Wall Degradation Research Articles

Suppression of a hexokinase gene SlHXK1 in tomato affects fruit setting and seed quality

Hexokinase is considered to be the key molecule in sugar signaling and metabolism. Here, we reported that silencing SlHXK1 resulted in a decrease in flower number, increased rate of flower dropping, abnormal thickening of the anther wall, and reduced pollen and seed viability. An anatomical analysis revealed the loss of small cells and abnormal thickening of anther walls in SlHXK1-RNAi lines. Treatment with auxin and 1-methylcyclopropene inhibited flower dropping from the pedicel abscission zone. qRT-PCR analysis revealed that the effect of SlHXK1 on abscission was associated with the expression levels of genes related to key meristem, auxin, ethylene, cell wall metabolism and programmed cell death. Pollen germination and pollen staining experiments showed that pollen viability was significantly reduced in the SlHXK1-RNAi lines. Physiological and biochemical analyses showed that hexokinase activity and starch content were markedly decreased in the transgenic lines. The expression of genes related to tomato pollen development was also suppressed in the transgenic lines. Although the RNAi lines eventually produced some viable seeds, the yield and quality of the seeds was lower than that of wild-type plants. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that SlHXK1 interacted with SlKINγ. Furthermore, SlPIF4 inhibited the transcriptional expression of SlHXK1. In conclusion, our results demonstrate that SlHXK1 may play important roles in pollen, anther, seed and the pedicel abscission zone by affecting starch accumulation or cell wall synthesis, as well as by regulating the number of the transcripts of genes that are involved in auxin, ethylene and cell wall degradation.

Integrated analysis of postharvest storage characteristics of seven apple cultivars and transcriptome data identifies MdBBX25 as a negative regulator of fruit softening during storage in apples

Apple is classified as a climacteric fruit, characterized by a rapid surge in ethylene levels at the onset of ripening. However, there is significant variation in the degree and timing of ripening and softening among different apple cultivars. Understanding the molecular mechanisms underlying fruit softening and the associated changes in cell wall integrity is crucial for improving fruit quality and extending shelf life. In this study, we conducted a comparative analysis of fruit firmness and ethylene production among seven apple cultivars with different softening patterns during storage. We also examined the expression patterns of genes and enzyme activities involved in cell wall metabolism. Our results showed that fruit firmness was negatively correlated with ethylene production rate, respiration rate, soluble pectin content, cellulase activity, polygalacturonase activity, and β-glucosidase activity, while it was positively correlated with protopectin content and cellulose content. Furthermore, we identified a BBX transcription factor gene, MdBBX25, that was negatively correlated with fruit softening during storage. Overexpression of MdBBX25 resulted in delayed fruit softening by suppressing ethylene biosynthesis and cell wall-related genes, whereas silencing of MdBBX25 accelerated fruit softening by promoting ethylene biosynthesis and cell wall-related genes in apple. Our findings provide insights into the role of MdBBX25 as a negative regulator of fruit softening through the modulation of ethylene biosynthesis and cell wall degradation during storage.

Development of composite film based on polyvinyl alcohol with binary nanoreinforcements for active packaging of fresh-cut apples

To develop a sustainable and environmentally-friendly preservation packaging for fresh-cut fruits and vegetables (FFV), this study synthesized the nanohybrid LDH@PCA using layered double hydroxide (LDH) loaded with p-coumaric acid (PCA). Subsequently, the nanohybrid and lignin nanoparticles (LPs) were integrated into a polyvinyl alcohol (PVA) matrix to prepare a binary nanocomposite packaging material named PVA-LPs-LDH@PCA. In this case, LDH@PCA and LPs were homogeneously dispersed inside PVA, relying on hydrogen bonding at 3 % (w/w) and 5 % (w/w), respectively, while electrostatic attraction also played a role. The reinforcement of the binary nanomaterials led to a significant increase in the radius of gyration and mass fractal dimension of the microregions within the PVA films. Additionally, the tensile strengths were 66 %, 32 %, and 8 % higher than those of the PVA, PVA-LPs, and PVA-LDH@PCA films, respectively. Moreover, the binary nanocomposite packaging exhibited enhanced water vapor, oxygen, UV barrier, and thermal stability, while synergistically improving its antioxidant activity compared to the aforementioned films. Remarkably, PCA in PVA-LPs-LDH@PCA demonstrated sustained release properties, consistent with Avrami and Arabolic diffusion models, for up to 55 h. Packaging of fresh-cut apples with PVA-LPs-LDH@PCA effectively maintained the texture, appearance, and nutritional quality. Transcriptomic and metabolomic analyses revealed that this packaging inhibited cell wall degradation, maintained cell membrane integrity, stimulated scavenging of reactive oxygen species, and inhibited polyphenol oxidase, attenuating the adverse effects of water loss stress on fresh-cut apples. These findings suggest that PVA binary nanocomposite films hold great potential as a sustainable solution for freshness preservation in FFV packaging.

