Decoding the effects of drought stress on popcorn (Zea mays var. everta) flowering combining proteomics and physiological analysis.

Under conditions of soil water limitation and adequate irrigation, we conducted an investigation into the growth dynamics, gas exchange performance, and proteomic profiles of two inbred popcorn lines-L71, characterized as drought-tolerant, and L61, identified as drought-sensitive. Our goal was to uncover the mechanisms associated with tolerance to soil water limitation during the flowering. The plants were cultivated until grain filling in a substrate composed of perlite and peat within 150cm long lysimeter, subjected to two water conditions (WC): i) irrigated (WW) at lysimeter capacity (LC - 100%), and ii) water-stressed (WS). Under WS conditions, the plants gradually reached 45% of LC and were maintained at this level for 10 days. Irrespective of the WC, L71 exhibited the highest values of dry biomass in both shoot and root systems, signifying its status as the most robust genotype. The imposed water limitation led to early senescence, chlorophyll degradation, and increased anthocyanin levels, with a more pronounced impact observed in L61. Traits related to gas exchange manifested differences between the lines only under WS conditions. A total of 1838 proteins were identified, with 169 differentially accumulated proteins (DAPs) in the tolerant line and 386 DAPs in the sensitive line. Notably, differences in energy metabolism, photosynthesis, oxidative stress response, and protein synthesis pathways were identified as the key distinctions between L71 and L61. Consequently, our findings offer valuable insights into the alterations in proteomic profiles associated with the adaptation to soil water limitation in popcorn.

Early selection for drought tolerance in popcorn based on gene effects estimated in seedlings.

Low rainfall rates are becoming increasingly frequent because of climate change, causing droughts and threatening world food security. For popcorn, drought is the most limiting abiotic factor for plant's growth and development. Thus, the water deficit directly impacts for crop productivity. Based on knowledge of the genetic basis of traits involved in stages of popcorn germination and seedling development under water stress, genotypes with potential for adaptation to adverse growing conditions can be selected early. Therefore, data on genetic effects and combining ability of 10 popcorn parents were compiled to propose breeding strategies for the development of cultivars with greater adaptation to water stress in the early stages. Forty-five diallel hybrids were evaluated under two different water regimes, that is, water stress and full irrigation. This corresponded to a water retention capacity of 25% and 70% of the germination paper. The plants were watered daily as needed for seven days. A range of factors were evaluated, that is, germination traits including the germination speed index and germination on the seventh day; shoot traits including length and dry weight; and root system including length, dry weight, root-to-shoot ratio, maximum root number, root network area, specific and root network length, and root volume. Breeding for drought adaption in the early stages of popcorn development can be successful when hybrids are used, because of the genetic effects of dominance (ϕs). These control the traits evaluated at the seedling stage. The combinations L61 x P2 and L71 x P3 were recommended, in view of the more successful performance estimated for traits related to the shoot and root system.

Exploring the Potential of Heterosis to Improve Nitrogen Use Efficiency in Popcorn Plants.

Nitrogen is crucial for plant growth and development, and improving nitrogen use efficiency (NUE) is a viable strategy for reducing dependence on nitrogen inputs and promoting sustainability. While the benefits of heterosis in corn are well known, the physiological mechanisms underlying this phenomenon in popcorn are less understood. We aimed to investigate the effects of heterosis on growth and physiological traits in four popcorn lines and their hybrids under two contrasting nitrogen conditions. We evaluated morpho-agronomic and physiological traits such as leaf pigments, the maximum photochemical efficiency of PSII, and leaf gas exchange. Components associated with NUE were also evaluated. N deprivation caused reductions of up to 65% in terms of plant architecture, 37% in terms of leaf pigments, and 42% in terms of photosynthesis-related traits. Heterosis had significant effects on growth traits, NUE, and foliar pigments, particularly under low soil nitrogen conditions. N-utilization efficiency was found to be the mechanism favoring superior hybrid performance for NUE. Non-additive genetic effects were predominant in controlling the studied traits, indicating that exploring heterosis is the most effective strategy for obtaining superior hybrids to promote NUE. The findings are relevant and beneficial for agro farmers seeking sustainable agricultural practices and improved crop productivity through the optimization of nitrogen utilization.

Hiding in the yolk: A unique feature of Legionella pneumophila infection of zebrafish.

