A Study on the Use of the Phyto-Courier Technology in Tobacco Leaves Infected by Agrobacterium tumefaciens.

Climate change results in exceptional environmental conditions and drives the migration of pathogens to which local plants are not adapted. Biotic stress disrupts plants' metabolism, fitness, and performance, ultimately impacting their productivity. It is therefore necessary to develop strategies for improving plant resistance by promoting stress responsiveness and resilience in an environmentally friendly and sustainable way. The aim of this study was to investigate whether priming tobacco plants with a formulation containing silicon-stabilised hybrid lipid nanoparticles functionalised with quercetin (referred to as GS3 phyto-courier) can protect against biotic stress triggered by Agrobacterium tumefaciens leaf infiltration. Tobacco leaves were primed via infiltration or spraying with the GS3 phyto-courier, as well as with a buffer (B) and free quercetin (Q) solution serving as controls prior to the biotic stress. Leaves were then sampled four days after bacterial infiltration for gene expression analysis and microscopy. The investigated genes increased in expression after stress, both in leaves treated with the phyto-courier and control solutions. A trend towards lower values was observed in the presence of the GS3 phyto-courier for genes encoding chitinases and pathogenesis-related proteins. Agroinfiltrated leaves sprayed with GS3 confirmed the significant lower expression of the pathogenesis-related gene PR-1a and showed higher expression of peroxidase and serine threonine kinase. Microscopy revealed swelling of the chloroplasts in the parenchyma of stressed leaves treated with B; however, GS3 preserved the chloroplasts' mean area under stress. Furthermore, the UV spectrum of free Q solution and of quercetin freshly extracted from GS3 revealed a different spectral signature with higher values of maximum absorbance (Amax) of the flavonoid in the latter, suggesting that the silicon-stabilised hybrid lipid nanoparticles protect quercetin against oxidative degradation.

Characterization of MdMYB68, a suberin master regulator in russeted apples.

Introduction: Apple russeting is mainly due to the accumulation of suberin in the cell wall in response to defects and damages in the cuticle layer. Over the last decades, massive efforts have been done to better understand the complex interplay between pathways involved in the suberization process in model plants. However, the regulation mechanisms which orchestrate this complex process are still under investigation. Our previous studies highlighted a number of transcription factor candidates from the Myeloblastosis (MYB) transcription factor family which might regulate suberization in russeted or suberized apple fruit skin. Among these, we identified MdMYB68, which was co-expressed with number of well-known key suberin biosynthesis genes. Method: To validate the MdMYB68 function, we conducted an heterologous transient expression in Nicotiana benthamiana combined with whole gene expression profiling analysis (RNA-Seq), quantification of lipids and cell wall monosaccharides, and microscopy. Results: MdMYB68 overexpression is able to trigger the expression of the whole suberin biosynthesis pathway. The lipid content analysis confirmed that MdMYB68 regulates the deposition of suberin in cell walls. Furthermore, we also investigated the alteration of the non-lipid cell wall components and showed that MdMYB68 triggers a massive modification of hemicelluloses and pectins. These results were finally supported by the microscopy. Discussion: Once again, we demonstrated that the heterologous transient expression in N. benthamiana coupled with RNA-seq is a powerful and efficient tool to investigate the function of suberin related transcription factors. Here, we suggest MdMYB68 as a new regulator of the aliphatic and aromatic suberin deposition in apple fruit, and further describe, for the first time, rearrangements occurring in the carbohydrate cell wall matrix, preparing this suberin deposition.

MdMYB52 regulates lignin biosynthesis upon the suberization process in apple.