Research on Flesh Texture and Quality Traits of Kiwifruit (cv. Xuxiang) with Fluctuating Temperatures during Cold Storage.

Kiwifruits are often exposed to various temperature fluctuations (TFs) during postharvest transportation and storage. To evaluate the effect of TFs on the qualities of kiwifruits during storage, kiwifruits were stored at 2 °C, 2 °C or 5 °C (TF2 °C-5 °C, alternating every 12 h), 2 °C or 7 °C (TF2 °C-7 °C, alternating every 12 h) for 3 d before long time storage at 2 °C. Observations revealed that kiwifruits stored at a constant 2 °C showed the lowest loss of weight and vitamin C because of minimized ethylene production and respiratory rate compared with that of TF2 °C-5 °C and TF2 °C-7 °C. Moreover, the results of RT-qPCR verified that the expression levels of genes encoding polygalacturonase, β-galacturonidase, and pectin methylesterase were significantly increased by the treatment of TF. Hence, TF accelerated the degradation of cell walls, softening, translucency, and relative conductivity of the flesh of kiwifruits. In addition, the impact of TF2 °C-7 °C on kiwifruits was more significant relative to TF2 °C-5 °C. The present study provides a theoretical basis for kiwifruit during cold storage.

Polyamine signaling communications play a key role in regulating the pathogenicity of Dickeya fangzhongdai.

Dickeya fangzhongdai is a devastating bacterial pathogen infecting a wide range of crops and ornamental plants worldwide. As a newly identified bacterial species in 2016, the regulatory mechanisms that govern its virulence are still a mystery. In this study, we explored the potential roles of polyamine-mediated cell-to-cell communication in regulation of D. fangzhongdai virulence. Null mutation of speA and speC in D. fangzhongdai strain ZXC1, which encodes polyamine biosynthesis through arginine and ornithine pathways, respectively, dramatically reduced bacterial motility, decreased production of plant cell wall degradation (PCWD) enzymes, and attenuated the bacterial virulence on taro and potato. We then tested the effect of various polyamine molecules in the restoration of the mutant phenotypes and showed that putrescine was the most potent signal in the regulation of virulence traits in strain ZXC1. In addition, we found that taro extract contained active signals to rescue putrescine-deficient phenotypes. High-performance liquid chromatography mass spectrometry analysis validated the speA was essential for production of putrescine in D. fangzhongdai ZXC1. We further showed that the putrescine transporters PotF and PlaP are required for putrescine-mediated cell-to-cell communication and virulence against taro and potato tubers. quantitative reverse transcription-PCR analysis demonstrated that putrescine influences the pathogenicity of D. fangzhongdai ZXC1 by regulating the expression of PCWD enzymes, bacterial chemotaxis, and flagellar-related genes. The findings from this study shed a new light for elucidating the pathogenic mechanisms of D. fangzhongdai and present useful clues for developing relevant disease control strategies. IMPORTANCE Dickeya fangzhongdai is a newly identified plant bacterial pathogen with a wide host range. A clear understanding of the cell-to-cell communication systems that modulate the bacterial virulence is of key importance for elucidating its pathogenic mechanisms and for disease control. In this study, we present evidence that putrescine molecules from the pathogen and host plants play an essential role in regulating the bacterial virulence. The significance of this study is in (i) demonstrating that putrescine signaling system regulates D. fangzhongdai virulence mainly through modulating the bacterial motility and production of PCWD enzymes, (ii) outlining the signaling and regulatory mechanisms with which putrescine signaling system modulates the above virulence traits, and (iii) validating that D. fangzhongdai could use both arginine and ornithine pathways to synthesize putrescine signals. To our knowledge, this is the first report to show that putrescine signaling system plays a key role in modulating the pathogenicity of D. fangzhongdai.

