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Abstract Background Botrytis cinerea is a broad-host-range pathogen causing gray mold disease and significant yield losses of numerous crops. However, the mechanisms underlying its rapid invasion and efficient killing of plant cells remain unclear. Results In this study, we elucidated the dynamics of B. cinerea infection in Arabidopsis thaliana by live cell imaging and dual RNA sequencing. We found extensive transcriptional reprogramming events in both the pathogen and the host, which involved metabolic pathways, signaling cascades, and transcriptional regulation. For the pathogen, we identified 591 candidate effector proteins (CEPs) and comprehensively analyzed their co-expression, sequence similarity, and structural conservation. The results revealed temporal co-regulation patterns of these CEPs, indicating coordinated deployment of effectors during B. cinerea infection. Through functional screening of 48 selected CEPs in Nicotiana benthamiana, we identified 11 cell death-inducing proteins (CDIPs) in B. cinerea. Conclusions The findings provide important insights into the transcriptional dynamics and effector biology driving B. cinerea pathogenesis. The rapid infection of this pathogen involves the temporal co-regulation of CEPs and the prominent role of CDIPs in host cell death. This work highlights significant changes in gene expression associated with gray mold disease, underscoring the importance of a diverse repertoire of effectors crucial for successful infection.

Background: Botrytis cinerea is a broad-host-range pathogen causing gray mold disease and significant yield losses of numerous crops. However, the mechanisms underlying its rapid invasion and efficient killing of plant cells remain unclear. Results: In this study, we elucidated the dynamics of B. cinerea infection in Arabidopsis thaliana by live cell imaging and dual RNA sequencing. We found extensive transcriptional reprogramming events in both the pathogen and the host, which involved metabolic pathways, signaling cascades, and transcriptional regulation. For the pathogen, we identified 591 candidate effector proteins (CEPs) and comprehensively analyzed their co-expression, sequence similarity, and structural conservation. The results revealed temporal co-regulation patterns of these CEPs, indicating coordinated deployment of effectors during B. cinerea infection. Through functional screening of 48 selected CEPs in Nicotiana benthamiana, we identified 11 cell death-inducing proteins (CDIPs) in B. cinerea. Conclusions: The findings provide important insights into the transcriptional dynamics and effector biology driving B. cinerea pathogenesis. The rapid infection of this pathogen involves the temporal co-regulation of CEPs and the prominent role of CDIPs in host cell death. This work highlights significant changes in gene expression associated with gray mold disease, underscoring the importance of a diverse repertoire of effectors crucial for successful infection. [ABSTRACT FROM AUTHOR]

Cytochrome P450 (CYP) is a crucial oxidoreductase enzyme that plays a significant role in plant defense mechanisms. In this study, a specific cytochrome P450 gene (MnCYP710A11) was discovered in mulberry (Morus notabilis). Bioinformatic analysis and expression pattern analysis were conducted to elucidate the involvement of MnCYP710A11 in combating Botrytis cinerea infection. After the infection of B. cinerea, there was a notable increase in the expression of MnCYP710A11. MnCYP710A11 is overexpressed in Arabidopsis and mulberry and strongly reacts to B. cinerea. The overexpression of the MnCYP710A11 gene in Arabidopsis and mulberry led to a substantial enhancement in resistance against B. cinerea, elevated catalase (CAT) activity, increased proline content, and reduced malondialdehyde (MDA) levels. At the same time, H2O2 and O2− levels in MnCYP710A11 transgenic Arabidopsis were decreased, which reduced the damage of ROS accumulation to plants. Furthermore, our research indicates the potential involvement of MnCYP710A11 in B. cinerea resistance through the modulation of other resistance-related genes. These findings establish a crucial foundation for gaining deeper insights into the role of cytochrome P450 in mulberry plants. [ABSTRACT FROM AUTHOR]

Botrytis cinerea, a necrotrophic fungus responsible for grey rot disease, causes substantial economic losses. However, recent studies have discovered distinct non-sporogenic and non-infective isolates of this species, such as the B459 field strain. Examination of these isolates is particularly intriguing in the context of the development of methodological applications that could be useful in the biocontrol of this phytopathogenic species. This investigation revealed that B459 exhibited a reduced growth rate yet displayed enhanced resilience to stressors like oxidative stress agents, SDS, ethanol, and PhITC. Notably, its ability to generate reactive oxygen species (ROS) and acidic compounds, crucial in plant–pathogen interactions, was impacted. Bio-targeted toxin identification assays and the metabolomic study of extracts obtained from fermentations at seven and fourteen days revealed that this strain does not biosynthesize botrydial and derivatives neither botcinin family toxins. Furthermore, its inability to infect tomato fruits, grape, and gerbera petals coincides with its lack of toxin production under culture conditions typically adapted for reference strain B05.10. [ABSTRACT FROM AUTHOR]

Strawberry is a major fruit crop worldwide because its nutritional and health benefits to human health, but its productivity is limited by Botrytis cinerea. Sucrose nonfermentation 1-related protein kinase 1 (SnRK1) has a defense function against pathogens, but the function of SnRK1 in the defense response to B. cinerea in plants is still unclear. In this study, FaSnRK1α-OE and RNAi fruits were constructed and then inoculated with B. cinerea. The result reveals a positive role of FaSnRK1α in the regulation of resistance to gray mold. FaSnRK1α affects SA content by regulating FaPAL1 and FaPAL2 expressions. The genes related to the SA signaling pathway (FaTGA1 and FaTGA2.1) were significantly increased/decreased in FaSnRK1α-OE or FaSnRK1α-RNAi fruit, respectively. FaSnRK1α interacted with the FaWRKY33.2 protein and negatively regulated FaWRKY33.2 expression, and FaWRKY33.2 acts as a repressor of disease resistance to B. cinerea. Finally, FaSnRK1α regulates the expression of six PR genes and the activities of antioxidant enzymes to boost defense response after B. cinerea inoculation. Our findings showed that FaSnRK1α increases the resistance of strawberry fruit to B. cinerea via SA signaling pathway and interaction with the FaWRKY33.2 transcription factor.

A series of flavonoid derivatives containing 1,2,4-triazolo[4,3-a]pyridine were designed, synthesized and evaluated for their antifungal activity. Bioactivity tests showed that some target compounds exhibited the strong antifungal activity against Botrytis cinerea (B. cinerea), Sclerotinia sclerotiorum (S. sclerotiorum), and Phomopsis sp. Among them, the half maximal effective concentration (EC50) value of S2 against B. cinerea was 3.3 μg/mL, which was less than that of the control drug azoxystrobin (21.0 μg/mL). The EC50 value of S2 against S. sclerotiorum was 12.7 μg/mL, which was better than that of azoxystrobin (28.1 μg/mL). In addition, the in vivo protective and curative activities of S2 against blueberry were 92.0 and 79.8 % at 200 μg/mL, respectively, which were higher than those of the control drug azoxystrobin (89.4 and 71.7 %). Scanning electron microscopy (SEM) and spore germination experiments showed that S2 could not only cause the mycelium damage but also inhibited the spore germination. Fluorescence microscopy (FM) observation, relative electrical conductivity measurement and cytoplasmic leakage assays indicated that S2 could affect cell membrane integrity by inducing lipid peroxidation and increasing cell membrane permeability as well as causing leakage of cytoplasmic contents. These results show that flavonoid derivatives containing 1,2,4-triazolo[4,3-a]pyridine had excellent inhibitory effects on B. cinerea, providing another supplement for the development of new pesticides.

