A local accumulation of the Ralstonia solanacearum PopA protein in transgenic tobacco renders a compatible plant–pathogen interaction incompatible

Plants activate disease resistance responses when they recognize pathogen-derived molecules (elicitors). Frequently, recognition results in a hypersensitive response (HR), which is characterized by local host cell death at the infection site. Here we describe a genetic engineering approach to generate an HR in plants, whether or not an invading micro-organism produces a recognized elicitor. To that aim we created transgenic tobacco plants in which the pathogen-inducible promoter of the hsr203J gene from tobacco controls the expression of the popA elicitor gene from Ralstonia solanacearum. Because PopA itself also induces the hsr203J promoter, transgenic plants rapidly accumulate the bacterial elicitor in the pathogen infection sites. The elicitor becomes converted in plant tissues into its fully active derivatives PopA1-PopA3, showing that the previously observed processing events are not dependent on the bacterial type III secretion system. The outcome of induced PopA accumulation is a localized HR and a high degree of resistance of the transgenic plants to an oomycete pathogen. The system is functional in hybrids between different tobacco varieties, and we show that the engineered resistance, but not the associated cell death, is dependent on the salicylic acid signalling cascade. Although the approach is powerful in generating oomycete resistance, the induced HR might affect plant health. Its application thus requires a careful selection of individual transgenic lines and trials with various pathogens.     

Effect of Ramadan fasting on feelings,dietary intake,rating of perceived exertion and repeated high intensity short-term maximal performance

The present study was designed to investigate the effect of Ramadan fasting on feelings, dietary intake, rating of perceived exertion (RPE) and repeated high-intensity short-term maximal performance. Thirteen physically active men (age: 21.2 ± 2.9 years, height: 175.6 ± 5.6 cm, body-mass: 72.4 ± 8.6 kg) performed a 5-m shuttle run test (6 × 30-s + 35-s of recovery in-between) during five experimental periods: fifteen days before Ramadan (BR), the first ten days of Ramadan (FR), the last ten days of Ramadan (ER), ten days after Ramadan (AR10) and 20 days after Ramadan (AR20). The study was carried out in Tunisia during the 2016 Ramadan month. During the 5-m shuttle run test, higher distance (HD), total distance (TD) and fatigue index (FI) were recorded. RPE was determined after a 5-min warm-up and after each repetition of the 5-m shuttle run test (the mean RPE score during the test was calculated). Moreover, a feelings scale (FS) was used after the warm-up and after the end of the 5-m shuttle run test. During the five experimental periods, dietary intake was assessed. The results showed that HD, TD and FI during the 5-m shuttle run test were not affected by Ramadan observance (p > 0.05). Likewise, FS scores recorded after the warm-up and the 5-m shuttle run test were not affected by Ramadan fasting (p > 0.05). However, mean RPE scores during the 5-m shuttle run test were significantly lower at ER (4.06 UA), AR10 (3.86 UA) and AR20 (3.71 UA) in comparison to BR (4.51 UA) (p < 0.05). The results showed also that Ramadan fasting has no adverse effect on energy intake, protein (g and %), fat (g and %) and carbohydrate (g). However, the fractional contribution of carbohydrate was significantly higher AR10 than FR (53.1% vs. 45.8%) and ER (53.1% vs. 46.5%) and AR20 than FR (5.92% vs. 45.8%) (p < 0.05). In conclusion, Ramadan fasting has no adverse effect on feelings, dietary intake, and short-term maximal performance. However, the RPE during repeated high intensity short-term maximal exercise was reduced AR20 in comparison to ER.

Abbreviations:

AR: After Ramadan; AR10: Ten days after Ramadan; AR20: Twenty days after Ramadan; BR: Fifteen days before Ramadan; ER: Last ten days of Ramadan; FI: Fatigue index; FR: First ten days of Ramadan; FS: Feelings scale; HD: Higher distance; PSQI: The Pittsburgh Sleep Quality Index; RPE: Rating of Perceived Exertion Scale; TD: Total distance     

L’insémination intrautérine dans l’éjaculation rétrograde. Importance du pH et de l’osmolarité sur la mobilité des spermatozoïdes

The effect of pH and osmolarity on motility of human spermatozoa in retrograde ejaculation was studied in a freshly voided urine specimen. The maximum rate of motility is obtained when the pH ranged from 7.0 to 7.5 and osmolarity from 300 to 400 m.osmol/Kg. Thus the control of these two parameters allowed us to improve sperm motility and to perform intrauterine insemination with ovarian hyperstimulation. The different causes of retrograde ejaculation in this study are diabetes, surgical injury and idiopathic. Fifty-one intrauterine insemination cycles were realized in twenty-three patients, and eleven pregnancies are obtained (21.5% per cycle).     

