RESUMEN
In order to fuel their relentless expansion, cancers must expand their vasculature to augment delivery of oxygen and essential nutrients. The disordered web of irregular vessels that results, however, leaves gaps in oxygen delivery that foster tumor hypoxia. At the same time, tumor cells increase their oxidative metabolism to cope with the energetic demands of proliferation, which further worsens hypoxia due to heightened oxygen consumption. In these hypoxic, nutrient-deprived environments, tumors and suppressive stroma evolve to flourish while antitumor immunity collapses due to a combination of energetic deprivation, toxic metabolites, acidification, and other suppressive signals. Reversal of cancer hypoxia thus has the potential to increase the survival and effector function of tumor-infiltrating T cells, as well as to resensitize tumors to immunotherapy. Early clinical trials combining hypoxia reduction with immune checkpoint blockade have shown promising results in treating patients with advanced, metastatic, and therapeutically refractory cancers.
Asunto(s)
Neoplasias , Microambiente Tumoral , Humanos , Hipoxia/metabolismo , Hipoxia/patología , Hipoxia/terapia , Inmunoterapia/métodos , Linfocitos TRESUMEN
BACKGROUND: Common bean (Phaseolus vulgaris) is one of the main nutritional resources in the world, and a low environmental impact source of protein. However, the majority of its cultivation areas are affected by drought and this scenario is only expected to worsen with climate change. Stomatal closure is one of the most important plant responses to drought and the MYB60 transcription factor is among the key elements regulating stomatal aperture. If targeting and mutating the MYB60 gene of common bean would be a valuable strategy to establish more drought-tolerant beans was therefore investigated. RESULTS: The MYB60 gene of common bean, with orthology to the Arabidopsis AtMYB60 gene, was found to have conserved regions with MYB60 typical motifs and architecture. Stomata-specific expression of PvMYB60 was further confirmed by q-RT PCR on organs containing stomata, and stomata-enriched leaf fractions. Further, function of PvMYB60 in promoting stomata aperture was confirmed by complementing the defective phenotype of a previously described Arabidopsis myb60-1 mutant. CONCLUSIONS: Our study finally points PvMYB60 as a potential target for obtaining more drought-tolerant common beans in the present context of climate change which would further greatly contribute to food security particularly in drought-prone countries.
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Cambio Climático , Resistencia a la Sequía , Phaseolus , Arabidopsis/genética , Arabidopsis/fisiología , Resistencia a la Sequía/genética , Regulación de la Expresión Génica de las Plantas/genética , Phaseolus/genética , Phaseolus/fisiología , Proteínas de Plantas/genética , Estomas de Plantas/genética , Estomas de Plantas/fisiología , Factores de Transcripción/genéticaRESUMEN
Cultivated cardoon (Cynara cardunculus var. altilis L.) is a promising candidate species for the development of plant cell cultures suitable for large-scale biomass production and recovery of nutraceuticals. We set up a protocol for Agrobacterium tumefaciens-mediated transformation, which can be used for the improvement of cardoon cell cultures in a frame of biorefinery. As high lignin content determines lower saccharification yields for the biomass, we opted for a biotechnological approach, with the purpose of reducing lignin content; we generated transgenic lines overexpressing the Arabidopsis thaliana MYB4 transcription factor, a known repressor of lignin/flavonoid biosynthesis. Here, we report a comprehensive characterization, including metabolic and transcriptomic analyses of AtMYB4 overexpression cardoon lines, in comparison to wild type, underlining favorable traits for their use in biorefinery. Among these, the improved accessibility of the lignocellulosic biomass to degrading enzymes due to depletion of lignin content, the unexpected increased growth rates, and the valuable nutraceutical profiles, in particular for hydroxycinnamic/caffeoylquinic and fatty acids profiles.