Botrytis cinerea is a necrotrophic fungus that can cause gray mold in over 1400 plant species. Once it is detected by Arabidopsis thaliana, several defense responses are activated against this fungus. The proper activation of these defenses determines plant susceptibility or resistance. It has been proposed that the RAC/ROP small GTPases might serve as a molecular link in this process. In this study, we investigate the potential role of the Arabidopsis RAC7 gene during infection with B. cinerea. For that, we evaluated A. thaliana RAC7-OX lines, characterized by the overexpression of the RAC7 gene. Our results reveal that these RAC7-OX lines displayed increased susceptibility to B. cinerea infection, with enhanced fungal colonization and earlier lesion development. Additionally, they exhibited heightened sensitivity to bacterial infections caused by Pseudomonas syringae and Pectobacterium brasiliense. By characterizing plant canonical defense mechanisms and performing transcriptomic profiling, we determined that RAC7-OX lines impaired the plant transcriptomic response before and during B. cinerea infection. Global pathway analysis of differentially expressed genes suggested that RAC7 influences pathogen perception, cell wall homeostasis, signal transduction, and biosynthesis and response to hormones and antimicrobial compounds through actin filament modulation. Herein, we pointed out, for first time, the negative role of RAC7 small GTPase during A. thaliana–B. cinerea interaction. [ABSTRACT FROM AUTHOR]

Botrytis cinerea is a fungal pathogen present in almost any environment, able to cause a severe postharvest disease on a wide range of crops, resulting in significant economic losses. Furthermore, B. cinerea is frequently found in plant tissues as a latent, asymptomatic infection that, when stimulated by favorable alterations in the environment or the physiology of the host, can swiftly develop into a significant symptomatic infection. In greenhouses, fields, and on propagation materials, the principal strategy adopted to control infection is the use of chemical fungicides or eco-friendly alternative methods. For the optimal success of conventional and biocontrol treatments, it is crucial to monitor the disease development and the fungal infection entity. The aim of this work was to develop a fast new method based on chip digital PCR (cdPCR) to estimate the extent of the B. cinerea infection in tomatoes. To better evaluate the amount of plant infection, a duplex assay able to co-amplify both fungal and host plant DNA was fine-tuned. The cdPCR assays were applied to quantify B. cinerea in tomato seedling samples, both naturally and artificially contaminated. The developed method offers sensitive detection, reliable identification, and precise pathogen quantification. The method can be used for B. cinerea diagnostics along the tomato production chain, starting from the seeds and transplanting seedlings to plants and crop residues in open fields and greenhouses. To the best of our knowledge, this is the first study directed at applying cdPCR to B. cinerea diagnosis in tomatoes. [ABSTRACT FROM AUTHOR]

Aims Botrytis cinerea is a pathogenic fungus that infests multiple crops, which causes a severe decrease in yield and generates substantial losses in the economy. Palmarosa essential oil (PEO) is a primary aromatic compound extracted from palmarosa that is commonly used for scent, medicine, and flavoring foods due to its diverse bioactive properties. In this study, we explored the antifungal activity and the main mechanism of action of PEO against B. cinerea. In addition, the components and control effects of PEO were also studied. Methods and Results The antifungal assay was tested using the mycelial growth rate method and colony morphology. The constituents of PEO were identified according to gas chromatography/mass spectrometry (GC–MS). The main mechanism of action of PEO was evaluated by measuring representative indicators, which consist of cell contents leakage, excess reactive oxygen species (ROS), and other related indicators. The results indicated that at a concentration of 0.60 ml l−1, PEO exhibits strong antifungal activity against B. cinerea. The PEO mainly included 13 compounds, of which citronellol (44.67%), benzyl benzoate (14.66%), and acetyl cedrene (9.63%) might be the main antifungal ingredients. The study elucidated the main mechanism of action of PEO against B. cinerea , which involved the disruption of cell membrane structure, resulting in altered the cell membrane permeability, leakage of cell contents, and accumulation of excess ROS. Conclusions PEO is a satisfactory biological control agent that inhibits B. cinerea in postharvest onions. PEO (0.60 ml l−1) exhibited strong antifungal activity by disrupting the cell membrane structure, altering cell membrane permeability, leading to the cell contents leakage, accumulation of excess ROS and increased level of Malondialdehyde (MDA) compared to the control group. [ABSTRACT FROM AUTHOR]

Botrytis cinerea, a necrotrophic fungus responsible for grey rot disease, causes substantial economic losses. However, recent studies have discovered distinct non-sporogenic and non-infective isolates of this species, such as the B459 field strain. Examination of these isolates is particularly intriguing in the context of the development of methodological applications that could be useful in the biocontrol of this phytopathogenic species. This investigation revealed that B459 exhibited a reduced growth rate yet displayed enhanced resilience to stressors like oxidative stress agents, SDS, ethanol, and PhITC. Notably, its ability to generate reactive oxygen species (ROS) and acidic compounds, crucial in plant–pathogen interactions, was impacted. Bio-targeted toxin identification assays and the metabolomic study of extracts obtained from fermentations at seven and fourteen days revealed that this strain does not biosynthesize botrydial and derivatives neither botcinin family toxins. Furthermore, its inability to infect tomato fruits, grape, and gerbera petals coincides with its lack of toxin production under culture conditions typically adapted for reference strain B05.10.

Galactitol synthetase (GolS) as a key enzyme in the raffinose family oligosaccharides (RFOs) biosynthesis pathway, which is closely related to stress. At present, there are few studies on GolS in biological stress. The expression of MnGolS2 gene in mulberry was increased under Botrytis cinerea infection. The MnGolS2 gene was cloned and ectopically expressed in Arabidopsis. The content of MDA in leaves of transgenic plants was decreased and the content of CAT was increased after inoculation with B. cinerea. In this study, the role of MnGolS2 in biotic stress was demonstrated for the first time. In addition, it was found that MnGolS2 may increase the resistance of B. cinerea by interacting with other resistance genes. This study offers a crucial foundation for further research into the role of the GolS2 gene. [ABSTRACT FROM AUTHOR]

Fluopyram, as a novel succinate dehydrogenase inhibitors (SDHIs) fungicide, was applied for controlling grey mould in China. In order to investigate the possible development of resistance development of Botrytis cinerea to fluopyram, Botrytis cinerea were collected from eight areas in Liaoning Province, and the sensitivities of these isolates were assessed by mycelium growth and the fitness and resistance mechanism of resistant isolates screened. The results showed that the sensitivity baseline of B. cinerea to fluopyram was (4.82 ± 1.49) μg/mL, and 5 low resistance isolates to fluopyram were detected. The fitness of resistant isolates showed a downward trend of several variables, such as mycelium growth, mycelium dry weight, sporulation and lesion diameter, which were significantly lower than those of sensitive isolates. Conidia germination did not differ significantly between sensitive and resistant isolates. There was no cross‐resistance between fluopyram and fludioxonil/boscalid/pyrimethanil/procymidone/carbendazim. The succinate dehydrogenase activity of resistant isolates was higher than that of sensitive isolates with fluopyram or not, and the inhibition of fluopyram on succinate dehydrogenase of sensitive isolates was greater than that of resistant isolates. Resistant isolates AS8 and AS14 carried the point mutation (N230I) in subunit B. These results provided that fluopyram belonged to a medium‐high resistance risk to B. cinerea. Information for managing resistance suggested that (1) the number of fluopyram applications should be limited to one per season and (2) fluopyram could be a valid alternative to fludioxonil, pyrimethanil, procymidone and carbendazim for the control of grey mould of tomato. [ABSTRACT FROM AUTHOR]

