•SNAC spraying partially alleviates drought effects on photosynthesis.•Spraying of encapsulated SNAC and GSNO enhanced physiological recovery of plants after drought stress.•SNP spraying maintained ...the oxidative damage in tissues even after rehydration.•Chitosan nanoparticles was effective for encapsulating S-nitrosothiols.
The combination of nitric oxide (NO) donors with nanomaterials for agricultural purposes is a promising approach. The encapsulation of NO donors emerged as a strategy for protecting these molecules from rapid degradation, besides allowing more controlled release. This study aimed to test the hypothesis that encapsulated NO donors attenuate oxidative stress and then enhance physiological recovery of sugarcane plants after water deficit. Well-hydrated sugarcane plants (control) were compared to plants subjected to water deficit and previously sprayed with water (WD) or encapsulated NO donors (100 μM): S-nitroso-mercaptosuccinic acid (SN-MSA); S-nitrosoglutathione (GSNO); S-nitroso-N-acetylcysteine (SNAC); or sodium nitroprusside (SNP). Our data indicated that SNAC spraying partially attenuated the negative impact of WD on the photosynthetic rate, maintained water use efficiency similar to control plants, and promoted growth under stressful conditions. In addition, spraying of encapsulated SNAC and GSNO improved sugarcane photosynthesis during the recovery period. Contrarily, SNP spraying was not effective in mitigating water deficit effects on sugarcane plants, which presented oxidative damage after rehydration. Overall, leaf spraying with SNAC or GSNO is an alternative to improve the physiological performance of sugarcane plants after water deficit, which would favor plant growth and crop yield due to a rapid recovery of photosynthesis.
Photosynthetic changes and protective mechanisms against oxidative damage were evaluated in
Jatropha curcas leaves subjected to drought and heat stresses, both individually and combined, in order to ...elucidate the synergistic and antagonistic mechanisms involved with these abiotic factors. Both the drought and heat stresses caused significant damage to the leaf membrane integrity and lipid peroxidation, and the combination of these stresses greatly enhanced these physiological disturbances. The leaf CO
2 assimilation rate, stomatal conductance and instantaneous carboxylation efficiency (
P
N/
C
I) were significantly decreased in all plants subjected to stressful conditions in comparison to unstressed plants (reference). In contrast, a reduction in photochemical activity was observed only in plants exposed to drought and drought
+
heat conditions. Catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities were stimulated only under heat stress, whereas APX activity was increased in all treated plants in comparison to the references. Moreover, the leaf H
2O
2 content was increased similarly under all studied stresses. However, the balance of reduced and oxidized ascorbate did not show significant differences between reference and stressed plants. Although
J. curcas plants acclimated to the studied stresses, they did not present an efficient mechanism for protection against drought-induced oxidative stress, especially when at high temperatures. However, heat-treated plants triggered an efficient enzymatic antioxidant system of reactive oxygen species scavenging and an effective protection against photochemical damages. The combination of drought and heat most significantly impaired the photosynthetic assimilation of CO
2 and the photochemical activity. These results indicate that drought greatly disturbs photosystem II activity and oxidative metabolism and that these negative effects are strongly stimulated by heat stress. The data also evidence that the combination of heat and drought triggers an intricate response involving antagonistic and synergistic interactions.
Several species of Tityus (Scorpiones, Buthidae) present multi-chromosomal meiotic associations and failures in the synaptic process, originated from reciprocal translocations. Holocentric ...chromosomes and achiasmatic meiosis in males are present in all members of this genus. In the present study, we investigated synapse dynamics, transcriptional silencing by γH2AX, and meiotic microtubule association in bivalents and a quadrivalent of the scorpion Tityus maranhensis. Additionally, we performed RT-PCR to verify the expression of mismatch repair enzymes involved in crossing-over formation in Tityus silvestris gonads. The quadrivalent association in T. maranhensis showed delay in the synaptic process and long asynaptic regions during pachytene. In this species, γH2AX was recorded only at the chromosome ends during early stages of prophase I; in metaphase I, bivalents and quadrivalents of T. maranhensis exhibited binding to microtubules along their entire length, while in metaphase II/anaphase II transition, spindle fibers interacted only with telomeric regions. Regarding T. silvestris, genes involved in the recombination process were transcribed in ovaries, testes and embryos, without significant difference between these tissues. The expression of these genes during T. silvestris achiasmatic meiosis is discussed in the present study. The absence of meiotic inactivation by γH2AX and holo/telokinetic behavior of the chromosomes are important factors for the maintenance of the quadrivalent in T. maranhensis and the normal continuation of the meiotic cycle in this species.
