Transcriptional regulation os phenylalaline biosynthesis and utilization

Conifer trees divert large quantities of carbon into the biosynthesis of phenylpropanoids, particularly to generate lignin, an important constituent of wood. Since phenylalanine is the precursor for phenylpropanoid biosynthesis, the precise regulation of phenylalanine synthesis and utilization should occur simultaneously. This crucial pathway is finely regulated primarily at the transcriptional level. Transcriptome analyses indicate that the transcription factors (TFs) preferentially expressed during wood formation in plants belong to the MYB and NAC families. Craven-Bartle et al. (2013) have shown in conifers that Myb8 is a candidate regulator of key genes in phenylalanine biosynthesis involved in the supply of the phenylpropane carbon skeleton necessary for lignin biosynthesis. This TF is able to bind AC elements present in the promoter regions of these genes to activate transcription. Constitutive overexpression of Myb8 in white spruce increased secondary-wall thickening and led to ectopic lignin deposition (Bomal et al. 2008). In Arabidopsis, the transcriptional network controlling secondary cell wall involves NAC-domain regulators operating upstream Myb transcription factors. Functional orthologues of members of this network described have been identified in poplar and eucalyptus, but in conifers functional evidence had only been obtained for MYBs. We have identified in the P. pinaster genome 37 genes encoding NAC proteins, which 3 NAC proteins could be potential candidates to be involved in vascular development (Pascual et al. 2015). The understanding of the transcriptional regulatory network associated to phenylpropanoids and lignin biosynthesis in conifers is crucial for future applications in tree improvement and sustainable forest management. This work is supported by the projects BIO2012-33797, BIO2015-69285-R and BIO-474 References: Bomal C, et al. (2008) Involvement of Pinus taeda MYB1 and MYB8 in phenylpropanoid metabolism and secondary cell wall biogenesis: a comparative in planta analysis. J Exp Bot. 59: 3925-3939. Craven-Bartle B, et al. (2013) A Myb transcription factor regulates genes of the phenylalanine pathway in maritime pine. Plant J, 74: 755-766. Pascual MB, et al. (2015) The NAC transcription factor family in maritime pine (Pinus pinaster): molecular regulation of two genes involved in stress responses. BMC Plant Biol, 15: 254.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Pollen viability and incompatibility in indigenous rice bean (Vigna umbellata (Thunb.) Ohwi & Ohashi)

Pollen viability, germination and compatibility are essential in determining the success of pollination and seed setting of high-valued crops. Rice bean (Vigna umbellata (Thunb.) Ohwi & Ohashi) is an underutilized and unexplored indigenous legume with high potential for commercial production. In this study, pollen quality, viability, germination rate and incompatibility among selected six rice bean (V. umbellata) accessions from Barili, Cebu, Philippines were evaluated to determine the barriers and effective pollination habit for increased productivity while retaining the important traits, including high tolerance in poor soils, superior climatic resilience and resistance to pest and diseases. Results of acetocarmine calorimetric assay showed that rice beans’ (V. umbellata) pollens are highly viable, with accessions VU 004 (56.33 ± 4.91%) and VU 007 (54.34 ± 4.53%) having the optimum viability rate. Brewbaker and Kwack medium treated with 0.2 g.l-1 and 0.3 g.l-1 boric acid (H3BO4) enhanced the germination rate in vitro (11.56 ± 5.53% and 9.47 ± 6.50% respectively). Bud (14.96 ± 1.53%) and post-anthesis pollens (10.28 ± 0.94%) have optimum germination rate in 0.2 g.l-1 boric acid media, while anthesis pollens are suitable in media supplemented with sucrose and boric acid alone (12.20 ± 1.50%) and with 0.1 g.l-1 myo-inositol supplementation (8.49 ± 1.86%). Pollination test revealed that rice bean accessions have high self-compatibility (50.76 + 3.45%) and low cross-compatibility (26.57 + 2.49%). The findings provide an important background in understanding the pollen quality and intraspecific interaction among indigenous rice bean (V. umbellata) accessions in Barili, Cebu to improve production and hybridization

The Effect of Perilla frutescens extract on the oxidative stability of model food emulsions