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Ácidos Cumáricos/metabolismo , Cynara/genética , Cynara/metabolismo , Lignina/metabolismo , Proteínas de Plantas/metabolismo , Ácido Quínico/análogos & derivados , Arabidopsis/genética , Arabidopsis/metabolismo , Biocombustibles , Biomasa , Técnicas de Cultivo de Célula , Flavonoides/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Ácido Quínico/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , TranscriptomaRESUMEN
Plant specialized metabolites (SMs) play an important role in the interaction with the environment and are part of the plant defense response. These natural products are volatile, semi-volatile and non-volatile compounds produced from common building blocks deriving from primary metabolic pathways and rapidly evolved to allow a better adaptation of plants to environmental cues. Specialized metabolites include terpenes, flavonoids, alkaloids, glucosinolates, tannins, resins, etc. that can be used as phytochemicals, food additives, flavoring agents and pharmaceutical compounds. This review will be focused on Mediterranean crop plants as a source of SMs, with a special attention on the strategies that can be used to modulate their production, including abiotic stresses, interaction with beneficial soil microorganisms and novel genetic approaches.
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Productos Biológicos/metabolismo , Productos Agrícolas/metabolismo , Resistencia a la Enfermedad/genética , Metabolismo Secundario/genética , Productos Agrícolas/crecimiento & desarrollo , Flavonoides/metabolismo , Humanos , Región Mediterránea , Redes y Vías Metabólicas/genética , Fitoquímicos/metabolismo , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Estrés Fisiológico/efectos de los fármacos , Terpenos/metabolismoRESUMEN
Since February 2020, the COVID-19 pandemic has spread to Italy affecting more than 100,000 people. Several studies have reported a high prevalence of gastrointestinal (GI) symptoms, and investigated their potential association with clinical outcomes.1 The timing, clinical significance, and possible impact on viral spread of GI symptoms presentation have not been fully elucidated. Elevation of liver function tests and other laboratory values has also been reported; however, their prognostic significance has not been clearly established.2.
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Betacoronavirus , Infecciones por Coronavirus/complicaciones , Enfermedades Gastrointestinales/diagnóstico , Hospitales/estadística & datos numéricos , Pandemias , Neumonía Viral/complicaciones , Anciano , COVID-19 , Infecciones por Coronavirus/epidemiología , Femenino , Enfermedades Gastrointestinales/complicaciones , Enfermedades Gastrointestinales/epidemiología , Humanos , Italia/epidemiología , Masculino , Neumonía Viral/epidemiología , Prevalencia , SARS-CoV-2RESUMEN
Fruits and seeds are the major food source on earth. Both derive from the gynoecium and, therefore, it is crucial to understand the mechanisms that guide the development of this organ of angiosperm species. In Arabidopsis, the gynoecium is composed of two congenitally fused carpels, where two domains: medial and lateral, can be distinguished. The medial domain includes the carpel margin meristem (CMM) that is key for the production of the internal tissues involved in fertilization, such as septum, ovules, and transmitting tract. Interestingly, the medial domain shows a high cytokinin signaling output, in contrast to the lateral domain, where it is hardly detected. While it is known that cytokinin provides meristematic properties, understanding on the mechanisms that underlie the cytokinin signaling pattern in the young gynoecium is lacking. Moreover, in other tissues, the cytokinin pathway is often connected to the auxin pathway, but we also lack knowledge about these connections in the young gynoecium. Our results reveal that cytokinin signaling, that can provide meristematic properties required for CMM activity and growth, is enabled by the transcription factor SPATULA (SPT) in the medial domain. Meanwhile, cytokinin signaling is confined to the medial domain by the cytokinin response repressor ARABIDOPSIS HISTIDINE PHOSPHOTRANSFERASE 6 (AHP6), and perhaps by ARR16 (a type-A ARR) as well, both present in the lateral domains (presumptive valves) of the developing gynoecia. Moreover, SPT and cytokinin, probably together, promote the expression of the auxin biosynthetic gene TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (TAA1) and the gene encoding the auxin efflux transporter PIN-FORMED 3 (PIN3), likely creating auxin drainage important for gynoecium growth. This study provides novel insights in the spatiotemporal determination of the cytokinin signaling pattern and its connection to the auxin pathway in the young gynoecium.