Botrytis cinerea is a devastating fungal pathogen that causes severe economic losses in global tomato cultivation. Understanding the molecular mechanisms driving tomatoes' response to this pathogen is crucial for developing effective strategies to counter it. Although the Micro-Tom (MT) cultivar has been used as a model, its stage-specific response to B. cinerea remains poorly understood. In this study, we examined the response of the MT and Ailsa Craig (AC) cultivars to B. cinerea at different time points (12–48 h post-infection (hpi)). Our results indicated that MT exhibited a stronger resistant phenotype at 18–24 hpi but became more susceptible to B. cinerea later (26–48 hpi) compared to AC. Transcriptome analysis revealed differential gene expression between MT at 24 hpi and AC at 22 hpi, with MT showing a greater number of differentially expressed genes (DEGs). Pathway and functional annotation analysis revealed significant differential gene expression in processes related to metabolism, biological regulation, detoxification, photosynthesis, and carbon metabolism, as well as some immune system-related genes. MT demonstrated an increased reliance on Ca2+ pathway-related proteins, such as CNGCs, CDPKs, and CaMCMLs, to resist B. cinerea invasion. B. cinerea infection induced the activation of PTI, ETI, and SA signaling pathways, involving the modulation of various genes such as FLS2, BAK1, CERK1, RPM, SGT1, and EDS1. Furthermore, transcription factors such as WRKY, MYB, NAC, and AUX/IAA families played crucial regulatory roles in tomatoes' defense against B. cinerea. These findings provide valuable insights into the molecular mechanisms underlying tomatoes' defense against B. cinerea and offer potential strategies to enhance plant resistance. [ABSTRACT FROM AUTHOR]

Recent evidence shows that small RNAs are transferred from a species to another through cross-species transmission and exhibit biological activities in the receptor. In this study, we focused on tomato-derived sRNAs play a role of defense against Botrytis cinerea. Bioinformatics method was firstly employed to identify tomatoencoded sRNAs as the cross-species antifungal factors targeting B. cinerea genes. Then the expression levels of some identifed sRNAs were checked in B. cinereainfected plant using qRT-PCR method. Exogenic RNA-induced gene silences analysis were performed to investigate the antifungal roles of the sRNAs, and the target genes in B. cinerea of antifungal sRNAs would be confirmed by using coexpression analysis. Results showed that a total of 21 B.cinerea-induced sRNAs with high abundance were identified as the cross-kingdom regulator candidates. Among them, three sRNAs containing a miRNA (miR396a-5p) and two siRNA (siR3 and siR14) were selected for experimental validation and bioassay analysis. qRTPCR confirmed that all of these 3 sRNAs were induced in tomato leaves by B. cinerea infection. Correspondingly, 4 virulence genes of B. cinerea respectively targeted by these 3 sRNAs were down-regulated. Bioassay revealed that all of these 3 cross-species sRNAs could inhibit the virulence and spore gemination of B. cinerea. Correspondingly, the coding genes of B. cinerea targeted by these sRNAs were also down-regulated. Moreover, the virulence inhibition by double strand sRNA was more effective than that by single strand sRNA. The inhibition efficiency of sRNA against B. cinerea increased with the increase of its concentration. Our findings provide new evidence into the coevolution of pathogens and host plants, as well as new directions for the use of plant-derived sRNAs to control pathogens. [ABSTRACT FROM AUTHOR]

Botrytis cinerea is a fungal pathogen present in almost any environment, able to cause a severe postharvest disease on a wide range of crops, resulting in significant economic losses. Furthermore, B. cinerea is frequently found in plant tissues as a latent, asymptomatic infection that, when stimulated by favorable alterations in the environment or the physiology of the host, can swiftly develop into a significant symptomatic infection. In greenhouses, fields, and on propagation materials, the principal strategy adopted to control infection is the use of chemical fungicides or eco-friendly alternative methods. For the optimal success of conventional and biocontrol treatments, it is crucial to monitor the disease development and the fungal infection entity. The aim of this work was to develop a fast new method based on chip digital PCR (cdPCR) to estimate the extent of the B. cinerea infection in tomatoes. To better evaluate the amount of plant infection, a duplex assay able to co-amplify both fungal and host plant DNA was fine-tuned. The cdPCR assays were applied to quantify B. cinerea in tomato seedling samples, both naturally and artificially contaminated. The developed method offers sensitive detection, reliable identification, and precise pathogen quantification. The method can be used for B. cinerea diagnostics along the tomato production chain, starting from the seeds and transplanting seedlings to plants and crop residues in open fields and greenhouses. To the best of our knowledge, this is the first study directed at applying cdPCR to B. cinerea diagnosis in tomatoes.

La moisissure grise causée par Botrytis cinerea provoque des dégâts sur plus de 200 espèces de cultures dans le monde. B. cinerea sporule pour former une pourriture grise sur les feuilles, les tiges et les fruits. Pour lutter contre B. cinerea, des fongicides synthétiques sont utilisés. Ces derniers mettent en danger la santé humaine et environnementale en plus de la résistance qu'ils peuvent occasionner chez les souches de B. cinerea. Les alternatives écologiques sont des solutions appropriées pour contrôler la moisissure grise tout en maintenant l’équilibre environnemental. L’objectif de cette étude est d'évaluer l’effet des isolats de Pseudomonas issus de la rhizosphère de la tomate sur B. cinerea. Les résultats ont montré que les 76 isolats testés inhibent le développement de B. cinerea in vitro. Cinq isolats de Pseudomonas (Q6B, Q13B, Q7B, Q14B et Q1B) ont provoqué des niveaux d'inhibition significatifs allant de 65 à 73%. Par ailleurs, ces isolats ont également inhibé B. cinerea sur les feuilles et le fruit de la tomate. Pour tenter d'élucider les mécanismes d'action, les cinq isolats ont montré une production des métabolites antifongiques tels que les sidérophores, le cyanure d'hydrogène et d’autres enzymes. Les résultats de cette étude ont montré que les isolats de Pseudomonas Q6B, Q13B, Q7B, Q14B et Q1B ont une forte efficacité dans la lutte biologique contre B. cinerea et peuvent être utilisés pour une lutte écologique durable.

Recent evidence shows that small RNAs are transferred from a species to another through cross-species transmission and exhibit biological activities in the receptor. In this study, we focused on tomato-derived sRNAs play a role of defense against Botrytis cinerea. Bioinformatics method was firstly employed to identify tomato-encoded sRNAs as the cross-species antifungal factors targeting B. cinerea genes. Then the expression levels of some identifed sRNAs were checked in B. cinerea-infected plant using qRT-PCR method. Exogenic RNA-induced gene silences analysis were performed to investigate the antifungal roles of the sRNAs, and the target genes in B. cinerea of antifungal sRNAs would be confirmed by using co-expression analysis. Results showed that a total of 21 B.cinerea-induced sRNAs with high abundance were identified as the cross-kingdom regulator candidates. Among them, three sRNAs containing a miRNA (miR396a-5p) and two siRNA (siR3 and siR14) were selected for experimental validation and bioassay analysis. qRT-PCR confirmed that all of these 3 sRNAs were induced in tomato leaves by B. cinerea infection. Correspondingly, 4 virulence genes of B. cinerea respectively targeted by these 3 sRNAs were down-regulated. Bioassay revealed that all of these 3 cross-species sRNAs could inhibit the virulence and spore gemination of B. cinerea. Correspondingly, the coding genes of B. cinerea targeted by these sRNAs were also down-regulated. Moreover, the virulence inhibition by double strand sRNA was more effective than that by single strand sRNA. The inhibition efficiency of sRNA against B. cinerea increased with the increase of its concentration. Our findings provide new evidence into the coevolution of pathogens and host plants, as well as new directions for the use of plant-derived sRNAs to control pathogens.

