Search

This study investigates the effects of environmental-related message on consumers' acceptance of artificial meat products in China. By focusing on the introduction of plant-based and cultured meat, a novel dataset involving 3441 research participants was collected in China through the online platform with randomized controlled experiments. The results show that for promotion-focused participants, gain-oriented message is effective while avoidance-oriented message is not in improving their acceptance of artificial meat. For prevention-focused participants, both gain- and avoidance-oriented messages are found to increase their acceptance of artificial meat effectively. To quantify the average impacts of environmental-related message and consumers' regulatory focus fit on the acceptance of plant-based meat and cultured meat, a seemingly unrelated regression model is applied. The results reveal that for a randomly selected individual, exposing with both gain- and avoidance-oriented messages would increase his or her acceptance of artificial meat comparing to exposing with neutral message. In addition, we find participants who use promotion focus more tend to have higher acceptance scores for both kinds of artificial meat on average.

WRKY, as one of the largest families of transcription factors (TFs), binds to cis-acting elements of downstream genes to regulate biotic and abiotic stress. However, the role of SlWRKY46 in fungal disease response induced by Botrytis cinerea (B.cinerea) and potential mechanism remains obscure. To ascertain the role of SlWRKY46 in response to B.cinerea, we constructed SlWRKY46-overexpression plants, which were then inoculated with B.cinerea. SlWRKY46-overexpression plants were more susceptible to B.cinerea and accompanied by the inhibited activities of phenylalanine ammonialyase (PAL), polyphenol oxidase (PPO), chitinase (CHI), and β-1,3-glucanase (GLU). Additionally, SlWRKY46-overexpression plants showed the decreased activities of ascorbate peroxidase (APX), superoxide dismutase (SOD) and the content of H2O2, and the increased content of O2•-. Moreover, over-expression of SlWRKY46 suppressed the salicylic acid (SA) and jasmonic acid (JA) marker genes, pathogenesis related protein (PR1), and proteinase inhibitors (PI Ⅰ and PI Ⅱ) and consequently aggravated the disease symptoms. Therefore, we speculated that SlWRKY46 played negative regulatory roles in B. cinerea infection probably by inhibiting the activities of antioxidants and disease resistance enzymes, regulating SA and JA signaling pathways and modulating reactive oxygen (ROS) homeostasis.

Basic helix-loop-helix (bHLH) transcription factors (TFs) are widely distributed in eukaryotes and play an important role in biological growth and development. The identification and functional analyses of bHLH genes/proteins in edible mushrooms (Agaricus bisporus) have yet to be reported. In the present study, we identified 10 putative bHLH members carrying the conserved bHLH domains. Phylogenetic analyses revealed that the 10 AbbHLHs were the closest to sequences of species belonging to 7 different fungal subgroups, which was supported by loop length, intron patterns, and key amino acid residues. The substantial increase after harvest and continuously elevated expression of AbbHLH1 during the development until the disruption of mushroom velum, and the preferential expression in cap and gill tissues suggest the important function of AbbHLH1 in postharvest development of A. bisporus. The relationship of arginine catabolism-related genes with the early stage of postharvest continuing development also was revealed by expression determination. Subcellular localization showed that AbbHLH1 could be localized in nucleus. Importantly, the electrophoretic mobility shift and dual-luciferase reporter assays showed that AbbHLH1 activated the promoters of AbOAT, AbSPDS, and AbSAMDC and suppressed the expression of AbARG, AbUREA, and AbODC, probably for the modulation of arginine catabolism and thus control of postharvest mushroom development. Taken together, the available data provide valuable functional insight into the role of AbbHLH proteins in postharvest mushrooms.

The development of the Internet has provided many opportunities for electronic commerce, and many e-commerce companies like Alibaba have achieved great success. Fresh produce industry has also atte...