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Proteínas de Arabidopsis/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Citocininas/metabolismo , Meristema/genética , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Flores/genética , Flores/crecimiento & desarrollo , Frutas/genética , Frutas/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos/metabolismo , Meristema/crecimiento & desarrollo , Semillas/genética , Semillas/crecimiento & desarrollo , Transducción de Señal , Triptófano-Transaminasa/genéticaRESUMEN
The role of secondary metabolites in the determination of cell identity has been an area of particular interest over recent years, and studies strongly indicate a connection between cell fate and the regulation of enzymes involved in secondary metabolism. In Arabidopsis thaliana, the maternally derived seed coat plays pivotal roles in both the protection of the developing embryo and the first steps of germination. In this regard, a characteristic feature of seed coat development is the accumulation of proanthocyanidins (PAs - a class of phenylpropanoid metabolites) in the innermost layer of the seed coat. Our genome-wide transcriptomic analysis suggests that the ovule identity factor SEEDSTICK (STK) is involved in the regulation of several metabolic processes, providing a strong basis for a connection between cell fate determination, development and metabolism. Using phenotypic, genetic, biochemical and transcriptomic approaches, we have focused specifically on the role of STK in PA biosynthesis. Our results indicate that STK exerts its effect by direct regulation of the gene encoding BANYULS/ANTHOCYANIDIN REDUCTASE (BAN/ANR), which converts anthocyanidins into their corresponding 2,3-cis-flavan-3-ols. Our study also demonstrates that the levels of H3K9ac chromatin modification directly correlate with the active state of BAN in an STK-dependent way. This is consistent with the idea that MADS-domain proteins control the expression of their target genes through the modification of chromatin states. STK might thus recruit or regulate histone modifying factors to control their activity. In addition, we show that STK is able to regulate other BAN regulators. Our study demonstrates for the first time how a floral homeotic gene controls tissue identity through the regulation of a wide range of processes including the accumulation of secondary metabolites.
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Proteínas de Arabidopsis/fisiología , Arabidopsis/genética , Proteínas de Dominio MADS/fisiología , Semillas/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Ontología de Genes , Germinación , Redes y Vías Metabólicas , NADH NADPH Oxidorreductasas/genética , NADH NADPH Oxidorreductasas/metabolismo , Proantocianidinas/biosíntesis , Regiones Promotoras Genéticas , Semillas/crecimiento & desarrollo , Semillas/metabolismoRESUMEN
The capsule robot (CR) is a promising endoscopic method in gastrointestinal diagnosis because of its low discomfort to users. Most CRs are used to acquire image information only and lack the ability to collect samples. Although some biopsy capsule robots (BCRs) have been developed, it remains challenging to acquire the intestinal tissue while avoiding tearing and adhesion due to the flexibility of colonic tissue. In this study, we develop a BCR with a novel sampling strategy in which soft tissue is scratched with sharp blades rotating at high speed to avoid tissue tearing. In the BCR design, a spiral spring with prestored energy is used to release high energy within a short period of time, which is difficult for a motor or magnet to perform within a small capacity installation space. The energy of the tightened spiral spring is transmitted to drive sharp blades to rotate quickly via a designed gear mechanism. To guarantee reliable sampling, a Bowden cable is used to transmit the user's manipulation to trigger the rotation of the blades, and the triggering force transmitted by the cable can be monitored in real time by a force sensor installed at the manipulating end. A prototype of the proposed BCR is designed and fabricated, and its performance is tested through in vitro experiments. The results show that the proposed BCR is effective and the size of its acquired samples satisfies clinical requirements.
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Two tomato genotypes were grown in open field by three cultivation systems (one conventional and two distinct organic for mulching) in three years, 2015, 2016 and 2017. Yields, sugars, organic acids, amino acids, ascorbic acid, biothiols, carotenoids and phenols were measured. Weather conditions largely differed among harvest years, with summer 2016 rainier and less warm, and an opposite summer 2017. Organic systems had lower yields than conventional one but also, interestingly, lower waste percentages. Furthermore, tilled and no-tilled organic systems provided comparable yields. With respect to 3-year average, sugars were higher in 2017, acids in 2016 and in organic fruits, and amino acids increased in 2015 and in conventional samples. A higher glutathione content was found in organic samples, and higher carotenoids in 2017. Phenols increased in 2016, with a higher chlorogenic acid content in organic tomatoes. Some differences between genotypes were observed, highlighting their different adaptability to growing systems.