This study aimed to evaluate the antifungal activity of the aqueous extracts of two wild Lamiaceae species against P. expansum and B. cinerea and the impact of these treatments on fruit quality parameters. The in vitro results showed significant effect of the two aqueous extracts on both fungi mycelial growth. A. alpinus exhibited high antifungal efficacy against P. expansum with an inhibition rate ranging from 34.32 to 90.76% whereas T. vulgaris exhibit an inhibition rate against B. cinerea ranging from 61.87 to 97.94%. These results indicated that A. alpinus and T. vulgaris were extremely potent against both pathogens with an EC50 ranging from 0.82 to 2.39%. The in vivo experiments on apple fruit were very promising with an approximate efficacy varying from 64 to 79% with no impacts on fruit quality parameters. These results provide evidence that both plant species are an effective alternative to control postharvest diseases of fruit. [ABSTRACT FROM AUTHOR]

Six α-amylase/subtilisin inhibitor genes (MnASIs) were identified from mulberry (Morus notabilis). In this study, bioinformatics and expression pattern analysis of six MnASIs were performed to determine their roles in resistance to B. cinerea. The expression of all six MnASIs was significantly increased under Botrytis cinerea infection. MnASI1, which responded strongly to B. cinerea, was overexpressed in Arabidopsis and mulberry. The resistance of Arabidopsis and mulberry overexpressing MnASI1 gene to B. cinerea was significantly improved, the catalase (CAT) activity was increased, and the malondialdehyde (MDA) content was decreased after inoculation with B. cinerea. At the same time, H2O2 and O2− levels were reduced in MnASI1 transgenic Arabidopsis, reducing the damage of ROS accumulation to plants. In addition, MnASI1 transgenic Arabidopsis increased the expression of the salicylic acid (SA) pathway-related gene AtPR1. This study provides an important reference for further revealing the function of α-amylase/subtilisin inhibitors. [ABSTRACT FROM AUTHOR]

Botrytis cinerea is a devastating fungal pathogen that causes severe economic losses in global tomato cultivation. Understanding the molecular mechanisms driving tomatoes’ response to this pathogen is crucial for developing effective strategies to counter it. Although the Micro-Tom (MT) cultivar has been used as a model, its stage-specific response to B. cinerea remains poorly understood. In this study, we examined the response of the MT and Ailsa Craig (AC) cultivars to B. cinerea at different time points (12–48 h post-infection (hpi)). Our results indicated that MT exhibited a stronger resistant phenotype at 18–24 hpi but became more susceptible to B. cinerea later (26–48 hpi) compared to AC. Transcriptome analysis revealed differential gene expression between MT at 24 hpi and AC at 22 hpi, with MT showing a greater number of differentially expressed genes (DEGs). Pathway and functional annotation analysis revealed significant differential gene expression in processes related to metabolism, biological regulation, detoxification, photosynthesis, and carbon metabolism, as well as some immune system-related genes. MT demonstrated an increased reliance on Ca2+ pathway-related proteins, such as CNGCs, CDPKs, and CaMCMLs, to resist B. cinerea invasion. B. cinerea infection induced the activation of PTI, ETI, and SA signaling pathways, involving the modulation of various genes such as FLS2, BAK1, CERK1, RPM, SGT1, and EDS1. Furthermore, transcription factors such as WRKY, MYB, NAC, and AUX/IAA families played crucial regulatory roles in tomatoes’ defense against B. cinerea. These findings provide valuable insights into the molecular mechanisms underlying tomatoes’ defense against B. cinerea and offer potential strategies to enhance plant resistance.

Strawberry fruits are subjected to many pathogens, especially the necrotrophic fungus Botrytis cinerea. Many salt compounds, plant extracts, and bio-agents were used to control gray mold in strawberry fruits caused by the fungus Botrytis cinerea. All the tested salt compounds reduced the mycelial growth of B. cinerea. The salt KH2PO4 was the most effective followed by the salt NaHCO3 and CaCl2 respectively. Fore disease severity, the highest concentration of any salt was the most effective in reducing disease severity. Spray strawberry fruits with three plant extract types, i.e., Garlic, Marjoram, and Thyme at two concentrations (10 and 20%) were effective in reducing mycelial growth. The highest effective concentration of Garlic extract in reducing disease severity was 20% compared with the other plant extracts and the control treatment. The results of the bio-agent experiment indicated that Trichoderma harzianum was the most effective in reducing the growth of B. cinerea in Petri dishes. In contrast, Trichoderma viride was the most effective one in reducing disease severity. All the tested fungicides gave sufficient control against strawberry fruit rot caused by the fungus B. cinerea in comparison with control during the two successive seasons. To the best of knowledge the allowable of the three used fungicides in strawberry fruits is unknown. So, one can say that strawberry fruits picked after spraying could not be marketed with apparent safety for human consumption until the strawberry fruits are free from any residues of the three fungicides. [ABSTRACT FROM AUTHOR]

The apple tree, belonging to the Rosaceae family producing pome fruit, holds global economic significance. Despite this, apples face considerable postharvest disease challenges, particularly blue mold caused by Penicillium expansum and gray mold Botrytis cinerea. Synthetic fungicides are traditionally used for control, but their drawbacks necessitate exploring environmentally friendly alternatives. The current research investigates the antifungal activity of Agave americana and Agave sisalana aqueous extracts against these post-harvest diseases. In vitro tests demonstrated a concentration-dependent antifungal effect, with A. americana completely inhibiting mycelial growth and spore germination at 50 g L−1. A. sisalana exhibited a 75% reduction at the same concentration. A. americana at 6 g L−1 inhibited 50% of spore germination, while A. sisalana at 8 and 9 g L−1 achieved the same for B. cinerea and P. expansum. Regarding In vivo tests, both extracts reduced infection severity, particularly A. americana, which lowered gray mold and blue mold incidences to 23 and 26%. High polyphenol and flavonoid content in Agave extracts likely contributed to their efficacy. Phytochemical analyses identified 35 metabolites, including citric acid and piscidic acid, which are potential inhibitors of the fungal cell enzyme sterol 14 α-demethylase (CYP51), according to the results of molecular Docking analyses. Similarly, FTIR results indicated compounds with significant antimicrobial activity. Importantly, these biological treatments preserved apple quality during storage, suggesting their potential as effective and sustainable alternatives to synthetic fungicides. • A.americana and A.sisalana aqueous extracts effectively controlled apple decays. • Both extracts, rich in polyphenols and flavonoids, exhibited potent antifungal effects. • Agave extracts could be a promising alternative to synthetic fungicides. [ABSTRACT FROM AUTHOR]