Microalgae as a Sustainable Source of Antioxidants in Animal Nutrition, Health and Livestock Development.

Microalgae are a renewable and sustainable source of bioactive compounds, such as essential amino acids, polyunsaturated fatty acids, and antioxidant compounds, that have been documented to have beneficial effects on nutrition and health. Among these natural products, the demand for natural antioxidants, as an alternative to synthetic antioxidants, has increased. The antioxidant activity of microalgae significantly varies between species and depends on growth conditions. In the last decade, microalgae have been explored in livestock animals as feed additives with the aim of improving both animals' health and performance as well as product quality and the environmental impact of livestock. These findings are highly dependent on the composition of microalgae strain and their amount in the diet. The use of carbohydrate-active enzymes can increase nutrient bioavailability as a consequence of recalcitrant microalgae cell wall degradation, making it a promising strategy for monogastric nutrition for improving livestock productivity. The use of microalgae as an alternative to conventional feedstuffs is becoming increasingly important due to food-feed competition, land degradation, water deprivation, and climate change. However, the cost-effective production and use of microalgae is a major challenge in the near future, and their cultivation technology should be improved by reducing production costs, thus increasing profitability.

Pathogenicity analysis and comparative genomics reveal the different infection strategies between the generalist Metarhizium anisopliae and the specialist Metarhizium acridum.

The fungal genera Metarhizium contain many important multiple species that are used as biocontrol agents and as model organisms for exploring insect-fungal interactions. Metarhizium spp. exhibit different traits of pathogenicity, suggesting that the pathogenesis can be quite distinctive. However, the underlying differences in their pathogenesis remain poorly understood. Pathogenicity analysis showed that Metarhizium anisopliae (strain CQMa421) displayed higher virulence against oriental migratory locusts, Locusta migratoria manilensis (Meyen), than the acridid-specific specie Metarhizium acridum (strain CQMa102). Relative to M. acridum, M. anisopliae possessed a higher conidial hydrophobicity, increased ability to penetrate the host, accelerated growth under hypoxia and enhanced ability for the utilization of different carbon sources. Different distributions of carbohydrate epitopes at cell wall surface of M. anisopliae might also contribute to successful evasion of host immune defenses. Comparative genomics showed that M. anisopliae has 98 more virulence-related secreted proteins (133) than M. acridum (35), which can be functionally classified as hydrolases, virulence effectors, cell wall degradation and stress tolerance-related proteins, and helpful to the cuticle penetration and host internal environment adaption. In addition, differences in genomic clusters specifically related to secondary metabolites, including the clusters of Indole-NRPS hybrid, T1PKS-NRPS like hybrid, Betalactone, Fungal-Ripp and NRPS-Terpene hybrid, may lead to differences in core virulence-related secondary metabolite genes in M. acridum (18) and M. anisopliae (36). The comparative study provided new insights into the different infection strategies between M. anisopliae and M. acridum, and further facilitate the identification of virulence-related genes for the improvement of mycoinsecticides. © 2023 Society of Chemical Industry.

Grain and malt quality of selected winter barley genetic resources

The present study evaluated the agronomic and malting quality of 18 selected winter barley varieties. The varieties were obtained from the Gene Bank of the Crop Research Institute in Prague-Ruzyně. The varieties were tested under field conditions in three-year trials of basic evaluation. After the harvest, grain was malted and malting quality was determined according to international methods (EBC and MEBAK). The highest extract content was found in the Atlantick variety (80.6%). Proteolytic modification of the varieties Absolut, KWS Ariane and the line QK19/08030A_18 was at an optimal level. Values of diastatic power were high in all varieties, which is typical for winter barley varieties, similarly as low levels of cell wall degradation (friability) and high β-glucan content in the sweet wort. The lowest β-glucan content in the sweet wort was recorded in the two-row winter barley variety KWS Ariane (241 mg/l). Of the six-row varieties, the line QK19/08030A_18 had the lowest β-glucan content in the sweet wort (382 mg/l).

