178 research outputs found

    In Arabidopsis thaliana Cd differentially impacts on hormone genetic pathways in the methylation defective ddc mutant compared to wild type

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    DNA methylation plays an important role in modulating plant growth plasticity in response to stress, but mechanisms involved in such control need further investigation. We used drm1 drm2 cmt3 mutant of Arabidopsis thaliana, defective in DNA methylation, to explore metabolic pathways downstream epigenetic modulation under cadmium (Cd) stress. To this aim, a transcriptomic analysis was performed on ddc and WT plants exposed to a long-lasting (21 d) Cd treatment (25/50 μM), focusing on hormone genetic pathways. Growth parameters and hormones amount were also estimated. Transcriptomic data and hormone quantification showed that, under prolonged Cd treatment, level and signalling of growth-sustaining hormones (auxins, CKs, GAs) were enhanced and/or maintained, while a decrease was detected for stress-related hormones (JA, ABA, SA), likely as a strategy to avoid the side effects of their long-lasting activation. Such picture was more effective in ddc than WT, already at 25 μM Cd, in line with its better growth performance. A tight relationship between methylation status and the modulation of hormone genetic pathways under Cd stress was assessed. We propose that the higher genome plasticity conferred to ddc by DNA hypomethylated status underlies its prompt response to modulate hormones genetic pathways and activity and assure a flexible growth

    The Encounter between the West and the Arab World in the Age of Nahdah (Renaissance). The Translation Movement in the Arab Literary Reviews

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    In quest'articolo si riflette sul ruolo giocato dalla riviste letterarie arabe nella diffusione della conoscenza della cultura occidentale. Il movimento di traduzione avviato durante la Nahda (la Rinascita) in Egitto e nella Grande Siria condusse a cambiamenti sostanziali dei canoni estetici, ma suscitò anche un movimento di forte opposizione da parte dei conservatori

    Cadmium affects cell niches maintenance in Arabidopsis thaliana post-embryonic shoot and root apical meristem by altering the expression of WUS/WOX homolog genes and cytokinin accumulation

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    Cadmium (Cd) is one of the most widespread polluting heavy metals in both terrestrial and aquatic environments and represents an extremely significant pollutant causing severe environmental and social problems due to its high toxicity and large solubility in water. In plants, the root is the first organ that get in contact with Cd. It is absorbed by the root system and translocated to the shoot and leaves through xylem loading, causing a variety of genetic, biochemical, and physiological damages. Cd inhibits both the root and shoot growth, but the mechanisms underlying this inhibition remain elusive. In this context in the present work we focused the attention on the effects of Cd on meristem size and organization of both shoot and root . To this aim morpho-histological and molecular analyses were carried out on 5 days old seedlings exposed or not to Cd (100 μM and 150 μM for 24) of wild type and transgenic lines expressing molecular markers with an important role in shoot and root pattern organization. More precisely, we monitored the expression pattern of WUS/CLV3 and WOX5 transcription factors involved in the establishment and maintenance of stem cell niche and the control of meristem size and of TCSn::GFP cytokinin-sensitive sensor as relevant components of hormone circuit controlling shoot and root growth.The results highlighted that the treatments with Cd impacts shoot and root size and shape by altering the paralogous WOX genes expression via cytokinin accumulation

    Augmented analysis of sensorial, volatilome and gene expression data from peach cultivars during cold storage to identify markers for fruit quality

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    Peach (Prunus persica (L. Batsch) produces high quality but perishable fruit appreciated for their distinctive aroma, and other organoleptic qualities including sweetness, colour, and texture which vary across different cultivars. Peaches are produced commercially in warmer temperate regions such as Southern Europe, and frequently exported to Northern Europe. Due to the long travel distances and complex supply chains peach fruit are transported cold to delay ripening and spoilage. However long periods of cold storage can result in chilling injury and loss of quality. Our understanding of how cold storage affects quality across different varieties can be explored through different approaches. Here effects were assessed in one peach ('Sagittaria') and one nectarine cultivar ( 'Big Top') through volatilome fingerprinting combined with gene expression profiling. For analysis of the volatile organic compounds (VOCs) contributing to the volatilome, we applied two-dimensional gas chromatography (GC×GC) combined with time-of-flight mass spectrometry (TOF-MS), as well as sensorial analysis. RNA-sequencing was applied to identify differentially expressed genes (DEGs) during post-harvest storage focusing on genes associated with VOCs. Peach fruits were analysed at harvest and during 14 days of cold storage at 1°C. Different numbers of VOCs were identified in the two cultivars: of 159 from ‘Sagittaria’, and 89 from ‘Big Top’ fruit. Canonical Analysis of Principal coordinates (or CAP) was able to discriminate amongst VOC profiles from the two cultivars and across post-harvest storage time points. A multitrait analysis of sensory, VOC and gene expression data supported the analysis based only on VOCs showing correlations between the expression profiles of VOC-related genes and VOC abundance. These data are of potential use to peach breeders for improving cold storage resilience in relation to sensory changes, and could form the basis for markers of use in assessing fruit quality through the supply chain

    From Italian Middle Ages to Brazilian contemporaneity: the journey of Dante\'s Beatrice as an idealized feminine figure