Determining attributes such as classification, creating taxonomies and nutrients for foods can be a challenging and resource-intensive task, albeit important for a better understanding of foods. In this study, a novel dataset, 134 k BFPD, was collected from USDA Branded Food Products Database with modification and labeled with three food taxonomy and nutrient values and became an artificial intelligence (AI) dataset that covered the largest food types to date. Overall, the Multi-Layer Perceptron (MLP)-TF-SE method obtained the highest learning efficiency for food natural language processing tasks using AI, which achieved up to 99% accuracy for food classification and 0.98 R

Tomato is one of the most popular horticultural crops, and many commercial tomato cultivars are particularly susceptible to Botrytis cinerea. Non-expressor of pathogenesis-related gene 1 (NPR1) is a critical component of the plant defense mechanisms. However, our understanding of how SlNPR1 influences disease resistance in tomato is still limited. In this study, two independent slnpr1 mutants were used to study the role of SlNPR1 in tomato resistance against B. cinerea. Compared to (WT), slnpr1 leaves exhibited enhanced resistance against B. cinerea with smaller lesion sizes, higher activities of chitinase (CHI), β-1, 3-glucanases (GLU) and phenylalanine ammonia-lyase (PAL), and significantly increased expressions of pathogenesis-related genes (PRs). The increased activities of peroxidase (POD), ascorbate peroxidase (APX) and decreased catalase (CAT) activities collectively regulated reactive oxygen species (ROS) homeostasis in slnpr1 mutants. The integrity of the cell wall in slnpr1 mutants was maintained. Moreover, the enhanced resistance was further reflected by induction of defense genes involved in jasmonic acid (JA) and ethylene (ET) signaling pathways. Taken together, these findings revealed that knocking out SlNPR1 resulted in increased activities of defense enzymes, changes in ROS homeostasis and integrity of cell walls, and activation of JA and ET pathways, which confers resistance against B. cinerea in tomato plants.

In plants, spermidine synthase (SPE) received detailed investigation due to its key roles in the biosynthesis of spermidine, a major form of polyamine. However, there is no report on the identifica...

Purpose The purpose of this paper is to discuss characteristics of organic food value chain governance and policy tools that can increase the supply of good quality of agri-products. Design/methodology/approach This paper discusses a national organic food supply system in China, identifying the link between an organization form with a social confidence crisis and information asymmetry as the main challenges. It develops an analytical model of the market structure of organic certification based on the contract theory, which considers the certification incentive driven by both farmers and processors. Two cases of raw milk producers and processors provide empirical data. Findings The argument which is brought forward is that product information asymmetry together with strict requirement for ensuring organic food integrity brings the organic milk value chain into a highly integrated organization pattern. A tight value chain is effective in the governance of organic food supply chain under third party certification (TPC), while a loose value chain discourages producing organic products because of transaction costs. TPC is found to be a positively correlation with a tight value chain, but it brings high organizational cost and it raises cost for consumers. Originality/value This is the first paper discussing the governance of organic food value chain in Chinese milk industry.

Trehalose increased drought tolerance of tomato plants, accompanied by reduced water loss and closed stomata, which was associated with the upregulated ABA signaling-related genes expression, but not in ABA accumulation. Drought is one of the principal abiotic stresses that negatively influence the growth of plant and yield. Trehalose has great agronomic potential to improve the stress tolerance of plants. However, little information is available on the role of ABA and its signaling components in trehalose-induced drought tolerance. The aim of this study is to elucidate the potential mechanism by which trehalose regulates ABA in response to drought stress. In this study, 6-week-old tomato (Solanum lycopersicum cv. Ailsa Craig) plants were treated with 0 or 15.0 mM trehalose solution. Results showed that trehalose treatment significantly enhanced drought tolerance of tomato plants, accompanied by encouraged stomatal closure and protected chloroplast ultrastructure. Compared with controls, trehalose-treated plants showed lower hydrogen peroxide content and higher antioxidant enzymes activities, which contributed to alleviate oxidative damage caused by drought. Moreover, trehalose treatment decreased ABA content, which was followed by the downregulation of ABA biosynthesis genes expression and the upregulation of ABA catabolism genes expression. In contrast, exogenous trehalose upregulated transcript levels of ABA signaling-related genes, including SlPYL1/3/4/5/6/7/9, SlSnRK2.3/4, SlAREB1/2, and SlDREB1. These results suggested that trehalose treatment enhanced drought tolerance of tomato plants, and it's ABA signaling rather than ABA metabolism that was involved in trehalose-induced drought tolerance in tomato plants. These findings provide evidence for the physiological role of trehalose and bring about a new understanding of the possible relationship between trehalose and ABA.