The zebrafish has become a powerful model organism to study host-pathogen interactions. Here, we developed a zebrafish model to dissect the innate immune response to Legionella pneumophila during infection. We show that L. pneumophila cause zebrafish larvae death in a dose dependent manner. Additionally, we show that macrophages are the first line of defence and cooperate with neutrophils to clear the infection. Immunocompromised humans have an increased propensity to develop pneumonia, similarly, when either macrophages or neutrophils are depleted, these "immunocompromised" larvae become lethally sensitive to L. pneumophila. Also, as observed in human infections, the adaptor signalling molecule Myd88 is not required to control disease in the larvae. Furthermore, proinflammatory cytokine genes il1ß and tnf-α were upregulated during infection, recapitulating key immune responses seen in human infection. Strikingly, we uncovered a previously undescribed infection phenotype in zebrafish larvae, whereby bloodborne, wild type L. pneumophila invade and grow in the larval yolk region, a phenotype not observed with a type IV secretion system deficient mutant that cannot translocate effectors into its host cell. Thus, zebrafish larva represents an innovative L. pneumophila infection model that mimics important aspects of the human immune response to L. pneumophila infection and will allow the elucidation of mechanisms by which type IV secretion effectors allow L. pneumophila to cross host cell membranes and obtain nutrients from nutrient rich environments.

Advanced Levels of Chronic Venous Insufficiency are Related to an Increased in Arterial Stiffness.

BACKGROUND: Chronic venous insufficiency (CVI) is characterized by progressive inflammatory changes. Inflammatory damage occurs in the veins, adjacent tissues, and can lead to structural changes in the arteries. The aim of this study is to analyze whether the degree of CVI is associated with arterial stiffness. METHODS: Cross-sectional study including patients with CVI classified by clinical, etiological, anatomical, and pathophysiological classification (CEAP) 1 to 6. We performed correlation between the degree of CVI, central and peripheral arterial pressure, and arterial stiffness measured by brachial artery oscillometry. RESULTS: We evaluated 70 patients, 53 of whom were women with a mean age of 54.7 years. Patients with advanced degrees of venous insufficiency CEAP 4,5,6, had higher levels of systolic, diastolic, central, and peripheral arterial pressures compared to those with early stages (CEAP 1,2,3). The CEAP 4,5,6 group had higher arterial stiffness indices than the CEAP 1,2,3 group: pulse wave velocity (PWV) 9.3 m/s vs. 7.0 m/s, P < 0.001; augmentation pressure (AP) 8.0 mm Hg vs. 6.3 mm Hg; P = 0.04. There was a positive correlation between the degree of venous insufficiency measured by the venous clinical severity score, villalta score and CEAP classification, and the arterial stiffness indices (Spearman's coefficient = 0.62 for PWV and CEAP, P < 0.01). The factors influencing PWV were age, peripheral systolic arterial pressure (SAPp), and AP. CONCLUSIONS: There is a correlation between the degree of venous disease and arterial structural changes characterized by arterial pressure and stiffness indices. Degenerative changes secondary to venous insufficiency are associated with impairment of the arterial system, which has implications for the development of cardiovascular disease.

Recurrent Interpopulation Selection in Popcorn: From Heterosis to Genetic Gains.

In view of the need to develop new popcorn cultivars and considering the uncertainties in choosing the most appropriate breeding methods to ensure consistent genetic progress, simultaneously for both popping expansion and grain yield, this study addressed the efficiency of interpopulation recurrent selection regarding genetic gains, the study of the response in genetic parameters as well as heterotic effects on the control of the main agronomic traits of popcorn. Two populations were established, Pop1 and Pop2. A total of 324 treatments were evaluated, which consisted of 200 half-sib families (100 from Pop1 and 100 from Pop2), 100 full-sib families from the two populations and 24 controls. The field experiment was arranged in a lattice design with three replications in two environments, in the north and northwest regions of the State of Rio de Janeiro, Brazil. The genotype × environment interaction was partitioned and the genetic parameters, heterosis and predicted gains were estimated by the Mulamba and Mock index, based on selection results in both environments. The genetic parameters detected variability that can be explored in successive interpopulation recurrent selection cycles. Exploring heterosis for GY, PE and yield components is a promising option to increase grain yield and quality. The Mulamba and Mock index was efficient in predicting the genetic gains in GY and PE. Interpopulation recurrent selection proved effective to provide genetic gains for traits with predominantly additive and dominance inheritance.

