Dispersal history of SARS-CoV-2 in Galicia, Spain.

The dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission are influenced by a variety of factors, including social restrictions and the emergence of distinct variants. In this study, we delve into the origins and dissemination of the Alpha, Delta, and Omicron-BA.1 variants of concern in Galicia, northwest Spain. For this, we leveraged genomic data collected by the EPICOVIGAL Consortium and from the GISAID database, along with mobility information from other Spanish regions and foreign countries. Our analysis indicates that initial introductions during the Alpha phase were predominantly from other Spanish regions and France. However, as the pandemic progressed, introductions from Portugal and the United States became increasingly significant. The number of detected introductions varied from 96 and 101 for Alpha and Delta to 39 for Omicron-BA.1. Most of these introductions left a low number of descendants (<10), suggesting a limited impact on the evolution of the pandemic in Galicia. Notably, Galicia's major coastal cities emerged as critical hubs for viral transmission, highlighting their role in sustaining and spreading the virus. This research emphasizes the critical role of regional connectivity in the spread of SARS-CoV-2 and offers essential insights for enhancing public health strategies and surveillance measures.

Dispersal history of SARS-CoV-2 in Galicia, Spain.

The dynamics of SARS-CoV-2 transmission are influenced by a variety of factors, including social restrictions and the emergence of distinct variants. In this study, we delve into the origins and dissemination of the Alpha, Delta, and Omicron variants of concern in Galicia, northwest Spain. For this, we leveraged genomic data collected by the EPICOVIGAL Consortium and from the GISAID database, along with mobility information from other Spanish regions and foreign countries. Our analysis indicates that initial introductions during the Alpha phase were predominantly from other Spanish regions and France. However, as the pandemic progressed, introductions from Portugal and the USA became increasingly significant. Notably, Galicia's major coastal cities emerged as critical hubs for viral transmission, highlighting their role in sustaining and spreading the virus. This research emphasizes the critical role of regional connectivity in the spread of SARS-CoV-2 and offers essential insights for enhancing public health strategies and surveillance measures.

Characterization of the genetic diversity, structure, and admixture of 7 Chilean chicken breeds.

The Mapuche fowl is an autochthonous breed raised in Chile and represents an important zoogenetic resource for the local economy. This study aimed at investigating the genetic diversity, relationship and population structure of 96 local Chilean chickens derived from 3 ecotype of Mapuche fowl (Kollonka, Ketro, and Kollonka de aretes), 2 ecotype Chilean (Trintre, Cogote pelado) and 2 breeds (Light Brahma and Barred Plymouth Rock) using 12 microsatellite markers. In total, 113 alleles were detected in all populations, with a mean of 7.6 alleles per population. In all population chicken breeds, the observed and expected heterozygosity ranged from 0.91 to 0.98 and from 0.69 to 0.79. Furthermore, all populations showed significant deviations from Hardy-Weinberg expectations. Across each population, the global heterozygosity deficit (FIT) was -0.174, population differentiation index (FST) was 0.073, and the global inbreeding of individuals within breed (FIS) was -0.267. The phylogenetic relationships of chickens were examined using neighbor-joining trees constructed at the level of population. The highest Nei's standard genetic distance value of 0.559 was observed between Barred Plymouth Rock and Light Brahma, whereas the minimum value (0.099) was found between Kollonka and Trintre. The neighbor-joining tree constructed at population level revealed 2 main clusters, with Light Brahma, Barred Plymouth Rock, Ketro and Kollonka de aretes in 1 cluster, and Kollonka, Trintre and Cogote pelado breeds in the second cluster. Based on the results of the STRUCTURE analysis, the most likely number of clustering of the population evaluated was at K = 3, with Light Brahma and Barred Plymouth Rock breeds forming their own distinct clusters, while Kollonka, Ketro, Kollonka de aretes, Trintre and Cogote pelado breeds clustered together. This study represents the first report of genetic diversity in these populations in Chile. These results can be used as baseline genetic information for genetic conservation program, for instance, to control inbreeding and to implement further genetic studies in local Chilean chickens.