Jasmonic acid (JA)- and ethylene-mediated signaling pathways are reported to have synergistic effects on inhibiting gray mold. The present study aimed to explain the role of ethylene perception in methyl jasmonate (MeJA)-mediated immune responses. Results showed that exogenous MeJA enhanced disease resistance, accompanied by the induction of endogenous JA biosynthesis and ethylene production, which led to the activation of the phenolic metabolism pathway. Blocking ethylene perception using 1-methylcyclopropene (1-MCP) either before or after MeJA treatment could differently weaken the disease responses induced by MeJA, including suppressing the induction of ethylene production and JA contents and reducing activities of lipoxygenase and allene oxide synthase compared to MeJA treatment alone. Consequently, MeJA-induced elevations in the total phenolic content and the activities of phenylalanine ammonia-lyase, cinnamate 4-hydroxylase, 4-coumarate:coenzyme A ligase, and peroxidase were impaired by 1-MCP. These results suggested that ethylene perception participated in MeJA-mediated immune responses in tomato fruit.

Melatonin acts as a crucial signaling molecule with multiple physiological functions in plant response to abiotic and biotic stresses. However, the impact and regulatory mechanism of melatonin on attenuating tomato fruit fungal decay are unclear. In this study, we investigated the potential roles of melatonin in modulating fruit resistance to Botrytis cinerea and explored related physiological and molecular mechanisms. The results revealed that disease resistance was strongly enhanced by melatonin treatment, and 50 μM was confirmed as the best concentration. Melatonin treatment increased the activities of defense-related enzymes and decreased hydrogen peroxide (H2O2) content with enhanced antioxidant enzyme activities. Moreover, we found that melatonin treatment increased methyl jasmonate (MeJA) content; up-regulated the expressions of SlLoxD, SlAOC, and SlPI II; and reduced the expressions of SlMYC2 and SlJAZ1. We postulated that melatonin played a positive role in tomato fruit resistance to Botrytis cinerea through regulating H2O2 level and JA signaling pathway.

Ethylene plays positive role in cold response of tomato fruit. CBFs (C-repeat/dehydration-responsive element binding factors) have been proved important in regulating plant chilling tolerance. Till now, the role that ethylene biosynthesis played in chilling response of tomato fruit is still unclear. In this study, we used antisense SlACS2 and wild-type Lichun tomato fruit as inhibited- and normal- ethylene biosynthesis models, in order to investigate whether inhibiting ethylene biosynthesis could affect chilling tolerance and SlCBF1 relative expression in tomato fruit. Results showed that antisense SlACS2 tomato fruit suffered more chilling injury, accompanied by higher malondialdehyde content and ion leakage, less proline and soluble protein content, as well as lower antioxidant enzymes activities, suggesting that inhibiting ethylene biosynthesis reduced tomato fruit chilling tolerance. Furthermore, SlCBF1 expression in transgenic fruit was lower than in WT, the second peak of SlCBF1 expression was coincidence with the peaks of both endogenous ethylene production and ACS activity, and there was significant correlation between ACC content and SlCBF1 relative expression, which implied that endogenous ethylene biosynthesis could contribute to upregulate SlCBF1 expression under cold stress. These results revealed that ethylene biosynthesis played important roles in regulating tomato fruit chilling tolerance and SlCBF1 relative expression in tomato fruit.

Funder: Renmin University of China; FundRef: https://doi.org/10.13039/501100004260, This article explores how the western concept of “organic agriculture” has been applied in the traditional Chinese tea industry and how it has been tested during the COVID-19 pandemic. Using in-depth interviews and observations made during 2017–2020, we analyzed different meanings of organic agriculture and values that were given by Chinese farmers who are certified organic producers. Although organic agriculture, particular certified by international certification standards, is a foreign concept, producers invested efforts that go beyond the commercial pursuit for profit. Most importantly, the combination of the reiterated cultural meaning and health benefits of the certified organic tea with the visionary strategy has allowed these producers to shift in a timely manner from export to domestic markets and adapt to the pandemic’s barriers presented to the global trade.

