Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.750
Filtrar
1.
Sci Rep ; 14(1): 21573, 2024 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-39284874

RESUMO

Herbal medicines are important for ensuring sustainable development goals (SDGs) in healthcare, particularly in developing countries with high rates of antimicrobial resistance (AMR) and little access to medical facilities. Thymus vulgaris is a widely used herbal medicinal plant known for its secondary metabolites and antimicrobial properties. The present study involved a comprehensive examination of the isolation, characterization, and antibacterial activity of Thymus vulgaris obtained from Ethiopia. The aerial part of the plant Thymus vulgaris was successively extracted with hexane, chloroform, and methanol based on differences in polarity. Phytochemical screening tests conducted against hexane, chloroform and MeOH crude extracts indicated the presence of some secondary metabolites. Based on the thin-layer chromatography tests, the chloroform extract was subjected to column chromatography, yielding Tv-2 compounds, namely 5-isopropyl-2-methylphenol. The structures of the compounds were elucidated via spectroscopic methods (UV-Vis, FT-IR and NMR). We investigated the antibacterial properties of hexane crude extract, chloroform crude extract, MeOH crude extract, and isolated fractions derived from T. vulgaris against various bacterial strains. This study contributes to a better understanding of the bioactive components present in Thymus vulgaris crude extracts and their potential role in tackling microbial infections.


Assuntos
Antibacterianos , Testes de Sensibilidade Microbiana , Extratos Vegetais , Thymus (Planta) , Thymus (Planta)/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Etiópia , Bactérias/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação
2.
Anat Histol Embryol ; 53(6): e13109, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39319558

RESUMO

The thymus, a primary lymphoid organ, plays a critical role in T lymphocyte development and adaptive immunity. This study focuses on the anatomical, histological and geometric morphometric characteristics of the thymus in dromedary camels (Camelus dromedarius) during postnatal development. Thymus samples were collected from camels aged approximately 4, 8, 12 and 16 months. Using photogrammetry and 3D modelling, the samples were analysed to generate landmarks and conduct geometric morphometry with the 3D Slicer and ALPACA algorithm. Principal component analysis (PCA) was then performed to evaluate shape variations. Histologically, the samples underwent Haematoxylin and Eosin and Masson's trichrome staining. Image analysis using QuPath software quantified trabeculae, adipose tissue and Hassall's corpuscles. The results revealed significant anatomical and histological changes in the thymus across the different age groups. Notable variations in tissue composition and structural integrity were observed, with the PCA highlighting distinct morphometric patterns associated with age-related development. These findings provide a deeper understanding of thymus maturation in dromedaries and offer valuable data for comparative anatomy and veterinary medicine. This comprehensive analysis enhances our knowledge of species-specific immune development, with important implications for the health and resilience of these animals in arid environments.


Assuntos
Camelus , Análise de Componente Principal , Timo , Animais , Timo/anatomia & histologia , Timo/crescimento & desenvolvimento , Camelus/anatomia & histologia , Camelus/embriologia , Camelus/crescimento & desenvolvimento , Feminino , Masculino , Imageamento Tridimensional/veterinária , Fotogrametria
3.
Biol Trace Elem Res ; 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39325335