The variability in response to conventional prostate cancer (PC) therapies, coupled with the emergent issue of drug resistance, underscores the critical need for innovative treatment strategies. ...Aerobic physical exercise reduced incidence of several cancers, but the mechanism underlying these effects associated the nanoemulsion not fully understood. The application of a lipid nanoemulsion (LDE) delivery system for docetaxel (DTX), showing marked enhancement in therapeutic efficacy when combined with aerobic physical exercise. This novel intervention potentiates the antitumor activity of LDE-delivered DTX by augmenting nanoparticle internalization and inducing cell cycle arrest. Our findings reveal that this synergistic treatment not only significantly reduces prostate weight and mitigates adenocarcinoma proliferation but also attenuates anti-apoptotic BCL-2 protein expression. Concurrently, it elevates pro-apoptotic proteins and diminishes inflammatory markers. Metabolic profiling of the combined therapy group disclosed additional benefits, such as reduced lipid and plasma glucose levels. Collectively, our data illuminate the profound impact of integrating LDE-mediated DTX delivery with structured physical exercise, which together spearhead a dual-front assault on PC. This multimodal approach heralds a new paradigm in PC management, accentuating the promise of combined pharmacological and non-pharmacological interventions to elevate tumor suppressor protein activity and refine patient outcomes.
•For the first time, plant stability and memory were associated using experimental data.•The overall stability (OSt) considers homeostasis and resistence against drought.•Leaf CO2 assimilation and ...stomatal conductance were robust traits for evaluating drought memory in sugarcane.
Stability is a key trait for plant growth and development in a changing environment, involving homeostasis and resilience. While homeostasis refers to the maintenance of the internal structural and functional plant integrity, resilience is associated with the plant ability in returning to the initial conditions after a given disturbance. Such concepts are especially relevant for perennial and semi-perennial plants facing seasonal and frequent stress conditions. Although plant memory is closely associated with plant performance under recurrent stresses, to date, there is no study evaluating how stress memory is linked to stability under varying water conditions. Herein, we evaluated the association between drought stability and memory in sugarcane plants and proposed a new stability index to evaluate plant memory. Two datasets were analyzed, the first deals with leaf gas exchange and photochemistry of sugarcane plants grown in nutrient solution and exposed to one, two or three water deficit cycles. The second takes into account the physiological performance of sugarcane propagules obtained by vegetative propagation from plants that faced drought. To quantify sugarcane stability, we estimated the drought impact, the disturbance rate (DR), drought perturbation, and recovery rate (RR) for plants from both datasets. Drought memory – given by improved performance after previous stress events or when origin material faced drought – was detected in both datasets, changing either DR or RR. Based on these indices, we proposed the overall stability (OSt), defined as the ratio between RR and DR. While DR is associated to plant homeostasis, RR is a measure of plant resilience. Sugarcane plants exposed to three cycles of water deficit or those propagules originated from stressed plants presented the highest OSt values, showing higher RR and/or lower DR when compared to well-watered plants or to propagules from well-watered plants. Regarding the physiological traits evaluated, leaf CO2 assimilation and stomatal conductance were the most consistent variables in revealing drought stability and memory. Concluding, OSt revealed consistently patterns of response associated with plant memory, besides quantifying plant stability under stressful conditions.
Heterozygous chromosomal rearrangements can result in failures during the meiotic cycle and the apoptosis of germline, making carrier individuals infertile. The Amazon frog Leptodactylus ...pentadactylus has a meiotic multivalent, composed of 12 sex chromosomes. The mechanisms by which this multi-chromosome system maintains fertility in males of this species remain undetermined. In this study we investigated the meiotic behavior of this multivalent to understand how synapse, recombination and epigenetic modifications contribute to maintaining fertility and chromosomal sexual determination in this species. Our sample had 2n = 22, with a ring formed by ten chromosomes in meiosis, indicating a new system of sex determination for this species (X1Y1X2Y2X3Y3X4Y4X5Y5). Synapsis occurs in the homologous terminal portion of the chromosomes, while part of the heterologous interstitial regions performed synaptic adjustment. The multivalent center remains asynaptic until the end of pachytene, with interlocks, gaps and rich-chromatin in histone H2A phosphorylation at serine 139 (γH2AX), suggesting transcriptional silence. In late pachytene, paired regions show repair of double strand-breaks (DSBs) with RAD51 homolog 1 (Rad51). These findings suggest that Rad51 persistence creates positive feedback at the pachytene checkpoint, allowing meiosis I to progress normally. Additionally, histone H3 trimethylation at lysine 27 in the pericentromeric heterochromatin of this anuran can suppress recombination in this region, preventing failed chromosomal segregation. Taken together, these results indicate that these meiotic adaptations are required for maintenance of fertility in L. pentadactylus.