Food image recognition systems facilitate dietary assessment and in turn track users' dietary behaviors. However, due to the diversity of Chinese food, a quick and accurate food image recognizing is a particularly challenging task. The success of deep learning in computer vision inspired us to investigate its potential in this task. To satisfy its requirement on large-scale data, we established the first open-access image database for Chinese dishes, named ChinaFood-100, with quantitative nutrient annotations. We collected 10,074 images covering 100 food categories, including staple, meat, seafood, and vegetables. Based on this dataset, we trained four state-of-art deep learning neural network architectures for image recognition and showed that deep learning model Inception V3 resulted in the most advantageous recognition performance 78.26% in top-1 accuracy and 96.62% in top-5 accuracy. Based on this image recognition posterior, we further compared three nutrition estimation algorithms for food nutrient estimation. The results showed that the top-5 Arithmetic Mean (AM) algorithm achieved the highest regression coefficient (R2) up to 0.73 for protein estimation, which validated its applicability in practice. In addition, we analyzed our algorithm in terms of precision-recall and Grad-CAM. The results achieved by deep learning for food nutrient estimation may encourage artificial intelligence to be applied to the field of food, which shed the light on improvement in the future.

While production and consumption of meat cast a shadow over the prospects for sustainable development, artificial meat may be the solution. However, consumer acceptability of artificial meat is a major impediment to its use as a suitable alternative. This study analyzed the relationship between regulatory focus and consumer acceptance of artificial meat using randomized controlled trial data. Results showed that promotion focus results in a higher acceptance of artificial meat products due to a higher perceived benefit and lower perceived risk, whereas prevention focus results in a lower acceptance of artificial meat products due to perceived benefit being lower and perceived risk being higher. The moderating effect of the message framing was investigated employing structural equation modeling (SEM). It was discovered that a gain-oriented message framing could greatly strengthen the association between promotion focus and perceived benefit, whereas an avoidance-oriented message framing could significantly diminish the relationship between prevention focus and perceived risk. This study has crucial implications for how policymakers and industries communicate with consumers about artificial meat.

Ferulic acid (FA, 4-hydroxy-3-methoxycinnamic acid) is a phenolic acid derivative of cinnamic acid and plays pleiotropic roles in biotic and abiotic stress response in plants. However, the involvements of FA in chilling stress tolerance and the molecular mechanisms related to mitogen-activated protein kinase (MAPK) in tomato fruit are still elusive. In this study, the effect of exogenous FA on chilling resistance of tomato fruit was investigated. In addition, CRISPR/Cas9-mediated slmapk3 mutants were used to investigate the relationship between FA and SlMAPK3 under chilling stress. The results showed that low temperature (4 ℃) induced increase of FA content and FA synthesis related genes (SlPAL5, SlC3H and SlCOMT) expression. In addition, exogenous FA reduced the severity of cold injury, up-regulated the expressions of SlMAPK3, SlCBF1 and SlICE1, and promoted the accumulation of proline and soluble protein content. However, knockout of SlMAPK3 reduced the chilling tolerance of tomato fruit and inhibited the activities of antioxidant enzymes (APX, POD, SOD and CAT) but induced the accumulation of H2O2. In the condition of low temperature (4 ℃), there was a high correlation between SlMAPK3 and FA synthesis related genes (SlPAL5, SlC3H, SlC4H and SlCOMT) in control fruit. However, knockout of SlMAPK3 inhibited the content of FA and the expression of those genes compared with the control, which suggested a close relationship between SlMAPK3 and FA. Specifically, the effects of FA on osmotic regulatory substance and antioxidant enzyme system as well as the gene expression of CBF (C-repeat binding transcription factor) pathway were reduced after knockout of SlMAPK3. These results unveil a function of FA in tomato fruit positively resistance to chilling stress by up-regulating the gene expression of CBF transcriptional pathway in MAPK3-dependent manner.

With commercialization of deep learning (DL) models, daily precision dietary record based on images from smartphones becomes possible. This study took advantage of DL techniques on visual recognition tasks and proposed a suite of big-data-driven DL models regressing from food images to their nutrient estimation. We established and publicized the first food image database from the Chinese market, named ChinaMartFood-109. It contained 10,921 images with 23 nutrient contents, covering 18 main food groups. Inception V3 was optimized using other state-of-the-art deep convolutional neural networks, achieving up to 78 % and 94 % for top-1 and top-5 accuracy, respectively. Besides, this research compared three nutrient estimation algorithms and achieved the best regression coefficient ( R 2 ) by normalization + AM compared with arithmetic mean and harmonic mean, validating applicability in practice as well as theory. These encouraging results provide further evidence supporting artificial intelligence in the field of food analysis.