RESUMO

Arsenic, a surreptitious presence in our environment, perpetuates a persistent global menace with its deleterious impacts. It possesses the capability to trigger substantial immunosuppression by instigating inflammation in critical organs like the thymus and spleen. L-Ascorbic acid (L-AA) exhibits robust immunoregulatory prowess by orchestrating the epigenetic terrain through TET and JHDM pathways. Conversely, α-tocopherol (α-T) demonstrates the capacity to dampen the production of pro-inflammatory cytokines by modulating the PI3K-Akt axis. Given these insights, this inquiry embarks on exploring the mitigative potential of L-AA and α-T co-supplementation at the transcriptome level within leukocytes under arsenic exposure. Concurrently, the research endeavours to unravel the potent anti-inflammatory effects of administering α-T and L-AA, alleviating inflammation within the spleen and thymus amidst arsenic-induced insult and delving deeply into their immunomodulatory mechanisms. The rats were randomly allocated into eight distinct groups for subsequent experimentation: (I) the control group was administered solely with distilled water as the vehicle (control); (II) NaAsO2-treated group (As); (III) NaAsO2 treated along with L-ascorbic acid and α-tocopherol supplemented group (As + L-AA + α-T); (IV) L-ascorbic acid and α-tocopherol supplemented group (L-AA + α-T); (V) NaAsO2 treated along with L-ascorbic acid supplemented group (As + L-AA); (VI) only L-ascorbic acid supplemented group (L-AA); (VII) NaAsO2 treated along with α-tocopherol supplemented group (As + α-T); (VIII) only α-tocopherol supplemented group (α-T). Rats treated with NaAsO2 exhibited an increased neutrophil count in their bloodstream, as revealed by a comprehensive transcriptomic analysis showcasing heightened expressions of ItgaM, MMP9, and Itga4 within circulating leukocytes under arsenic exposure. Concurrently, arsenic heightened the expression of pro-inflammatory cytokines within the thymus and spleen. This elevated cytokine activity promoted the upregulation of ICAM-1 on vascular endothelial cells, facilitating the infiltration of Ly6g + leukocytes into the afflicted thymus and spleen. Remarkably, the combination of L-AA acid and α-T demonstrated substantial therapeutic efficacy, adeptly reducing the influx of Ly6g + leukocytes into these immune sites and subsequent reduction of excessive collagen deposition. The dynamic duo of L-AA and α-T achieved this amelioration by suppressing the expression of ItgaM, MMP9, and Itga4 mRNA within circulating leukocytes and moderating tissue levels of pro-inflammatory cytokines in arsenic-exposed thymus and spleen.

4.
Cureus ; 16(8): e67142, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39295696

RESUMO

A 74-year-old Asian man presented with sacral bone metastasis-related pain caused by a metastatic thymoma. Computed tomography revealed an approximately 6-cm sacral mass, which was confirmed as a metastatic thymoma. The patient was referred to our department and underwent stereotactic ablative radiation therapy (SABR) using volumetric modulated arc therapy and received a total dose of 35 Gy in five fractions. One year after SABR, the sacral lesion had decreased in size, and the pain medication was reduced. After two years, the patient no longer required pain medication, indicating successful management of bone metastases in recurrent Type A Thymoma.

5.
Toxicol Lett ; 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39326644

RESUMO

The primary goals of this study were to investigate the formation of abasic sites (AP sites) induced by methyl methanesulfonate (MMS) and hydrogen peroxide (H2O2), and to characterize specific types of these pro-mutagenic DNA lesions in calf thymus DNA (CT-DNA), and BEAS-2B human lung normal cell line. Furthermore, these profiles were compared with those observed in leukocytes derived from healthy controls (HC), breast cancer patients (BCP) before treatment, and 5-year survivors. Results indicated that both H2O2 and MMS induced the concentration- and time-dependent formation of AP sites in CT-DNA. To characterize the specific types of AP sites induced by H2O2 or MMS, we performed AP site cleavage assay using putrescine, T7 exonuclease (T7 Exo), and exonuclease III (Exo III). Results showed that the AP sites induced by H2O2 in CT-DNA were predominantly 5'-and 3'-nicked AP sites and no intact AP sites were detected. By contrast, the majority of AP sites generated by MMS in CT-DNA are not excisable and are classified as residual and intact AP sites. Similar approaches were performed in human BEAS-2B cells and comparable observations were confirmed in the cell-based model. Further investigation indicated that the profile of the AP sites observed in Taiwanese HC is identical to that of BEAS-2B cells treated with H2O2 whereas the pattern of AP sites detected in BCP is similar to that of CT-DNA exposed to H2O2, suggesting that these AP sites were produced primarily through reactive oxygen species (ROS) generation. More than 70% of the AP sites in leukocytes derived from BCP were 5'-nicked and residual AP sites. Furthermore, the characteristics of the AP sites detected in 5-year survivors are comparable with the ones in HC by using putrescine cleavage assay. Overall, we speculate that deficiency in the DNA repair cascade may play a role in mediating the formation of specific types of AP sites detected in BCP.

