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1.
Plants (Basel) ; 13(17)2024 Aug 25.
Article in English | MEDLINE | ID: mdl-39273850

ABSTRACT

Abscisic acid (ABA) and gibberellic acid (GA3) are regulators of fruit color and sugar levels, and the application of these hormones is a common practice in commercial vineyards dedicated to the production of table grapes. However, the effects of exogenous ABA and GA3 on wine cultivars remain unclear. We investigated the impact of ABA and GA3 application on Malbec grapevine berries across three developmental stages. We found similar patterns of berry total anthocyanin accumulation induced by both treatments, closely associated with berry H2O2 levels. Quantitative proteomics from berry skins revealed that ABA and GA3 positively modulated antioxidant defense proteins, mitigating H2O2. Consequently, proteins involved in phenylpropanoid biosynthesis were downregulated, leading to decreased anthocyanin content at the almost ripe stage, particularly petunidin-3-G and peonidin-3-G. Additionally, we noted increased levels of the non-anthocyanins E-viniferin and quercetin in the treated berries, which may enhance H2O2 scavenging at the almost ripe stage. Using a linear mixed-effects model, we found statistical significance for fixed effects including the berry H2O2 and sugar contents, demonstrating their roles in anthocyanin accumulation. In conclusion, our findings suggest a common molecular mechanism by which ABA and GA3 influence berry H2O2 content, ultimately impacting anthocyanin dynamics during ripening.

2.
Annu Rev Genet ; 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38986032

ABSTRACT

Plants are exposed to temperature conditions that fluctuate over different time scales, including those inherent to global warming. In the face of these variations, plants sense temperature to adjust their functions and minimize the negative consequences. Transcriptome responses underlie changes in growth, development, and biochemistry (thermomorphogenesis and acclimation to extreme temperatures). We are only beginning to understand temperature sensation by plants. Multiple thermosensors convey complementary temperature information to a given signaling network to control gene expression. Temperature-induced changes in protein or transcript structure and/or in the dynamics of biomolecular condensates are the core sensing mechanisms of known thermosensors, but temperature impinges on their activities via additional indirect pathways. The diversity of plant responses to temperature anticipates that many new thermosensors and eventually novel sensing mechanisms will be uncovered soon.

3.
Plant Cell ; 34(6): 2188-2204, 2022 05 24.
Article in English | MEDLINE | ID: mdl-35234947

ABSTRACT

Despite the identification of temperature sensors and downstream components involved in promoting stem growth by warm temperatures, when and how previous temperatures affect current plant growth remain unclear. Here we show that hypocotyl growth in Arabidopsis thaliana during the night responds not only to the current temperature but also to preceding daytime temperatures, revealing a short-term memory of previous conditions. Daytime temperature affected the levels of PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) and LONG HYPOCOTYL 5 (HY5) in the nucleus during the next night. These factors jointly accounted for the observed growth kinetics, whereas nighttime memory of prior daytime temperature was impaired in pif4 and hy5 mutants. PIF4 promoter activity largely accounted for the temperature-dependent changes in PIF4 protein levels. Notably, the decrease in PIF4 promoter activity triggered by cooling required a stronger temperature shift than the increase caused by warming, representing a typical hysteretic effect; this hysteretic pattern required EARLY-FLOWERING 3 (ELF3). Warm temperatures promoted the formation of nuclear condensates of ELF3 in hypocotyl cells during the afternoon but not in the morning. These nuclear speckles showed poor sensitivity to subsequent cooling. We conclude that ELF3 achieves hysteresis and drives the PIF4 promoter into the same behavior, enabling a short-term memory of daytime temperature conditions.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Phytochrome , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Basic Helix-Loop-Helix Transcription Factors/metabolism , Gene Expression Regulation, Plant/genetics , Hypocotyl , Phytochrome/metabolism , Temperature , Transcription Factors/genetics , Transcription Factors/metabolism
4.
Plant J ; 105(1): 22-33, 2021 01.
Article in English | MEDLINE | ID: mdl-33098600

ABSTRACT

Plants experience temperature fluctuations during the course of the daily cycle, and although stem growth responds rapidly to these changes we largely ignore whether there is a short-term memory of previous conditions. Here we show that nighttime temperatures affect the growth of the hypocotyl of Arabidopsis thaliana seedlings not only during the night but also during the subsequent photoperiod. Active phytochrome B (phyB) represses nighttime growth and warm temperatures reduce active phyB via thermal reversion. The function of PHOTOPERIODIC CONTROL OF HYPOCOTYL1 (PCH1) is to stabilise active phyB in nuclear bodies but, surprisingly, warmth reduces PCH1 gene expression and PCH1 stability. When phyB was active at the beginning of the night, warm night temperatures enhanced the levels of nuclear phyB and reduced hypocotyl growth rate during the following day. However, when end-of-day far-red light minimised phyB activity, warm night temperatures reduced the levels of nuclear phyB and enhanced the hypocotyl growth rate during the following day. This complex growth pattern was absent in the phyB mutant. We propose that temperature-induced changes in the levels of PCH1 and in the size of the physiologically relevant nuclear pool of phyB amplify the impact of phyB-mediated temperature sensing.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Metallochaperones/metabolism , Phytochrome B/metabolism , Arabidopsis/physiology , Arabidopsis Proteins/physiology , Gene Expression Regulation, Plant , Metallochaperones/physiology , Photoperiod , Phytochrome B/physiology , Seedlings/metabolism , Seedlings/physiology , Temperature
5.
Physiol Plant ; 171(4): 728-738, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33159334