Tomato early blight and grey mould are common diseases that affect tomato yield and quality. Endophytic bacteria are a class of biocontrol microorganisms that exist widely in plants that can, along with their metabolites, be used to develop new bacterial agents to control plant diseases and regulate plant growth while reducing the need for chemical pesticides. We previously isolated an endophytic bacterium ZJ1, Bacillus velezensis, from the stem of Buddleja lindleyana. The volatile organic compounds (VOCs) from ZJ1 exhibited significant antifungal activity against Alternaria solani and Botrytis cinerea. The VOCs were identified via gas chromatography–mass spectrometry of solid-phase microextraction samples (SPME–GC–MS). The results revealed eight main VOCs released by the strain ZJ1, among which isooctanol and 2-nonanol showed inhibitory effects on the mycelia growth of A. solani and B. cinerea. Furthermore, 2-nonanol and isooctanol showed good in vitro antifungal activity and in vivo control effect against the two pathogens. The 500 million CFU mL−1 ZJ1 strain oil suspension with 200 times dilution had the highest control effect, the protective and therapeutic effects were both greater than 80%. Additionally, treatment with ZJ1 and its VOCs caused the mycelium of A. solani to become thin, twisted, deformed, bifurcated, and fractured, with a wrinkled and cracked surface. The VOCs caused leakage of the mycelia intracellular contents, thereby causing withering. Collectively, these findings suggest that the preparation of the ZJ1 strain and its VOC products, 2-nonanol and isooctanol, has good application prospects for the control of tomato early blight and grey mould. [ABSTRACT FROM AUTHOR]

Botrytis cinerea, a responsible for grey rot that mainly affects fruit and represent a problem in fruit-exporting countries. Synthetic antifungals are used for its control. However, it has developed a specific resistance towards them. Therefore, a search for new natural alternatives that are friendly to the environment has increased in the last decade. In this work, the activity of in vitro-cultured C. quitensis extracts was analysed. Extract was characterized using LC-MS/MS and evaluated in vitro, and in vivo using edible coatings in table grapes. The application of extracts inhibited the development of conidia and mycelium of B. cinerea, with EC50 values of 0.071 ± 0.008 g L−1 and 0.074 ± 0.09 g L−1, respectively, inducing oxidative stress in vitro; on the other hand, in vivo assays showed a protection and preservation of anthocyanins and sugars in table grapes. These results suggest that C. quitensis extracts represent a good alternative to control B. cinerea. [ABSTRACT FROM AUTHOR]

ABSTRACT Lytic polysaccharide monooxygenases (LPMOs) mediate oxidative degradation of plant polysaccharides. The genes encoding LPMOs are most commonly arranged with one catalytic domain, while a few are found tethered to additional noncatalytic units, i.e., cellulase linker and carbohydrate-binding module (CBM). The presence of CBM is known to facilitate catalysis by directing the enzymes toward cellulosic polymer, while the role of linkers is poorly understood. Based on limited experimental evidence, linkers are believed to serve merely as flexible spacers between the structured domains. Thus, this study aims to unravel the role of the linker regions present in LPMO sequences. For this, we analyzed the genome of Botrytis cinerea and found 9 genes encoding cellulose lytic monooxygenases (AA9 family), of which BcAA9C was overexpressed in cellulose-inducible conditions. We designed variants of flLPMO (full-length enzyme) with truncation of either linker or CBM to examine the role of linker in activity, binding, and thermal stability of the associated monooxygenase. Biochemical assays predicted that the deletion of linker does not impact the potential of flLPMO for catalyzing the oxidation of Amplex Red, but that it does have a major influence on the capability of flLPMO to degrade recalcitrant polysaccharide substrate. Langmuir isotherm and SEM analysis demonstrated that linker domain aids in polysaccharide binding during flLPMO-mediated deconstruction of plant cell wall. Interestingly, linker domain was also found to contribute toward the thermostability of flLPMO. Overall, our study reveals that linker is not merely a spacer, but plays a key role in LPMO-mediated biomass fibrillation; these findings are broadly applicable to other polysaccharide-degrading enzymes. IMPORTANCE The polysaccharide-disintegrating carbohydrate-active enzymes (CAZymes) are often found with multimodular architecture, where the catalytic domain is connected to an accessory CBM domain with the help of a flexible linker region. So far, the linker has been understood merely as a flexible spacer between the two domains. Therefore, the current study is designed to determine the role of linker in polysaccharide fibrillation. To conceive this study, we have selected LPMO as a model enzyme, as it is not only an industrially relevant enzyme but it also harbors a catalytic domain, linker region, and CBM domain. The present study highlighted the crucial and indispensable role of the linker region in mediating polysaccharide disintegration. Considering its role in binding, thermostability, and activity toward polysaccharide substrate, we propose linker as a potential candidate for future CAZyme engineering.

Zn(II)2Cys6 proteins constitute the largest group of fungal-specific transcription factors. However, little is known about their functions in the crop killer Botrytis cinerea . In this work, a T-DNA insertion strain M13448 was identified which was inserted into the Zn(II)2Cys6 TF-encoding gene BcTBS1 . Knockout of BcTBS1 did not affect mycelia growth, appressorium formation, and sclerotium germination, but impaired fungal conidiation, conidial morphogenesis, conidial germination, infection cushion development, and sclerotial formation. Accordingly, Δ Bctbs1 mutants showed reduced virulence in its host plants. Further study proved that BcTBS1 , BCIN_15g03870 , and BCIN_12g06630 were induced by cellulose. Subsequent cellulase activity assays revealed that the loss of BcTBS1 significantly decreased cellulase activity. In addition, we verified that the BCIN_15g03870 and BCIN_12g06630 genes were positive regulated by BcTBS1 by quantitative real-time reverse-transcription-polymerase chain reaction (qRT-PCR). Taken together, these results suggested that BcTBS1 can promote pathogenicity by modulating cellulase-encoding genes that participate in host cellulose degradation.

Generalist necrotrophic pathogens including Botrytis cinerea cause significant yield and financial losses on Brassica crops. However, there is little knowledge about the mechanisms underlying the complex interactions encoded by both host and pathogen genomes in this interaction. This potentially includes multiple layers of plant defense and pathogen virulence mechanisms that could complicate in breeding broad spectrum resistance within Brassica species. Glucosinolates (GSLs) are a diverse group of defense metabolites that play a key role in interaction between Brassica and biotic attackers. In this study, we utilized a collection of diverse B. cinerea isolates to investigate resistance within the Brassica rapa R500 × IMB211 recombinant inbred line population. We tested variation on lesion development and glucosinolate accumulation in parental lines and all population lines. We then mapped quantitative trait loci (QTL) for both resistances to B. cinerea and defense metabolites in this population. Phenotypic analysis and QTL mapping demonstrate that the genetic basis of resistance to B. cinerea in B. rapa is isolate specific and polygenic with transgressive segregation that both parents contribute resistance alleles. QTLs controlling defensive GSLs are highly dependent on pathogen infection. An overlap of two QTLs identified between resistance to B. cinerea and defense metabolites also showed isolate specific effects. This work suggests that directly searching for resistance loci may not be the best approach at improving resistance in B. rapa to necrotrophic pathogen.