Research Note: Characterization of peasant family poultry farming in Southern Chile.

The poultry industry produces most of the meat and eggs for human consumption worldwide. However, family poultry farming still plays an important role in developing countries providing high quality animal products including eggs and poultry meat for family and local consumption. A field survey was taken to 145 family poultry farmers off the commune of Maullin, Los Lagos Region of Southern Chile, to describe their husbandry and breeding practices, and provide information for future development and conservation priorities. Egg production in these poultry systems of the Maullín commune is a family tradition, run mostly by women, provides an extra income from the sale of extra eggs and chicken meat during autumn and winter months. Flocks of 15 to 30 native, creole or indigenous hens, reach point of lay at 5 or 6 months old. Egg production with a mean rate of 40%, peaks during September. Brown eggs are the most frequent, followed by blue-greenish eggs derived from Mapuche fowl ancestry. A ratio of 10 to 20 females per rooster results in ca. 60% hatching rate from natural incubation. While males are kept for two seasons only, females are kept longer, some until old. Diet is based on locally available or self-produced grains, complemented by pasture browsing, scavenging, and kitchen waste. Sanitary management is low or none and technical knowledge derives from ancestral tradition. Investment in accommodation and feeding is low. Results provide information on these systems in non-tropical areas of developing countries where it is scarce, and highlights how these systems can respond to the challenges of future poultry production, considering both climate change and consumers demand for more wholesome, human and sustainable products.

Phyllotaxis transition over the lifespan of a palm tree using Magnetic Resonance Imaging (MRI) and Terrestrial Laser Scanning (TLS): the case of Jubaea chilensis.

BACKGROUND: Jubaea chilensis (Molina) Baillon, is a uniquely large palm species endemic to Chile. It is under threatened status despite its use as an ornamental species throughout the world. This research seeks to identify the phyllotaxis of the species based on an original combination of non-destructive data acquisition technologies, namely Magnetic Resonance Imaging (MRI) in saplings and young individuals and Terrestrial Laser Scanning (TLS) in standing specimens, and a novel analysis methodology. RESULTS: Two phyllotaxis parameters, parastichy pairs and divergence angle, were determined by analyzing specimens at different developmental stages. Spiral phyllotaxis patterns of J. chilensis progressed in complexity from parastichy pairs (3,2) and (3,5) in juvenile specimens and (5,3), (8,5) and (8,13) for adult specimens. Divergence angle was invariable and averaged 136.9°, close to the golden angle. Phyllotactic pattern changes associated with establishment phase, the adult vegetative and the adult reproductive phases were observed. Both technologies, MRI and TLS proved to be adequate for the proposed analysis. CONCLUSIONS: Understanding phyllotactic transitions may assist identification of developmental stages of wild J. chilensis specimens. The proposed methodology may also be useful for the study of other palm species.

The first wave of the COVID-19 epidemic in Spain was associated with early introductions and fast spread of a dominating genetic variant.

The coronavirus disease 2019 (COVID-19) pandemic has affected the world radically since 2020. Spain was one of the European countries with the highest incidence during the first wave. As a part of a consortium to monitor and study the evolution of the epidemic, we sequenced 2,170 samples, diagnosed mostly before lockdown measures. Here, we identified at least 500 introductions from multiple international sources and documented the early rise of two dominant Spanish epidemic clades (SECs), probably amplified by superspreading events. Both SECs were related closely to the initial Asian variants of SARS-CoV-2 and spread widely across Spain. We inferred a substantial reduction in the effective reproductive number of both SECs due to public-health interventions (Re < 1), also reflected in the replacement of SECs by a new variant over the summer of 2020. In summary, we reveal a notable difference in the initial genetic makeup of SARS-CoV-2 in Spain compared with other European countries and show evidence to support the effectiveness of lockdown measures in controlling virus spread, even for the most successful genetic variants.