Additive and Non-Additive Effects on the Control of Key Agronomic Traits in Popcorn Lines under Contrasting Phosphorus Conditions.

Phosphorus is a non-renewable natural resource that will run out of reserves in the upcoming decades, making it essential to understanding the inheritance of nutrient use efficiency for selecting superior genotypes. This study investigated the additive and non-additive effects of commercially relevant traits for the popcorn crop (grain yield-GY, popping expansion-PE, and expanded popcorn volume per hectare-PV) in different conditions of phosphorus (P) availability in two locations in Rio de Janeiro State, Brazil. Six S7 lines previously selected for P use-L59, L70, and P7, efficient and responsive; and L54, L75, and L80, inefficient and non-responsive-were used as testers in crosses with 15 progenies from the fifth cycle of intrapopulation recurrent selection of UENF-14, with adaptation to the North and Northwest regions of Rio de Janeiro State. Using the Griffing diallel analysis, P use efficiency was predominantly additive in the expression of PE, and non-additive effects were prominent for GY and PV. For obtaining genotypes that are efficient for phosphorus use, it is recommended that heterosis with parents that provide additive gene accumulation for PE be explored.

All Are in a Drought, but Some Stand Out: Multivariate Analysis in the Selection of Agronomic Efficient Popcorn Genotypes.

The search for productive germplasm adapted to adverse conditions is an important action to mitigate the harmful effects of climate change. The aim was to identify the yield potential of 50 popcorn inbred lines grown in field conditions, in two crop seasons (CS), and under contrasting water conditions (WC). Morphoagronomic, physiological, and root system traits were evaluated. Joint and individual analyses of variance were performed, in addition to the multivariate GT bip-lot analysis. Expressive reductions between WC were observed in 100-grain weight (100 GW), popping expansion (PE), grain yield (GY), expanded popcorn volume per ha (EPV), row number per ear (RNE), plant height (PH), relative chlorophyll content (SPAD), and nitrogen balance index (NBI). It was found that the SPAD, 100 GW, GY, PE, and grain number per ear (GNE) traits had the most significant impact on the selection of genotypes. Regardless of WC and CS, the ideal lines were L294 and L688 for PE; L691 and L480 for GY; and L291 and L292 for both traits. SPAD, 100 GW, and GNE can contribute to the indirect selection. Our work contributes to understanding the damage caused by drought and the integration of traits for the indirect selection of drought-tolerant popcorn genotypes.

Audiovisual production and embodied pedagogy as health promotion: The experience of a university extension project in partnership with the Casa Nem LGBTQIA+ shelter in Brazil.

The project "Audiovisual production and vital strategies" interwove art, life, academic research, and activism with decolonial feminist perspectives. It was carried out as part of an audiovisual laboratory with students from the Federal State University of Rio de Janeiro and Casa Nem, a squatters' settlement, cultural and educational project in Rio de Janeiro led by transgender people in situations of high social vulnerability. The audiovisual Lab was facilitated by a group of artists and educators, and the majority of project participants were Black people who identified as trans* or LGBTQIA+. We worked with critical and emancipatory pedagogies that allowed the impacts of each participants racialized and gendered life experiences to guide the entire creative processes. The project's creative processes were inspired by bodywork dynamics from the field of performance art, and focused on uncovering profound dialogues and depths in each participant's life narratives. In this essay, we reflect critically on aesthetic choices and modes of creation. Through our discussion of the images and processes as a whole, we discuss how reimagining the encounter between pedagogy and audiovisual production established new modes of mediating relationships inside and outside of the university, and connect these processes to broader questions of health promotion.

Precision-cut lung slices: A powerful ex vivo model to investigate respiratory infectious diseases.

Respiratory infections are a leading cause of mortality worldwide. Most of the research on the underlying disease mechanisms is based on cell culture, organoid, or surrogate animal models. Although these provide important insights, they have limitations. Cell culture models fail to recapitulate cellular interactions in the lung and animal models often do not permit high-throughput analysis of drugs or pathogen isolates; hence, there is a need for improved, scalable models. Precision-cut lung slices (PCLS), small, uniform tissue slices generated from animal or human lungs are increasingly recognized and employed as an ex vivo organotypic model. PCLS retain remarkable cellular complexity and the architecture of the lung, providing a platform to investigate respiratory pathogens in a near-native environment. Here, we review the generation and features of PCLS, their use to investigate the pathogenesis of viral and bacterial pathogens, and highlight their potential to advance respiratory infection research in the future.