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    O presente trabalho se propõe a fazer uma análise da construção de Beatriz como uma figura feminina idealizada nos textos Vita Nova e Divina Commedia, de maneira a destacar as nuances de uma representação moldada pela visão cristã dominante na Idade Média. A partir disso, pretende-se também investigar relevância de Beatriz na literatura brasileira contemporânea como uma imagem feminina ideal que ressoa em diversas obras, mesmo 700 anos após a morte de seu autor. Com o aporte teórico de autores como Auerbach (2020 e 2022), Candido (1969 e 2006) e Casini (2021 e 2023), é possível, nos textos literários aqui estudados, perceber a presença da mulher idealizada, seja de maneira tradicional que se aproximada da composição do poeta italiano, ou por meio de uma reinterpretação que dialogue com questões contemporâneas sobre o feminino. A partir da análise da amada de Dante, evidencia-se a necessidade de levantar reflexões sobre a condição feminina e os papéis que as mulheres ocupam na sociedade ao longo das transformações culturais e sociais enfrentadas pelo mundo com o passar do tempo. Os textos brasileiros selecionados para ilustrar essa análise de uma Beatriz moderna foram a música Beatriz (1983), de Chico Buarque e os livros A audácia dessa mulher (1999), de Ana Maria Macho, e Purgatório: a verdadeira história de Dante e Beatriz (2007), de Mário PrataThis work aims to analyze the construction of Beatrice as an idealized female figure in the texts Vita Nova and Divina Commedia. The goal is to highlight the nuances of a representation shaped by the dominant Christian point of view in the Middle Ages. From this, it also intends to investigate the relevance of Beatrice in contemporary Brazilian literature as a female role model image that resonates in various works, even 700 years after the death of her author. With the theoretical support of authors such as Auerbach (2020 and 2022), Candido (1969 and 2006), and Casini (2021 and 2023), it is possible, in the literary texts studied here, to perceive the presence of the idealized woman, either in a traditional way that approaches the composition of the Italian poet or through a reinterpretation that engages with contemporary issues regarding femininity. Through the analysis of Dante\'s beloved, the necessity of raising reflections on the condition of women and their societal roles throughout the cultural and social transformations the world has undergone over time becomes evident. The Brazilian texts selected to illustrate this analysis of a modern Beatrice were the song Beatriz (1983) by Chico Buarque, and the books A audácia dessa mulher (1999) by Ana Maria Machado, and Purgatório: a verdadeira história de Dante e Beatriz (2007) by Mário Prat

    Fruit volatilome profiling through GC × GC-ToF-MS and gene expression analyses reveal differences amongst peach cultivars in their response to cold storage

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    Peaches have a short shelf life and require chilling during storage and transport. Peach aroma is important for consumer preference and determined by underlying metabolic pathways and gene expression. Differences in aroma (profiles of volatile organic compounds, VOCs) have been widely reported across cultivars and in response to cold storage. However, few studies used intact peaches, or used equilibrium sampling methods subject to saturation. We analysed VOC profiles using TD‑GC × GC‑ToF‑MS and expression of 12 key VOC pathway genes of intact fruit from six cultivars (three peaches, three nectarines) before and after storage at 1 °C for 7 days including 36 h shelf life storage at 20 °C. Two dimensional GC (GC × GC) significantly enhances discrimination of thermal desorption gas chromatography time‑of‑flight mass spectrometry (TD‑GC‑ToF‑MS) and detected a total of 115 VOCs. A subset of 15 VOCs from analysis with Random Forest discriminated between cultivars. Another 16 VOCs correlated strongly with expression profiles of eleven key genes in the lipoxygenase pathway, and both expression profiles and VOCs discriminated amongst cultivars, peach versus nectarines and between treatments. The cultivar‑specific response to cold storage underlines the need to understand more fully the genetic basis for VOC changes across cultivars

    The KNOTTED-like genes of peach (Prunus persica L. Batsch) are differentially expressed during drupe growth and the class 1 KNOPE1 contributes to mesocarp development

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    The KNOTTED-like transcription factors (KNOX) contribute to plant organ development. The expression patterns of peach KNOX genes showed that the class 1 members act precociously (S1-S2 stages) and differentially during drupe growth. Specifically, the transcription of KNOPE1 and 6 decreased from early (cell division) to late (cell expansion) S1 sub-stages, whilst that of STMlike1, 2, KNOPE2, 2.1 ceased at early S1. The KNOPE1 role in mesocarp was further addressed by studying the mRNA localization in the pulp cells and vascular net at early and late Si. The message signal was first diffuse in parenchymatous cells and then confined to hypodermal cell layers, showing that the gene down-tuning accompanied cell expansion. As for bundles, the mRNA mainly featured in the procambium/phloem of collateral open types and subsequently in the phloem side of complex structures (converging bundles, ducts). The KNOPE1 overexpression in Arabidopsis caused fruit shortening, decrease of mesocarp cell size, diminution of vascular lignification together with the repression of the major gibberellin synthesis genes AtGA20ox1 and AtGA3ox1. Negative correlation between the expression of KNOPE1 and PpGA3ox1 was observed in four cultivars at S1, suggesting that the KNOPE1 repression of PpGA3ox1 may regulate mesocarp differentiation by acting on gibberellin homeostasis
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