6.
Cell Rep ; 43(9): 114705, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39264810

RESUMO

The "innate-like" T cell compartment, known as Tinn, represents a diverse group of T cells that straddle the boundary between innate and adaptive immunity. We explore the transcriptional landscape of Tinn compared to conventional T cells (Tconv) in the human thymus and blood using single-cell RNA sequencing (scRNA-seq) and flow cytometry. In human blood, the majority of Tinn cells share an effector program driven by specific transcription factors, distinct from those governing Tconv cells. Conversely, only a fraction of thymic Tinn cells displays an effector phenotype, while others share transcriptional features with developing Tconv cells, indicating potential divergent developmental pathways. Unlike the mouse, human Tinn cells do not differentiate into multiple effector subsets but develop a mixed type 1/type 17 effector potential. Cross-species analysis uncovers species-specific distinctions, including the absence of type 2 Tinn cells in humans, which implies distinct immune regulatory mechanisms across species.


Assuntos
Imunidade Inata , Fenótipo , Humanos , Animais , Camundongos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Timo/imunologia , Timo/citologia , Análise de Célula Única , Diferenciação Celular , Camundongos Endogâmicos C57BL
8.
Artigo em Inglês | MEDLINE | ID: mdl-39303894

RESUMO

Congenital athymia is a life-limiting disorder due to rare inborn errors of immunity causing impaired thymus organogenesis or abnormal thymic stromal cell development and function. Athymic infants have a T-B+NK+ immunophenotype with profound T lymphocyte deficiency and are susceptible to severe infections and autoimmunity. Patients variably display syndromic features. Expanding access to newborn screening for severe combined immunodeficiency (SCID) and T lymphocytopaenia and broad genetic testing, including next-generation sequencing technologies, increasingly facilitate their timely identification. The recommended first-line treatment is allogeneic thymus transplantation, which is a specialized procedure available in Europe and the United States. Outcomes for athymic patients are best with early diagnosis and thymus transplantation before the development of infectious and inflammatory complications. These guidelines on behalf of the European Society of Immunodeficiencies provide a comprehensive review for clinicians who manage patients with inborn thymic stromal cell defects, and offer clinical practice recommendations focused on the diagnosis, investigation, risk stratification and management of congenital athymia, with the aim of improving patient outcomes.

9.
Int J Biol Macromol ; : 135813, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39306167

RESUMO

Mitoxantrone, an anthraquinone derivative, is a widely used anticancer drug with its well-known ability to engage in complex interactions with DNA. Although known for its intercalating ability, the enigma surrounding its binding modes with DNA persists. The existing corpus of literature primarily focuses on mitoxantrone-DNA interactions with short DNA sequences, thereby yielding insights into its interactive nature is limited to this specific sequence. This study aims to elucidate the diverse modes with which mitoxantrone interacts with calf thymus DNA using a combination of spectroscopy, calorimetry and in silico studies. The findings from spectroscopic, calorimetric and molecular dynamic results in correlation with existing literature, unveil a fascinating narrative: mitoxantrone intercalates at lower concentrations but promotes condensation at higher concentrations. Although intercalation with side chains positioned in the minor/major groove is the major binding mode in GC-rich sequences, molecular modelling studies hint at an alternative binding mode in AT-rich sequences where it exclusively displays pure electrostatic interaction. These findings underscore the pivotal role of both drug structure and base sequence in dictating binding mode and affinity. Such insights not only deepen the understanding of structure-activity relationships but also hold promise for guiding future drug design strategies.