Consumer preferences and sensory characteristics of eggs from family farms.

The objective of this study was to evaluate consumer habits as well as the sensory perception and characteristics of farm eggs produced in Los Ríos, Chile. Data were collected from an online survey of 197 respondents and a sensory evaluation carried out by 30 untrained panelists of 4 types of eggs (brown-shell and blue-shell eggs acquired from family farms, free-range eggs acquired from large, industrial systems, and white-shell cage eggs from industrial, cage systems.) To evaluate differences and preferences, data were analyzed in a GLM. In addition, sensory evaluation was analyzed using principal component analysis. In accordance with the survey, 99% of the participants eat eggs (P < 0.001), 58% eat 1 to 3 eggs/wk, and 84% declared to consume eggs at home (<0.0001). Surveyed participants reported that price and size are the determining factors (31%) when purchasing eggs. Among the physical characteristic for consumers, yolk color was the most important attribute rather than white color, egg appearance, texture, flavor, or odor. In the consumer acceptability test, farm eggs (either brown or blue shell) received the most favorable sensory evaluation by the panel and were preferred to both free-range and white-shell cage eggs. Yolk color was the most influential parameter in making this difference. Brown farm eggs were predominately selected for greatest general satisfaction by participants in both the sensory evaluation (P = 0.008) and in the survey (40%; P = 0.026). There were no differences between farm eggs (brown and blue shell, P > 0.05) in the evaluated parameters. There was a consequence in the information given from surveyed consumers and the sensory panel with the yolk color.

European and Asian contribution to the genetic diversity of mainland South American chickens.

Chickens (Gallus gallus domesticus) from the Americas have long been recognized as descendants of European chickens, transported by early Europeans since the fifteenth century. However, in recent years, a possible pre-Columbian introduction of chickens to South America by Polynesian seafarers has also been suggested. Here, we characterize the mitochondrial control region genetic diversity of modern chicken populations from South America and compare this to a worldwide dataset in order to investigate the potential maternal genetic origin of modern-day chicken populations in South America. The genetic analysis of newly generated chicken mitochondrial control region sequences from South America showed that the majority of chickens from the continent belong to mitochondrial haplogroup E. The rest belongs to haplogroups A, B and C, albeit at very low levels. Haplogroup D, a ubiquitous mitochondrial lineage in Island Southeast Asia and on Pacific Islands is not observed in continental South America. Modern-day mainland South American chickens are, therefore, closely allied with European and Asian chickens. Furthermore, we find high levels of genetic contributions from South Asian chickens to those in Europe and South America. Our findings demonstrate that modern-day genetic diversity of mainland South American chickens appear to have clear European and Asian contributions, and less so from Island Southeast Asia and the Pacific Islands. Furthermore, there is also some indication that South Asia has more genetic contribution to European chickens than any other Asian chicken populations.

The Role of UV-B light on Small RNA Activity During Grapevine Berry Development.