Asunto(s)
Solanum lycopersicum , Antioxidantes/análisis , Carotenoides/análisis , Frutas/química , Genotipo , Solanum lycopersicum/química , Valor Nutritivo , Fenoles/análisis , Azúcares/análisisRESUMEN
The development of effective tools for the sustainable supply of phyto-ingredients and natural substances with reduced environmental footprints can help mitigate the dramatic scenario of climate change. Plant cell cultures-based biorefineries can be a technological advancement to face this challenge and offer a potentially unlimited availability of natural substances, in a standardized composition and devoid of the seasonal variability of cultivated plants. Monounsaturated (MUFA) fatty acids are attracting considerable attention as supplements for biodegradable plastics, bio-additives for the cosmetic industry, and bio-lubricants. Cardoon (Cynara cardunculus L. var. altilis) callus cultures accumulate fatty acids and polyphenols and are therefore suitable for large-scale production of biochemicals and valuable compounds, as well as biofuel precursors. With the aim of boosting their potential uses, we designed a biotechnological approach to increase oleic acid content through Agrobacterium tumefaciens-mediated metabolic engineering. Bioinformatic data mining in the C. cardunculus transcriptome allowed the selection and molecular characterization of SAD (stearic acid desaturase) and FAD2.2 (fatty acid desaturase) genes, coding for key enzymes in oleic and linoleic acid formation, as targets for metabolic engineering. A total of 22 and 27 fast-growing independent CcSAD overexpressing (OE) and CcFAD2.2 RNAi knocked out (KO) transgenic lines were obtained. Further characterization of five independent transgenic lines for each construct demonstrated that, successfully, SAD overexpression increased linoleic acid content, e.g., to 42.5%, of the relative fatty acid content, in the CcSADOE6 line compared with 30.4% in the wild type (WT), whereas FAD2.2 silencing reduced linoleic acid in favor of the accumulation of its precursor, oleic acid, e.g., to almost 57% of the relative fatty acid content in the CcFAD2.2KO2 line with respect to 17.7% in the WT. Moreover, CcSADOE6 and CcFAD2.2KO2 were also characterized by a significant increase in total polyphenolic content up to about 4.7 and 4.1 mg/g DW as compared with 2.7 mg/g DW in the WT, mainly due to the accumulation of dicaffeoyl quinic and feruloyl quinic acids. These results pose the basis for the effective creation of an engineered cardoon cells-based biorefinery accumulating high levels of valuable compounds from primary and specialized metabolism to meet the industrial demand for renewable and sustainable sources of innovative bioproducts.
RESUMEN
Seed size is the result of complex molecular networks controlling the development of the seed coat (of maternal origin) and the two fertilization products, the embryo and the endosperm. In this study we characterized the role of Arabidopsis thaliana MADS-domain transcription factor SEEDSTICK (STK) in seed size control. STK is known to regulate the differentiation of the seed coat as well as the structural and mechanical properties of cell walls in developing seeds. In particular, we further characterized stk mutant seeds. Genetic evidence (reciprocal crosses) of the inheritance of the small-seed phenotype, together with the provided analysis of cell division activity (flow cytometry), demonstrate that STK acts in the earlier phases of seed development as a maternal activator of growth. Moreover, we describe a molecular mechanism underlying this activity by reporting how STK positively regulates cell cycle progression via directly activating the expression of E2Fa, a key regulator of the cell cycle. Altogether, our results unveil a new genetic network active in the maternal control of seed size in Arabidopsis.