10.
Int Rev Cell Mol Biol ; 388: 1-19, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39260934

RESUMO

Chemokine receptors are a complex superfamily of surface G protein-coupled receptors present mostly in leukocytes. In this chapter, we review the presence and functions of chemokine receptors in the immune cells of the primary and secondary lymphoid organs. Those include bone marrow, thymus, spleen, lymph nodes, and Peyer's patches as the main components of the gut-associated lymphoid tissue. There are general groups of chemokine receptors: conventional and atypical. We will mostly cover the role of conventional chemokine receptors, which are divided into four classes (CC, CXC, CX3C, and XC). Some relevant members are CXCR4, CXCR5, CCR4 and CCR7. For example, CXCR4 is a key chemokine receptor in the bone marrow controlling from the homing of progenitor cells into the bone marrow, the development of B cells, to the homing of long-lived plasma cells to this primary lymphoid organ. CCR7 and CCR4 are two of the main players in the thymus. CCR7 along with CCR9 control the traffic of thymic seed progenitors into the thymus, while CCR4 and CCR7 are critical for the entry of thymocytes into the medulla and as controllers of the central tolerance in the thymus. CXCR4 and CXCR5 have major roles in the spleen, guiding the maturation and class-switching of B cells in the different areas of the germinal center. In the T-cell zone, CCR7 guides the differentiation of naïve T cells. CCR7 also controls and directs the entry of T cells, B cells, and dendritic cells into secondary lymphoid tissues, including the spleen and lymph nodes. As new technologies emerge, techniques such as high dimensional spectral flow cytometry or single-cell sequencing allow a more comprehensive knowledge of the chemokine receptor network and their ligands, as well as the discovery of new interactions mediating unknown and overlooked mechanisms in health and disease.


Assuntos
Tecido Linfoide , Receptores de Quimiocinas , Humanos , Animais , Receptores de Quimiocinas/metabolismo , Tecido Linfoide/metabolismo , Timo/metabolismo , Timo/citologia
11.
Front Immunol ; 15: 1443910, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39257583

RESUMO

The thymus plays a pivotal role in generating a highly-diverse repertoire of T lymphocytes while preventing autoimmunity. Thymus seeding progenitors (TSPs) are a heterogeneous group of multipotent progenitors that migrate to the thymus via CCR7 and CCR9 receptors. While NOTCH guides thymus progenitors toward T cell fate, the absence or disruption of NOTCH signaling renders the thymus microenvironment permissive to other cell fates. Following T cell commitment, developing T cells undergo multiple selection checkpoints by engaging with the extracellular matrix, and interacting with thymic epithelial cells (TECs) and other immune subsets across the different compartments of the thymus. The different selection checkpoints assess the T cell receptor (TCR) performance, with failure resulting in either repurposing (agonist selection), or cell death. Additionally, environmental cues such as inflammation and endocrine signaling induce acute thymus atrophy, contributing to the demise of most developing T cells during thymic selection. We discuss the occurrence of acute thymus atrophy in response to systemic inflammation. The thymus demonstrates high plasticity, shaping inflammation by abrogating T cell development and undergoing profound structural changes, and facilitating regeneration and restoration of T cell development once inflammation is resolved. Despite the challenges, thymic selection ensures a highly diverse T cell repertoire capable of discerning between self and non-self antigens, ultimately egressing to secondary lymphoid organs where they complete their maturation and exert their functions.


Assuntos
Atrofia , Linfócitos T , Timo , Timo/imunologia , Timo/patologia , Humanos , Animais , Linfócitos T/imunologia , Movimento Celular/imunologia , Transdução de Sinais , Diferenciação Celular/imunologia , Inflamação/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia
12.
Front Immunol ; 15: 1465775, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39267733

RESUMO

Neuroendocrine neoplasms of the thymus (tNENs), including typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell carcinoma, are rare tumors with scarce clinical and pathological data available in the literature. They share many common features with neuroendocrine neoplasms in other organs, such as those in the lungs, while demonstrating some distinct clinical and pathological features. This review aims to give an updated overview of each category of tNENs, focusing primarily on the pathologic diagnosis and differential diagnosis of these tumors.


Assuntos
Tumores Neuroendócrinos , Neoplasias do Timo , Humanos , Neoplasias do Timo/diagnóstico , Neoplasias do Timo/patologia , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/patologia , Diagnóstico Diferencial , Timo/patologia , Timo/imunologia , Biomarcadores Tumorais
13.
Virchows Arch ; 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39223347