Host manipulation by bacterial type III and type IV secretion system effector proteases.

Proteases are powerful enzymes, which cleave peptide bonds, leading most of the time to irreversible fragmentation or degradation of their substrates. Therefore they control many critical cell fate decisions in eukaryotes. Bacterial pathogens exploit this power and deliver protease effectors through specialised secretion systems into host cells. Research over the past years revealed that the functions of protease effectors during infection are diverse, reflecting the lifestyles and adaptations to specific hosts; however, only a small number of peptidase families seem to have given rise to most of these protease virulence factors by the evolution of different substrate-binding specificities, intracellular activation and subcellular targeting mechanisms. Here, we review our current knowledge about the enzymology and function of protease effectors, which Gram-negative bacterial pathogens translocate via type III and IV secretion systems to irreversibly manipulate host processes. We highlight emerging concepts such as signalling by protease cleavage products and effector-triggered immunity, which host cells employ to detect and defend themselves against a protease attack. TAKE AWAY: Proteases irreversibly cleave proteins to control critical cell fate decisions. Gram-negative bacteria use type III and IV secretion systems to inject effectors. Protease effectors are integral weapons for the manipulation of host processes. Effectors evolved from few peptidase families to target diverse substrates. Effector-triggered immunity upon proteolytic attack emerges as host defence.

ETIOPATHOGENIC, EPIDEMIOLOGIC AND CLINICAL-THERAPEUTIC COMPARISON OF NON-HODGKIN'S LYMPHOMA AND KAPOSI'S SARCOMA.

BACKGROUND: Non-Hodgkin's lymphomas (NHL) are primary neoplasms derived from lymphocytes, and Kaposi's sarcoma (SK) is a multicentric disease of viral etiology and is associated with HIV. AIM: To study the etiopathogenesis and clinical characteristics of NHL and KS, describing their mutual factors. METHODS: This retrospective investigation was performed on 101 medical charts. The patients were studied according to their age, gender, and HIV-positivity, following the PRISMA guidelines. The characteristics of the tumors and comorbidities were analyzed according to their age and lymphatic metastasis. RESULTS: The mean age of the patients ranged between 15-87 years for NHL and between 25-54 for KS, but the age of patients with NHL associated with HIV did not surpass 34 years. The ratio male: female was 1,8:1 for NHL, but only men presented KS. HIV-positivity was found in five patients with NHL and in 14 with KS. The stages of NHL were: I (21%), II (18,4%), III (26,3%), and IV (34,2%), but KS were found only at III (40%) and IV (60%) stages. The lymphatic metastases were positive in 62 patients NHL and in four with KS. HIV-positivity occurred in 60% of patients with NHL and in 50% with KS. CONCLUSION: The HIV seropositivity was revealed for most of patients during the NHL and SK propaedeutic and none of them present clinical manifestations of AIDS. NHL associated with HIV was found only in young patients. NHL and KS patients have similar epidemiological, clinical, and therapeutic characteristics.

Etiopathogenic, epidemiologic and clinical-therapeutic comparison of non-hodgkins lymphoma and kaposis sarcoma / Comparação etiopatogênica, epidemiológica e clinicoterapêutica de linfoma não hodgkin e sarcoma de kaposi

