The genetic basis of plant response to light and heat stresses had been unveiled, and different molecular mechanisms of leaf cell homeostasis to keep high physiological performances were recognized ...in grapevine varieties. However, the ability to develop heat stress tolerance strategies must be further elucidated since the morpho-anatomical and physiological traits involved may vary with genotype × environment combination, stress intensity, and duration. A 3-year experiment was conducted on potted plants of Sardinian red grapevine cultivars Cannonau (syn. Grenache) and Carignano (syn. Carignan), exposed to prolonged heat stress inside a UV-blocking greenhouse, either submitted to low daily UV-B doses of 4.63 kJ m −2 d −1 (+UV) or to 0 kJ m −2 d −1 (−UV), and compared to a control (C) exposed to solar radiation (4.05 kJ m −2 d −1 average UV-B dose). Irrigation was supplied to avoid water stress, and canopy light and thermal microclimate were monitored continuously. Heat stress exceeded one-third of the duration inside the greenhouse and 6% in C. In vivo spectroscopy, including leaf reflectance and fluorescence, allowed for characterizing different patterns of leaf traits and metabolites involved in oxidative stress protection. Cannonau showed lower stomatal conductance under C (200 mmol m −2 s −1 ) but more than twice the values inside the greenhouse (400 to 900 mmol m −2 s −1 ), where water use efficiency was reduced similarly in both varieties. Under severe heat stress and −UV, Cannonau showed a sharper decrease in primary photochemical activity and higher leaf pigment reflectance indexes and leaf mass area. UV-B increased the leaf pigments, especially in Carignano, and different leaf cell regulatory traits to prevent oxidative damage were observed in leaf cross-sections. Heat stress induced chloroplast swelling, plastoglobule diffusion, and the accumulation of secretion deposits in both varieties, aggravated in Cannonau −UV by cell vacuolation, membrane dilation, and diffused leaf blade spot swelling. Conversely, in Carignano UV-B, cell wall barriers and calcium oxalate crystals proliferated in mesophyll cells. These responses suggest an adaptive divergence among cultivars to prolonged heat stress and UV-B light. Further research on grapevine biodiversity, heat, and UV-B light interactions may give new insights on the extent of stress tolerance to improve viticulture adaptive strategies in climate change hotspots.
Grape canes are a waste product from viticulture that show potential as an industrially extractable source of stilbenes, which are valuable for medical and other purposes. In this work, grape canes ...collected in three consecutive years (2014-2016) at six different places in South Moravia, Czech Republic were extracted, and the contents of
-resveratrol,
-ε-viniferin, and r2-viniferin were determined by high-performance liquid chromatography. The study included three blue grape varieties of
L. (Cabernet Moravia, Blaufränkisch, and Piwi variety Laurot) and four white grape varieties (Chardonnay, Green Veltliner, Piwi variety Hibernal, and Piwi variety Malverina). From the viewpoint of producing extracts with high stilbenes content, the Hibernal variety is clearly the best. The mean amounts of the stilbenes for this variety at all localities and for all three years were 4.99 g/kg for
-resveratrol, 3.24 g/kg for
-ε-viniferin, and 1.73 g/kg for r2-viniferin. The influence of vintage, locality, and variety on the amounts of stilbenes was studied using PCA analysis. In contrast to expectations, there was no strong impact of locality on stilbenes content. The differences were varietal for most varieties, regardless of the area of cultivation. Laurot and Hibernal varieties did differ significantly in that respect, however, as they exhibited clear dependence on location.
Summary
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.
Significance statement
While the R2R3‐MYBA genes within the grapevine berry color locus represent the major genetic determinants of fruit color variation, a novel locus located on a different chromosome is responsible for the coloring of vegetative organs. The MYBA genes from this new region have diverged in expression, function and regulation (reflecting both subspecialization and subfunctionalization processes) and differ from the previously characterized berry MYBAs in their capacity to regulate the tri‐hydroxylated sub‐branch of the anthocyanin pathway.
