Mitochondrial biogenesis in mammals: the role of endogenous nitric oxide

Nitric oxide was found to trigger mitochondrial biogenesis in cells as diverse as brown adipocytes and 3T3-L1, U937, and HeLa cells. This effect of nitric oxide was dependent on guanosine 3',5'-monophosphate (cGMP) and was mediated by the induction of peroxisome proliferator-activated receptor gamma coactivator 1alpha, a master regulator of mitochondrial biogenesis. Moreover, the mitochondrial biogenesis induced by exposure to cold was markedly reduced in brown adipose tissue of endothelial nitric oxide synthase null-mutant (eNOS-/-) mice, which had a reduced metabolic rate and accelerated weight gain as compared to wild-type mice. Thus, a nitric oxide-cGMP-dependent pathway controls mitochondrial biogenesis and body energy balance.     

Phenotyping a diversity panel of quinoa using UAV-retrieved leaf area index,SPAD-based chlorophyll and a random forest approach

Given its high nutritional value and capacity to grow in harsh environments, quinoa has significant potential to address a range of food security concerns. Monitoring the development of phenotypic traits during field trials can provide insights into the varieties best suited to specific environmental conditions and management strategies. Unmanned aerial vehicles (UAVs) provide a promising means for phenotyping and offer the potential for new insights into relative plant performance. During a field trial exploring 141 quinoa accessions, a UAV-based multispectral camera was deployed to retrieve leaf area index (LAI) and SPAD-based chlorophyll across 378 control and 378 saline-irrigated plots using a random forest regression approach based on both individual spectral bands and 25 different vegetation indices (VIs) derived from the multispectral imagery. Results show that most VIs had stronger correlation with the LAI and SPAD-based chlorophyll measurements than individual bands. VIs including the red-edge band had high importance in SPAD-based chlorophyll predictions, while VIs including the near infrared band (but not the red-edge band) improved LAI prediction models. When applied to individual treatments (i.e. control or saline), the models trained using all data (i.e. both control and saline data) achieved high mapping accuracies for LAI (R²?=?0.977–0.980, RMSE?=?0.119–0.167) and SPAD-based chlorophyll (R²?=?0.983–0.986, RMSE?=?2.535–2.861). Overall, the study demonstrated that UAV-based remote sensing is not only useful for retrieving important phenotypic traits of quinoa, but that machine learning models trained on all available measurements can provide robust predictions for abiotic stress experiments.

     

Heavy Metals Contamination in Century-Old Manmade Technosols of Hope Bay, Antarctic Peninsula

Technosols are anthropogenic soils that may be strongly impacted by heavy metal deposition, which have not yet been described in Antarctica. In this paper, we present a chemical study of what is supposedly the oldest manmade soil from Antarctic Peninsula, developed in the vicinity of Trinity House and Nordenskjold Hut at Hope Bay. Chemical and morphological soil attributes indicate that a former ornithogenic site (penguin rookery) was further subjected to human disturbance, following local exploration since 1903. We detected very high amounts of heavy metals such as Cd, Cu, Pb, and Zn. For the most impacted site, pseudototal concentrations of these elements reach 47, 2,082, 19,381, and 5,225 mg kg^?1, respectively. Enrichment factors were calculated using Zr as reference element, and high values were found for these contaminated sites, qualifying some of them as extremely polluted. Also, both the mobilizable and mobile fraction of Cd and Pb indicate the need of intervention in the affected area. These findings are all consistent with the human impacts and strong contamination. Strong positive correlation between the pseudototal concentrations of Cd, Cu, Mn, Ni, Pb, and Zn indicates a similar source of pollution. These soils may represent the oldest Technosols in Antarctic Continent.     

