populations with putative drought tolerance in Mediterranean environments did not exhibit a unique phenotypic strategy for facing severe water stress. Populations APG44669 and Alta Sierra showed divergent phenotypic expression in terms of stomatal conductance, leaf traits, root architecture, and root biomass partitioning profile
Views of Multiple Sclerosis Patients About Key Elements for a Decision Aid: A Qualitative Study
Multiple SclerosisEsclerosi múltipleEsclerosis múltipleBACKGROUND: Patients with multiple sclerosis (MS) may experience decisional conflict during treatment choice. Shared decision making (SDM), whereby patients and health professionals, primarily nurses, collaborate in making decisions, reduces this decisional conflict. It requires understanding large amounts of information and may be complex, especially when decisions affect patients' autonomy and quality and prolongation of life. Patient decision aids are tools in facilitating SDM. This study aimed to identify the key elements from the perspective of patients with relapsing-remitting MS to create a patient decision aid in the Spanish sociocultural context. METHODS: This is a qualitative study using focus groups led by a clinical nurse specialist. Semistructured interviews included healthcare needs and demands, the SDM process, and general characteristics of a peer support program. After the transcription of interview recordings, data were analyzed by thematic analysis and a constructivist naturalistic approach. RESULTS: Patients with MS (27) from Spain participated in 4 focus groups of 90 to 120 minutes each. Three overarching themes were identified: information access to sufficient high-quality data; knowledge of available treatment options, including efficacy, adverse effects, frequency, administration route, and the impact on daily life; decision-making role, engaged versus nonengaged patients. The former require support in facilitating their active involvement in decisions, whereas the latter prefer more passive health models. CONCLUSION: The needs identified by patients with relapsing-remitting MS regarding treatment choice in the Spanish setting align with those reported by other studies. The identified themes provide valuable information to design and develop a virtual patient decision aid jointly by clinical MS nurses and patients according to the International Patient Decision Aid Standards Collaboration criteria. This aid will help improve understanding between nurses and patients during SDM and facilitate the process
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