ABSTRACT

Light is a main environmental factor that determines leaf microclimate within the vine, as well as its photosynthesis and carbohydrate metabolism. This study aimed to examine the relationships between photosynthesis, carbohydrate metabolism, and the expression of related genes in leaves of grapevine grown under different radiation regimes. During the 2014/2015 growing season, an experiment was conducted on a Malbec vineyard (Vitis vinifera L.) in which four radiation exposure treatments were established on the leaves: (1) East, (2) West, (3) Sun, and (4) Shade (i.e., reduction in light intensity). Diurnal dynamics of photosynthesis and non-structural carbohydrates were measured and leaf export rates were calculated. Transcript profiles of leaf sugar transporters (VvHT1, VvHT3, VvSUC27), a sucrose phosphate synthase enzyme (VvSPS), and invertases (VvGIN1, VvCWI) were also examined. We showed that East and Sun leaves had higher daily photosynthetic and export rates than West leaves, which was mainly explained by the environmental conditions (air and leaf temperature, VPDleaf-air ) and leaf water status. Shade leaves accumulated less starch and soluble sugars than exposed leaves, which correlated with a higher expression of hexose transporters and invertases. The hypotheses that these sugars in Shade leaves would play a role as signaling molecules and/or have increased sink strength and phloem unloading are discussed. These results allow us to understand the physiological and molecular behavior of leaves exposed to different radiation regimes, which can be used to design appropriate vineyard management practices.


Subject(s)
Plant Leaves , Vitis , Carbohydrates , Hexoses , Photosynthesis
6.
Rev. cient. Esc. Univ. Cienc. Salud ; 6(1): 6-12, ene.-jun. 2019. graf, tab
Article in Spanish | LILACS | ID: biblio-1022955

ABSTRACT

La mortalidad neonatal es un problema de salud mundial y un indicador de la atención materno infantil. Objetivo: Identificar los factores de riesgo asociados a mortalidad neonatal en pacientes atendidos en los Hos-pitales de Santa Bárbara e Intibucá, de marzo 2017 a febrero 2018. Pacientes y Métodos: Se realizó un estudio cuantitativo, descriptivo, de corte transversal. El Mues-treo fue no probabilístico, con una muestra de 32 pacientes. La recolección de datos fue mediante cuestionario validado por el alfa de Cronbach con fiabilidad de 0.709. Los datos fueron procesados en SPSS versión 22.0. Las variables estudiadas fueron los factores de riesgo socio demográficos, natales, rela-cionados al parto y los asociados al riesgo postnatal de las madres. Resultados: 53% de las madres tenían una edad entre 12 a 19 años; 44% eran analfabetas, 84% de proce-dencia rural y 56% no tuvieron controles prenatales. Asimismo, el 93% presentó vagi-nosis. El porcentaje de neonatos fallecidos en Santa Bárbara fue del 62.5% y en Intibu-cá 37.5%. Conclusión: Los factores de riesgo identificados en mortalidad neonatal fueron el analfabetismo, embarazos en ado-lescentes y ser procedente del área rural.Más de la mitad no tuvieron controles prena-tales y casi todas tuvieron vaginosis. Las causas de muerte neonatal fueron: sepsis, prematurez, asfixia, síndrome de aspiración meconial y malformaciones congénitas...(AU)


Subject(s)
Humans , Pregnancy , Primary Health Care/methods , Infant Mortality , Data Collection/statistics & numerical data , Hospital Care
8.
Phytochemistry ; 135: 34-52, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27998613