Erosion Model for Wind-Blown Sand Flow at Earthen Sites in Arid Environment, Northwest China

ABSTRACT This study investigates the erosive impact of wind-blown sand on earthen sites within arid environments through the establishment of meteorological observation equipment. Over a span of 47 months, a comprehensive approach encompassing numerical simulation, plume analysis, particle examination, three-dimensional scanning, and photo monitoring was employed to continuously monitor the patterns of wind-blown sand movement and the degradation of test walls. The study identifies six distinct zones extending from five times the windward side to ten times the leeward side of the test wall’s height. Notably, a negative correlation between captured particle mass and the height of the sand traps is observed, with 70% of particles concentrated within 50 cm from the base of the test wall. Three primary erosion mechanisms for wind-blown sand are elucidated, including frontal impact, side abrasion, and reverse sapping. Furthermore, the study highlights pronounced erosion at the base of the wall due to vortex flow, with depth erosion affecting the lower, side, and upper sections of the test walls. This paper delves into the erosion mechanisms and operational models of wind-blown sand flow surrounding discontinuous site walls, offering valuable insights for the conservation of ancient earthen sites.

Nitric Oxide-Induced Morphological Changes to Bacteria.

Antimicrobial resistance poses a serious threat to global health, necessitating research for alternative approaches to treating infections. Nitric oxide (NO) is an endogenously produced molecule involved in multiple physiological processes, including the response to pathogens. Herein, we employed microscopy- and fluorescence-based techniques to investigate the effects of NO delivered from exogenous NO donors on the bacterial cell envelopes of pathogens, including resistant strains. Our goal was to assess the role of NO donor architecture (small molecules, oligosaccharides, dendrimers) on bacterial wall degradation to representative Gram-negative bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecium) upon treatment. Depending on the NO donor, bactericidal NO doses spanned 1.5-5.5 mM (total NO released). Transmission electron microscopy of bacteria following NO exposure indicated extensive membrane damage to Gram-negative bacteria with warping of the cellular shape and disruption of the cell wall. Among the small-molecule NO donors, those providing a more extended release (t1/2 = 120 min) resulted in greater damage to Gram-negative bacteria. In contrast, rapid NO release (t1/2 = 24 min) altered neither the morphology nor the roughness of these bacteria. For Gram-positive bacteria, NO treatments did not result in any drastic change to cellular shape or membrane integrity, despite permeation of the cell wall as measured by depolarization assays. The use of positively charged quaternary ammonium (QA)-modified NO-releasing dendrimer proved to be the only NO donor system capable of penetrating the thick peptidoglycan layer of Gram-positive bacteria.

Dissecting the Role of Cell Wall Changes in Chilling Injury-Induced Gel Formation, Rubberiness, and Mealiness in Apricots

In apricots and other stonefruit, chilling injury (CI) symptoms like mealiness, rubberiness, and gel formation are associated with cell wall properties. Apricots were stored at 0 °C for 5 weeks and ripened at 20 °C to induce CI and compared with fruit ripened at 20 °C from harvest at similar firmness. In those apricots without CI, degradation of middle-lamella pectin during softening weakened cell-cell adhesion and intercellular junctions. Pectin was still present in middle lamella regions but pectin that filled the intercellular spaces at harvest had disappeared. Fruit with combinations of CI symptoms showed different pectin solubilities, molecular weight distribution, and differences in pectin staining compared with fruit that were severely chilling-injured, exhibiting all symptoms. The perception of mealiness correlated with the presence of pectin in the cell lumen, and rubberiness with the presence of pectin in tricellular corners. We concluded that in chilling-injured apricots, the normal softening process is not being resumed after fruit have been taken out of cold storage. Cell wall degradation is disrupted, affecting the normal weakening of cell walls during softening. Hence, cell walls were less likely to break open during chewing, and when cells did break, any juice released might be bound by pectin present in the cell walls and cell lumen, leaving a sensation of rubberiness and mealiness.

