A ploidy chimera reveals the effects of tetraploidy in date palm

In the oasis of Tozeur (Tunisia) a peculiar date palm ploidy chimera was discovered, showing a diploid (2n = 2x) and a tetraploid (2n =4x) sector and a uniform tetraploid offshoot. This chimera allowed to describe the effects of chromosome doubling on some selected features. Because both ploidies occur within one plant, there was no environmental bias. Tetraploid leaves are longer, bear larger leaflets and spines and have a thicker rachis than normal diploid leaves. During three seasons, tetraploid inflorescences appeared ten days later than their diploid counterparts. The tetraploid sector formed bunches with stalks bearing larger fruits, with a higher percentage of inedible parthenocarpic fruits, than bunches that arose from the diploid sector. Tetraploid fruits are significantly longer, wider and heavier than diploid fruits, with a larger pulp diameter, irrespective of whether they are seeded or parthenocarpic. Diploid parthenocarpic fruits are longer than seeded fruits, while tetraploid parthenocarpic and seeded fruits both show the same size. The occurrence of tetraploidy opens new perspectives in date palm breeding. Pollination of tetraploid pistils with pollen from diploid males gave rise to a relatively low number of triploid plantlets, suggesting a triploid block

Combined effect of UV–C and passive modified atmosphere packaging to preserve the physicochemical and bioactive quality of fresh figs during storage

Figs are an important constituent of the Mediterranean diet, widely consumed fresh. Due to their very short shelf life, postharvest techniques to preserve quality and safety should be implemented. The current work aimed to study the combined effect of a postharvest UV–C treatment (5 or 10 kJ m−2) followed by packaging under passive modified atmosphere (MAP) on physicochemical and bioactive quality of fresh figs (cv. ‘Colar’) stored up to 12 d at 0 ºC (90–95% RH). As controls, UV–C untreated and air-stored (AIR) samples were used. The flesh firmness, skin colour, soluble solids content (SSC), titratable acidity (TA), pH, total phenolic content and total antioxidant activity were monitored. The steady-state modified atmosphere reached since day 8 was 17 kPa CO2 and 4 kPa O2. UV-C treated samples did not show visual decay incidence, while mycelial growth was observed in untreated figs on day 12. Figs treated with 10 kJ m-2 UV–C and stored under MAP conditions showed the highest flesh firmness with values of 0.6 N, which is 50% higher than in AIR. Skin darkening observed among samples was higher in 10 kJ m-2 with Chroma decreases of 2.6 units on day 12 under MAP, although panellists preferred this treatment according to its visual appearance. Higher SSC and TA differences were found in UVC-treated samples during storage. Moreover, 10 kJ m-2 UV–C and MAP induced the highest total phenolic content accumulation, with 260% and 540% higher values from day 4 to day 12 for skin and flesh, respectively. In conclusion, a 10 kJ m−2 UV–C treatment after harvesting followed by packaging under MAP conditions may be considered a good tool to preserve the physicochemical and bioactive quality of fresh figs during 12 d at 0 ºC.The authors express their gratitude to CAPES (Higher Education Personnel Improvement Coordination) for a research grant (8578/11–7) made to Manoel Souza. The authors are grateful to the Tunisian Ministry of Higher Education and Scientific Research for a predoctoral grant to Monia Jemni. The authors express want also to thank Pablo Melgarejo (Universidad Miguel Hernández) for providing the plant material used in this study

Molecular diagnosis of distal renal tubular acidosis in Tunisian patients: proposed algorithm for Northern Africa populations for the ATP6V1B1, ATP6V0A4 and SCL4A1 genes