Tomato is one of the most popular horticultural crops, and many commercial tomato cultivars are particularly susceptible to Botrytis cinerea. Non-expressor of pathogenesis-related gene 1 (NPR1) is a critical component of the plant defense mechanisms. However, our understanding of how SlNPR1 influences disease resistance in tomato is still limited. In this study, two independent slnpr1 mutants were used to study the role of SlNPR1 in tomato resistance against B. cinerea. Compared to (WT), slnpr1 leaves exhibited enhanced resistance against B. cinerea with smaller lesion sizes, higher activities of chitinase (CHI), β-1, 3-glucanases (GLU) and phenylalanine ammonia-lyase (PAL), and significantly increased expressions of pathogenesis-related genes (PRs). The increased activities of peroxidase (POD), ascorbate peroxidase (APX) and decreased catalase (CAT) activities collectively regulated reactive oxygen species (ROS) homeostasis in slnpr1 mutants. The integrity of the cell wall in slnpr1 mutants was maintained. Moreover, the enhanced resistance was further reflected by induction of defense genes involved in jasmonic acid (JA) and ethylene (ET) signaling pathways. Taken together, these findings revealed that knocking out SlNPR1 resulted in increased activities of defense enzymes, changes in ROS homeostasis and integrity of cell walls, and activation of JA and ET pathways, which confers resistance against B. cinerea in tomato plants.

Mitogen-activated protein kinase (MAPK) cascades are universal signal transduction stimulus decoder that can translate extracellular signals into intracellular responses and play a crucial role in plant biotic and abiotic stress responses. However, no direct evidence of SlMAPK3 in response to salt stress of tomato plants had been obtained until now. Here, SlMAPK3 over-expression line (OE.MAPK3–5) and SlMAPK3 knock-out line (slmapk3–8) were used to investigate the role of SlMAPK3 in regulating tomato plants response to salt stress. The results showed that OE.MAPK3–5 plants showed higher fresh weight and seedlings height as well as seminal root length than wild type (WT) plants and slmapk3–8 plants under salt stress, which indicated that SlMAPK3 improved tomato tolerance to salt stress. In addition, knockout of SlMAPK3 increased salt sensitivity as revealed by the accumulation of H2O2 and MDA, reduction of soluble sugar and soluble protein contents, and suppression of antioxidant enzymes activities (POD, SOD, CAT and APX). High salinity induced cell death and chlorophyll degradation were more severe in slmapk3–8 plants but slighter in OE.MAPK3–5 plants compared with WT. Moreover, OE.MAPK3–5 plants exhibited increased expression of salt overly sensitive (SOS) pathway genes (SlSOS1, SlSOS2, SlSOS3) and ethylene signaling pathways genes (SlACS2, SlEIN2, SlERF2) compared with WT and slmapk3–8 plants under salt stress. These results unveil an expected function for SlMAPK3 in tomato plants positively response to salt stress by scavenging ROS accumulation and up-regulating the expression of ethylene signaling related genes.

Background: In the present study, we investigated the role of ornithine decarboxylase (ODC) in the methyl jasmonate (MeJA)-regulated postharvest quality maintenance of Agaricus bisporus (J. E. Kange) Imbach button mushrooms by pretreating mushrooms with a specific irreversible inhibitor called α-difluoromethylornithine (DFMO) before exposure to MeJA vapor.; Results: Mushrooms were treated with 0 or 100 µmol L-1 MeJA or a combination of 120 µmol L-1 DFMO and 100 µmol L-1 MeJA, respectively, before storage at 4 °C for 21 days. Treatment with MeJA alone induced the increase in ODC activity whereas this effect was greatly suppressed by pretreatment with DFMO. α-Difluoromethylornithine strongly attenuated the effect of MeJA on decreasing cap opening, slowing the decline rate of soluble protein and total sugar, and accumulating total phenolics and flavonoids. α-Difluoromethylornithine pretreatment also counteracted the ability of MeJA to inhibit polyphenol oxidase and lipoxygenase activities, and malondialdehyde production, and to stimulate superoxide dismutase and catalase activities. It also largely downregulated MeJA-induced accumulation of free putrescine (Put).; Conclusion: These results reveal that ODC is involved in MeJA-regulated postharvest quality retention of button mushrooms, and this involvement is likely to be associated with Put levels. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.