The chemical composition of a plant cuticle can change in response to various abiotic or biotic stresses and plays essential functions in disease resistance responses. Arabidopsis thaliana mutants altered in cutin content are resistant to Botrytis cinerea , presumably because of increased cuticular water and solute permeability, allowing for faster induction of defense responses. Within this context, our knowledge of wax mutants is limited against this pathogen. We tested the contribution of cuticular components to immunity to B. cinerea using mutants altered in either cutin or wax alone, or in both cutin and wax contents. We found that even all the tested mutants showed increased permeability and reactive oxygen species (ROS) accumulation in comparison with wild-type plants and that only cutin mutants showed resistance. To elucidate the early molecular mechanisms underlying cuticle-related immunity, we performed a transcriptomic analysis. A set of upregulated genes involved in cell wall integrity and accumulation of ROS were shared by the cutin mutants bdg , lacs2-3 , and eca2 , but not by the wax mutants cer1-4 and cer3-6. Interestingly, these genes have recently been shown to be required in B. cinerea resistance. In contrast, we found the induction of genes involved in abiotic stress shared by the two wax mutants. Our study reveals new insight that the faster recognition of a pathogen by changes in cuticular permeability is not enough to induce resistance to B. cinerea , as has previously been hypothesized. In addition, our data suggest that mutants with resistant phenotype can activate other defense pathways, different from those canonical immune ones. [ABSTRACT FROM AUTHOR]

The chemical composition of a plant cuticle can change in response to various abiotic or biotic stresses and plays essential functions in disease resistance responses. Arabidopsis thaliana mutants altered in cutin content are resistant to Botrytis cinerea, presumably because of increased cuticular water and solute permeability, allowing for faster induction of defense responses. Within this context, our knowledge of wax mutants is limited against this pathogen. We tested the contribution of cuticular components to immunity to B. cinerea using mutants altered in either cutin or wax alone, or in both cutin and wax contents. We found that even all the tested mutants showed increased permeability and reactive oxygen species (ROS) accumulation in comparison with wild-type plants and that only cutin mutants showed resistance. To elucidate the early molecular mechanisms underlying cuticle-related immunity, we performed a transcriptomic analysis. A set of upregulated genes involved in cell wall integrity and accumulation of ROS were shared by the cutin mutants bdg, lacs2-3, and eca2, but not by the wax mutants cer1-4 and cer3-6. Interestingly, these genes have recently been shown to be required in B. cinerea resistance. In contrast, we found the induction of genes involved in abiotic stress shared by the two wax mutants. Our study reveals new insight that the faster recognition of a pathogen by changes in cuticular permeability is not enough to induce resistance to B. cinerea, as has previously been hypothesized. In addition, our data suggest that mutants with resistant phenotype can activate other defense pathways, different from those canonical immune ones.

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 H 2 O 2 , and the increased content of O 2 •−. 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. [Display omitted] • Over-expression of SlWRKY46 in tomato plant increases susceptibility to B.cinerea. • SlWRKY46 overexpressor reduced gene expression involved in SA and JA pathways. • Over-expression of SlWRKY46 decreased H 2 O 2 content and increased O 2.•− content. [ABSTRACT FROM AUTHOR]

Autophagy is critical for plant defense against necrotrophic pathogens, which causes serious yield loss on crops. However, the post-translational regulatory mechanisms of autophagy pathway in plant resistance against necrotrophs remain poorly understood. In this study, we report that phosphorylation modification on ATG18a, a key regulator of autophagosome formation in Arabidopsis thaliana, constitutes a post-translation regulation of autophagy, which attenuates plant resistance against necrotrophic pathogens. We found that phosphorylation of ATG18a suppresses autophagosome formation and its subsequent delivery into the vacuole, which results in reduced autophagy activity and compromised plant resistance against Botrytis cinerea. In contrast, overexpression of ATG18a dephosphorylation-mimic form increases the accumulation of autophagosomes and complements the plant resistance of atg18a mutant against B. cinerea. Moreover, BAK1, a key regulator in plant resistance, was identified to physically interact with and phosphorylate ATG18a. Mutation of BAK1 blocks ATG18a phosphorylation at four of the five detected phosphorylation sites after B. cinerea infection and strongly activates autophagy, leading to enhanced resistance against B. cinerea. Collectively, the identification of functional phosphorylation sites on ATG18a and the corresponding kinase BAK1 unveiled how plant regulates autophagy during resistance against necrotrophic pathogens. Abbreviations:35s: the cauliflower mosaic virus 35s promoter; A. thaliana: Arabidopsis thaliana; A. brassicicola: Alternaria brassicicola; ABA: abscisic acid; ATG: autophagy-related; ATG18a: autophagy-related protein 18a in A. thaliana; ATG8a: autophagy-related protein 8a in A. thaliana; ATG8–PE: ATG8 conjugated with PE; B. cinerea: Botrytis cinerea; BAK1: Brassinosteroid insensitive 1-associated receptor kinase1 in A. thaliana; BiFC: biomolecular fluorescence complementation; BIK1: Botrytis-insensitive kinase 1 in A. thaliana; BKK1: BAK1-like 1 in A. thaliana; BR: brassinosteroid; Co-IP: coimmunoprecipitation; dai: days after inoculation; DAMPs: damage-associated molecular patterns; E. coli: Escherochia coli; ER: endoplasmic reticulum; ETI: effector-triggered immunity; GFP: green fluorescent protein; HA: hemagglutinin; IP: immunoprecipitation; LC-MS/MS: liquid chromatography-tandem mass spectrometry; LCI: luciferase complementation imaging; MPK3: mitogen-activated protein kinase 3 in A. thaliana; MPK4: mitogen-activated protein kinase 4 in A. thaliana; MPK6: mitogen-activated protein kinase 6 in A. thaliana; N. benthamiana: Nicotiana benthamiana; NES: nuclear export sequence; PAMP: pathogen-associated molecular pattern; PCR: polymerase chain reaction; PE: phosphatidylethanolamine; PRR: pattern recognition receptor; PtdIns(3,5)P2: phosphatidylinositol (3,5)-biphosphate; PtdIns3P: phosphatidylinositol 3-biphosphate; PTI: PAMP-triggered immunity; qRT-PCR: quantitative reverse transcription PCR; SnRK2.6: SNF1-related protein kinase 2.6 in A. thaliana; TORC1: the rapamycin-sensitive Tor complex1; TRAF: tumor necrosis factor receptor-associated factor; WT: wild type plant; Yc: C-terminal fragment of YFP; YFP: yellow fluorescent protein; Yn: N-terminal fragment of YFP [ABSTRACT FROM AUTHOR]

SKIP, a component of the spliceosome, is involved in numerous signaling pathways. However, there is no direct genetic evidence supporting the function of SKIP in defense responses. In this paper, two SKIPs, namely, SlSKIP1a and SlSKIP1b, were analyzed in tomato. qRT-PCR analysis showed that the SlSKIP1b expression was triggered via Pseudomonas syringae pv. tomato (Pst) DC3000 and Botrytis cinerea (B. cinerea), together with the defense-associated signals. In addition, the functions of SlSKIP1a and SlSKIP1b in disease resistance were analyzed in tomato through the virus-induced gene silencing (VIGS) technique. VIGS-mediated SlSKIP1b silencing led to increased accumulation of reactive oxygen species (ROS), along with the decreased expression of defense-related genes (DRGs) after pathogen infection, suggesting that it reduced B. cinerea and Pst DC3000 resistance. There was no significant difference in B. cinerea and Pst DC3000 resistance in TRV-SlSKIP1a-infiltrated plants compared with the TRV-GUS-silencing counterparts. As suggested by the above findings, SlSKIP1b plays a vital role in disease resistance against pathogens possibly by regulating the accumulation of ROS as well as the expression of DRGs.