We explored the effects of ultraviolet B radiation (UV-B) on the developmental dynamics of microRNAs and phased small-interfering-RNA (phasi-RNAs)-producing loci by sequencing small RNAs in vegetative and reproductive organs of grapevine (Vitis vinifera L.). In particular, we tested different UV-B conditions in in vitro-grown plantlets (high-fluence exposition) and in berries from field-grown (radiation filtering) and greenhouse-grown (low- and high-fluence expositions) adult plants throughout fruit development and ripening. The functional significance of the observed UV-coordinated miRNA responses was supported by degradome evidences of ARGONAUTE (AGO)-programmed slicing of mRNAs. Co-expression patterns of the up-regulated miRNAs miR156, miR482, miR530, and miR828 with cognate target gene expressions in response to high-fluence UV-B was tested by q-RT-PCR. The observed UV-response relationships were also interrogated against two published UV-stress and developmental transcriptome datasets. Together, the dynamics observed between miRNAs and targets suggest that changes in target abundance are mediated transcriptionally and, in some cases, modulated post-transcriptionally by miRNAs. Despite the major changes in target abundance are being controlled primarily by those developmental effects that are similar between treatments, we show evidence for novel miRNA-regulatory networks in grape. A model is proposed where high-fluence UV-B increases miR168 and miR530 that target ARGONAUTE 1 (AGO1) and a Plus-3 domain mRNA, respectively, while decreasing miR403 that targets AGO2, thereby coordinating post-transcriptional gene silencing activities by different AGOs. Up-regulation of miR3627/4376 could facilitate anthocyanin accumulation by antagonizing a calcium effector, whereas miR395 and miR399, induced by micronutrient deficiencies known to trigger anthocyanin accumulation, respond positively to UV-B radiation. Finally, increases in the abundance of an anthocyanin-regulatory MYB-bHLH-WD40 complex elucidated in Arabidopsis, mediated by UV-B-induced changes in miR156/miR535, could contribute to the observed up-regulation of miR828. In turn, miR828 would regulate the AtMYB113-ortologues MYBA5, A6 and A7 (and thereby anthocyanins) via a widely conserved and previously validated auto-regulatory loop involving miR828 and phasi TAS4abc RNAs.

Comparative evaluation of the identification of rapidly growing non-tuberculous mycobacteria by mass spectrometry (MALDI-TOF MS), GenoType Mycobacterium CM/AS assay and partial sequencing of the rpoß gene with phylogenetic analysis as a reference method.

INTRODUCTION: The American Thoracic Society and the Infectious Diseases Society of America recommend that clinically significant non-tuberculous mycobacteria (NTM) should be identified to the species level in order to determine their clinical significance. The aim of this study was to evaluate identification of rapidly growing NTM (RGM) isolated from clinical samples by using MALDI-TOF MS and a commercial molecular system. The results were compared with identification using a reference method. METHODS: We included 46 clinical isolates of RGM and identified them using the commercial molecular system GenoType® CM/AS (Hain, Lifescience, Germany), MALDI-TOF MS (Bruker) and, as reference method, partial rpoß gene sequencing followed by BLAST and phylogenetic analysis with the 1093 sequences available in the GeneBank. RESULTS: The degree of agreement between GenoType® and MALDI-TOF MS and the reference method, partial rpoß sequencing, was 27/43 (62.8%) and 38/43 cases (88.3%) respectively. For all the samples correctly classified by GenoType®, we obtained the same result with MALDI-TOF MS (27/27). However, MALDI-TOF MS also correctly identified 68.75% (11/16) of the samples that GenoType® had misclassified (p=0.005). CONCLUSIONS: MALDI-TOF MS classified significantly better than GenoType®. When a MALDI-TOF MS score >1.85 was achieved, MALDI-TOF MS and partial rpoß gene sequencing were equivalent. GenoType® was not able to distinguish between species belonging to the M. fortuitum complex. MALDI-TOF MS methodology is simple, rapid and associated with lower consumable costs than GenoType®. The partial rpoß sequencing methods with BLAST and phylogenetic analysis were not able to identify some RGM unequivocally. Therefore, sequencing of additional regions would be indicated in these cases.

A Heterologous Cell Model for Studying the Role of T-Cell Intracellular Antigen 1 in Welander Distal Myopathy.