ABSTRACT Background: Non-Hodgkin's lymphomas (NHL) are primary neoplasms derived from lymphocytes, and Kaposi's sarcoma (SK) is a multicentric disease of viral etiology and is associated with HIV. Aim: To study the etiopathogenesis and clinical characteristics of NHL and KS, describing their mutual factors. Methods: This retrospective investigation was performed on 101 medical charts. The patients were studied according to their age, gender, and HIV-positivity, following the PRISMA guidelines. The characteristics of the tumors and comorbidities were analyzed according to their age and lymphatic metastasis. Results: The mean age of the patients ranged between 15-87 years for NHL and between 25-54 for KS, but the age of patients with NHL associated with HIV did not surpass 34 years. The ratio male: female was 1,8:1 for NHL, but only men presented KS. HIV-positivity was found in five patients with NHL and in 14 with KS. The stages of NHL were: I (21%), II (18,4%), III (26,3%), and IV (34,2%), but KS were found only at III (40%) and IV (60%) stages. The lymphatic metastases were positive in 62 patients NHL and in four with KS. HIV-positivity occurred in 60% of patients with NHL and in 50% with KS. Conclusion: The HIV seropositivity was revealed for most of patients during the NHL and SK propaedeutic and none of them present clinical manifestations of AIDS. NHL associated with HIV was found only in young patients. NHL and KS patients have similar epidemiological, clinical, and therapeutic characteristics.

RESUMO Racional: Os linfomas não Hodgkin (LNH) são neoplasias primárias derivadas de linfócitos e o sarcoma de Kaposi (SK) é doença multicêntrica de etiologia viral, ambas associadas ao HIV. Objetivo: Avaliar características clínicas dos LNH e SK, relacionando fatores etiopatogênicos mútuos. Métodos: Foram avaliados retrospectivamente 101 prontuários. Os doentes foram analisados quanto a idade, sexo e soropositividade para o HIV, de acordo com o PRISMA guidelines. Os tumores foram classificados por estadiamento, presença de linfonodos regionais invadidos e tipo celular. Resultados: A idade variou entre 15 e 87 anos para o LNH e 25 a 54 anos para o SK, mas a idade dos pacientes com LNH associado com o HIV não ultrapassou 34 anos. A proporção homem: mulher foi de 1,8:1 para o LNH, enquanto SK foi registrado apenas em homens. A soropositividade para o HIV ocorreu em cinco pacientes com LNH e 14 com SK. A invasão de linfonodos regionais foi positiva em 62 com LNH e quatro com SK. Os linfomas foram 27,9% de baixo grau, 17,4% de grau intermediário e 12,8% de alto grau. A soropositividade para HIV, foi diagnosticada durante a propedêutica do tumor em 60% dos pacientes com LNH e 50% dos com SK. Conclusão: A maioria dos pacientes portadores de HIV descobriram a soropositividade durante propedêutica para LNH e SK, sem manifestações clínicas de AIDS. Todos os pacientes com LNH associado com o HIV eram jovens. Pacientes com LNH e com SK apresentam características epidemiológicas, clínicas e terapêuticas semelhantes entre si.

Genomic insights into the Agromyces-like symbiont of earthworms and its distribution among host species.

The nephridia (excretory organs) of lumbricid earthworms generally harbor symbiotic bacteria. In the compost worms Eisenia fetida and E. andrei, these comprise Verminephrobacter, Ca. Nephrothrix and an Agromyces-like symbiont. While diversity, transmission, and function of the first two symbionts has been unraveled in recent years, little is known about the biology of the uncultured Agromyces-like symbiont or about its distribution within lumbricid earthworms.In this study, we sequenced a cocoon metagenome of E. andrei and assembled a 96.3% complete genome of the Agromyces-like symbiont, which indicates a heterotrophic and potentially microaerophilic lifestyle. A 16S rRNA gene based survey showed that the Agromyces-like symbiont has a narrow host range (present in 10 out of 51 investigated lumbricid earthworm species) and is likely species-specific or at least specific for groups of closely related host species. The Agromyces-like symbionts form a monophyletic group and feature a reduced genome with AT-bias and very low genome-wide similarity to closely related Agromyces spp. (average amino acid identity of 64%); therefore, we suggest establishing a novel genus for the Agromyces-like symbionts of earthworms, for which we propose the name Candidatus Lumbricidophila, with the specific symbiont of Eisenia andrei as novel species Ca. L. eiseniae.

Distinct effects of the nephridial symbionts Verminephrobacter and Candidatus Nephrothrix on reproduction and maturation of its earthworm host Eisenia andrei.