Activation of goat primordial follicles in vitro: Influence of alginate and ovarian tissue

The present study aimed to evaluate the effect of three culture systems on caprine primordial follicle activation in vitro: follicles cultured either in the isolated form within alginate (Isolated follicles + Alginate treatment), or enclosed in ovarian tissue (in situ), with or without alginate (Fragment + Alginate, and Fragment alone treatments, respectively). After culture, the Isolated follicles + Alginate treatment presented a percentage of morphologically normal follicles (MNF) similar to both the non-cultured control and the Fragment Alone treatments. Nevertheless, Fragment + Alginate treatment showed a significant reduction in the number of MNF when compared to the other treatments. Regarding follicle development, our results showed that regardless of the alginate, the presence of ovarian tissue limited primordial follicle activation during in vitro culture. Remarkably, the Isolated primordial follicle + Alginate treatment was the only one that significantly promoted follicle activation and increased both follicle and oocyte diameters during IVFC, pointing out a higher cell proliferation. In conclusion, the presence of ovarian tissue with or without alginate limited follicle development (activation) after culture. Nevertheless, when primordial follicles were isolated and encapsulated in alginate they presented suitable survival rates, higher rates of follicle activation and continued to grow throughout the culture period.     

Polymorphism of the PE domain of PE/PE_PGRS sequences in clinical isolates of Mycobacterium bovis in Mexico

Polymorphism of the PE domain of PE/PE_PGRS sequences was studied in Mycobacterium bovis isolates from different Mexican states. Samples were analyzed by spolygotyping and RFLP using IS6110 and a 235-bp fragment of the PE domain of PE/PE_PGRS as probes. With the PE probe, three different genotypes were observed, one being predominant in all states. These results confirm the high conservation of the PE domain and suggests a potential role for PE sequence as a stable genetic marker for bovine tuberculosis.     

Consequences of Landscape Heterogeneity on Grassland Diversity and Productivity in the Espinal Agroforestry System of Central Chile

The current land use system in the anthropogenic savannas (Espinales) of the Mediterranean climate region of Chile, has resulted in considerable heterogeneity at the landscape level which is associated with different covers of the legume tree, Acacia caven. The effects of landscape heterogeneity on the diversity and productivity of herbaceous plant communities were studied in 29 plots of 1000 m², with a wide range of woody cover. A detrended correspondence analysis of the species × plots matrix explained 73% of the total variation and revealed the existence of two trends of variation in floristic composition: one associated with physiographic position (hillsides and flatlands) and the other related to the number of years since the last cutting, or coppicing, of A. caven. Despite the great majority of the original herbaceous species having disappeared as a result of the prevailing land use system, some native species have been able to survive especially on hillside areas with low grazing intensity. Woody cover was a good indicator of spatial heterogeneity and land use history. It was also correlated with stocking rate, above-ground biomass of herbaceous vegetation, and soil fertility (organic matter, nitrogen and phosphorus concentration), both on hillsides and flatlands. The relationship between woody cover and herbaceous plant species richness was significant and unimodal in flat land areas, and linear, and marginally significant, on hillsides. The consequences of land use changes on the conservation of the ecological and productive values of grasslands are analyzed.     

Methods of collection,extender type,and freezability of semen collected from creole bulls raised in the tropical highlands of Ecuador

This study was conducted to determine the best combination between two collection method and two extenders in the cryopreservation of semen from creole bulls adapted to highlands of the Ecuadorian Andes. Sixty ejaculates from three adult Creole bulls were evaluated after collection by artificial vagina (AV) and electroejaculation (EE). Semen samples were split into two aliquots and diluted with a soy lecithin extender (Andromed®; A) or an egg yolk-containing extender (Triladyl®; T) and packed in straws of 0.25 ml with 20 × 10⁶ sperms. Optical microscopy and computer-assisted semen analysis system (CASA) were used to evaluate semen quality characteristics. The effects of collection methods and extender type as well as its interaction were evaluated by a factorial ANOVA and Bonferroni’s test. Semen samples collected with EE and frozen with T (EE-T) and A (EE-A) had greater proportion of spermatozoa with optical assessed individual progressive motility (IPM), plasmatic membrane intact (HosT), and lower tail abnormalities than those obtained with AV and frozen with the same extenders (AV-T and AV-A); however, differences were significant only between EE-A and AV-T. CASA assessment indicated that the total mobility (TM) was greater (P < 0.05) in semen samples diluted with T, although these samples had a greater proportion (P < 0.05) of sperms with local motility (LM) and fewer immobile sperms (IS), than those extended with A. Generally, semen samples obtained with EE or AV and diluted with T seems to be the best option to ciopreserve gametes of Creole bulls raised in highlands of Ecuadorian Andes.