Botrytis cinerea is an important necrotrophic fungal pathogen with a broad host range and the ability to causing great economic losses in cucumber. However, the resistance mechanism against this pathogen in cucumber was not well understood. In this study, the microscopic observation of the spore growth, redox status measurements and transcriptome analysis were carried out after Botrytis cinerea infection in the resistant genotype No.26 and its susceptible mutant 26M. Results revealed shorter hypha, lower rate of spore germination, less acceleration of H2O2, O2-, and lower total glutathione content (GSH+GSSG) in No.26 than that in 26M, which were identified by the staining result of DAB and NBT. Transcriptome data showed that after pathogen infection, a total of 3901 and 789 different expression genes (DEGs) were identified in No.26 and 26M respectively. These DEGs were highly enriched in redox regulation pathway, hormone signaling pathway and plant-pathogen interaction pathway. The glutathione S-transferase genes, putative peroxidase gene, and NADPH oxidase were up-regulated in No.26 whereas these genes changed little in 26M after Botrytiscinerea infection. Jasmonic acid and ethylene biosynthesis and signaling pathways were distinctively activated in No.26 comparing with 26M upon infection. Much more plant defense related genes including mitogen-activated protein kinases, calmodulin, calmodulin-like protein, calcium-dependent protein kinase, and WRKY transcription factor were induced in No.26 than 26M after pathogen infection. Finally, a model was established which elucidated the resistance difference between resistant cucumber genotype and susceptible mutant after B. cinerea infection.

SKIP, a component of the spliceosome, is involved in numerous signaling pathways. However, there is no direct genetic evidence supporting the function of SKIP in defense responses. In this paper, two SKIPs , namely, SlSKIP1a and SlSKIP1b , were analyzed in tomato. qRT-PCR analysis showed that the SlSKIP1b expression was triggered via Pseudomonas syringae pv. tomato (Pst) DC3000 and Botrytis cinerea (B. cinerea), together with the defense-associated signals. In addition, the functions of SlSKIP1a and SlSKIP1b in disease resistance were analyzed in tomato through the virus-induced gene silencing (VIGS) technique. VIGS-mediated SlSKIP1b silencing led to increased accumulation of reactive oxygen species (ROS), along with the decreased expression of defense-related genes (DRGs) after pathogen infection, suggesting that it reduced B. cinerea and Pst DC3000 resistance. There was no significant difference in B. cinerea and Pst DC3000 resistance in TRV- SlSKIP1a -infiltrated plants compared with the TRV- GUS -silencing counterparts. As suggested by the above findings, SlSKIP1b plays a vital role in disease resistance against pathogens possibly by regulating the accumulation of ROS as well as the expression of DRGs. [ABSTRACT FROM AUTHOR]

Amino acid metabolic pathways are involved in the plant immune system. Pipecolic acid (Pip), a lysine‐derived non‐protein amino acid, acts as an important regulator of disease resistance. Here, we report the functions of Pip on tomato disease resistance. Tomato seedlings treated with 0.5 mM Pip showed increased resistance to Pst DC3000 and B. cinerea compared with the control. After pathogen infection, the expression of defence‐related genes increased in plants pretreated with Pip, while reactive oxygen species (ROS) accumulation decreased. These data demonstrated that exogenous application of Pip induced resistance against Pst DC3000 and B. cinerea in tomatoes, possibly through the regulation of ROS accumulation and defence‐related gene expression. [ABSTRACT FROM AUTHOR]

Botrytis cinerea is an important necrotrophic fungal pathogen with a broad host range and the ability to causing great economic losses in cucumber. However, the resistance mechanism against this pathogen in cucumber was not well understood. In this study, the microscopic observation of the spore growth, redox status measurements and transcriptome analysis were carried out after Botrytis cinerea infection in the resistant genotype No.26 and its susceptible mutant 26M. Results revealed shorter hypha, lower rate of spore germination, less acceleration of H2O2, O2-, and lower total glutathione content (GSH+GSSG) in No.26 than that in 26M, which were identified by the staining result of DAB and NBT. Transcriptome data showed that after pathogen infection, a total of 3901 and 789 different expression genes (DEGs) were identified in No.26 and 26M respectively. These DEGs were highly enriched in redox regulation pathway, hormone signaling pathway and plant-pathogen interaction pathway. The glutathione S-transferase genes, putative peroxidase gene, and NADPH oxidase were up-regulated in No.26 whereas these genes changed little in 26M after Botrytis cinerea infection. Jasmonic acid and ethylene biosynthesis and signaling pathways were distinctively activated in No.26 comparing with 26M upon infection. Much more plant defense related genes including mitogen-activated protein kinases, calmodulin, calmodulin-like protein, calcium-dependent protein kinase, and WRKY transcription factor were induced in No.26 than 26M after pathogen infection. Finally, a model was established which elucidated the resistance difference between resistant cucumber genotype and susceptible mutant after B. cinerea infection. [ABSTRACT FROM AUTHOR]

Copyright of Arab Journal of Plant Protection is the property of Arab Society for Plant Protection and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] A series of flavonoid derivatives containing 1,2,4-triazolo[4,3- a ]pyridine were designed, synthesized and evaluated for their antifungal activity. Bioactivity tests showed that some target compounds exhibited the strong antifungal activity against Botrytis cinerea (B. cinerea), Sclerotinia sclerotiorum (S. sclerotiorum), and Phomopsis sp. Among them, the half maximal effective concentration (EC 50) value of S2 against B. cinerea was 3.3 μg/mL, which was less than that of the control drug azoxystrobin (21.0 μg/mL). The EC 50 value of S2 against S. sclerotiorum was 12.7 μg/mL, which was better than that of azoxystrobin (28.1 μg/mL). In addition, the in vivo protective and curative activities of S2 against blueberry were 92.0 and 79.8 % at 200 μg/mL, respectively, which were higher than those of the control drug azoxystrobin (89.4 and 71.7 %). Scanning electron microscopy (SEM) and spore germination experiments showed that S2 could not only cause the mycelium damage but also inhibited the spore germination. Fluorescence microscopy (FM) observation, relative electrical conductivity measurement and cytoplasmic leakage assays indicated that S2 could affect cell membrane integrity by inducing lipid peroxidation and increasing cell membrane permeability as well as causing leakage of cytoplasmic contents. These results show that flavonoid derivatives containing 1,2,4-triazolo[4,3- a ]pyridine had excellent inhibitory effects on B. cinerea , providing another supplement for the development of new pesticides. [ABSTRACT FROM AUTHOR]

