Acclimation of plants to water deficit involves biochemical and physiological adjustments. Here, we studied how ultraviolet (UV)‐B exposure and exogenously applied hydrogen peroxide (H2O2) ...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 H2O2 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 + H2O2‐treated plants increased total antioxidant capacity and foliar epidermal flavonol index. H2O2‐ and UV‐B + H2O2‐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) H2O2 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 H2O2 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 H2O2 to improve drought tolerance which could become a useful tool to reduce water use.
•Beans germination percentage was maintained with low concentration of all elicitors.•All concentrations of salicylic acid and H2O2 increased radicle size.•High and medium concentrations of all ...elicitors reduced antinutrients in sprouts.•Salicylic acid and chitosan increased phenolic acids and flavonoids in sprouts.•2mM salicylic acid and 20mM H2O2 treatments exerted the greatest beneficial effect.
The aim of this study was to determine the effect of chitosan (CH), salicylic acid (SA) and hydrogen peroxide (H2O2) at different concentrations on the antinutritional and nutraceutical content, as well as the antioxidant capacity of bean sprouts (cv Dalia). All elicitors at medium and high concentrations reduced the antinutritional content of lectins (48%), trypsin inhibitor (57%), amylase inhibitor (49%) and phytic acid (56%). Sprouts treated with CH, SA and H2O2 (7μM; 1 and 2mM, and 30mM respectively) increased the content of phenolic compounds (1.8-fold), total flavonoids (3-fold), saponins (1.8-fold) and antioxidant capacity (37%). Furthermore, the UPLC-ESI-MS/MS analysis showed an increase of several nutraceutical compounds in bean sprouts treated with SA such as coumaric (8.5-fold), salicylic (115-fold), gallic (25-fold) and caffeic (1.7-fold) acids, as well as epigallocatechin (63-fold), rutin (41-fold) and quercetin (16.6-fold) flavonoids. The application of elicitors in bean seed during sprouting enhances their nutraceutical properties.
Hydrogen peroxide (H2O2) is an important ROS molecule (Reactive oxygen species) that serves as a signal of oxidative stress and activation of signaling cascades as a result of the early response of ...the plant to biotic stress. This response can also be generated with the application of elicitors, stable molecules that induce the activation of transduction cascades and hormonal pathways, which trigger induced resistance to environmental stress. In this work, we evaluated the endogenous H2O2 production caused by salicylic acid (SA), chitosan (QN), and H2O2 elicitors in Capsicum annuum L. Hydrogen peroxide production after elicitation, catalase (CAT) and phenylalanine ammonia lyase (PAL) activities, as well as gene expression analysis of cat1, pal, and pathogenesis-related protein 1 (pr1) were determined. Our results displayed that 6.7 and 10 mM SA concentrations, and, 14 and 18 mM H2O2 concentrations, induced an endogenous H2O2 and gene expression. QN treatments induced the same responses in lesser proportion than the other two elicitors. Endogenous H2O2 production monitored during several days, showed results that could be an indicator for determining application opportunity uses in agriculture for maintaining plant alert systems against a stress.
Low-temperature conditioning of garlic “seed” cloves accelerated the development of the crop cycle, decreased plant growth, and increased the synthesis of phenolic compounds and anthocyanins in the ...outer scale leaves of the bulbs at harvest time, leading to 3-fold content increase compared with those conditioned at room temperature. Cold conditioning of “seed” cloves also altered the anthocyanin profile during bulb development and at harvest. Two new anthocyanins are reported for the first time in garlic. The high phenolics and anthocyanin contents in bulbs of plants generated from “seed” cloves conditioned at 5 °C for 5 weeks were preceded by overexpression of some putative genes of the phenolic metabolism 6-fold for phenylalanine ammonia lyase (PAL) and anthocyanin synthesis 1-fold for UDP-sugar:flavonoid 3-O-glycosyltransferase (UFGT) compared with those conditioned at room temperature.
Plants are fundamental elements of the human diet, either as direct sources of nutrients or indirectly as feed for animals. During the past few years, the main goal of agriculture has been to ...increase yield in order to provide the food that is needed by a growing world population. As important as yield, but commonly forgotten in conventional agriculture, is to keep and, if it is possible, to increase the phytochemical content due to their health implications. Nowadays, it is necessary to go beyond this, reconciling yield and phytochemicals that, at first glance, might seem in conflict. This can be accomplished through reviewing food requirements, plant consumption with health implications, and farming methods. The aim of this work is to show how both yield and phytochemicals converge into a new vision of agricultural management in a framework of integrated agricultural practices.