Chilling stress is the main constraint in tomato ( Solanum lycopersicum) production, as this is a chilling-sensitive horticultural crop. The highly conserved C-repeat binding factors (CBFs) are cold-response-system components found in many species. In this study, we generated slcbf1 mutants using the CRISPR-Cas9 system and investigated the role of SlCBF1 in tomato-plant chilling tolerances. The slcbf1 mutants exhibited more severe chilling-injury symptoms with higher electrolyte leakage and malondialdehyde levels than wild-type (WT) plants. Additionally, slcbf1 mutants showed lower proline and protein contents and higher hydrogen peroxide contents and activities of antioxidant enzymes than WT plants. Knockout of SlCBF1 significantly increased indole acetic acid contents but decreased methyl jasmonate, abscisic acid, and zeatin riboside contents. The reduced chilling tolerance of the slcbf1 mutants was further reflected by the down-regulation of CBF-related genes. These results contribute to a better understanding of the molecular basis underlying SlCBF1 mediation of tomato chilling sensitivity.

Mitogen-activated protein kinases (MAPKs) play an important role in defense responses to biotic and abiotic stresses. In order to investigate the role of SlMAPK3 in tomato plant resistance to Botrytis cinerea, two lines of slmapk3 mutants and wild-type (WT) tomato plants were used. The results showed that slmapk3 mutants were more susceptible to B. cinerea and that knockout of SlMAPK3 reduced the activities of defense enzymes and enhanced the accumulation of reactive oxygen species (ROS). Furthermore, we detected the expressions of salicylic acid (SA) and jasmonic acid (JA) signaling-related genes and found that knockout of SlMAPK3 enhanced the expressions of SlPR1, SlPAD4 and SlEDS1, whereas reduced the expressions of SlLoxC, SlPI I and SlPI II and enhanced the expressions of SlJAZ1 and SlMYC2. We postulate that SlMAPK3 plays a positive role in tomato plant resistance to B. cinerea through regulating ROS accumulation and SA and JA defense signaling pathways.

Drought stress is one of the most destructive environmental factors that affect plant growth and agricultural production. Mitogen-activated protein kinase (MAPK) cascades are important signaling pathways that participate in both biotic and abiotic stresses, which include drought. In this study, SlMAPK1 was induced by various abiotic stresses and hormone treatments. Transgenic tomato plants overexpressing SlMAPK1 were generated to further investigate the role that SlMAPK1 plays in drought tolerance. Three independent T2 transgenic lines and wild-type (WT) tomato plants were used for analysis of drought tolerance. Compared with WT plants, SlMAPK1-overexpressing lines exhibited less severe wilting, less severe cell membrane damage, and higher soluble protein and soluble sugar content, accumulated less hydrogen peroxide (H2O2), showed higher activities in the antioxidant enzymes including ascorbate peroxidase, catalase, peroxidase, and superoxide dismutase, and had an elevated transcript level of stress-related genes. Taken together, the results suggest that SlMAPK1 plays a positive role in response to drought stress by activating antioxidant enzymes, reducing oxidative damage, and modulating transcription of stress-related genes.

This study was to explore the effect of ferulic acid (FA) treatment in response to Botrytis cinerea (B. cinerea) infection of tomato fruit and potential mechanisms of action. The results showed that fruit treated with 100 μM FA increased resistance against B. cinerea as revealed by decreased disease incidence and lesion area. In addition, the activities of phenylalanine ammonialyase (PAL), polyphenol oxidase (PPO), chitinase (CHI) and β-1,3-glucanase (GLU) were significantly higher in tomato fruit treated with 100 μM FA. The increase of disease resistance was accompanied by a higher expression of genes (PR1, NPR1, MYC2, LoxD) related to salicylicacid (SA) and jasmonic acid (JA) signaling pathway. Furthermore, the activity of nitric oxide synthase (NOS) also enhanced by FA treatment and consequently increased the content of nitric oxide (NO). However, the simultaneous addition of 0.2 mM Nω-nitro-l-arginine ( l -NNA), a specific inhibitor of NOS, abolished such effects of 100 μM FA produced as well as decreased the expression of genes (C3H, C4H, COMT, PAL) related to FA biosynthesis. Additionally, FA treatment improved the correlations of NOS with MYC2 (r = 0.85*), GLU (r = 0.93**) and CHI (r = 0.94**). These findings indicated that FA treatment could be a promising approach to improve resistance against B. cinerea in tomato fruit, which was related to NO signaling pathway.