Our previous studies, comparing russeted vs. waxy apple skin, highlighted a MYeloBlastosys (Myb) transcription factor (MdMYB52), which displayed a correlation with genes associated to the suberization process. The present article aims to assess its role and function in the suberization process. Phylogenetic analyses and research against Arabidopsis thaliana MYBs database were first performed and the tissue specific expression of MdMYB52 was investigated using RT-qPCR. The function of MdMYB52 was further investigated using Agrobacterium-mediated transient overexpression in Nicotiana benthamiana leaves. An RNA-Seq analysis was performed to highlight differentially regulated genes in response MdMYB52. Transcriptomic data were supported by analytical chemistry and microscopy. A massive decreased expression of photosynthetic and primary metabolism pathways was observed with a concomitant increased expression of genes associated with phenylpropanoid and lignin biosynthesis, cell wall modification and senescence. Interestingly key genes involved in the synthesis of suberin phenolic components were observed. The analytical chemistry displayed a strong increase in the lignin content in the cell walls during MdMYB52 expression. More specifically, an enrichment in G-Unit lignin residues was observed, supporting transcriptomic data as well as previous work describing the suberin phenolic domain as a G-unit enriched lignin-like polymer. The time-course qPCR analysis revealed that the observed stress response, might be explain by this lignin biosynthesis and by a possible programmed senescence triggered by MdMYB52. The present work supports a crucial regulatory role for MdMYB52 in the biosynthesis of the suberin phenolic domain and possibly in the fate of suberized cells in russeted apple skins.

Physico-chemical properties and toxicological effects on plant and algal models of carbon nanosheets from a nettle fibre clone.

Carbon nanosheets are two-dimensional nanostructured materials that have applications as energy storage devices, electrochemical sensors, sample supports, filtration membranes, thanks to their high porosity and surface area. Here, for the first time, carbon nanosheets have been prepared from the stems and leaves of a nettle fibre clone, by using a cheap and straight-forward procedure that can be easily scaled up. The nanomaterial shows interesting physical parameters, namely interconnectivity of pores, graphitization, surface area and pore width. These characteristics are similar to those described for the nanomaterials obtained from other fibre crops. However, the advantage of nettle over other plants is its fast growth and easy propagation of homogeneous material using stem cuttings. This last aspect guarantees homogeneity of the starting raw material, a feature that is sought-after to get a nanomaterial with homogeneous and reproducible properties. To evaluate the potential toxic effects if released in the environment, an assessment of the impact on plant reproduction performance and microalgal growth has been carried out by using tobacco pollen cells and the green microalga Pseudokirchneriella subcapitata. No inhibitory effects on pollen germination are recorded, while algal growth inhibition is observed at higher concentrations of leaf carbon nanosheets with lower graphitization degree.

A Review on the Beneficial Role of Silicon against Salinity in Non-Accumulator Crops: Tomato as a Model.

Salinity is an abiotic stress that affects agriculture by severely impacting crop growth and, consequently, final yield. Considering that sea levels rise at an alarming rate of >3 mm per year, it is clear that salt stress constitutes a top-ranking threat to agriculture. Among the economically important crops that are sensitive to high salinity is tomato (Solanum lycopersicum L.), a cultivar that is more affected by salt stress than its wild counterparts. A strong body of evidence in the literature has proven the beneficial role of the quasi-essential metalloid silicon (Si), which increases the vigor and protects plants against (a)biotic stresses. This protection is realized by precipitating in the cell walls as opaline silica that constitutes a mechanical barrier to the entry of phytopathogens. With respect to Si accumulation, tomato is classified as a non-accumulator (an excluder), similarly to other members of the nightshade family, such as tobacco. Despite the low capacity of accumulating Si, when supplied to tomato plants, the metalloid improves growth under (a)biotic stress conditions, e.g., by enhancing the yield of fruits or by improving vegetative growth through the modulation of physiological parameters. In light of the benefits of Si in crop protection, the available literature data on the effects of this metalloid in mitigating salt stress in tomato are reviewed with a perspective on its use as a biostimulant, boosting the production of fruits as well as their post-harvest stability.

Impact of Nitrogen Nutrition on Cannabis sativa: An Update on the Current Knowledge and Future Prospects.