The regulatory mechanisms of delayed senescence of nitric oxide treatment of hyacinth beans

The effects of exogenous NO generated from sodium nitroprusside (SNP) on hyacinth bean have been investigated with metabolomic, transcriptomic, and Assay for Transposase-Accessible Chromatin with high-throughput Sequencing (ATAC-seq) analyses. Comparative analysis revealed 421 and 253 differentially accumulated metabolites (DAMs) in control 0 d vs control 8 d, and control 0 d vs SNP 8 d, respectively. Flavonoid biosynthesis accounted for 50% and 66% of the DAMs in the two comparative groups, respectively. The key flavonoid synthesis genes (PAL, CHS, CHI) were downregulated in NO treated beans. NO also downregulated genes related to cell wall degradation, lignin synthesis, plant pathogen interaction, and ethylene signal transduction. ATAC-seq analysis identified 14 co-enriched transcription factors from the ERF /DREB family, suggesting their role in regulating bean senescence. Overall, NO regulated flavonoid metabolism, cell wall degradation, lignin synthesis, plant hormones, flavonoid biosynthesis, plant pathogen interaction genes, and the ERF /DREB transcription factor family. These findings provide information about postharvest quality regulation of bean senescence.

Use of Roflumilast on the incidence of exacerbations in patients with non-fibrocystic supurative bronchiectasis

Bronchiectasis is an irreversible inflammatory disease of the airways, noted on chest high-resolution tomography (HRCT). The dilation is provoked by the elastic and muscular degradation of the bronchial walls and its appearance is conditioned to genetic and acquired factors. Manifested with persistent cough, associated with expectoration of mucopurulent sputum, dyspnea, hemoptysis. After accompanying the treatment of patients in 3 public hospitals and 1 private practice in the city of João Pessoa, this text presents the use of Roflumilast as a therapeutic option for the prevention of exacerbations of bronchiectasis.

Alleviatory effects of salicylic acid on postharvest softening and cell wall degradation of 'Jinshayou' pummelo (Citrus maxima Merr.): A comparative physiological and transcriptomic analysis.

The regulatory mechanisms underlying the salicylic acid (SA)-mediated inhibition of senescence in pummelo fruit, the largest known citrus variety, remain unclear. Herein, postharvest 0.3% SA treatment was demonstrated to delay postharvest 'Jinshayou' pummelo senescence, as evidenced by the inhibitions in firmness loss, electrolyte leakage increase, and color change. Using comparative transcriptomic data, a total of 4367, 3769, and 1659 DEGs were identified between CK0 and CK60, CK0 and SA60, and CK60 and SA60, respectively. Further GO analysis revealed that DEGs were mainly implicated in the processes of cell wall modification and phenylpropanoid pathway during fruit senescence. More importantly, postharvest exogenous 0.3% SA treatment was observed to inhibit CWDEs activities and their encoding gene expression, retain higher protopectin, cellulose, and hemicelluloses contents, as well as reduce WSP content, thus maintaining cell wall structure. These findings collectively indicated that postharvest SA treatment was a green and useful preservative for alleviating fruit senescence and prolonging the storage life of harvested 'Jiashayou' pummelo fruit.

The Zinc Finger Protein MaCCCH33-Like2 Positively Regulates Banana Fruit Ripening by Modulating Genes inStarch andCell Wall Degradation.