Background: Primary distal renal tubular acidosis (dRTA) caused by mutations in the genes that codify for the H+ -ATPase pump subunits is a heterogeneous disease with a poor phenotype-genotype correlation. Up to now, large cohorts of dRTA Tunisian patients have not been analyzed, and molecular defects may differ from those described in other ethnicities. We aim to identify molecular defects present in the ATP6V1B1, ATP6V0A4 and SLC4A1 genes in a Tunisian cohort, according to the following algorithm: first, ATP6V1B1 gene analysis in dRTA patients with sensorineural hearing loss (SNHL) or unknown hearing status. Afterwards, ATP6V0A4 gene study in dRTA patients with normal hearing, and in those without any structural mutation in the ATP6V1B1 gene despite presenting SNHL. Finally, analysis of the SLC4A1 gene in those patients with a negative result for the previous studies. Methods: 25 children (19 boys) with dRTA from 20 families of Tunisian origin were studied. DNAs were extracted by the standard phenol/chloroform method. Molecular analysis was performed by PCR amplification and direct sequencing. Results: In the index cases, ATP6V1B1 gene screening resulted in a mutation detection rate of 81.25%, which increased up to 95% after ATP6V0A4 gene analysis. Three ATP6V1B1 mutations were observed: one frameshift mutation (c.1155dupC; p.Ile386fs), in exon 12; a G to C single nucleotide substitution, on the acceptor splicing site (c.175-1G > C; p.?) in intron 2, and one novel missense mutation (c. 1102G > A; p. Glu368Lys), in exon 11. We also report four mutations in the ATP6V0A4 gene: one single nucleotide deletion in exon 13 (c.1221delG; p. Met408Cysfs* 10); the nonsense c.16C > T; p.Arg6*, in exon 3; and the missense changes c.1739 T > C; p.Met580Thr, in exon 17 and c.2035G > T; p.Asp679Tyr, in exon 19. Conclusion: Molecular diagnosis of ATP6V1B1 and ATP6V0A4 genes was performed in a large Tunisian cohort with dRTA. We identified three different ATP6V1B1 and four different ATP6V0A4 mutations in 25 Tunisian children. One of them, c.1102G > A; p.Glu368Lys in the ATP6V1B1 gene, had not previously been described. Among deaf since childhood patients, 75% had the ATP6V1B1 gene c. 1155dupC mutation in homozygosis. Based on the results, we propose a new diagnostic strategy to facilitate the genetic testing in North Africans with dRTA and SNHL.This research study was supported by PI09/90888 and PI11/01412 grants, from the Instituto de Salud Carlos III (Spain), by BIO08/ER/020 grant, from the EITB Maratoia-Bioef (Basque Foundation for Health Innovation and Research) and by the Tunisian Ministry of Scientific Research (Research Unit code 05/UR-09-04, University of Monastir) for DEH mobility

Molecular study of the perforin gene in familial hematological malignancies

Perforin gene (PRF1) mutations have been identified in some patients diagnosed with the familial form of hemophagocytic lymphohistiocytosis (HLH) and in patients with lymphoma. The aim of the present study was to determine whether patients with a familial aggregation of hematological malignancies harbor germline perforin gene mutations. For this purpose, 81 unrelated families from Tunisia and France with aggregated hematological malignancies were investigated. The variants detected in the PRF1 coding region amounted to 3.7% (3/81). Two of the three variants identified were previously described: the p.Ala91Val pathogenic mutation and the p.Asn252Ser polymorphism. A new p.Ala 211Val missense substitution was identified in two related Tunisian patients. In order to assess the pathogenicity of this new variation, bioinformatic tools were used to predict its effects on the perforin protein structure and at the mRNA level. The segregation of the mutant allele was studied in the family of interest and a control population was screened. The fact that this variant was not found to occur in 200 control chromosomes suggests that it may be pathogenic. However, overexpression of mutated PRF1 in rat basophilic leukemia cells did not affect the lytic function of perforin differently from the wild type protein

Identification of strain isolated from dates (Phœnix dactylifera L.) for enhancing very high gravity ethanol production

International audienceEthanol production from by-products of dates in very high gravity was conducted in batch fermentation using two yeasts, Saccharomyces cerevisiae and Zygosaccharomyces rouxii, as well as a native strain: an osmophilic strain of bacteria which was isolated for the first time from the juice of dates (Phoenix dactylifera L.). The phylogenetic analysis based on the 16S ribosomal RNA and gyrB sequence and physiological analysis indicated that the strain identified belongs to the genus of Bacillus, B. amyloliquefaciens. The ethanol yields produced from the syrup of dates (175 g L(-1) and 360 g L(-1) of total sugar) were 40.6% and 29.5%, respectively. By comparing the ethanol production by the isolated bacteria to that obtained using Z. rouxii and S. cerevisiae, it can be concluded that B. amyloliquefaciens was suitable for ethanol production from the syrup of dates and can consume the three types of sugar (glucose, fructose, and sucrose). Using Z. rouxii, fructose was preferentially consumed, while glucose was consumed only after fructose depletion. From this, B. amyloliquefaciens was promising for the bioethanol industry. In addition, this latter showed a good tolerance for high sugar concentration (36%), allowing ethanol production in batch fermentation at pH 5.0 and 28 °C in date syrup medium. Promising ethanol yield produced to sugar consumed were observed for the two osmotolerant microorganisms, Z. rouxii and B. amyloliquefaciens, nearly 32-33%, which were further improved when they were cocultivated, leading to an ethanol to glucose yield of 42-43%

Effect of flowering stage and storage conditions on pollen quality of six male date palm genotypes

Availability of efficient male genotypes is critical for successful artificial pollination and regular bearing of female date palms. The effect of flowering stage and storage conditions on pollen quality of six male date palm genotypes encoded 'ABD1', 'P4', 'P3', 'P8', 'P7' and 'P13'were evaluated. Pollen collected from spathes developed at the middle of flowering stage exhibited the best viability (90%) and germinability (85%) compared to other stages. Pollen viability was greater than 90%, except for 'P8' that exhibited 80%, while, germinability greatly varied among the genotypes. Pollen quality decreased during 4 months of storage upon genotype and temperature, with a minimum reduction at -30 degrees C followed by 4 degrees C. Heat shock exposure (33 +/- 2 degrees C) following storage revealed that pollen stored at -30 degrees C or 4 degrees C should be used for pollination on the same day of take out to avoid dramatic quality loss. The 'ABD1', an early flowering genotype, proved highest pollen quality both at fresh stage and after storage. While, the 'P3', a late flowering genotype, retained its pollen quality during storage. However, the 'P13' genotype exhibited excellent pollen quality when fresh, but greatly loses germinability during storage. (C) 2021 The Author(s). Published by Elsevier B.V. on behalf of King Saud University