Phytophthora capsici is a highly destructive pathogen of crops. Although chemical pesticides are the most widely used strategy to counter phytopathogens, they have been inefficient to combat P. ...capsici and have produced significant environmental and health problems. Therefore, sustainable alternatives to control soilborne pathogens, such as the inhibitory effect of self‐extracellular DNA (eDNA), have been proposed. This inhibition phenomenon has been attributed to the action of self‐eDNA as a damage‐associated molecular pattern (DAMP). Here, we describe the effect of self‐eDNA on P. capsici zoospore germination rate, antioxidant enzymes activity and MAPK gene expression. Also, the effect of P. capsici eDNA on the protection of chilli pepper (Capsicum annuum) plants against P. capsici was investigated. The results highlight that P. capsici can sense 2–500 µg/ml self‐eDNA and induce stress‐related responses like SAK1 gene expression, and superoxide dismutase and catalase activities. Moreover, in vitro zoospore germination rate was suppressed with self‐eDNA concentrations ranging from 50 to 500 µg/ml. Interestingly, drench applications of P. capsici eDNA at 60 and 100 µg/ml on chilli pepper plants did not show any protective effect against the phytopathogen, whereas 2 µg/ml of P. capsici eDNA drench application showed a lower percentage of plants with symptoms and lower disease severity. Moreover, phenols and total flavonoids were increased in chilli pepper plants, therefore inducing plant immunity. This study showed that self‐eDNA acts as a DAMP in P. capsici and provides insight into the use of eDNA for the protection of crops of agronomic interest.
This study showed that self‐eDNA acts as a DAMP in P. capsici inducing stress‐related responses, giving an insight into the use of self‐eDNA in field‐like conditions against the phytopathogen.
In Mexico one in 14 deaths are caused by diabetes mellitus (DM) or by the macro and microvascular disorders derived from it. A continuous hyperglycemic state is characteristic of DM, resulting from a ...sustained state of insulin resistance and/or a dysfunction of β-pancreatic cells.
is a little studied species showing a significant antioxidant activity that can be used as treatment of this disease or preventive against the complications. The objective of this study was to explore the effect of oral administration of
methanol extract on physiological parameters of streptozotocin-induced diabetic rats. The results indicated a significant reduction in blood glucose levels, an increase in serum insulin concentration, a decrease in lipid levels and an improvement in the parameters of kidney damage by applying a concentration of 100 mg/Kg B.W. However, glucose uptake activity was not observed in the adipocyte assay. Moreover, the extract of
displayed potential for the complementary treatment of diabetes and its complications likely due to the presence of bioactive compounds such as protocatechuic acid. This study demonstrated that methanol extract of
has an antidiabetic effect by reducing the levels of glucose, insulin and improved physiological parameters, hypolipidemic effect, oxidative stress and renal damage in diabetic rats.
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.
The immune response against pathogens, both in plants and animals, relies on a complex recognition system of danger signs. This system is based on the recognition of exogenous molecules termed ...Microbe- or Pathogen-Associated Molecular Patterns (MAMPs/PAMPs), and endogenous signals called “Damage-Associated Molecular Patterns” (DAMPs). This review will focus on DAMPs, which are molecules with a normal physiological state inside the cell, but at the time of damage or infection are usually released to the extracellular media, indicating cell damage. DAMPS are represented by a wide range of molecules consisting in small peptides, proteins, carbohydrates, cell wall fragments, extracellular ATP (eATP), extracellular DNA (eDNA) and volatile organic compounds (VOCs). Here we review plant DAMPs types and a new approach in eDNA use as biotechnological molecules for plant disease prevention. In particular, self-eDNA has gained importance due to its function of growth inhibition observed over a wide variety of organisms, this function is being studied as a new strategy for biological control to obtain highly pathogen-specific products, without wasting time and research resources. On the other hand, eDNA, as other DAMPs, could act as an immune response elicitor, which could conduce to a new approach for the protection of crops against pests.
Hydrogen peroxide (H
O
) 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 H
O
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 H
O
and a 14-day UV-B treatment (1.75 kJ m
d
biologically effective UV-B). Subsequently, these plants were subjected to a 7-day moderate drought treatment to evaluate the impact on drought resistance of H
O
- and UV-dependent stimulation of the plants' antioxidant system. The UV-B treatment enhanced H
O
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 H
O
-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 H
O
content in N. tabacum cv Xanthi.
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