Welander distal myopathy (WDM) is a muscle dystrophy characterized by adult-onset distal muscle weakness, prevalently impacting the distal long extensors of the hands and feet. WDM is an autosomal dominant disorder caused by a missense mutation (c.1362G>A; p.E384K) in the TIA1 (T-cell intracellular antigen 1) gene, which encodes an RNA-binding protein basically required for the posttranscriptional regulation of RNAs. We have developed a heterologous cell model of WDM to study the molecular and cellular events associated with mutated TIA1 expression. Specifically, we analyzed how this mutation affects three regulatory functions mediated by TIA1: (i) control of alternative SMN2 (survival motor neuron 2) splicing; (ii) formation, assembly, and disassembly of stress granules; and (iii) mitochondrial dynamics and its consequences for mitophagy, autophagy, and apoptosis. Our results show that whereas WDM-associated TIA1 expression had only a mild effect on SMN2 splicing, it led to suboptimal adaptation to environmental stress, with exacerbated stress granule formation that was accompanied by mitochondrial dysfunction and autophagy. Overall, our observations indicate that some aspects of the cell phenotype seen in muscle of patients with WDM can be recapitulated by ectopic expression of WDM-TIA1 in embryonic kidney cells, highlighting the potential of this model to investigate the pathogenesis of this degenerative disease and possible therapeutics.

Transcriptome-wide analysis links the short-term expression of the b isoforms of TIA proteins to protective proteostasis-mediated cell quiescence response.

Control of gene expression depends on genetics and environmental factors. The T-cell intracellular antigens T-cell intracellular antigen 1 (TIA1), TIA1-like/related protein (TIAL1/TIAR) and human antigen R (HuR/ELAVL1) are RNA-binding proteins that play crucial roles in regulating gene expression in both situations. This study used massive sequencing analysis to uncover molecular and functional mechanisms resulting from the short-time expression of the b isoforms of TIA1 and TIAR, and of HuR in HEK293 cells. Our gene profiling analysis identified several hundred differentially expressed genes (DEGs) and tens of alternative splicing events associated with TIA1b, TIARb and HuR overexpression. Gene ontology analysis revealed that the controlled expression of these proteins strongly influences the patterns of DEGs and RNA variants preferentially associated with development, reproduction, cell cycle, metabolism, autophagy and apoptosis. Mechanistically, TIA1b and TIARb isoforms display both common and differential effects on the regulation of gene expression, involving systematic perturbations of cell biosynthetic machineries (splicing and translation). The transcriptome outputs were validated using functional assays of the targeted cellular processes as well as expression analysis for selected genes. Collectively, our observations suggest that early TIA1b and TIARb expression operates to connect the regulatory crossroads to protective proteostasis responses associated with a survival quiescence phenotype.

Proteomic profile changes associated with diminished expression of T-cell intracellular antigens reveal a hormesis response.

T-cell intracellular antigen (TIA) proteins function as regulators of cell homeostasis by controlling global gene expression in response to dynamic regulatory changes and environmental stress. Here, we used two-dimensional differential in-gel electrophoresis (2D-DIGE) and mass spectrometry (MALDI-TOF/TOF) to identify protein changes associated with the down-regulated expression of TIA proteins. We detected 30 differentially expressed proteins (DEPs), 24 of which were identified, and some of these DEPs were validated by western blotting. In silico analysis showed that DEPs were associated with metabolic processes, detoxification and proteostasis. We mapped the DEPs to the available biological pathways and networks, which included the metabolism of small molecules such as sugars, lipids, amino acids, and nucleotides. Our findings support previous studies and suggest that low expression of TIA proteins might act as a potential adaptive switch to link gene expression reprogramming to a proliferative phenotype mediated by a hormesis phenomenon.

Exogenous Applications of Brassinosteroids Improve Color of Red Table Grape (Vitis vinifera L. Cv. "Redglobe") Berries.

Color and other quality parameters of "Redglobe" grape (Vitis vinifera L.) berries were evaluated after treatment with brassinosteroid (BR) analogs. Three BRs analogs (24-epibrassinolide, Triol, or Lactone) were applied at three concentrations (0.0, 0.4, or 0.8 mg⋅L-1), at the onset of veraison. A commercial formulation (B-2000®) was also applied, at a recommended rate of 0.06 mg⋅L-1. The tested BR analogs were effective improving berry color (evaluated as color index for red grapes, CIRG), increasing the levels of soluble solids and anthocyanins, and changing the types of anthocyanins present without altering other quality and yield parameters. The effects of BR analogs on color enhancement could be explained by an increase in soluble solids content and/or anthocyanin content. Treatment with 24-epibrassinolide (at 0.4 mg⋅L-1) or the commercial formulation tended to favor the production of dihydroxylated anthocyanins, which are responsible for the red and pink colors of grape berries. Results indicate that the use of BRs constitutes a potential tool in the production of table grapes. This is the first report of this enhancement effect in a productive context.