As zinc finger protein transcription factors (TFs), the molecular mechanism of Cys-Cys-Cys-His (CCCH) TFs in regulating plant development, growth and stress response has been well studied. However, the roles of CCCH TFs in fruit ripening are still obscure. Herein, we report that MaCCCH33-like2 TF and its associated proteins modulate the fruit softening of 'Fenjiao' bananas. MaCCCH33-like2 interacts directly with the promoters of three genes: isoamylase2 (MaISA2), sugar transporter14-like (MaSUR14-like) and β-d-xylosidase23 (MaXYL23), all of which are responsible for encoding proteins involved in the degradation of starch and cell wall components. Additionally, MaCCCH33-like2 forms interactions with abscisic acid-insensitive 5 (ABI5)-like and ethylene F-box protein 1 (MaEBF1), resulting in enhanced binding and activation of promoters of genes related to starch and cell wall degradation. When MaCCCH33-like2 is transiently and ectopically overexpressed in 'Fenjiao' banana and tomato fruit, it facilitates softening and ripening processes by promoting the degradation of cell wall components and starch and the production of ethylene. Conversely, the temporary silencing of MaCCCH33-like2 using virus-induced gene silencing (VIGS) inhibits softening and ripening in the 'Fenjiao' banana by suppressing ethylene synthesis, as well as starch and cell wall degradation. Furthermore, the promoter activity of MaCCCH33-like2 is regulated by MaABI5-like. Taken together, we have uncovered a novel MaCCCH33-like2/MaEBF1/MaABI5-like module that participates in fruit softening regulation in bananas.

Genomic Insights into Paucibacter aquatile DH15, a Cyanobactericidal Bacterium, and Comparative Genomics of the Genus Paucibacter.

Microcystis blooms threaten ecosystem function and cause substantial economic losses. Microorganism-based methods, mainly using cyanobactericidal bacteria, are considered one of the most ecologically sound methods to control Microcystis blooms. This study focused on gaining genomic insights into Paucibacter aquatile DH15 that exhibited excellent cyanobactericidal effects against Microcystis. Additionally, a pan-genome analysis of the genus Paucibacter was conducted to enhance our understanding of the ecophysiological significance of this genus. Based on phylogenomic analyses, strain DH15 was classified as a member of the species Paucibacter aquatile. The genome analysis supported that strain DH15 can effectively destroy Microcystis, possibly due to the specific genes involved in the flagellar synthesis, cell wall degradation, and the production of cyanobactericidal compounds. The pan-genome analysis revealed the diversity and adaptability of the genus Paucibacter, highlighting its potential to absorb external genetic elements. Paucibacter species were anticipated to play a vital role in the ecosystem by potentially providing essential nutrients, such as vitamins B7, B12, and heme, to auxotrophic microbial groups. Overall, our findings contribute to understanding the molecular mechanisms underlying the action of cyanobactericidal bacteria against Microcystis and shed light on the ecological significance of the genus Paucibacter.

Comparative Physiological and Transcriptome Analyses Reveal Mechanisms of Salicylic-Acid-Reduced Postharvest Ripening in 'Hosui' Pears (Pyrus pyrifolia Nakai).

Postharvest ripening of sand pear fruit leads to quality deterioration, including changes in texture, flavor, and fruit color. Salicylic acid (SA), an important defense-related hormone, delays fruit ripening and maintains fruit quality, but the underling mechanism remains unclear. Herein, we evaluated the efficacy of SA in delaying the ripening process of Pyrus pyrifolia cv. 'Hosui' pear fruit, as evidenced by the reduction in fruit weight loss, inhibition of firmness loss, cell wall degradation and soluble sugars, and retention of total phenols. Based on comparative transcriptomic data, a total of 3837 and 1387 differentially expressed genes (DEGs) were identified during room-temperature storage of control fruit and between SA-treated and control fruit, respectively. Further KEGG analysis revealed that the DEGs were mainly implicated in plant hormone signal transduction, starch and sugar metabolism, and cell wall modification. Moreover, exogenous SA treatment also altered the expression of many transcription factor (TF) families, including those in the ethylene-responsive factor (ERF), NAM, ATAF, CUC (NAC), basic helix-loop-helix (bHLH), basic leucine zipper (bZIP), and v-myb avian myeloblastosis viral oncogene homolog (MYB) families. Together, the results offer important insights into the role of SA-responsive genes in controlling fruit ripening in sand pears.

SlERF.G3-Like mediates a hierarchical transcriptional cascade to regulate ripening and metabolic changes in tomato fruit.