Copyright of Arab Journal of Plant Protection is the property of Arab Society for Plant Protection and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: The efficacy of Candida sake CPA‐1 as a biocontrol agent against several diseases has been studied since it was isolated 20 years ago. However, it was only recently that two suitable and effective film‐forming formulations based on potato starch and maltodextrins were developed using the fluidized‐bed spray‐drying system. The present work aimed to confirm the capability of both novel formulations by testing their resilience on grapes at different temperatures (0, 22, and 30 °C), relative humidities (40% and 85%), and simulated rainfall levels. Another objective was to examine the control of Botrytis cinerea in different hosts. RESULTS: The CPA‐1 cells from both dried formulations survived better than the liquid formulation on grapes stored at 0 and 22 °C regardless of the relative humidity. After simulated rainfall, potato starch formulation achieved significantly higher populations than maltodextrin formulation, although the highest reduction was −1.6 log N N0−1. A positive effect of cell establishment prior to the simulated rainfall was shown, and recovered cells from the potato starch formulation were significantly higher after 72 h of cell establishment. Finally, both formulations reduced the incidence and severity of B. cinerea on pears, apples, and tomatoes. CONCLUSION: The potential of these novel film‐forming formulations of C. sake CPA‐1 was verified. The resilience of formulated C. sake was better than the commercialized liquid formulation, the adherence of the formulations to the grapes improved after an establishment period prior to rain exposure, and the control of B. cinerea was verified in a wider range of hosts. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Polyamines (PAs) are ubiquitous small aliphatic polycations important for growth, development, and environmental stress responses in plants. Here, we demonstrate that exogenous application of spermine (Spm) and spermidine (Spd) induced cell death at high concentrations, but primed resistance against the necrotrophic fungus Botrytis cinerea in Arabidopsis. At low concentrations, Spm was more effective than Spd. Treatments with higher exogenous Spd and Spm concentrations resulted in a biphasic endogenous PA accumulation. Exogenous Spm induced the accumulation of H2O2 after treatment but also after infection with B. cinerea. Both Spm and Spd induced the activities of catalase, ascorbate peroxidase, and guaiacol peroxidase after treatment but also after infection with B. cinerea. The soluble sugars glucose, fructose, and sucrose accumulated after treatment with high concentrations of PAs, whereas only Spm induced sugar accumulation after infection. Total and active nitrate reductase (NR) activities were inhibited by Spm treatment, whereas Spd inhibited active NR at low concentrations but promoted active NR at high concentrations. Finally, γaminobutyric acid accumulated after treatment and infection in plants treated with high concentrations of Spm. Phenylalanine and asparagine also accumulated after infection in plants treated with a high concentration of Spm. Our data illustrate that Spm and Spd are effective in priming resistance against B. cinerea, opening the door for the development of sustainable alternatives for chemical pesticides.

Table grapes artificially inoculated with B. Cinerea were tested under four different ozonation strategies in order to achieve prolongation of table grapes’ shelf-life time. Decay incidence, external disease appearance, number of infected grapes, weight loss and a variety of quality parameters such as sugars and proteins content were checked after every 3 days. No significant alteration of table grapes quality characteristics was observed after their exposure to ozone atmosphere. Moreover, the low ozone dosage process (0.3 ppm) caused sufficient restriction of fruit decay due to fungal contamination and secured a 40-days-period of storage time. However, the observed weight loss was somewhat higher on the treated samples compared to the untreated ones. From technical and economical point of view the low dosage (0.3 ppm) ozonation process on a daily basis combined with the cold storage appears to a very promising method for table grapes preservation. [ABSTRACT FROM AUTHOR]

Peru has a high productive potential due to ideal climatic conditions and a favorable soil for the cultivation of different agricultural export products, but the phytosanitary problems caused by different pathogens in the different phenological stages of the crop generate significant losses in quality and quantity of product harvested in the field and after harvest. Therefore, this research aimed to measure the effectiveness of chemical products through the poisoned food test. In vitro, seven active ingredients were tested: tiabendazole, azoxystrobin, carbendazim, copper sulfate pentahydrate, copper phosphite, chlorothalonil and extract of Melaleuca alternifolia. For this, the percentage of inhibition of mycelial growth (PIMG) was evaluated. In this in vitro test, 100 % PIMG was obtained for: R. solani with copper sulfate pentahydrate; P. infestans and S. sclerotiorum with azoxystrobin; R. solani, F. oxysporum, L. theobromae, S. sclerotiorum, C. gloeosporoides and Penicillium spp. with carbendazim; F. oxysporum, B. cinerea, L. theobromae, S. sclerotiorum with copper phosphite; R. solani, F. oxysporum, L. theobromae and Penicillium spp. with tiabendazole. The extract of Melaleuca alternifolia had the lowest PIMG for F. oxysporum and R. solani with an inhibition of the pathogen of 69.50 and 64.75 % respectively. [ABSTRACT FROM AUTHOR]

Arabidopsis contains two proline dehydrogenase (ProDH) genes, ProDH1 and ProDH2, encoding for homologous and functional isoenzymes. Although ProDH1 has been studied extensively, especially under abiotic stress, ProDH2 has only started to be analysed in recent years. These genes display distinctive expression patterns and show weak transcriptional co-regulation, but are both activated in pathogen-infected tissues. We have demonstrated previously that Arabidopsis plants with silenced ProDH1/2 expression fail to trigger defences against the hemibiotrophic bacterial pathogen Pseudomonas syringae pv. tomato AvrRpm1 ( Pst-AvrRpm1), and that ProDH1 and ProDH2 are differentially regulated by salicylic acid (SA). In the current work, we used prodh1 and prodh2 single-mutant plants to assess the particular contribution of each gene to resistance against Pst-AvrRpm1 and the necrotrophic fungal pathogen Botrytis cinerea. In addition, we studied the sensitivity of ProDH1 and ProDH2 to the jasmonic acid (JA) defence pathway. We found that ProDH1 and ProDH2 are both necessary to achieve maximum resistance against Pst-AvrRpm1 and B. cinerea. However, ProDH2 has a major effect on early restriction of B. cinerea growth. Interestingly, ProDH1 is up-regulated by SA and JA, whereas ProDH2 is only activated by JA, and both genes display transcriptional inter-regulation at basal and infection conditions. These studies provide the first evidence of the contribution of ProDH2 to disease resistance, and describe the differential regulation and non-redundant but complementary function of both enzyme isoforms in infected tissues, providing support for a fundamental role of ProDH in the control of biotrophic and necrotrophic pathogens. [ABSTRACT FROM AUTHOR]

Plant pathogens cause huge yield losses. Plant defense often depends on toxic secondary metabolites that inhibit pathogen growth. Because most secondary metabolites are also toxic to the plant, specific transporters are needed to deliver them to the pathogens. To identify the transporters that function in plant defense, we screened Arabidopsis thaliana mutants of full-size ABCG transporters for hypersensitivity to sclareol, an antifungal compound. We found that atabcg34 mutants were hypersensitive to sclareol and to the necrotrophic fungi Alternaria brassicicola and Botrytis cinerea. AtABCG34 expression was induced by A. brassicicola inoculation as well as by methyl-jasmonate, a defense-related phytohormone, and AtABCG34 was polarly localized at the external face of the plasma membrane of epidermal cells of leaves and roots. atabcg34 mutants secreted less camalexin, a major phytoalexin in A. thaliana, whereas plants overexpressing AtABCG34 secreted more camalexin to the leaf surface and were more resistant to the pathogen. When treated with exogenous camalexin, atabcg34 mutants exhibited hypersensitivity, whereas BY2 cells expressing AtABCG34 exhibited improved resistance. Analyses of natural Arabidopsis accessions revealed that AtABCG34 contributes to the disease resistance in naturally occurring genetic variants, albeit to a small extent. Together, our data suggest that AtABCG34 mediates camalexin secretion to the leaf surface and thereby prevents A. brassicicola infection. [ABSTRACT FROM AUTHOR]