A compact bio‐inspired electromagnetic bandgap integrated wearable antenna (Bio‐EBG‐iwA) is proposed in this work. The Bio‐EBG‐iwA is based on the hybridization of semi‐Vitis vinifera leaf‐shaped ...patch, asymmetric feedline, reflected G‐shaped slot, partial ground, and a stub on the ground plane. The antenna is built on the locally made textile material called Aso‐oke (Alari) with permittivity and a loss tangent of 1.43 and 0.019, respectively. The dimension of the proposed antenna is 0.2λg×0.1λg×0.0089λg (22 mm × 12 mm × 0.7 mm) at 2.45 GHz. Despite its compactness, the gain of −0.48 and 2.5 dBi are achieved at 2.45 and 5.7 GHz respectively without electromagnetic bandgap (EBG). A dual‐band textile‐based uniplanar compact electromagnetic bandgap (UC‐EBG) is introduced to create isolation between the human tissue and the antenna. The dual‐band UC‐EBG is realized through the use of a modified slitted‐square ring (MSSR) and the 90° rotated H‐shaped patch on Aso‐oke (Alari) with a thickness of 2.1 mm. The periodicity of the proposed UC‐EBG is 34.5 mm. The antenna is placed on a 2 × 2 array of the proposed UC‐EBG separated by a 3 mm foam thickness. The radiation efficiency of 88.97% and 79.85% are achieved at 2.45 and 5.7 GHz respectively. The gain of the proposed UC‐EBG integrated antenna increased from −0.48 and 2.5 dBi to 5.9 and 10.7 dBi at 2.45 and 5.7 GHz, respectively. The front‐to‐back ratio (FBR) of 26.3 dB is achieved with the use of UC‐EBG. The use of UC‐EBG results in a 98.31% and 99.4% reduction in average SAR at 2.45 and 5.7 GHz, respectively. The off‐body and on‐body performance analysis of the proposed UC‐EBG integrated antenna show that the proposed EBG integrated antenna (Bio‐EBG‐iwA) is a suitable candidate for wearable application. To the best of our knowledge, this is the most compact wearable antenna with suitable gain, radiation efficiency, and high FBR. In addition, our proposed UC‐EBG shows that slitting is an effective way of miniaturizing the EBG structure.
Abstract
Lasiodiplodia theobromae is a causal agent of Botryosphaeria dieback, which seriously threatens grapevine production worldwide. Plant pathogens secrete diverse effectors to suppress host ...immune responses and promote the progression of infection, but the mechanisms underlying the manipulation of host immunity by L. theobromae effectors are poorly understood. In this study, we characterized LtCre1, which encodes a L. theobromae effector that suppresses BAX-triggered cell death in Nicotiana benthamiana. RNAi-silencing and overexpression of LtCre1 in L. theobromae showed impaired and increased virulence, respectively, and ectopic expression in N. benthamiana increased susceptibility. These results suggest that LtCre1 is as an essential virulence factor for L. theobromae. Protein–protein interaction studies revealed that LtCre1 interacts with grapevine RGS1-HXK1-interacting protein 1 (VvRHIP1). Ectopic overexpression of VvRHIP1 in N. benthamiana reduced infection, suggesting that VvRHIP1 enhances plant immunity against L. theobromae. LtCre1 was found to disrupt the formation of the VvRHIP1–VvRGS1 complex and to participate in regulating the plant sugar-signaling pathway. Thus, our results suggest that L. theobromae LtCre1 targets the grapevine VvRHIP1 protein to manipulate the sugar-signaling pathway by disrupting the association of the VvRHIP1–VvRGS1 complex.
The Lasiodiplodia theobromaeLtCre1 effector disrupts the formation of the VvRHIP1–VvRGS1 complex in grapevine, which interferes with sugar signaling and suppresses the expression of genes related to plant immunity
is an important necrotroph in vineyards. Primary infections are mostly initiated by airborne conidia from overwintered sources around bloom, then the fungus remains quiescent from bloom till maturity ...and egresses at ripeness. We previously described in detail the process of flower infection and quiescence initiation. Here, we complete the characterization studying the cross-talk between the plant and the fungus during pathogen quiescence and egression by an integrated transcriptomic and metabolic analysis of the host and the pathogen. Flowers from fruiting cuttings of the cv. Pinot Noir were inoculated with a GFP-labeled strain of
at full cap-off stage, and molecular analyses were carried out at 4 weeks post inoculation (wpi, fungal quiescent state) and at 12 wpi (fungal pre-egression and egression states). The expressed fungal transcriptome highlighted that the fungus remodels its cell wall to evade plant chitinases besides undergoing basal metabolic activities. Berries responded by differentially regulating genes encoding for different PR proteins and genes involved in monolignol, flavonoid, and stilbenoid biosynthesis pathways. At 12 wpi, the transcriptome of
in the pre-egressed samples showed that virulence-related genes were expressed, suggesting infection process was initiated. The egressed
expressed almost all virulence and growth related genes that enabled the pathogen to colonize the berries. In response to egression, ripe berries reprogrammed different defense responses, though futile. Examples are activation of membrane localized kinases, stilbene synthases, and other PR proteins related to SA and JA-mediated responses. Our results indicated that hard-green berries defense program was capable to hamper
growth. However, ripening associated fruit cell wall self-disassembly together with high humidity created the opportunity for the fungus to egress and cause bunch rot.