RESUMEN
Seed development is under the control of complex and coordinated molecular networks required for the formation of its different components. The seed coat development largely determines final seed size and shape, in addition to playing a crucial role in protecting the embryo and promoting germination. In this study, we investigated the role of three transcription factors known to be active during seed development in Arabidopsis thaliana: SEEDSTICK (STK) and GORDITA (GOA), two MADS-domain proteins, and AUXIN RESPONSE FACTOR 2 (ARF2), belonging to the ARF family. Through a reverse genetic approach, we characterized the seed phenotypes of all the single, double and triple loss-of-function mutants in relation to seed size/shape and the effects on metabolic pathways occurring in the seed coat. This approach revealed that dynamic networks involving these TFs are active throughout ovule and seed development, affecting the formation of the seed coat. Notably, while the genetic interaction among these genes results in synergies that control the promotion of cell expansion in the seed coat upon pollination and production of proanthocyanidins, functional antagonists arise in the control of cell proliferation and release of mucilage.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Dominio MADS , Proteínas Represoras , Semillas , Factores de Transcripción , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/ultraestructura , Proteínas de Arabidopsis/fisiología , Proliferación Celular/fisiología , Regulación de la Expresión Génica de las Plantas , Proteínas de Dominio MADS/fisiología , Mucílago de Planta/metabolismo , Proteínas Represoras/fisiología , Semillas/crecimiento & desarrollo , Semillas/ultraestructura , Factores de Transcripción/fisiologíaRESUMEN
Phytic acid (PA) represents the major storage form of seed phosphate (P). During seed maturation, it accumulates as phytate salts chelating various mineral cations, therefore reducing their bioavailability. During germination, phytase dephosphorylates PA releasing both P and cations which in turn can be used for the nutrition of the growing seedling. Animals do not possess phytase, thus monogastric animals assimilate only 10% of the phytate ingested with feed, whilst 90% is excreted and may contribute to cause P pollution of the environment. To overcome this double problem, nutritional and environmental, in the last four decades, many low phytic acid (lpa) mutants (most of which affect the PA-MRP transporters) have been isolated and characterized in all major crops, showing that the lpa trait can increase the nutritional quality of foods and feeds and improve P management in agriculture. Nevertheless, these mutations are frequently accompanied by negative pleiotropic effects leading to agronomic defects which may affect either seed viability and germination or plant development or in some cases even increase the resistance to cooking, thus limiting the interest of breeders. Therefore, although some significant results have been reached, the isolation of lpa mutants improved for their nutritional quality and with a good field performance remains a goal so far not fully achieved for many crops. Here, we will summarize the main pleiotropic effects that have been reported to date in lpa mutants affected in PA-MRP transporters in five productive agronomic species, as well as addressing some of the possible challenges to overcome these hurdles and improve the breeding efforts for lpa mutants.
RESUMEN
Seed phytic acid reduces mineral bioavailability by chelating minerals. Consumption of common bean seeds with the low phytic acid 1 (lpa1) mutation improved iron status in human trials but caused adverse gastrointestinal effects, presumably due to increased stability of lectin phytohemagglutinin L (PHA-L) compared to the wild type (wt). A hard-to-cook (HTC) defect observed in lpa1 seeds intensified this problem. We quantified the HTC phenotype of lpa1 common beans with three genetic backgrounds. The HTC phenotype in the lpa1 black bean line correlated with the redistribution of calcium particularly in the cell walls, providing support for the "phytase-phytate-pectin" theory of the HTC mechanism. Furthermore, the excess of free cations in the lpa1 mutation in combination with different PHA alleles affected the stability of PHA-L lectin.
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Calcio/química , Lectinas/química , Phaseolus/química , Ácido Fítico/química , Fitohemaglutininas/química , Culinaria , Dureza , Calor , Mutación , Phaseolus/genética , Semillas/química , Semillas/genéticaRESUMEN
The industrial transformation of tomato (Lycopersicon esculentum Mill.) produces processed foods, such as dried tomatoes. In this study two varieties (SaAb and PerBruzzo), grown in three cropping systems (one conventional and two organic ones), were processed by two types of small-scale drying (oven or sun drying), over two years of production. The dried samples were analyzed for their non-volatile and volatile composition, relating the results with sensory analysis. The multivariate analysis performed on collected data allowed a detailed comparison of the effects of processing, year-to year variation and cropping systems. Results indicated that drying methods mainly influenced the composition and flavor profile, also affected by the production year. The cropping system significantly influenced some quality indices, such as the acid and sugar amounts, and the aldehydes, respectively higher and lower in organic samples. The comprehensive PCA analysis allowed discrimination of drying methods and, to a lesser extent, cropping systems.
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Aromatizantes/química , Solanum lycopersicum/química , Nariz Electrónica , Aromatizantes/análisis , Liofilización , Frutas/química , Frutas/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Solanum lycopersicum/metabolismo , Agricultura Orgánica , Análisis de Componente Principal , Estaciones del Año , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/químicaRESUMEN
Key message: Overview of seed size control. Human and livestock nutrition is largely based on calories derived from seeds, in particular cereals and legumes. Unveiling the control of seed size is therefore of remarkable importance in the frame of developing new strategies for crop improvement. The networks controlling the development of the seed coat, the endosperm and the embryo, as well as their interplay, have been described in Arabidopsis thaliana. In this review, we provide a comprehensive description of the current knowledge regarding the molecular mechanisms controlling seed size in Arabidopsis.