The tomato ripening process contains complex changes, including ethylene signalling, cell wall softening and numerous metabolic changes. So far, much is still unknown about how tomato plants precisely coordinate fruit maturation and metabolic regulation. In this paper, the ERF family transcription factor SlERF.G3-Like in tomato was found to be involved in the regulation of ethylene synthesis, cell wall degradation and the flavonoid pathway. We show that the master ripening regulator SlRIN was found to directly bind to the promoter region of SlERF.G3-Like to activate its expression. In addition, we managed to increase the production of resveratrol derivatives from ~1.44 mg/g DW in E8:VvStSy line to ~2.43 mg/g DW by crossing p35S: SlERF.G3-Like with the E8:VvStSy line. Our data provide direct evidence that SlERF.G3-Like, a hierarchical transcriptional factor, can directly manipulate pathways in which tomatoes can coordinate fruit maturation and metabolic changes. We also attest that SlERF.G3-Like can be used as an effective tool for phenylpropanoid metabolic engineering.

A metabolome and transcriptome survey to tap the dynamics of fruit prolonged shelf-life and improved quality within Greek tomato germplasm.

Tomato is a high economic value crop worldwide with recognized nutritional properties and diverse postharvest potential. Nowadays, there is an emerging awareness about the exploitation and utilization of underutilized traditional germplasm in modern breeding programs. In this context, the existing diversity among Greek accessions in terms of their postharvest life and nutritional value remains largely unexplored. Herein, a detailed evaluation of 130 tomato Greek accessions for postharvest and nutritional characteristics was performed, using metabolomics and transcriptomics, leading to the selection of accessions with these interesting traits. The results showed remarkable differences among tomato Greek accessions for overall ripening parameters (color, firmness) and weight loss. On the basis of their postharvest performance, a balance between short shelf life (SSL) and long shelf life (LSL) accessions was revealed. Metabolome analysis performed on 14 selected accessions with contrasting shelf-life potential identified a total of 206 phytonutrients and volatile compounds. In turn, transcriptome analysis in fruits from the best SSL and the best LSL accessions revealed remarkable differences in the expression profiles of transcripts involved in key metabolic pathways related to fruit quality and postharvest potential. The pathways towards cell wall synthesis, polyamine synthesis, ABA catabolism, and steroidal alkaloids synthesis were mostly induced in the LSL accession, whereas those related to ethylene biosynthesis, cell wall degradation, isoprenoids, phenylpropanoids, ascorbic acid and aroma (TomloxC) were stimulated in the SSL accession. Overall, these data would provide valuable insights into the molecular mechanism towards enhancing shelf-life and improving flavor and aroma of modern tomato cultivars.

Ultrasonic Pulse Velocity Testing for Monitoring the Degradation of Infill Masonry Walls and Access Their Impact on the Durability of the Envelope of Buildings with Reinforced Concrete Structure

Buildings with reinforced concrete structure (RCS buildings), including unreinforced masonry (URM) infill walls, can be negatively affected by anomalies in their envelope, such as cracking and water penetration, which worsen the aesthetic aspect and reduce the safety and level of comfort of those buildings. To access the relevance of these anomalies and their evolution along service life, a corresponding survey and monitoring during service life are essential. Non-destructive test methods (NDT), in particular ultrasonic pulse velocity (UPV) testing, are currently used in that survey and monitoring. In the context of monitoring the degradation of the URM infill walls and access their impact on the durability of the RCS building envelope, UPV testing can be a type of NDT method to be used, considering that it can contribute to the evaluation of the state of conservation of the construction elements, such as masonry and concrete. It is intended here to access the potential use of UPV testing in the monitoring of anomalies related to the degradation of building facades due, particularly, to cracking and to water penetration associated with WDR (wind driven-rain). The preliminary assessment of the use of UPV testing is made through the previous analysis of the results of the application of UPV testing for the detection of sub-surface and surface cracking in compression tests of masonry specimens. Following that analysis, an evaluation is made of the conditioning aspects of the use of UPV testing to access durability problems of the building envelope. Particularly, the main characteristics of cracking with interest for the assessment of the potential use of UPV testing are generally discussed. And, finally, an evaluation is made of the risk of water penetration through the cracks, for potential use of UPV testing in monitoring the presence of humidity in the cracks.