In this study, the feasibility of discriminating monovarietal red wines from Touriga Nacional (TN), Touriga Franca (TF), and Tinta Roriz (TR) from Douro Demarcated Region (DDR) using the anthocyanin ...profile was investigated in combination with partial least squares – discrimination analysis (PLS-DA), classification and regression trees (CART) and artificial neural networks (ANN). CART and ANN were more accurate in the classification of monovarietal wines according to their origin with a 100% classification rate in the test set. PLS-DA presented an accuracy of 91.4%. The variables most important for monovarietal wines authentication were petunidin-3-glucoside, malvidin-3-acetylglucoside, and cyanidin-3-glucoside for the PLS-DA, petunidin-3-glucoside, peonidin-3-acetylglucoside, and malvidin-3-acetylglucoside for CART analysis, and malvidin-3-acetylglucoside, petunidin-3-glucoside, malvidin-3-glucoside, peonidin-3-coumaroylglucoside and delphinidin-3-glucoside for ANN. The results demonstrate that the anthocyanin profile of Touriga Nacional, Touriga Franca, and Tinta Roriz Douro Denomination of Origin monovarietal red wines combined with multivariate analysis is an effective tool for verifying their authenticity.
•Anthocyanin profile of the most important Douro DO monovarietal wines were studied.•The feasibility of wine's anthocyanin profile for authentication purposes was studied.•CART and ANN models were more accurate than PLS-DA model for validation set.•Petunidin-3glucoside and malvidin-3acetylglucoside were the most important variables.•Anthocyanin profile can be used for authentication of Douro DO monovarietal wines.
In grapevine research the acquisition of phenotypic data is largely restricted to the field due to its perennial nature and size. The methodologies used to assess morphological traits and phenology ...are mainly limited to visual scoring. Some measurements for biotic and abiotic stress, as well as for quality assessments, are done by invasive measures. The new evolving sensor technologies provide the opportunity to perform non-destructive evaluations of phenotypic traits using different field phenotyping platforms. One of the biggest technical challenges for field phenotyping of grapevines are the varying light conditions and the background. In the present study the Phenoliner is presented, which represents a novel type of a robust field phenotyping platform. The vehicle is based on a grape harvester following the concept of a moveable tunnel. The tunnel it is equipped with different sensor systems (RGB and NIR camera system, hyperspectral camera, RTK-GPS, orientation sensor) and an artificial broadband light source. It is independent from external light conditions and in combination with artificial background, the Phenoliner enables standardised acquisition of high-quality, geo-referenced sensor data.
Grapevine leafroll is the most complex and intriguing viral disease of grapevine (
Vitis
spp.). Several monopartite closteroviruses (family
Closteroviridae
) from grapevines have been molecularly ...characterized, yet their role in disease etiology is not completely resolved. Hence, these viruses are currently designated under the umbrella term of Grapevine leafroll-associated viruses (GLRaVs). This review examines our current understanding of the genetically divergent GLRaVs and highlights the emerging picture of several unique aspects of the leafroll disease pathosystem. A systems biology approach using contemporary technologies in molecular biology, -omics, and cell biology aids in exploring the comparative molecular biology of GLRaVs and deciphering the complex network of host-virus-vector interactions to bridge the gap between genomics and phenomics of leafroll disease. In addition, grapevine-infecting closteroviruses have a great potential as designer viruses to pursue functional genomics and for the rational design of novel disease intervention strategies in this agriculturally important perennial fruit crop.
Climate change is a major concern in grape production worldwide. Nights have been warming much faster than the days, raising attention on the effect of night temperatures on grape and wine ...composition. In this study we evaluated the effect of night temperatures on grape coloration in the cv. Corvina (Vitis vinifera L.). In 2015 and 2016 potted plants were cooled overnight (10-11 °C) during two berry ripening phases, veraison (TV) or post-veraison (TPV), and compared to control vines (C) grown at ambient night temperature (15-20 °C on average). Cooling treatment around veraison (TV) hastened berry anthocyanin accumulation, while the same treatment applied after veraison (TPV) was ineffective. Molecular analysis revealed an increased transcription of four key genes in anthocyanin biosynthesis (CHS3, F3H1, MYBA1 and UFGT) in TV treatment. These results suggest that the anthocyanin biosynthesis capacity was enhanced by cool nights during veraison. However, since the gene expression was not always temporally correlated to the increase in anthocyanin concentration, we speculate on the presence of mechanisms, such as enzymatic regulation or anthocyanin transport, which may contribute in determining the anthocyanin accumulation under low night temperatures.
PDF