ABSTRACT

Plants are able to synthesize a large number of organic compounds. Among them, primary metabolites are known to participate in plant growth and development, whereas secondary metabolites are mostly involved in defense and other facultative processes. In grapevine, one of the major fruit crops in the world, secondary metabolites, mainly polyphenols, are of great interest for the wine industry. Even though there is an extensive literature on the content and profile of those compounds in berries, scarce or no information is available regarding polyphenols in other organs. In addition, little is known about the effect of plant growth regulators (PGRs), ABA and GA3 (extensively used in table grapes) on the synthesis of primary and secondary metabolites in wine grapes. In table grapes, cultural practices include the use of GA3 sprays shortly before veraison, to increase berry and bunch size, and sugar content in fruits. Meanwhile, ABA applications to the berries on pre-veraison improve the skin coloring and sugar accumulation, anticipating the onset of veraison. Accordingly, the aim of this study was to assess and characterize primary and secondary metabolites in leaves, berries and roots of grapevine plants cv. Malbec at veraison, and changes in compositions after ABA and GA3 aerial sprayings. Metabolic profiling was conducted using GC-MS, GC-FID and HPLC-MWD. A large set of metabolites was identified: sugars, alditols, organic acids, amino acids, polyphenols (flavonoids and non-flavonoids) and terpenes (mono-, sesqui-, di- and triterpenes). The obtained results showed that ABA applications elicited synthesis of mono- and sesquiterpenes in all assessed tissues, as well as L-proline, acidic amino acids and anthocyanins in leaves. Additionally, applications with GA3 elicited synthesis of L-proline in berries, and mono- and sesquiterpenes in all the tissues. However, treatment with GA3 seemed to block polyphenol synthesis, mainly in berries. In conclusion, ABA and GA3 applications to grapevine plants cv. Malbec influenced the synthesis of primary and secondary metabolites known to be essential for coping with biotic and abiotic stresses.


Subject(s)
Abscisic Acid/metabolism , Gibberellins/metabolism , Plant Growth Regulators/metabolism , Abscisic Acid/chemistry , Anthocyanins/metabolism , Flavonoids/analysis , Fruit/chemistry , Gas Chromatography-Mass Spectrometry , Gibberellins/chemistry , Molecular Structure , Plant Leaves/metabolism , Polyphenols/analysis , Proline/metabolism , Vitis/metabolism
9.
Physiol Plant ; 156(3): 323-37, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26411544

ABSTRACT

Grape quality for winemaking depends on sugar accumulation and metabolism in berries. Abscisic acid (ABA) and gibberellins (GAs) have been reported to control sugar allocation in economically important crops, although the mechanisms involved are still unknown. The present study tested if ABA and gibberellin A3 (GA3) enhance carbon allocation in fruits of grapevines by modifying phloem loading, phloem area and expression of sugar transporters in leaves and berries. Pot-grown Vitis vinifera cv. Malbec plants were sprayed with ABA and GA3 solutions. The amount of soluble sugars in leaves and berries related to photosynthesis were examined at three points of berry growth: pre-veraison, full veraison and post-veraison. Starch levels and amylase activity in leaves, gene expression of sugar transporters in leaves and berries and phloem anatomy were examined at full veraison. Accumulation of glucose and fructose in berries was hastened in ABA-treated plants at the stage of full veraison, which was correlated with enhancement of Vitis vinifera HEXOSE TRANSPORTER 2 (VvHT2) and Vitis vinifera HEXOSE TRANSPORTER 6 (VvHT6) gene expression, increases of phloem area and sucrose content in leaves. On the other hand, GA3 increased the quantity of photoassimilates delivered to the stem thus increasing xylem growth. In conclusion, stimulation of sugar transport by ABA and GA3 to berries and stems, respectively, was due to build-up of non-structural carbohydrates in leaves, modifications in phloem tissue and modulation in gene expression of sugar transporters.


Subject(s)
Abscisic Acid/pharmacology , Carbohydrates/chemistry , Carbon/metabolism , Gibberellins/pharmacology , Phloem/metabolism , Plant Leaves/metabolism , Plant Proteins/genetics , Vitis/metabolism , Biomass , Fruit/drug effects , Fruit/genetics , Gene Expression Regulation, Plant/drug effects , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Phloem/drug effects , Photosynthesis/drug effects , Plant Leaves/drug effects , Plant Leaves/genetics , Plant Proteins/metabolism , Plant Stomata/cytology , Plant Stomata/genetics , Plant Stomata/physiology , Starch/metabolism , Vacuoles/drug effects , Vacuoles/metabolism , Vitis/drug effects , Vitis/genetics , Xylem/drug effects , Xylem/metabolism
10.
Clin Neuropsychol ; 21(5): 776-88, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17676543

ABSTRACT

The objective of this study was to examine differences between fluent English-speaking ethnically diverse (ED) individuals (from Hispanic, Asian, and Middle-Eastern descent) and monolingual English-speaking Anglo-Americans (MEAA) on the Wechsler Abbreviated Scale of Intelligence (WASI). A sample of 86 (50 ED and 36 MEAA) healthy individuals participated. The results revealed that the MEAA group outperformed the ED group on the verbal (i.e., Vocabulary and Similarities), but not the nonverbal (i.e., Block Design and Matrix Reasoning) subtests. Various cultural factors such as the level of acculturation and the degree to which the English language was used correlated with verbal skills. Number of years the education was obtained outide of the US was an important predictor of verbal and some nonverbal performance in the ED group. The findings from this study underscore the importance of taking cultural factors, particularly level of acculturation, into account when interpreting test scores of ED individuals.


Subject(s)
Cognition , Culture , Ethnicity , Neuropsychological Tests , Adult , Aged , Female , Humans , Male , Middle Aged
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