Transcriptome-Wide Identification of Novel UV-B- and Light Modulated Flavonol Pathway Genes Controlled by VviMYBF1.

Flavonols constitute a group of flavonoids with important photoprotective roles in plants. In addition, flavonol content and composition greatly influences fruit quality. We previously demonstrated that the grapevine R2R3-MYB transcription factor (TF) VviMYBF1 promotes flavonol accumulation by inducing the expression of flavonol synthase (VviFLS1/VviFLS4), a key step of the initial flavonol pathway. Despite this, gene networks underlying flavonol modification in grapevine including both structural and regulatory genes remain poorly understood. In order to identify flavonol modifying genes and TFs acting downstream of VviMYBF1 a microarray-based transcriptome analysis was performed on grapevine hairy roots ectopically expressing VviMYBF1 or a Green Fluorescent Protein as control. VviFLS1 was induced in VviMYBF1 transgenic roots and glycosylated flavonols accumulated significantly compared with control lines. Among the differentially expressed genes, potential flavonol-modifying enzymes with predicted rhamnosyltransferase (e.g., RhaT1) or glycosyltransferase (e.g., GT3) activities were identified. In addition, important TFs of the MYB and bZIP families such as the proanthocyanidin regulator VviMYBPA1 and the UV-B light responsive HY5 homolog VviHYH were significantly altered in their expression pattern by overexpression of VviMYBF1. Co-temporal expression analysis demonstrated positive correlation of VviMYBF1 with VviFLS1, VviGT3, and VviRhaT1 during berry development and in fruits ripened with different light and UV-B radiation conditions at field. These results show that VviMYBF1 overexpression led to the identification of novel genes of the flavonol pathway and that the flavonol modifying machinery can be influenced by agricultural practices to optimize flavonol composition in grapes.

T-Cell Intracellular Antigens and Hu Antigen R Antagonistically Modulate Mitochondrial Activity and Dynamics by Regulating Optic Atrophy 1 Gene Expression.

Mitochondria undergo frequent morphological changes to control their function. We show here that T-cell intracellular antigens (TIA1b/TIARb) and Hu antigen R (HuR) have antagonistic roles in mitochondrial function by modulating the expression of mitochondrial shaping proteins. Expression of TIA1b/TIARb alters the mitochondrial dynamic network by enhancing fission and clustering, which is accompanied by a decrease in respiration. In contrast, HuR expression promotes fusion and cristae remodeling and increases respiratory activity. Mechanistically, TIA proteins downregulate the expression of optic atrophy 1 (OPA1) protein via switching of the splicing patterns of OPA1 to facilitate the production of OPA1 variant 5 (OPA1v5). Conversely, HuR enhances the expression of OPA1 mRNA isoforms through increasing steady-state levels and targeting translational efficiency at the 3' untranslated region. Knockdown of TIA1/TIAR or HuR partially reversed the expression profile of OPA1, whereas knockdown of OPA1 or overexpression of OPA1v5 provoked mitochondrial clustering. Middle-term expression of TIA1b/TIARb triggers reactive oxygen species production and mitochondrial DNA damage, which is accompanied by mitophagy, autophagy, and apoptosis. In contrast, HuR expression promotes mitochondrion-dependent cell proliferation. Collectively, these results provide molecular insights into the antagonistic functions of TIA1b/TIARb and HuR in mitochondrial activity dynamics and suggest that their balance might contribute to mitochondrial physiopathology.

A group of grapevine MYBA transcription factors located in chromosome 14 control anthocyanin synthesis in vegetative organs with different specificities compared with the berry color locus.