The polyphenolic profile of leaves and stalks of Perilla frutescens, was assessed as a source of natural antioxidants. The amount of caffeic and rosmarinic acids, determined by high-performance liquid chromatography (HPLC), were 0.51 mg/g dry weight (DW) and 2.29 mg/g DW, respectively. The measurement of scavenging capacity against the 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation, the oxygen radical absorbance capacity (ORAC), and the ferric reducing antioxidant power (FRAP) were 65.03 mg Trolox equivalents (TE)/g DW, 179.60 mg TE/g DW and 44.46 mg TE/g DW, respectively. P. frutescens extracts also showed good antioxidant properties in 10% sunflower oil-in-water emulsions during storage at 32 °C. Perilla extract at 320 ppm was as effective as butylated hydroxyanisole (BHA) at 20 ppm in slowing down the formation of hydroperoxides as measured by peroxide value, thiobarbituric acid reactive substances and hexanal content. The results of this study indicate that extract of P. frutescens may be suitable for use in the food matrix to help achieve potential health benefits

The miRNA199a/SIRT1/P300/Yy1/sST2 signaling axis regulates adverse cardiac remodeling following MI.

Left ventricular remodeling following myocardial infarction (MI) is related to adverse outcome. It has been shown that an up-regulation of plasma soluble ST2 (sST2) levels are associated with lower pre-discharge left ventricular (LV) ejection fraction, adverse cardiovascular outcomes and mortality outcome after MI. The mechanisms involved in its modulation are unknown and there is not specific treatment capable of lowering plasma sST2 levels in acute-stage HF. We recently identified Yin-yang 1 (Yy1) as a transcription factor related to circulating soluble ST2 isoform (sST2) expression in infarcted myocardium. However, the underlying mechanisms involved in this process have not been thoroughly elucidated. This study aimed to evaluate the pathophysiological implication of miR-199a-5p in cardiac remodeling and the expression of the soluble ST2 isoform. Myocardial infarction (MI) was induced by permanent ligation of the left anterior coronary artery in C57BL6/J mice that randomly received antimiR199a therapy, antimiR-Ctrl or saline. A model of biomechanical stretching was also used to characterize the underlying mechanisms involved in the activation of Yy1/sST2 axis. Our results show that the significant upregulation of miR-199a-5p after myocardial infarction increases pathological cardiac hypertrophy by upregulating circulating soluble sST2 levels. AntimiR199a therapy up-regulates Sirt1 and inactivates the co-activator P300 protein, thus leading to Yy1 inhibition which decreases both expression and release of circulating sST2 by cardiomyocytes after myocardial infarction. Pharmacological inhibition of miR-199a rescues cardiac hypertrophy and heart failure in mice, offering a potential therapeutic approach for cardiac failure.This study was supported by a grant from the Seneca Foundation-Agency of Science and Technology of the Region of Murcia (20652/JLI/18) and a grant from the Instituto de Salud Carlos III (PI19/00519) which is cofinanced through the European Union's European Regional Development Fund (FEDER). Dr. Lax is a Ramon and Cajal researcher at the Department of Medicine, University of Murcia.S

Comparison of stresses in 3D v. 2D geomechanical modelling of salt structures in the Tarfaya Basin, West African coast

We predict stresses and strains in the Tarfaya salt basin on the West African coast using a 3D static geomechanical model and compare the results against a simplified 2D plane-strain model. Both models are based on present-day basin geometries, are drained, and use a poroelastic description for the sediments and visco-plastic description for salt. We focus on a salt diapir, where an exploratory well has been drilled crossing a major fault. The 3D model shows a significant horizontal stress reduction in sediments at the top of the diapir, validated with measured data later obtained from the well. The 2D model predicts comparable stress reduction in sediments at the crest of the diapir. However, it shows a broader area affected by the stress reduction, overestimating its magnitude by as much as 1.5 MPa. Both models predict a similar pattern of differential displacement in sediments along both sides of the major fault, above the diapir. These displacements are the main cause of horizontal stress reduction detected at the crest of the diapir. Sensitivity analysis in both models shows that the elastic parameters of the sediments have a minimal effect on the stress-strain behaviour. In addition, the 2D sensitivity analysis concludes that the main factors controlling stress and strain changes are the geometry of the salt and the difference in rock properties between encasing sediments and salt. Overall, our study demonstrates that carefully built 2D models at the exploration stage can provide stress information and useful insights comparable to those from more complex 3D geometrie