     

Monitoring of Brazilian wheat blast field populations reveals resistance to QoI,DMI, and SDHI fungicides

Wheat blast is one of the most important and devastating fungal diseases of wheat in South America, South-east Asia, and now in southern Africa. The disease can reduce grain yield by up to 70% and is best controlled using integrated disease management strategies. The difficulty in disease management is compounded by the lack of durable host resistance and the ineffectiveness of fungicide sprays. New succinate dehydrogenase inhibitor (SDHI) fungicides were recently introduced for the management of wheat diseases. Brazilian field populations of the wheat blast pathogen Pyricularia oryzae Triticum lineage (PoTl) sampled from different geographical regions in 2012 and 2018 were shown to be resistant to both QoI (strobilurin) and DMI (azole) fungicides. The main objective of the current study was to determine the SDHI baseline sensitivity in these populations. Moderate levels of SDHI resistance were detected in five out of the six field populations sampled in 2012 and in most of the strains isolated in 2018. No association was found between target site mutations in the sdhB, sdhC, and sdhD genes and the levels of SDHI resistance, indicating that a pre-existing resistance mechanism not associated with target site mutations is probably present in Brazilian wheat blast populations.     

Multiplex RT-PCR for detection and identification of three necroviruses that infect olive trees

An optimized multiplex RT-PCR assay was developed to discriminate three necrovirus (Olive latent virus 1 (OLV-1), Tobacco necrosis virus D (TNV-D) and Olive mild mosaic virus (OMMV)) that infect olive trees. An olive orchard consisting of 54 trees of cv. “Galega vulgar” in the south of Portugal was surveyed. dsRNA fraction was used as template and revealed the 3 viruses, singly or in multiple infections, present in 17 out of 54 trees in the orchard. OMMV was the most frequent occurring in 15 trees, followed by OLV-1 in 12 and TNV-D in 4 plants. The results obtained showed that necrovirus- specific dsRNAs do exist in infected tissues in amounts below the resolution permitted by gel electrophoresis analysis and that the developed multiplex PCR based assay is of much higher sensitivity. The design of the specific primers described enabled, for the first time, to discriminate between OMMV and TNV-D by means of RT-PCR assays, an indispensable tool in identification, epidemiology and survey studies.     

Toxicity of soybean-registered agrochemicals to <Emphasis Type="Italic">Telenomus podisi</Emphasis> and <Emphasis Type="Italic">Trissolcus basalis</Emphasis> immature stages

Biological control of phytophagous bugs in soybean crops is efficiently performed by egg parasitoids, such as Telenomus podisi and Trissolcus basalis. Based on this, the use of agrochemicals in these crops must be managed consciously, making use of pesticides that are selective to the egg of these parasitoids, in order to ensure a balanced ecosystem. The aim of this study was to assess the selectivity of 15 registered pesticides to the immature stages (pre and post-parasitism) of T. podisi and T. basalis, following the method proposed by the “International Organization for Biological and Integrated Control” (IOBC). Pesticides were classified as class 1 – harmless (RP?<?30%); class 2 – slightly harmful (30%?≤?RP?≤?79%); class 3 – moderately harmful (80%?≤?RP?≤?99%); and class 4 – harmful (RP?>?99%). During pre-parasitism, the insecticides imidacloprid+beta-cyfluthrin, deltamethrin, lambda-cyhalothrin+thiamethoxam, acephate, and fenitrothion reduced parasitism of both parasitoids. The others: flubendiamide, diflubenzuron, Bacillus thuringiensis, lufenuron, and the herbicide isopropylamine were selective, i.e. harmless (class 1), to both parasitoids, except for pyraclostrobin+metconazole, which significantly reduced T. basalis parasitism, being considered slightly harmful (class 2). In post parasitism, all the aforementioned pesticides were harmless to T. podisi and T. basalis. Moreover, in pre-parasitism, T. basalis was found to be more sensitive to the tested pesticides when compared to T. podisi. Still, more studies must be conducted to provide a better understanding of the impact of agrochemicals on these parasitoid species in semi-field conditions.