The objective of this study was to determine the effects of low-concentration acidic electrolyzed water (LcEW) combined with ultrasound (US) on fresh-sliced button mushrooms (Agaricus bisporus), by evaluating the enzymatic browning, physio-biochemical changes, and microbial loads. The sliced button mushrooms were divided randomly into three groups (control, LcEW, and LcEW+US) and treated separately with tap water, LcEW, and LcEW+US for 3 min, and afterwards, they were stored at 5 °C for 8 days. The results indicated that LcEW delayed surface browning and maintained the flesh firmness of fresh-cut mushrooms compared with the control, and ultrasound enhanced these effects. Moreover, LcEW+US slowed down the electrolyte leakage (EL) rate and malondialdehyde (MDA) content, which were 5.29% and 0.5227 μmol/fresh weight less than those in control at day 8, respectively. The combined treatment of LcEW and US also significantly inhibited the activities of polyphenol oxidase (PPO) and peroxidase (POD) and controlled the counts of total bacteria (TBC) and yeast and mold counts (Y&M). Meanwhile, LcEW+US maintained a high level of total soluble protein and total phenolic contents, which were 1.49 and 1.24 times higher than those in control at the end of the storage time, respectively, and the combined treatment was more effective than LcEW treatment alone. These results demonstrated that the combination of LcEW and US could be an effective pretreatment technology in maintaining the product quality and prolonging the shelf life of fresh-sliced button mushrooms.

It has been demonstrated that Agaricus bisporus (J.E. Kange) Imbach fruit body exerts enhanced postharvest quality retention when treated with 100 μmol L −1 exogenous methyl jasmonate (MeJA) vapor. In this study, fruit bodies of A. bisporus were treated with 100 μmol L −1 MeJA vapor or the combination of 100 μmol L −1 MeJA and 20 μmol L −1 N ω -hydroxy-nor- l -arginine (nor-NOHA, an inhibitor of arginase), respectively, before they were stored for 21 d at 4 °C. Our data showed that treatment with MeJA alone indeed induced the increased transcription and activity of arginase whereas this effect was largely inhibited by pretreatment with nor-NOHA. In correspondence to this observation, nor-NOHA suppressed the ability of MeJA to decrease open caps and to down-regulate malondialdehyde (MDA) production and polyphenol oxidase (PPO) and lipoxygenase (LOX) activities. Biochemical analysis further demonstrated that nor-NOHA counteracted the MeJA in stimulating antioxidant enzyme activities of catalase (CAT) and superoxide dismutase (SOD) and accumulating total phenolics and flavonoids. In addition, the effect of MeJA in slowing the decline rate of soluble protein and total sugar contents was also partially impaired by nor-NOHA. Taken together, our findings firmly showed that arginase acts as an important regulatory factor in maintaining the MeJA-induced mushroom quality retention during postharvest storage.

Drought stress is one of the most destructive environmental factors that affect tomato plants adversely. Mitogen-activated protein kinases (MAPKs) are important signaling molecules that respond to drought stress. In this study, SlMAPK3 was induced by drought stress, and the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) system was utilized to generate slmapk3 mutants. Two independent T1 transgenic lines and wild-type (WT) tomato plants were used for analysis of drought tolerance. Compared with WT plants, slmapk3 mutants exhibited more severe wilting symptom, higher hydrogen peroxide content, lower antioxidant enzymes activities, and suffered more membrane damage under drought stress. Furthermore, knockout of SlMAPK3 led to up- or down-regulated expressions of drought stress-responsive genes including SlLOX, SlGST, and SlDREB. The results suggest that SlMAPK3 is involved in drought response in tomato plants by protecting cell membranes from oxidative damage and modulating transcription of stress-related genes.