RESUMO

Insulinoma-associated protein 1 (INSM1) immunohistochemistry has been established as a sensitive and reliable immunohistochemical marker for detecting neuroendocrine differentiation in tumors across various organ systems. However, this marker has not been adequately investigated in primary thymic neuroendocrine tumors. We have studied a series of 27 cases of primary neuroendocrine carcinomas of the thymus, including 3 typical carcinoids, 18 atypical carcinoids, 4 large cell neuroendocrine carcinomas, and 2 small cell carcinomas. Immunostaining on whole tissue sections for INSM-1 was evaluated. Results of immunostaining for chromogranin and synaptophysin were also evaluated. 26/27 tumors (96%) demonstrated nuclear positivity for INSM1. 18 tumors (67%) showed strong and diffuse nuclear staining (3 +), 3 tumors (11%) moderate (2 +) nuclear staining, and 5 tumors (19%) showed weak (1 +) nuclear staining. The average percentage of tumor cells positive for INSM1 was 76%. Only one tumor, a small cell carcinoma, was negative. All tumors were positive for synaptophysin, and 26/27 (96%) were positive for chromogranin A. This study confirms that INSM1 immunohistochemistry is a sensitive marker of neuroendocrine differentiation in primary thymic neuroendocrine neoplasms and demonstrates similar performance characteristics compared to other organ systems. The nuclear staining with this marker offers the advantage of eliminating some of the ambiguity in the interpretation sometimes encountered with other markers. An added advantage is the consistent staining across the entire spectrum of neuroendocrine tumors of this organ.

15.
Geroscience ; 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39222198

RESUMO

Telomere shortening occurs with aging in immune cells and may be related to immunosenescence. Exercise can upregulate telomerase activity and attenuate telomere shortening in immune cells, but it is unknown if exercise impacts other immune tissues such as the thymus. This study aimed to examine human telomerase reverse transcriptase (hTERT) alternative splicing (AS) in response to aging and exercise in thymus tissue. Transgenic mice with a human TERT bacterial artificial chromosome integrated into its genome (hTERT-BAC) were utilized in two different exercise models. Mice of different ages were assigned to an exercise cage (running wheel) or not for 3 weeks prior to thymus tissue excision. Middle-aged mice (16 months) were exposed or not to treadmill running (30 min at 60% maximum speed) prior to thymus collection. hTERT transcript variants were measured by RT-PCR. hTERT transcripts decreased with aging (r = - 0.7511, p < 0.0001) and 3 weeks of wheel running did not counteract this reduction. The ratio of exons 7/8 containing hTERT to total hTERT transcripts increased with aging (r = 0.3669, p = 0.0423) but 3 weeks of voluntary wheel running attenuated this aging-driven effect (r = 0.2013, p = 0.4719). Aging increased the expression of senescence marker p16 with no impact of wheel running. Thymus regeneration transcription factor, Foxn1, went down with age with no impact of wheel running exercise. Acute treadmill exercise did not induce any significant changes in thymus hTERT expression or AS variant ratio (p > 0.05). In summary, thymic hTERT expression is reduced with aging. Exercise counteracted a shift in hTERT AS ratio with age. Our data demonstrate that aging impacts telomerase expression and that exercise impacts dysregulated splicing that occurs with aging.

16.
J Comp Pathol ; 215: 1-9, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39276725

RESUMO

Although hyperthyroidism is the most common endocrine disorder in elderly cats, systematic studies investigating the prevalence of thyroid lesions in feline animals are scarce. Our objective was to evaluate morphological changes in the thyroid glands of 61 cats submitted to necropsy without clinical suspicion of hyperthyroidism. Thirteen (13/61 [21.3%]) cats had thyroid enlargement and 54/61 (88.5%) had some histological thyroid changes. Proliferative lesions were histologically seen in 33/61 (54%) cats while non-proliferative lesions were observed in 48/61 (78.7%) cats. Thyroid hyperplasia (18/33 [54.5%]) and cystic adenoma (6/33 [18.2%]) were the most prevalent proliferative changes and lesions with little or no clinical significance (37/61 [60.6%]), degenerative (31/61 [50.8%]) and inflammatory changes (12/61 [19.7%]) were the most common non-proliferative changes. Among cats with proliferative lesions, 16/33 (48.4%) had a proliferation grade ≥A4, a grade previously associated with clinical hyperthyroidism. Although the cats from this study did not have any clinical diagnosis of thyroid disease, it is possible that one or more had some degree of clinically unnoticed thyroid dysfunction. The high prevalence of follicular lesions in this study highlights the importance of a more careful clinical and pathological investigation regarding thyroid diseases in mature and elderly cats.