Th9 cells orchestrate allergic lung inflammation by promoting recruitment and activation of eosinophils and mast cells, and by stimulating epithelial mucus production, which is known to be mainly ...dependent on IL-9. These cells share developmental pathways with induced regulatory T cells that may determine the generation of one over the other subset. In fact, the FOXP3 transcription factor has been shown to bind
locus and repress IL-9 production. The microbiota-derived short-chain fatty acids (SCFAs) butyrate and propionate have been described as FOXP3 inducers and are known to have anti-inflammatory properties. While SCFAs attenuate lung inflammation by inducing regulatory T cells and suppressing Th2 responses, their effects on Th9 cells have not been addressed yet. Therefore, we hypothesized that SCFAs would have a protective role in lung inflammation by negatively modulating differentiation and function of Th9 cells. Our results demonstrated that butyrate is more effective than propionate in promoting FOXP3 expression and IL-9 repression. In addition, propionate was found to negatively impact
differentiation of IL-13-expressing T cells. Butyrate treatment attenuated lung inflammation and mucus production in OVA-challenged mice, which presented lower frequency of lung-infiltrated Th9 cells and eosinophils. Both Th9 cell adoptive transfer and IL-9 treatment restored lung inflammation in butyrate-treated OVA-challenged mice, indicating that the anti-inflammatory effects of butyrate may rely on suppressing Th9-mediated immune responses.
The mammalian gastrointestinal tract harbors a diverse microbial community with which dynamic interactions have been established over millennia of coevolution. Commensal bacteria and their products ...are sensed by innate receptors expressed in gut epithelia and in gut-associated immune cells, thereby promoting the proper development of mucosal immune system and host homeostasis. Many studies have demonstrated that host-microbiota interactions play a key role during local and systemic immunity. Therefore, this review will focus on how innate sensing of the gut microbiota and their metabolites through inflammasome and toll-like receptors impact the modulation of a distinct set of inflammatory and autoimmune diseases. We believe that a better understanding of the fine-tuning that governs host-microbiota interactions will further improve common prophylactic and therapeutic applications.
Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency in adults. CVID patients often present changes in the frequency and function of B lymphocytes, ...reduced number of Treg cells, chronic immune activation, recurrent infections, high incidence of autoimmunity and increased risk for malignancies. We hypothesized that the frequency of B10 cells would be diminished in CVID patients because these cells play an important role in the development of Treg cells and in the control of T cell activation and autoimmunity. Therefore, we evaluated the frequency of B10 cells in CVID patients and correlated it with different clinical and immunological characteristics of this disease. Forty-two CVID patients and 17 healthy controls were recruited for this study. Cryopreserved PBMCs were used for analysis of T cell activation, frequency of Treg cells and characterization of B10 cells by flow cytometry. IL-10 production by sorted B cells culture and plasma sCD14 were determined by ELISA. We found that CVID patients presented decreased frequency of IL-10-producing CD24hiCD38hi B cells in different cell culture conditions and decreased frequency of IL-10-producing CD24hiCD27+ B cells stimulated with CpG+PIB. Moreover, we found that CVID patients presented lower secretion of IL-10 by sorting-purified B cells when compared to healthy controls. The frequency of B10 cells had no correlation with autoimmunity, immune activation and Treg cells in CVID patients. This work suggests that CVID patients have a compromised regulatory B cell compartment which is not correlated with clinical and immunological characteristics presented by these individuals.
•Sugarcane and energy canes were evaluated during plant cane and first ratoon cycles.•Energy canes showed higher light interception efficiency than sugarcane due to higher tillering.•Energy canes ...presented lower photosynthetic activity at leaf and crop levels than sugarcane during unstressed growth.•Under drought, energy canes had similar leaf photosynthesis and higher light conversion efficiency than sugarcane.•Yield was more stable between crop cycles in energy canes than in sugarcane.
Using the same production system as sugarcane, energy cane (Saccharum spp. hybrid, as sugarcane) can produce more biomass, which can be associated with its high tillering and a vigorous root system with rhizomes. These traits enable energy cane to capture natural resources efficiently and convert more energy into biomass than sugarcane. Our aim is to understand the morpho-physiological bases of biomass production by energy cane. We evaluated the efficiencies of light interception and light conversion into biomass in a field experiment, measuring morphological and physiological traits of energy canes (Vertix 2 and Vertix 3) and sugarcane (IACSP95-5000). When plants have a low leaf area index (< 4 m2 m−2), the high tillering of energy cane increases the efficiency of light interception. High leaf insertion angles also favored light interception by canopies with high tiller density, as one found in Vertix 3. However, high tiller density likely caused excessive self-shading in energy cane canopy and then energy canes exhibited similar or lower photosynthetic activity than sugarcane, depending on environmental conditions. All three genotypes faced severe water stress during the ratoon cycle, but energy cane was less sensitive when considering light conversion efficiency and biomass yield.
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