Hydrogen peroxide (H2O2) acts as a signaling molecule in response to cold stress. Mitogen-activated protein kinases (MAPKs) and C-repeat/dehydration-responsive factor (CBF) play important roles in cold response regulation. To investigate the roles of MAPKs and CBF in H2O2-induced chilling tolerance, tomato (Solanum lycopersicum cv. Ailsa Craig) plants were treated with 1 mM H2O2 before chilling treatment. The results showed that H2O2 treatment protected subcellular structure, increased concentrations of abscisic acid (ABA), zeatin riboside (ZR), and methyl jasmonate (MeJA), but decreased the concentration of gibberellic acid (GA3). Furthermore, 1 mM H2O2 treatment enhanced the activities of antioxidant enzymes. Meanwhile, relative expressions of SlMAPK1/2/3 and SlCBF1 in H2O2-treated plants were higher than those in the control. Our findings suggest that H2O2 treatment might enhance the chilling tolerance of tomato plants by activating SlMAPK1/2/3 and SlCBF1 gene expression and by regulating phytohormone ...

β-Aminobutyric acid (BABA) has consistently been reported to enhance plant immunity. However, the specific mechanisms and downstream components that mediate this resistance are not yet agreed upon. Nitric oxide (NO) is an important signal molecule involved in a diverse range of physiological processes, and whether NO is involved in BABA-induced resistance is interesting. In this study, treatment with BABA significantly increased NO accumulation and reduced the sensitivity to Botrytis cinerea in tomato plants. BABA treatment reduced physical signs of infection and increased both the transcription of key defense marker genes and the activity of defensive enzymes. Interestingly, compared to treatment with BABA alone, treatment with BABA plus cPTIO (NO specific scavenger) not only significantly reduced NO accumulation, but also increased disease incidence and lesion area. These results suggest that NO accumulation plays an important role in BABA-induced resistance against B. cinerea in tomato plants.

Background NPR1, nonexpressor of pathogenesis-related gene 1, is a master regulator involved in plant defense response to pathogens, and its regulatory mechanism in the defense pathway has been relatively clear. However, information about the function of NPR1 in plant response to abiotic stress is still limited. Tomato is the fourth most economically crop worldwide and also one of the best-characterized model plants employed in genetic studies. Because of the lack of a stable tomato NPR1 (SlNPR1) mutant, little is known about the function of SlNPR1 in tomato response to biotic and abiotic stresses. Results Here we isolated SlNPR1 from tomato ‘Ailsa Craig’ and generated slnpr1 mutants using the CRISPR/Cas9 system. Analysis of the cis-acting elements indicated that SlNPR1 might be involved in tomato plant response to drought stress. Expression pattern analysis showed that SlNPR1 was expressed in all plant tissues, and it was strongly induced by drought stress. Thus, we investigated the function of SlNPR1 in tomato-plant drought tolerance. Results showed that slnpr1 mutants exhibited reduced drought tolerance with increased stomatal aperture, higher electrolytic leakage, malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels, and lower activity levels of antioxidant enzymes, compared to wild type (WT) plants. The reduced drought tolerance of slnpr1 mutants was further reflected by the down-regulated expression of drought related key genes, including SlGST, SlDHN, and SlDREB. Conclusions Collectively, the data suggest that SlNPR1 is involved in regulating tomato plant drought response. These results aid in further understanding the molecular basis underlying SlNPR1 mediation of tomato drought sensitivity. Electronic supplementary material The online version of this article (10.1186/s12870-018-1627-4) contains supplementary material, which is available to authorized users.

Table S1. NPR1 homologous proteins investigated in this study. (DOCX 17 kb)

Table S4. Oligonucleotide primers used in mutation detection. (DOCX 15 kb)

Figure S2. Genome editing type of 26 CR-NPR1 mutants. (DOCX 1857 kb)

Table S5. Oligonucleotide primers used for off-target sites mutation analysis. (DOCX 15 kb)

Table S1. Sequences of specific primers used for qPCR analysis. (DOCX 31 kb)

Figure S1. Survival rate of tomato plants described in Fig. 2c. (DOCX 4305 kb)