Grapevine organs accumulate anthocyanins in a cultivar-specific and environmentally induced manner. The MYBA1-A2 genes within the berry color locus in chromosome 2 represent the major genetic determinants of fruit color. The simultaneous occurrence of transposon insertions and point mutations in these genes is responsible for most white-skinned phenotypes; however, the red pigmentation found in vegetative organs suggests the presence of additional regulators. This work describes a genomic region of chromosome 14 containing three closely related R2R3-MYB genes, named MYBA5, MYBA6 and MYBA7. Ectopic expression of the latter two genes in grapevine hairy roots promoted anthocyanin accumulation without affecting other phenylpropanoids. Transcriptomic profiling of hairy roots expressing MYBA1, MYBA6 and MYBA7 showed that these regulators share the activation of late biosynthetic and modification/transport-related genes, but differ in the activation of the FLAVONOID-3'5'-HYDROXYLASE (F3'5'H) family. An alternatively spliced MYBA6 variant was incapable of activating anthocyanin synthesis, however, because of the lack of an MYC1 interaction domain. MYBA1, MYBA6.1 and MYBA7 activated the promoters of UDP-GLUCOSE:FLAVONOID 3-O-GLUCOSYLTRANSFERASE (UFGT) and ANTHOCYANIN 3-O-GLUCOSIDE-6″-O-ACYLTRANSFERASE (3AT), but only MYBA1 induced F3'5'H in concordance with the low proportion of tri-hydroxylated anthocyanins found in MYBA6-A7 hairy roots. This putative new color locus is related to the red/cyanidic pigmentation of vegetative organs in black- and white-skinned cultivars, and forms part of the UV-B radiation response pathway orchestrated by ELONGATED HYPOCOTYL 5 (HY5). These results demonstrate the involvement of additional anthocyanin regulators in grapevine and suggest an evolutionary divergence between the two grape color loci for controlling additional targets of the flavonoid pathway.

The photomorphogenic factors UV-B RECEPTOR 1, ELONGATED HYPOCOTYL 5, and HY5 HOMOLOGUE are part of the UV-B signalling pathway in grapevine and mediate flavonol accumulation in response to the environment.

Grapevine (Vitis vinifera L.) is a species well known for its adaptation to radiation. However, photomorphogenic factors related to UV-B responses have not been molecularly characterized. We cloned and studied the role of UV-B RECEPTOR (UVR1), ELONGATED HYPOCOTYL 5 (HY5), and HY5 HOMOLOGUE (HYH) from V. vinifera We performed gene functional characterizations, generated co-expression networks, and tested them in different environmental conditions. These genes complemented the Arabidopsis uvr8 and hy5 mutants in morphological and secondary metabolic responses to radiation. We combined microarray and RNA sequencing (RNA-seq) data with promoter inspections to identify HY5 and HYH putative target genes and their DNA binding preferences. Despite sharing a large set of common co-expressed genes, we found different hierarchies for HY5 and HYH depending on the organ and stress condition, reflecting both co-operative and partially redundant roles. New candidate UV-B gene markers were supported by the presence of HY5-binding sites. These included a set of flavonol-related genes that were up-regulated in a HY5 transient expression assay. We irradiated in vitro plantlets and fruits from old potted vines with high and low UV-B exposures and followed the accumulation of flavonols and changes in gene expression in comparison with non-irradiated conditions. UVR1, HY5, and HYH expression varied with organ, developmental stage, and type of radiation. Surprisingly, UVR1 expression was modulated by shading and temperature in berries, but not by UV-B radiation. We propose that the UV-B response machinery favours berry flavonol accumulation through the activation of HY5 and HYH at different developmental stages at both high and low UV-B exposures.

Exogenous application of pectin-derived oligosaccharides to grape berries modifies anthocyanin accumulation, composition and gene expression.