Nitrogen (N) availability represents one of the most critical factors affecting cultivated crops. N is indeed a crucial macronutrient influencing major aspects, from plant development to productivity and final yield of lignocellulosic biomass, as well as content of bioactive molecules. N metabolism is fundamental as it is at the crossroad between primary and secondary metabolic pathways: Besides affecting the synthesis of fundamental macromolecules, such as nucleic acids and proteins, N is needed for other types of molecules intervening in the response to exogenous stresses, e.g. alkaloids and glucosinolates. By partaking in the synthesis of phenylalanine, N also directly impacts a central plant metabolic 'hub'-the phenylpropanoid pathway-from which important classes of molecules are formed, notably monolignols, flavonoids and other types of polyphenols. In this review, an updated analysis is provided on the impact that N has on the multipurpose crop hemp (Cannabis sativa L.) due to its renewed interest as a multipurpose crop able to satisfy the needs of a bioeconomy. The hemp stalk provides both woody and cellulosic fibers used in construction and for biocomposites; different organs (leaves/flowers/roots) are sources of added-value secondary metabolites, namely cannabinoids, terpenes, flavonoids, and lignanamides. We survey the available literature data on the impact of N in hemp and highlight the importance of studying those genes responding to both N nutrition and abiotic stresses. Available hemp transcriptomic datasets obtained on plants subjected to salt and drought are here analyzed using Gene Ontology (GO) categories related to N metabolism. The ultimate goal is to shed light on interesting candidate genes that can be further studied in hemp varieties growing under different N feeding conditions and showing high biomass yield and secondary metabolite production, even under salinity and drought.

Nutraceutical Characteristics of Ancient Malus x domestica Borkh. Fruits Recovered across Siena in Tuscany.

Background: A diet rich in fruits and vegetables contributes to lowering the risk of chronic diseases. The fruits of Malus x domestica are a rich dietary source of bioactive compounds, namely vitamins and antioxidants, with recognized action on human health protection. Tuscany is known for its rich plant biodiversity, especially represented by ancient varieties of fruit trees. Particularly noteworthy are the many ancient Tuscan varieties of apple trees. Methods: Sugar quantification via HPLC and spectrophotometric assays to quantify the antioxidant power and total polyphenol content revealed interesting differences in 17 old varieties of Malus x domestica Borkh. recovered in Siena (Tuscany). Results: The quantification of antioxidants, polyphenols, and the main free sugars revealed that their content in the old fruits was often superior to the widespread commercial counterparts ('Red Delicious' and 'Golden Delicious'). Such differences were, in certain cases, dramatic, with 8-fold higher values. Differences were also present for sugars and fibers (pectin). Most ancient fruits displayed low values of glucose and high contents of xylitol and pectin. Conclusions: The results reported here suggest the possible use of ancient apple varieties from Siena for nutraceutical purposes and draw attention to the valorization of local old varieties.

Epidemiological, demographic and clinical data on chronic viral hepatitis C in Tuscany.

BACKGROUND: Recent introduction of direct antiviral agents (DAAs) has completely changed the scenario regarding hepatitis C virus (HCV) treatment. Certain countries' economic health programs prioritize DAAs according to specific clinical features of HCV-infected patients. The aim of this study was to define epidemiological, demographic and clinical characteristics of HCV-infected patients in the Tuscany region of central Italy. METHODS: We enrolled HCV patients with chronic viral hepatitis who were referred to the outpatient services of 16 hospitals in Tuscany from 1 January 2015 to 31 December 2015. Case report forms contained patient information including main demographic data, blood chemistry data, viral hepatitis markers, instrumental evaluations (liver biopsy or transient elastometry, liver ultrasound), eligibility for DAAs, and liver transplantation or therapy already in progress. RESULTS: Of all patients considered, 2919 HCV patients were enrolled (mean age: 57.44 ± 15.15; 54% males, 46% females). All routes of transmission were well represented (intravenous drug use in 20.7%; nosocomial/dental care in 20.6%; and coagulation factors/blood transfusions in 13.3%). Diabetes was the highest represented comorbidity (20.8%), followed by metabolic syndrome (15.5%) and ischemic heart disease (6.2%). The most prevalent HCV genotypes were 1b (47.4%) and 2 (16.5%). In the whole cohort of patients, 32.8% were cirrhotic (40 patients were listed for liver transplantation). Signs of portal hypertension were present mostly in the group older than 45 years (92.3%). Extrahepatic HCV-related diseases were present in 13.3% of cases (cryoglobulinemic syndrome in 58.3% and B-cell non-Hodgkin's lymphoma in 10.5%). CONCLUSIONS: Our study provides evidence of a high prevalence of epidemiological changes in HCV infection with a major prevalence of advanced liver disease, such as portal hypertension, in this elderly cohort of patients.