Two mitochondrial haplotypes in Pterochloroides persicae (Hemiptera: Aphididae: Lachninae) associated with different feeding sites

Pterochloroides persicae (Cholodkovsky) is an aphid species belonging to the subfamily Lachninae that uses different members of Rosaceae (specially Prunus spp.) as hosts. Partial sequences from the mitochondrial cytochrome c oxidase 1 (COI) and the nuclear long‐wave opsin genes were obtained for approximately 100 P. persicae aphid individuals sampled from 34 colonies collected mainly in Tunisia and other Mediterranean locations. The variability found at the mitochondrial locus revealed the presence of two maternal haplotypes in the studied area that differed in a single nucleotide. The nuclear gene analyzed, however, failed to reveal any variability in this species. The variability found at the COI locus was related to the season of aphid sampling and with the site of feeding, with haplotype I mostly detected in samples collected in spring and summer on trunks and branches and haplotype II only detected in aphids collected in autumn on roots. The observed pattern of molecular variation suggests the presence of two clonal races of P. persicae coexisting in the studied area differentially adapted to conditions prevalent in the alternative seasons and/or to different feeding sites.     

Morphometry and biological parameters of different instars of the giant brown peach aphid: Pterochloroides persicae Cholodkovsky 1899 (Hemiptera: Aphididae) in Tunisia

Summary. Individuals of Pterochloroides persicae reared under controlled conditions were used to describe the morphometry and biological parameters of instars of this aphid. Our results showed that P. persicae developed four instars before reaching the adult stage. The first and the second larval instars both have five antennal segments, although the others have six segments. A significant difference was observed between instars in the first antennal segment (F = 56.11; df = 4, P = 0.026), in the body length (F = 115.38; df = 4, p = 0.014) and in the cauda length (F = 72, 77; df = 4, p = 0.021). The study of developmental and reproductive performance of P. persicae showed that the first instar lasted for 3.17 days, the second instar 2.35 days, the third instar 4.68 days, the fourth instar 5.035 days and the adult 6.86 days. We demonstrate also that the generation time lasted for 15.26 days. The life span was 22.11 days. As for fecundity, a single female of P. persicae gave birth to 29.68 ± 7.38 nymphs with an average reproductive rate per day of 4.32 ± 2.16.     

Phytophthora polonica, a new species isolated from declining Alnus glutinosa stands in Poland

In a survey of Phytophthora associated with alder decline in Poland, several isolates of a homothallic Phytophthora sp., which could not be assigned to other taxa including Phytophthora alni subspecies, were consistently recovered from rhizosphere soil samples. Their morphology and pathogenicity, as well as sequence data for three nuclear regions (internal transcribed spacer rDNA, elongation factor-1alpha and beta-tubulin) and a coding mitochondrial DNA region (nadh1), were examined. The new Phytophthora species is characterized by the moderate to slow growth rate of its colony in carrot agar at 20 degrees C, high optimal (c. 30 degrees C) and maximum (c. 38 degrees C) growth temperatures, formation of catenulate, often lateral, hyphal swellings, large chlamydospores in agar media and in soil extract, persistent, ovoid to ellipsoid nonpapillate sporangia and large oogonia with paragynous and sometimes amphigynous antheridia. Phytophthora polonica was slightly pathogenic to alder twigs and not pathogenic to trunks of several tree species. In a phylogenetic analysis using either Bayesian inference or maximum likelihood methods, P. polonica falls in clade 8 'sensu Kroon et al. (2004)' of Phytophthora.     

Pythium recalcitrans sp. nov. revealed by multigene phylogenetic analysis

A new species of Pythium collected from grapevine roots (Vitis vinifera) in South Africa and roots of common beet (Beta vulgaris) in Majorca, Spain, is described. The phylogenetic position of the new species was investigated by multigene sequence analyses of the internal transcribed spacers (ITS1 and ITS2) of the rDNA region, as well as three other nuclear and three mitochondrial coding genes. Maximum likelihood phylogenetic analyses based on ITS rDNA and concatenated beta-tubulin and cytrochrome c oxidase II alignment place Pythium recalcitrans together with P. sylvaticum and P. intermedium. Pythium recalcitrans sp. nov. is morphologically almost indistinguishable from other Pythium species that only form hyphal swellings in culture. However its species status is justified by the distinctiveness of the DNA sequences in all the genes examined. In culture P. recalcitrans exhibits fast radial growth, abundant spherical to subglobose hyphal swellings but produces no zoosporangia. Sexual structures are not seen in agar media but form in autoclaved grass blades floated on water. Multiple antheridia (1-7) are encountered with most of them diclinous and crook-necked. Oospores are thin-walled and either aplerotic or plerotic. P. recalcitrans was pathogenic to seedlings of Beta vulgaris and Solanum lycopersicum.     

Possible gastrointestinal disorders for athletes during Ramadan: an overview

Ramadan is considered to be the month of the stomach break. It has been reported that Ramadan has some health benefits. In most Muslims countries, there is a huge modification in the diet during this month. These changes could induce some gastrointestinal (GI) disorders (e.g. diarrhea, cramps, fullness, nausea). The aims of the present overview were to present some challenges that could be observed for athletes during the training sessions or competition and present some practical recommendations to avoid GI disorders during Ramadan. Based on previous studies, we could advance that the prevalence of GI disorders will be more pronounced when athletes travel for international competitions during Ramadan. Besides, GI disorders are more frequent for athletes when there is a huge modification in the training load. Dehydration observed during Ramadan is one of the factors that may induce GI disorders. The latter could be exacerbated by sweat loss during training sessions. Carbohydrate is frequently used by athletes to improve performance and is associated with some GI disorders. Therefore, during Ramadan, coaches and athletes should be advised to maintain the same diet and a good hydration as before the fasting month, and avoid air travel when preparing for competitions.