Anthocyanins are secondary metabolites synthesized in grape berry skins via the phenylpropanoid pathway, with functions ranging from skin coloration to protection against pathogens or UV light. Accumulation of these compounds is highly variable depending on genetics, environmental factors and viticultural practices. Besides their biological functions, anthocyanins improve wine quality, as a high anthocyanin content in berries has a positive impact on the color, total phenolic concentration and, ultimately, the price of wine. The present work studies the effect of the pre-veraison application of pectin derived oligosaccharides (PDO) on the synthesis and accumulation of these compounds, and associates the changes observed with the expression of key genes in the phenylpropanoid pathways. To this end, pre-veraison Cabernet Sauvignon bunches were treated with PDO to subsequently determine total anthocyanin content, the anthocyanin profile (by HPLC-DAD) and gene expression (by qRT-PCR), using Ethrel and water treatments for comparison. The results show that PDO were as efficient as Ethrel in generating a significant rise in total anthocyanin content at 30 days after treatment (dat), compared with water treatments (1.32, 1.48 and 1.02 mg e.Mv-3G/g FW respectively) without any undesirable effect on berry size, soluble solids, tartaric acid concentration or pH. In addition, a significant alteration in the anthocyanin profile was observed. Specifically, a significant increase in the relative concentration of malvidin was observed for both PDO and Ethrel treatments, compared with water controls (52.8; 55.0 and 48.3%, respectively), with a significant rise in tri-hydroxylated forms and a fall in di-hydroxylated anthocyanins. The results of gene expression analyses suggest that the increment in total anthocyanin content is related to a short term increase in phenylalanine ammonia-lyase (PAL) expression, mediated by a decrease in MYB4A expression. A longer term increase in UDP-glucose flavonoid 3-O-glucosyltransferase (UFGT) expression, probably mediated by a rise in MYBA1 was also observed. Regarding the anthocyanin profile, despite the increase observed in MYB5A expression in PDO and Ethrel treatments, no changes in flavonoid 3'-hydroxylase (F-3'-H); flavonoid 3'5'-hydroxylase (F-3'5'-H) or O-methyltransferase (OMT) could be related with the profile modifications described. Overall, this study highlights that application of PDO is a novel means of altering specific grape berry anthocyanins, and could be a means of positively influencing wine quality without the addition of agrochemicals.

Use of plant woody species electrical potential for irrigation scheduling.

The electrical response of plants to environmental stimuli can be measured and quantitatively related to the intensity of several stimulating sources, like temperature, solar radiation, soil water content, evapotranspiration rates, sap flow and dendrometric cycles. These relations can be used to assess the influence of different environmental situations on soil water availability to plants, defined as a steady state condition between leaf transpirative flow and soil water flow to plant roots. A restricted soil water flow due to soil dryness can trigger water stress in plants, if the atmospheric evaporative demand is high, causing partial stomata closure as a physiological response to avoid plant dehydration; water stressed and unstressed plants manifest a differential electrical response. Real time plant electrical response measurements can anticipate actions that prevent the plant reaching actual stress conditions, optimizing stomata gas exchange and photosynthetic rates. An electrophysiological sensor developed in this work, allows remote real-time recording information on plant electrical potential (EP) in the field, which is highly related to EP measurements obtained with a laboratory Keithley voltmeter sensor used in an highly controlled experimental setup. Our electrophysiological sensor is a wireless, autonomous devise, which transmits EP information via Internet to a data server. Using both types of sensors (EP electrodes with a Keithley voltmeter and the electrophysiological sensor), we measured in real time the electrical responses of Persea americana and Prunus domestica plants, to induced water deficits. The differential response for 2 scenarios: irrigation and water restriction is identified by a progressive change in slope on the daily maximal and minimal electric signal values in stressed plants, and a zero-slope for similar signals for well-watered plants. Results show a correspondence between measured signals obtained by our electrophysiological sensor and the EP electrodes connected to the Keithley voltmeter in each irrigation stage. Also, both sensors show a daily cyclical signal (circadian cycle).