18.
World J Clin Cases ; 12(25): 5646-5652, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39247750

RESUMO

We point out the issue of differential diagnosis regarding the finding of ectopically localised thymic tissue (a thymic cyst) in the neck. Thymic tissue can be found anywhere along its developmental tract of descent, from the angle of the mandible to the upper mediastinum. Disruption of the thymic descent can result in ectopically/abnormally localised islets of accessory thymic tissue, which may undergo cystic changes, as described in a case report by Sun et al. This anatomical variation of the thymus may be clinically misinterpreted as a neoplasm or other congenital anomalies as a branchial cyst, lymphatic malformation or cystic hygroma. The present editorial focuses on the challenge of establishing a diagnosis of ectopically localised tissue of thymus often presented as a lateral cervical mass, especially in the case of cystic variation/degeneration of this thymic tissue. We summarise hypotheses on the origin of such congenital cervical thymic cysts from the point of view of evolutionary history and embryology. We also discuss lesser-known facts about the anatomy, histopathology and developmental biology of the thymus as one of the most enigmatic organs in the human body.

19.
Int J Mol Sci ; 25(17)2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39273192

RESUMO

We aimed to determine the effects of maternal nutrient restriction (MNR) on the DNA methylation and gene expression patterns associated with metabolism and immunopoiesis in the thymuses of fetal Wagyu cattle. Pregnant cows were allocated to two groups: a low-nutrition (LN; 60% nutritional requirement; n = 5) and a high-nutrition (HN; 120% nutritional requirement, n = 6) group, until 8.5 months of gestation. Whole-genome bisulfite sequencing (WGBS) and RNA sequencing were used to analyze DNA methylation and gene expression, while capillary electrophoresis-Fourier transform mass spectrometry assessed the metabolome. WGBS identified 4566 hypomethylated and 4303 hypermethylated genes in the LN group, with the intergenic regions most frequently being methylated. Pathway analysis linked hypoDMGs to Ras signaling, while hyperDMGs were associated with Hippo signaling. RNA sequencing found 94 differentially expressed genes (66 upregulated, 28 downregulated) in the LN group. The upregulated genes were tied to metabolic pathways and oxidative phosphorylation; the downregulated genes were linked to natural killer cell cytotoxicity. Key overlapping genes (GRIA1, CACNA1D, SCL25A4) were involved in cAMP signaling. The metabolomic analysis indicated an altered amino acid metabolism in the MNR fetuses. These findings suggest that MNR affects DNA methylation, gene expression, and the amino acid metabolism, impacting immune system regulation during fetal thymus development in Wagyu cattle.


Assuntos
Metilação de DNA , Desnutrição , Timo , Animais , Bovinos , Feminino , Gravidez , Timo/metabolismo , Timo/imunologia , Desnutrição/genética , Desnutrição/imunologia , Feto/metabolismo , Fenômenos Fisiológicos da Nutrição Materna
20.
Plants (Basel) ; 13(17)2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39273883

RESUMO

Agroecological ecosystems produce significant carbon dioxide fluxes; however, the equilibrium of their carbon sequestration, as well as emission rates, faces considerable uncertainties. Therefore, sustainable cropping practices represent a unique opportunity for carbon sequestration, compensating greenhouse gas emissions. In this research, we evaluated the short-term effect of different management practices in alleys (tillage, no tillage, alley cropping with Rosmarinus officinalis and Thymus hyemalis on soil properties, carbon sequestration, and CO2 emissions in a grapefruit orchard under semiarid climate). For two years every four months, soil sampling campaigns were performed, soil CO2 emissions were measured, and rhizosphere soils were sampled at the end of the experimental period. The results show that alley cropping with Thymus and Rosmarinus contributed to improve soil fertility, increasing soil organic carbon (SOC), total nitrogen, cation exchange capacity, and nutrients. The CO2 emission rates followed the soil temperature/moisture pattern. Tillage did not contribute to higher overall CO2 emissions, and there were no decreased SOC contents. In contrast, alley crops increased CO2 emission rates, especially Rosmarinus; however, the bigger root system and biomass of Rosmarinus contributed to soil carbon sequestration at a greater rate than Thymus. Therefore, Rosmarinus is positioned as a better option than Thymus to be used as an alley crop, although long-term monitoring is required to evaluate if the reported short-term benefits are maintained over time.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA