Inhibition of pepper huasteco yellow veins virus by foliar application of ZnO nanoparticles in Capsicum annuum L.

The Pepper huasteco yellow vein virus (PHYVV) is an endemic geminivirus in Mexico causing partial or total losses in the pepper crop since the damage caused by the virus has not been fully controlled. In this work, we evaluated the effect of ZnO NPs (0, 50, 100, 150, and 200 mM) as a preventive (72 h before) and curative (72 h after) treatment of PHYVV infection in two jalapeño pepper varieties. In this study, we observed a decrease in symptoms, and it could be caused by an induction of the defense system in pepper plants and a direct action on PHYVV by foliar application of ZnO NPs. Our findings suggest that ZnO NP application significantly decreased the viral titer for both varieties at 200 mM by 15.11-fold. However, this effect was different depending on the timing of application and the variety of pepper. The greatest decrease in the viral titer in the preventive treatment in both varieties was at the concentration of 200 mM (1781.17 and 274.5 times, respectively). For curative treatment in cv. Don Pancho at the concentration of 200 mM (333.33 times) and cv. Don Benito at 100 mM (43.10 folds). compared to control. Furthermore, virus mobility was generally restricted for both varieties at 100 mM (15.13-fold) compared to the control. The results possibly delineated that ZnO NPs increased plant resistance possibly by increasing POD (2.08 and 0.25 times) and SOD (0.998 and 1.38) in cv. Don Pancho and cv. Don Benito, respectively. On the other hand, in cv. Don Pancho and cv. Don Benito presented a decrease in CAT (0.61 and 0.058) and PAL (0.78 and 0.77), respectively. Taken together, we provide the first evidence to demonstrate the effect of ZnO NPs on viral symptoms depending on the plan-virus-ZnO NP interaction.

Antioxidant and drought-acclimation responses in UV-B-exposed transgenic Nicotiana tabacum displaying constitutive overproduction of H2O2.

Hydrogen peroxide (H2O2) is an important molecule that regulates antioxidant responses that are crucial for plant stress resistance. Exposure to low levels of ultraviolet-B radiation (UV-B, 280-315 nm) can also activate antioxidant defenses and acclimation responses. However, how H2O2 and UV-B interact to promote stress acclimation remains poorly understood. In this work, a transgenic model of Nicotiana tabacum cv Xanthi nc, with elevated Mn-superoxide dismutase (Mn-SOD) activity, was used to study the interaction between the constitutive overproduction of H2O2 and a 14-day UV-B treatment (1.75 kJ m-2 d-1 biologically effective UV-B). Subsequently, these plants were subjected to a 7-day moderate drought treatment to evaluate the impact on drought resistance of H2O2- and UV-dependent stimulation of the plants' antioxidant system. The UV-B treatment enhanced H2O2 levels and altered the antioxidant status by increasing the epidermal flavonol index, Trolox Equivalent Antioxidant Capacity, and catalase, peroxidase and phenylalanine ammonia lyase activities in the leaves. UV-B also retarded growth and suppressed acclimation responses in highly H2O2-overproducing transgenic plants. Plants not exposed to UV-B had a higher drought resistance in the form of higher relative water content of leaves. Our data associate the interaction between Mn-SOD transgene overexpression and the UV-B treatment with a stress response. Finally, we propose a hormetic biphasic drought resistance response curve as a function of leaf H2O2 content in N. tabacum cv Xanthi.

Management of Antracnosis with Electrochemically Activated Salt Solutions (EASSs) on Bean Culture.

Common bean (Phaseolus vulgaris L.) is an important crop for food security and for national economics for several countries worldwide. One of the most important factors of risk in common bean production is the fungal disease anthracnose caused by Colletotrichum lindemuthianum, which, in some cases, causes complete yield losses; this kind of plant disease is usually managed through the application of chemical products such as fungicides that are commonly not accepted by society. This rejection is based on the relationship of pesticides with health damage and environmental contamination. In order to help in solving these drawbacks, the present work proposes the use of electrochemically activated salt solutions (EASSs) as a safer pathogen control agent in crops, due to it having shown an elicitor and biostimulant effect on plants. With this background, this manuscript presents in vitro results of the evaluation of the inhibitory effect for multiple bean pathogens and in vivo results of EASS in the common bean-Colletotrichum pathosystem by evaluation of the infection severity and defense activation, such as secondary metabolite production and antioxidant activity. EASS presence in growth media had a strong inhibitory effect at the beginning of experiments for some of the evaluated fungi. EASSs showed an effect against the development of the disease when applied in specific doses to prevent distress in plants.

Plant hormesis: Revising of the concepts of biostimulation, elicitation and their application in a sustainable agricultural production.

Current research in basic and applied knowledge of plant science has aimed to unravel the role of the interaction between environmental factors and the genome in the physiology of plants to confer the ability to overcome challenges in a climate change scenario. Evidence shows that factors causing environmental stress (stressors), whether of biological, chemical, or physical origin, induce eustressing or distressing effects in plants depending on the dose. The latter suggests the induction of the "hormesis" phenomenon. Sustainable crop production requires a better understanding of hormesis, its basic concepts, and the input variables to make its management feasible. This implies that acknowledging hormesis in plant research could allow specifying beneficial effects to effectively manage environmental stressors according to cultivation goals. Several factors have been useful in this regard, which at low doses show beneficial eustressing effects (biostimulant/elicitor), while at higher doses, they show distressing toxic effects. These insights highlight biostimulants/elicitors as tools to be included in integrated crop management strategies for reaching sustainability in plant science and agricultural studies. In addition, compelling evidence on the inheritance of elicited traits in plants unfolds the possibility of implementing stressors as a tool in plant breeding.

Characterization of the Key Compounds of Bell Pepper by Spectrophotometry and Gas Chromatography on the Effects of Induced Stress on the Concentration of Secondary Metabolite.

Sweet peppers are consumed worldwide, and traditional uses have sparked interest in their applications as dietary antioxidants, which can be enhanced in plants using elicitors. These are endowed with phytochemicals with potential health benefits such as antioxidants, bioavailability, and bioaccessibility. The trend in metabolomics shows us chemical fingerprints linking metabolomics, innovative analytical form, and bioinformatics tools. The objective was to evaluate the impact of multiple stress interactions, elicitor concentrations, and electrical conductivity on the concentration of secondary metabolites to relate their response to metabolic pathways through the foliar application of a cocktail of said elicitors in pepper crops under greenhouse conditions. The extracts were analyzed by spectrophotometry and gas chromatography, and it was shown that the PCA analysis identified phenolic compounds and low molecular weight metabolites, confirming this as a metabolomic fingerprint in the hierarchical analysis. These compounds were also integrated by simultaneous gene and metabolite simulants to obtain effect information on different metabolic pathways. Showing changes in metabolite levels at T6 (36 mM H2O2 and 3.6 dS/m) and T7 (0.1 mM SA and 3.6 dS/m) but showing statistically significant changes at T5 (3.6 dS/m) and T8 (0.1 mM SA, 36 mM H2O2, and 3.6 dS/m) compared to T1 (32 dS/m) or control. Six pathways changed significantly (p < 0.05) in stress-induced treatments: aminoacyl t-RNA and valine-leucine-isoleucine biosynthesis, and alanine-aspartate-glutamate metabolism, glycoxylate-dicarboxylate cycle, arginine-proline, and citrate. This research provided a complete profile for the characterization of metabolomic fingerprint of bell pepper under multiple stress conditions.

Biostimulant and Elicitor Responses to Cricket Frass (Acheta domesticus) in Tomato (Solanum lycopersicum L.) under Protected Conditions.

Agriculture in the current century is seeking sustainable tools in order to generate plant production systems with minimal negative environmental impact. In recent years it has been shown that the use of insect frass is an option to be used for this purpose. The present work studied the effect of low doses (0.1, 0.5, and 1.0% w/w) of cricket frass (Acheta domesticus) in the substrate during the cultivation of tomatos under greenhouse conditions. Plant performance and antioxidant enzymatic activities were measured in the study as explicative variables related to plant stress responses in order to determine possible biostimulant or elicitor effects of cricket frass treatments during tomato cultivation under greenhouse conditions. The main findings of this study indicated that tomato plants responded in a dose dependent manner to cricket frass treatments, recalling the hormesis phenomenon. On the one hand, a 0.1% (w/w) cricket frass treatment showed typical biostimulant features, while on the other hand, 0.5 and 1.0% treatments displayed elicitor effects in tomato plants under evaluated conditions in the present study. These results support the possibility that low doses of cricket frass might be used in tomato cultivation (and perhaps in other crops) for biostimulant/elicitor input into sustainable production systems.

Elicitation of Bacillus cereus-Amazcala (B.c-A) with SiO2 Nanoparticles Improves Its Role as a Plant Growth-Promoting Bacteria (PGPB) in Chili Pepper Plants.

Agriculture needs to decrease the use of agrochemicals due to their high toxicity and adopt new strategies to achieve sustainable food production. Therefore, nanoparticles (NPs) and plant growth-promoting bacteria (PGPB) have been proposed as viable strategies to obtain better crop yields with less environmental impact. Here, we describe the effect of silica nanoparticles (SiO2-NPs) on survival, antioxidant enzymatic activity, phosphate solubilization capacity, and gibberellin production of Bacillus cereus-Amazcala (B.c-A). Moreover, the effect of the co-application of SiO2-NPs and B.c-A on seed germination, physiological characteristics, and antioxidant enzymatic activity of chili pepper plants was investigated under greenhouse conditions. The results indicated that SiO2-NPs at 100 ppm enhanced the role of B.c-A as PGPB by increasing its phosphate solubilization capacity and the production of GA7. Moreover, B.c-A catalase (CAT) and superoxide dismutase (SOD) activities were increased with SiO2-NPs 100 ppm treatment, indicating that SiO2-NPs act as a eustressor, inducing defense-related responses. The co-application of SiO2-NPs 100 ppm and B.c-A improved chili pepper growth. There was an increase in seed germination percentage, plant height, number of leaves, and number and yield of fruits. There was also an increase in CAT and PAL activities in chili pepper plants, indicating that bacteria-NP treatment induces plant immunity.

Fermentation Extract of Naringenin Increases the Expression of Estrogenic Receptor ß and Modulates Genes Related to the p53 Signalling Pathway, miR-200c and miR-141 in Human Colon Cancer Cells Exposed to BPA.

The estrogenic receptor beta (ERß) protects against carcinogenesis by stimulating apoptosis. Bisphenol A (BPA) is related to promoting cancer, and naringenin has chemoprotective activities both can bind to ERß. Naringenin in the colon is metabolized by the microbiota. Cancer involves genetic and epigenetic mechanisms, including miRNAs. The objective of the present study was to evaluate the co-exposure effect of colonic in vitro fermented extract of naringenin (FEN) and BPA, to elucidate molecular effects in HT-29 colon cancer cell line. For this, we quantified genes related to the p53 signaling pathway as well as ERß, miR-200c, and miR-141. As an important result, naringenin (IC50 250 µM) and FEN (IC50 37%) promoted intrinsic pathways of apoptosis through phosphatase and tensin homolog (PTEN) (+2.70, +1.72-fold, respectively) and CASP9 (+3.99, +2.03-fold, respectively) expression. BPA decreased the expression of PTEN (-3.46-fold) gene regulated by miR-200. We suggest that once co-exposed, cells undergo a greater stress forcing them to mediate other extrinsic apoptosis mechanisms associated with death domain FASL. In turn, these findings are related to the increase of ERß (5.3-fold with naringenin and 13.67-fold with FEN) gene expression, important in the inhibition of carcinogenic development.

Black-Box Mathematical Model for Net Photosynthesis Estimation and Its Digital IoT Implementation Based on Non-Invasive Techniques: Capsicum annuum L. Study Case.

Photosynthesis is a vital process for the planet. Its estimation involves the measurement of different variables and its processing through a mathematical model. This article presents a black-box mathematical model to estimate the net photosynthesis and its digital implementation. The model uses variables such as: leaf temperature, relative leaf humidity, and incident radiation. The model was elaborated with obtained data from Capsicum annuum L. plants and calibrated using genetic algorithms. The model was validated with Capsicum annuum L. and Capsicum chinense Jacq. plants, achieving average errors of 3% in Capsicum annuum L. and 18.4% in Capsicum chinense Jacq. The error in Capsicum chinense Jacq. was due to the different experimental conditions. According to evaluation, all correlation coefficients (Rho) are greater than 0.98, resulting from the comparison with the LI-COR Li-6800 equipment. The digital implementation consists of an FPGA for data acquisition and processing, as well as a Raspberry Pi for IoT and in situ interfaces; thus, generating a useful net photosynthesis device with non-invasive sensors. This proposal presents an innovative, portable, and low-scale way to estimate the photosynthetic process in vivo, in situ, and in vitro, using non-invasive techniques.

Comparative Analysis of the NDVI and NGBVI as Indicators of the Protective Effect of Beneficial Bacteria in Conditions of Biotic Stress.

Precision agriculture has the objective of improving agricultural yields and minimizing costs by assisting management with the use of sensors, remote sensing, and information technologies. There are several approaches to improving crop yields where remote sensing has proven to be an important methodology to determine agricultural maps to show surface differences which may be associated with many phenomena. Remote sensing utilizes a wide variety of image sensors that range from common RGB cameras to sophisticated, hyper-spectral image cameras which acquire images from outside the visible electromagnetic spectrum. The NDVI and NGBVI are computer vision vegetation index algorithms that perform operations from color masks such as red, green, and blue from RGB cameras and hyper-spectral masks such as near-infrared (NIR) to highlight surface differences in the image to detect crop anomalies. The aim of the present study was to determine the relationship of NDVI and NGBVI as plant health indicators in tomato plants (Solanum lycopersicum) treated with the beneficial bacteria Bacillus cereus-Amazcala (B. c-A) as a protective agent to cope with Clavibacter michiganensis subsp. michiganensis (Cmm) infections. The results showed that in the presence of B. c-A after infection with Cmm, NDVI and NGBVI can be used as markers of plant weight and the activation of the enzymatic activities related to plant defense induction.

Machine Learning for Plant Stress Modeling: A Perspective towards Hormesis Management.

Plant stress is one of the most significant factors affecting plant fitness and, consequently, food production. However, plant stress may also be profitable since it behaves hormetically; at low doses, it stimulates positive traits in crops, such as the synthesis of specialized metabolites and additional stress tolerance. The controlled exposure of crops to low doses of stressors is therefore called hormesis management, and it is a promising method to increase crop productivity and quality. Nevertheless, hormesis management has severe limitations derived from the complexity of plant physiological responses to stress. Many technological advances assist plant stress science in overcoming such limitations, which results in extensive datasets originating from the multiple layers of the plant defensive response. For that reason, artificial intelligence tools, particularly Machine Learning (ML) and Deep Learning (DL), have become crucial for processing and interpreting data to accurately model plant stress responses such as genomic variation, gene and protein expression, and metabolite biosynthesis. In this review, we discuss the most recent ML and DL applications in plant stress science, focusing on their potential for improving the development of hormesis management protocols.

Nanostructured mesoporous silica materials induce hormesis on chili pepper (Capsicum annuum L.) under greenhouse conditions.

Current agricultural practices for vegetable production are unsustainable, and the use of certain nanomaterials has shown significant potential for either plant growth promotion or defense induction in crop species. The aim of the present work was to evaluate the possible effects of two SBA nano-structured silica materials differing in morphology; SBA-15, with porous structure in parallel and with a highly ordered hexagonal array and SBA-16, with spheric nano-cages located in cubic arrays, as plant growth promoters/eustressors on chili pepper (Capsicum annuum L.) during cultivation under greenhouse conditions. The study was carried out at three foliarly applied concentrations (20, 50 and 100 ppm) of either SBA materials to determine effects on seed germination, seedling growth, plant performance and cold tolerance under greenhouse. Phytotoxicity tests were carried out using higher concentrations (100, 1000 and 200 ppm) applied by dipping or spraying onto chili pepper plants. Deionized water controls were included. The results showed that the SBA materials did not affect seed germination; however, SBA-15 at 50 ppm and 100 ppm applied by imbibition significantly increased seedling height (up to 8-fold) and provided enhanced growth performance in comparison with controls under select treatment regimes. Weekly application of SBA-15 at 20 ppm significantly increased stem diameter and cold tolerance; however, SBA-16 showed significant decreases in plant height (20 ppm biweekly applied) and stem diameter (20, 50 and 100 ppm biweekly applied). The results demonstrate that both SBA materials provided hormetic effects in a dose dependent manner on chili pepper production and protection to cold stress. No phytotoxic response was evident. These findings suggested the nanostructured mesoporous silica have potential as a sustainable amendment strategy to increase crop production under stress-inducing cultivation conditions.

Delayed Senescence and Marketability Index Preservation of Blackberry Fruit by Preharvest Application of Chitosan and Salicylic Acid.

Blackberry fruits are appreciated as a source of nutrients and compounds related to benefit human health. However, they are highly perishable and very susceptible to decay factors. Current methods to improve and maintain blackberry quality are limited in use because of the fruit's fragile physical properties. Regarding these properties, it has been reported that the activities of certain enzymes are linked to senescence and fruit softening processes. This study was aimed to assess the effect of salicylic acid (SA) and chitosan (COS) as preharvest treatments on the physiology related to improving fruit conservation and preserving the marketability index of blackberry fruit. The preharvest treatments were foliar sprayed on blackberry plants at different concentrations. The activities of enzymes superoxide dismutase (SOD), catalase (CAT), phenylalanine ammonia-lyase (PAL), and polygalacturonase (PG) were measured. Total soluble solids (TSS), titratable acidity (TA), TSS/TA ratio, and marketability index (MI) were analyzed after 144 h of storage. The application of 3 mM of SA and 0.25% of COS treatments preserved the MI of blackberries by reducing leakage, red drupelet reversion (RDR), and mycelium presence in the fruit. SA application increased SOD, CAT, and PAL activities. Our results also showed that SA and COS preharvest treatments modified the activity of the cell wall degrading enzyme PG, which might play a role in improving the shelf life and resistance to decay factors of blackberry fruit without any significant effects on physicochemical properties like TSS, TA, and the TSS/TA ratio.

Extracellular DNA: Insight of a Signal Molecule in Crop Protection.

Agricultural systems face several challenges in terms of meeting everyday-growing quantities and qualities of food requirements. However, the ecological and social trade-offs for increasing agricultural production are high, therefore, more sustainable agricultural practices are desired. Researchers are currently working on diverse sustainable techniques based mostly on natural mechanisms that plants have developed along with their evolution. Here, we discuss the potential agricultural application of extracellular DNA (eDNA), its multiple functioning mechanisms in plant metabolism, the importance of hormetic curves establishment, and as a challenge: the technical limitations of the industrial scale for this technology. We highlight the more viable natural mechanisms in which eDNA affects plant metabolism, acting as a damage/microbe-associated molecular pattern (DAMP, MAMP) or as a general plant biostimulant. Finally, we suggest a whole sustainable system, where DNA is extracted from organic sources by a simple methodology to fulfill the molecular characteristics needed to be applied in crop production systems, allowing the reduction in, or perhaps the total removal of, chemical pesticides, fertilizers, and insecticides application.

Effect of hydric stress-related acoustic emission on transcriptional and biochemical changes associated with a water deficit in Capsicum annuum L.

At specific vibration frequencies like ones generated by insects such as caterpillar chewing and bee's buzz-pollination turn on the plants secondary metabolism and their respective pathways gets activated. Thus, studies report that vibrations and sound waves applied to plants improves their fitness performance. Commonly, acoustic treatments for plants have used arbitrarily random frequencies. In this work, a group of signals obtained from hydric-stressed plants was recorded as vibrational patterns using a laser vibrometer. These vibration-signals were classified as representative of each condition and then externally applied as Acoustic Emission Patterns (AEP). The present research hypothesized that specific vibration frequencies could "emulate" a plant signal through mechanical energy based on tplant's ability to recognize vibration pattern similarity to a hydric status. This investigation aimed to apply the AEP's as characteristic vibrations classified as Low hydric stress (LHS), medium hydric stress (MHS), and high hydric stress (HHS) to evaluate their effect on healthy-well watered plants at two developmental stages. In the vegetative stage, the gene expression related to antioxidant and hydric stress responses was assessed. The LHS, MHS, and HHS acoustic treatments up-regulated the peroxidase (Pod) (~2.8, 1.9, and 3.6-fold change, respectively). The superoxide dismutase (Mn-sod) and phenylalanine ammonia-lyase (Pal) genes were up-regulated by HHS (~0.23 and ~0.55-fold change, respectively) and, the chalcone synthase (Chs) gene was induced by MHS (~0.63-fold-change). At the fructification stage, the MHS treatment induced a significant increase in Capsaicin content (5.88-fold change), probably through the at3and kas gene activation. Findings are correlated for a better understanding of plant responses to different multi frequency-signals tones from vibrations with potential for agricultural applications.

Ultraviolet-B exposure and exogenous hydrogen peroxide application lead to cross-tolerance toward drought in Nicotiana tabacum L.

Acclimation of plants to water deficit involves biochemical and physiological adjustments. Here, we studied how ultraviolet (UV)-B exposure and exogenously applied hydrogen peroxide (H2 O2 ) potentiates drought tolerance in tobacco (Nicotiana tabacum L. cv. xanthi nc). Separate and combined applications for 14 days of 1.75 kJ m-2  day-1 UV-B radiation and 0.2 mM H2 O2 were assessed. Both factors, individually and combined, resulted in inhibition of growth. Furthermore, the combined treatment led to the most compacted plants. UV-B- and UV-B + H2 O2 -treated plants increased total antioxidant capacity and foliar epidermal flavonol index. H2 O2 - and UV-B + H2 O2 -pre-treated plants showed cross-tolerance to a subsequent 7-day moderate drought treatment, which was assessed as the absence of negative impact on growth, leaf wilting, and leaf relative water content. Plant responses to the pre-treatment were notably different: (1) H2 O2 increased the activity of catalase (EC 1.11.1.6), phenylalanine ammonia lyase (EC 4.3.1.5), and peroxidase activities (EC 1.11.1.7), and (2) the combined treatment induced epidermal flavonols which were key to drought tolerance. We report synergistic effects of UV-B and H2 O2 on transcription accumulation of UV RESISTANCE LOCUS 8, NAC DOMAIN PROTEIN 13 (NAC13), and BRI1-EMS-SUPPRESSOR 1 (BES1). Our data demonstrate a pre-treatment-dependent response to drought for NAC13, BES1, and CHALCONE SYNTHASE transcript accumulation. This study highlights the potential of combining UV-B and H2 O2 to improve drought tolerance which could become a useful tool to reduce water use.

A Novel Isolate of Bacillus cereus Promotes Growth in Tomato and Inhibits Clavibacter michiganensis Infection under Greenhouse Conditions.

The need to produce food in a sustainable way to counteract the effects of excessive use of agrochemicals opens the door to the generation of new technologies that are not based on fossil fuels and are less toxic to ecosystems. Plant growth-promoting bacteria (PGPB) could represent an alternative to chemical biofertilizers and pesticides offering protection for biotic and abiotic stresses. In this work, a bacterial isolate from roots of castor bean (Ricinus communis) was identified and named as Bacillus cereus strain "Amazcala" (B.c-A). This isolate displayed the ability to solubilize inorganic phosphate and produce gibberellic acid (GA3). Moreover, this bacterium provided significant increases in height, stem width, dry weight, and total chlorophyll content in tomato plants. Interestingly, B.c-A also significantly decreased the severity of bacterial canker disease on tomato caused by Clavibacter michiganensis (Cmm) in preventive disease assays under greenhouse conditions. Based on our results, B.c-A can be considered as PGPB and a useful tool in Cmm disease control on tomato plant under greenhouse conditions.

Effect on plant growth parameters and secondary metabolite content of lettuce (Lactuca sativa L.), coriander (Coriandrum sativum), and chili pepper (Capsicum annuum L.) watered with disinfected water by Ag-TiO2 nanoparticles.

Nowadays, the use of different nanoscale structures has been introduced to a large number of research areas. One of these is the treatment and remediation of water through photocatalytic processes, seeking to reuse wastewater for agriculture. In this paper, Lactuca sativa, Coriandrum sativum, and Capsicum annuum were used as crop models to observe the effects in plant growth and the secondary metabolism of different water qualities and types used in the watering process. Initial results show that the photocatalytic process's water maintains a pH and ion concentration within the allowed limits, significantly reducing the number of bacteria. Along the growth process, an influence on germination times, appearance of true leaves, maturation, and fruit production depending on the type of water used is observed, obtaining the best results in both growth times and quantity of fruits, for the 50% and 70% disinfected water/tap water (DW/TAW) study groups. Secondary metabolites, such as phenols, flavonoids, and antioxidant activity, were studied to evaluate changes in the vegetables' composition, showing increased concentration for the disinfected water groups in most specimens. Additionally, no traces of metals and microorganisms were detected, concluding that the crops are viable to be consumed by human beings.

Whole-Genome DNA Methylation Analysis in Hydrogen Peroxide Overproducing Transgenic Tobacco Resistant to Biotic and Abiotic Stresses.

Epigenetic regulation is a key component of stress responses, acclimatization and adaptation processes in plants. DNA methylation is a stable mark plausible for the inheritance of epigenetic traits, such that it is a potential scheme for plant breeding. However, the effect of modulators of stress responses, as hydrogen peroxide (H2O2), in the methylome status has not been elucidated. A transgenic tobacco model to the CchGLP gene displayed high H2O2 endogen levels correlated with biotic and abiotic stresses resistance. The present study aimed to determine the DNA methylation status changes in the transgenic model to obtain more information about the molecular mechanism involved in resistance phenotypes. The Whole-genome bisulfite sequencing analysis revealed a minimal impact of overall levels and distribution of methylation. A total of 9432 differential methylated sites were identified in distinct genome regions, most of them in CHG context, with a trend to hypomethylation. Of these, 1117 sites corresponded to genes, from which 83 were also differentially expressed in the plants. Several genes were associated with respiration, energy, and calcium signaling. The data obtained highlighted the relevance of the H2O2 in the homeostasis of the system in stress conditions, affecting at methylation level and suggesting an association of the H2O2 in the physiological adaptation to stress functional linkages may be regulated in part by DNA methylation.