Verminephrobacter, the most common specific symbionts in the nephridia (excretory organs) of lumbricid earthworms, have been shown to improve reproduction of the garden earthworm Aporrectodea tuberculata under nutrient limitation. It is unknown how general this beneficial trait is in the Verminephrobacter-earthworm symbiosis, whether other nephridial symbionts also affect host fitness and what the mechanism of the fitness increase is. Here we report beneficial effects of Verminephrobacter and Candidatus Nephrothrix on life history traits of the compost worm Eisenia andrei, which in addition to these two symbionts also hosts Agromyces-like bacteria in its mixed nephridial community: while growth was identical between control, Verminephrobacter-free and aposymbiotic worms, control worms produced significantly more cocoons and offspring than both Verminephrobacter-free and aposymbiotic worms, confirming the reproductive benefit of Verminephrobacter in a second host with different ecology and feeding behavior. Furthermore, worms with Verminephrobacter and Ca. Nephrothrix, or with only Ca. Nephrothrix present, reached sexual maturity significantly earlier than aposymbiotic worms; this is the first evidence for a beneficial role of Ca. Nephrothrix in earthworms. Riboflavin content in cocoons and whole earthworms was unaffected by the presence or absence of nephridial symbionts, suggesting that nutritional supplementation with this vitamin does not play a major role in this symbiosis.

Manipulation of Autophagy by Bacterial Pathogens Impacts Host Immunity.

Autophagy is a highly conserved catabolic process, degrading unnecessary or damaged components in the eukaryotic cell to maintain cellular homeostasis, but it is also an intrinsic cellular defence mechanism to remove invading pathogens. A crosstalk between autophagy and innate or adaptive immune responses has been recently reported, whereby autophagy influences both, innate and adaptive immunity like the production and secretion of pro-inflammatory cytokines or MHC class II antigen presentation to T cells. Pathogenic bacteria have evolved diverse strategies to manipulate autophagy, mechanisms that also impact host immune responses at different levels. Here we discuss the influence of autophagy on self-autonomous, innate and adaptive immunity and then focus on how bacterial mechanisms that shape autophagy may impact the host immune system.

Legionella pneumophila Modulates Mitochondrial Dynamics to Trigger Metabolic Repurposing of Infected Macrophages.

The intracellular bacteria Legionella pneumophila encodes a type IV secretion system (T4SS) that injects effector proteins into macrophages in order to establish and replicate within the Legionella-containing vacuole (LCV). Once generated, the LCV interacts with mitochondria through unclear mechanisms. We show that Legionella uses both T4SS-independent and T4SS-dependent mechanisms to respectively interact with mitochondria and induce mitochondrial fragmentation that ultimately alters mitochondrial metabolism. The T4SS effector MitF, a Ran GTPase activator, is required for fission of the mitochondrial network. These effects of MitF occur through accumulation of mitochondrial DNM1L, a GTPase critical for fission. Furthermore mitochondrial respiration is abruptly halted in a T4SS-dependent manner, while T4SS-independent upregulation of cellular glycolysis remains elevated. Collectively, these alterations in mitochondrial dynamics promote a Warburg-like phenotype in macrophages that favors bacterial replication. Hence the rewiring of cellular bioenergetics to create a replication permissive niche in host cells is a virulence strategy of L. pneumophila.

Earthworm ecology affects the population structure of their Verminephrobacter symbionts.

Earthworms carry species-specific Verminephrobacter symbionts in their nephridia (excretory organs). The symbionts are vertically transmitted via the cocoon, can only colonize the host during early embryonic development, and have co-speciated with their host for about 100 million years. Although several studies have addressed Verminephrobacter diversity between worm species, the intra-species diversity of the symbiont population has never been investigated. In this study, symbiont population structure was examined by using a multi-locus sequence typing (MLST) approach on Verminephrobacter isolated from two contrasting ecological types of earthworm hosts: the high population density, fast reproducing compost worms, Eisenia andrei and Eisenia fetida, and the low-density, slow reproducing Aporrectodea tuberculata, commonly found in garden soils. Three distinct populations were investigated for both types and, according to MLST analysis of 193 Verminephrobacter isolates, the symbiont community in each worm individual was very homogeneous. The more solitary A. tuberculata carried unique symbiont populations in 9 out of 10 host individuals, whereas the symbiont populations in the social compost worms were homogeneous across host individuals from the same population. These data suggested that host ecology shaped the population structure of Verminephrobacter symbionts. The homogeneous symbiont populations in the compost worms led to the hypothesis that Verminephrobacter could be transferred bi-parentally or via leaky horizontal transmission in high-density, frequently mating worm populations.