Caracterización morfológica, química y sensorial de quatro variedades de brevas

The current work studies the main morphological, chemical and sensory characteristics of four varieties of figs grown in the southeastern of Spain (Orihuela, Alicante). Selected cultivars were Colar, San Antonio, Cuello de Dama Negro and Tiberio, grown in a experimental farm under homogeneous conditions. The monitored attributes were weight, calibers, ostiole diameter, pH, total soluble solids (TSS), titratable acidity (TA), and sugars content. The acceptability of the fruits for consumption was monitored by a sensory evaluation (external visual appearance, flavor, texture, presence of striations and overall quality). In all morphological attributes significant differences among cultivars weredetected. Colar showed the highest weight (75.26 g) and calibers (46.67 mm) with a small ostiole(4.57 mm), and the lowest AT (0.12% citric acid). The pH ranged from 4.79 to 5.35 and the SST from17.0 to 18.6 °Brix. The sugars levels ranged from 3.55 to 4.63 g/100 g fructose and from 5.25 to 7.20g/100 g glucose. Cuello de Dama Negro showed the lowest fructose content. As main conclusion Colar cv. showed the best morphological characteristics, without differences in the chemical characteristicsand sensory evaluation. On the other hand Tiberio cv. showed the lowest sensory quality.El presente trabajo estudia las principales características morfológicas, químicas y sensoriales de cuatrovariedades de higuera, cultivadas en el sureste de España (Orihuela, Alicante). Las variedades seleccionadasfueron: Colar, San Antonio, Cuello de Dama Negro y Tiberio, procedentes de un cultivo experimental encondiciones homogéneas. Las características analizadas fueron peso, calibres, diámetro del ostiolo, pH, sólidossolubles totales (SST), acidez titulable (AT) y contenido en azúcares. También se analizó la aceptabilidad de losfrutos para el consumo mediante una evaluación sensorial (apariencia visual externa, sabor, textura, presenciade estrías y calificación global). Se detectaron diferencias significativas en todos los atributos morfológicos.Colar destacó por sus frutos del mayor peso (75,26g) y calibres (46,67mm), con pequeño ostiolo (4,57mm) y lamenor AT (0,12% ácido cítrico). El pH varió de 4,79 a 5.35 y los SST de 17,0 a 18,6 °Brix. La concentración de azúcares varió de 3,55 a 4,63 g/100 g de fructosa y de 5,25 a 7,20 g/100 g de glucosa. Cuello de Dama Negro mostró el menor contenido en fructosa. Como principal conclusión Colar presentó las mejores características morfológicas, sin diferencias respecto a las otras variedades en las químicas y sensoriales (calificación global). Por su parte, Tiberio mostró la menor apariencia visual externa, textura, valoración global y aceptabilidad

Effect of hyperthermia and physical activity on circulating growth hormone

The aim of this study was to differentiate the effects of hyperthermia and physical activity on circulating growth hormone (GH) secretion. Nine healthy volunteer adults performed two 40 min exercise trials and two 50 min passive standing trials. The exercise was performed in either thermo-neutral (N-Ex: air temperature 18 8C, air humidity 40%, and wet bulb globe temperature (WBGT) 17.7 8C) or hot environmental conditions (H-Ex: air temperature 33 8C, air humidity 30%, and WBGT 34.6 8C). The passive exposure trials were also performed in either a comfortable (N-P: air temperature 18 8C, air humidity 40%, and WBGT 17.7 8C) or a hot climatic chamber (H-P: air temperature 40 8C, air humidity 100%, and WBGT 97.1 8C). Plasma GH, plasma volume (PV), tympanic temperature (Tty), and body mass loss (BML) were measured before and after each trial. The decrease in PV was significantly higher during H-Ex and H-P sessions than during N-Ex and N-P sessions. Comparisons showed significantly lower BML in the N-Ex session (1.5% ± 0.3%) than in the H-Ex and H-P sessions (2.1% ± 0.3% and 1.9% ± 0.2%, respectively) (p < 0.001). The rise in Tty was significantly higher during the H-P session (2.9 ± 0.4 8C) (p < 0.001) when compared with the other sessions. Plasma GH concentration increased significantly during all the trials, particularly during the H-Ex session (45 ± 7 ng�mL–1) (p < 0.01). Both exercise and heat exposure, separately, are sufficient to increase significantly the plasma GH concentration, and their combined effect induced a highly synergistic rise in GH