Chitosan-Based Nanoparticles Containing Cherry Extract from Prunus avium L. to Improve the Resistance of Endothelial Cells to Oxidative Stress.

Cherries are known for their nutraceutical properties, in particular for their antioxidant ability due to their polyphenol content, which causes a reduction of cardiovascular disease (CVD) risk factors. However, once ingested these molecules are degraded in the Gastrointestinal (GI) tract before reaching the blood, which is the action site. The object of the present work is to evaluate the ability of cherry extract (CE), encapsulated in nanoparticles (NPs) based on different chitosan (Ch) derivatives, to promote a protective effect of human umbilical vein endothelial cells (HUVECs) involved in vascular dysfunction against oxidative stress. CE-loaded NPs based on quaternary ammonium chitosan (NP1) and an S-protected thiolated derivative thereof (NP2) were prepared. The mean particle size (NP1 344.9 ± 17.8, NP2 339.9 ± 68.2 nm), the polydispersity index, the encapsulation efficiency (NP1 78.4 ± 4.5, NP2 79.8 ± 0.6%), and the zeta potential (NP1 14.8 ± 0.3, NP2 15.8 ± 0.5 mV) did not appear to be significantly different. Both NP types improved the CE apparent permeation parameters with respect to the control. Conversely, CE-loaded NP2 protected HUVECs from oxidative stress and reduced reactive oxygen species (ROS) production more than CE-loaded NP1 and free CE. In addition to promoting HUVEC resistance, NP2 could be a useful tool to overcome the problem of cherry seasonality.

Functional Molecules in Locally-Adapted Crops: The Case Study of Tomatoes, Onions, and Sweet Cherry Fruits From Tuscany in Italy.

The human diet is characterized by highly energetic molecules, but it also requires non-energetic compounds that are equally useful for cell functioning and for preserving the organism's health status. These "functional" molecules are represented by a wide variety of plant secondary metabolites, such as terpenoids, vitamins and polyphenols with antioxidant power. Widespread commercial crop varieties often contain scarce levels of functional molecules, because they have been mostly selected for productivity, rather than for the content of secondary metabolites. Different scenarios (global economic situation, foreseeable environmental changes) are pushing farmers to review the use of high yield crops and to focus on the valorization of locally-adapted plants. This renewed interest is strengthened by the growing need of consumers for functional foods with beneficial effects on human health and by the willingness to promote sustainable low-input agricultural practices exploiting local climate, soil, water, and (micro)biota. Here, we want to discuss a specific case study concerning locally-adapted crops in Tuscany (Italy). Analyses of nutraceutical molecules in locally-grown crop varieties (namely tomatoes, sweet cherries and onions) have shown that they are characterized by substantially higher functional molecule contents than commercial varieties. Our goal is to promote the high-throughput study of locally-adapted varieties to understand, in a medium-term perspective, whether the cultivation of such plants is a valuable support for the diet and an adequate local economic resource. Such plants can provide a boost to the regional economy, by diversifying the local crop-market landscape. Moreover, the exploitation of locally-grown plants results in the manufacture of fully-traceable products (from the raw bioresource to the finished product) with a "0 km" concept that minimizes the C footprint.