PpNAC1, a main regulator of phenylalanine biosynthesis in p. Pinaster

The metabolism of phenylalanine plays a central role in the channeling of carbon from photosynthesis to the biosynthesis of phenylpropanoids duringwood formation. This crucial pathway is finely regulated primarily at the transcriptional level by MYB and NAC transcription factors. In Arabidopsis, poplar and eucalyptus, the transcriptional network controlling secondary cell wall involves NAC-domain regulators operating upstream Myb transcription factors, but in conifers functional evidence had only been obtained for MYBs. We showed that PpMYB8 is a regulator of phenylpropanoid metabolism and lignin synthesis genes (Craven-Bartle et al. 2013) and three NAC genes PpNAC1, PpNAC30 and PpNAC31 were associated to vascular development in maritime pine (Pascual et al. 2015). Of all of them, PpNAC1 is expressed in the secondary xylem and compression wood of adult trees and phylogenetic analysis classified PpNAC1 as potential candidates to be involved in a transcriptional regulatory network controlling phenylalanine metabolism in maritime pine. This NAC transcription factor has been thoroughly characterized and its role upstream the transcriptional network involving Mybs TFs will be discussed. Understanding the molecular switches controlling wood formation is of paramount importance for fundamental tree biology and has important implications in tree biotechnology.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Resistance gene pool to co-trimoxazole in non-susceptible Nocardia strains

The soil-borne pathogen Nocardia sp. causes severe cutaneous, pulmonary, and central nervous system infections. Against them, co-trimoxazole (SXT) constitutes the mainstay of antimicrobial therapy. However, some Nocardia strains show resistance to SXT, but the underlying genetic basis is unknown. We investigated the presence of genetic resistance determinants and class 1-3 integrons in 76 SXT-resistant Nocardia strains by PCR and sequencing. By E test, these clinical strains showed SXT minimum inhibitory concentrations of ≥32:608 mg/L (ratio of 1:19 for trimethoprim: sulfamethoxazole). They belonged to 12 species, being the main representatives Nocardia farcinica (32%), followed by N. flavorosea (6.5%), N. nova (11.8%), N. carnea (10.5%), N. transvalensis (10.5%), and Nocardia sp. (6.5%). The prevalence of resistance genes in the SXT-resistant strains was as follows: sul1 and sul2 93.4 and 78.9%, respectively, dfrA(S1) 14.7%, blaTEM-1 and blaZ 2.6 and 2.6%, respectively, VIM-2 1.3%, aph(3')-IIIa 40.8%, ermA, ermB, mefA, and msrD 2.6, 77.6, 14.4, and 5.2%, respectively, and tet(O), tet(M), and tet(L) 48.6, 25.0, and 3.9%, respectively. Detected amino acid changes in GyrA were not related to fluoroquinolone resistance, but probably linked to species polymorphism. Class 1 and 3 integrons were found in 93.42 and 56.57% strains, respectively. Class 2 integrons and sul3 genes were not detected. Other mechanisms, different than dfrA(S1), dfrD, dfrF, dfrG, and dfrK, could explain the strong trimethoprim resistance shown by the other 64 strains. For first time, resistance determinants commonly found in clinically important bacteria were detected in Nocardia sp. sul1, sul2, erm(B), and tet(O) were the most prevalent in the SXT-resistant strains. The similarity in their resistome could be due to a common genetic platform, in which these determinants are co-transferred.This study was presented at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy, ICAAC2014, Washington, DC, USA. We thank Adrian Burton for editing and language assistance (http://physicalevidence.es/english/welcome). We are very grateful to all persons who took part in this study, and to the sample providers.S

PpNAC1, un regulador principal de la biosíntesis y utilización de fenilalanina en pino

La regulación transcripcional del metabolismo de la fenilalanina es particularmente importante en las coníferas, especies de vida larga que usan grandes cantidades de carbono en la formación de madera. El factor de transcripción PpNAC1 es un regulador principal de la biosíntesis de fenilalanina y su utilización en Pinus pinaster. El análisis filogenético lo clasifica dentro del grupo de proteínas NST y se expresa predominantemente en el xilema secundario y madera de compresión de árboles adultos. El silenciamiento de PpNAC1 en P. pinaster da como resultado la alteración del patrón vascular radial del tallo y la represión de la expresión de genes asociados con la biogénesis de pared celular y metabolismo secundario. Además, ensayos de transactivación y EMSA han mostrado que PpNAC1 puede activar su propia expresión y al promotor PpMyb4. A su vez PpMyb4 es capaz de activar a PpMyb8, un regulador transcripcional de la biosíntesis de fenilalanina y lignina en pino marítimo. En conjunto, estos resultados sugieren que PpNAC1 es un ortólogo funcional de los genes de Arabidopsis SND1 y NST1 y respalda la idea de que los reguladores clave que gobiernan la formación de la pared celular secundaria podrían estar conservados entre gimnospermas y angiospermas. Identificarlos interruptores moleculares que controlan la formación de la madera es de suma importancia importancia para la biología fundamental de los árboles y allana el camino para las aplicaciones biotecnológicas en coníferas.Universidad de Málaga. Campus de excelencia Internacional Andalucía Tec