Pathogenesis-related Research Articles

Identification of new salicylic acid signaling regulators for root development and microbiota composition in plants.

Besides playing a crucial role in plant immunity via the nonexpressor of pathogenesis-related (NPR) proteins, increasing evidence shows that salicylic acid (SA) can also regulate plant root growth. However, the transcriptional regulatory network controlling this SA response in plant roots is still unclear. Here, we found that NPR1 and WRKY45, the central regulators of SA response in rice leaves, control only a reduced sector of the root SA signaling network. We demonstrated that SA attenuates root growth via a novel NPR1/WRKY45-independent pathway. Furthermore, using regulatory network analysis and mutant characterization, we identified a set of new NPR1/WRKY45-independent regulators that conservedly modulate the root development and root-associated microbiota composition in both Oryza sativa (monocot) and Arabidopsis thaliana (dicot) in response to SA. Our results established the SA signaling as a central element regulating plant root functions under ecologically relevant conditions. These results provide new insights to understand how regulatory networks control plant responses to abiotic and biotic stresses.

Isolation and functional characterization of a pathogenesis-related protein 4 gene from Panax notoginseng

Isolation and functional characterization of a pathogenesis-related protein 4 gene from Panax notoginseng

Impact of homologous overexpression of PR10a gene on improving salt stress tolerance in transgenic Solanum tuberosum

Abiotic stresses severely affected crop productivity and considered to be a major yield limiting factor for crop plant. The tolerance to these stresses is a very complex phenomenon involving a wide array of molecular, biochemical and physiological changes in plant cells. Therefore, it is challenging to understand the molecular basis of abiotic stress tolerance to manipulate it for improving abiotic stress tolerance of major crops. Biotechnological approaches and genetic engineering including homologous gene overexpression can be implemented to understand gene functions under well-defined conditions. The Pathogenesis-related proteins (PR10) such as PR10a play multiple roles in biotic and abiotic stress tolerance and, hence, plant development. A PR10a gene from potato cv. Deseree was introduced into three cultivars of potato (Solanum tuberosum L.) by Agrobacterium tumefaciens-mediated genetic transformation. Transgenic plants were selected on a medium containing 1.0 mg/l phosphinothricin (PPT) and confirmed by polymerase chain reaction (PCR), herbicide (BASTA®) leaf paint assay, and Real-Time- quantitative PCR analyses (qPCR). All of the selected transformants showed completely tolerance to the application of PPT application. Experiments designed for testing salt tolerance revealed that there was enhanced salt tolerance of the transgenic lines in vitro in terms of morphological (plant FW, plant DW and plant height) and antioxidant activates as compared to the non-transgenic control plants. qRT-PCR showed that the expression of PR10a gene in the transgenic potato is higher than that in non-transgenic control under salt stress. The relative PR10a gene-expression patterns in the transgenic plants shed lights into the molecular response of homologues overexpressed PR10a potato to salt-stress conditions. The obtained results provide insights on the fact that PR10a plays a major role regarding salt stress tolerance in potato plants

Characterization of the chitinase gene family in Saccharum reveals the disease resistance mechanism of ScChiVII1.

A chitinase gene ScChiVII1 which is involved in defense against pathogen stress was characterized in sugarcane. Chitinases, a subclass of pathogenesis-related proteins, catalyze chitin hydrolysis and play a key role in plant defense against chitin-containing pathogens. However, there is little research on disease resistance analysis of chitinase genes in sugarcane, and the systematic identification of their gene families has not been reported. In this study, 85 SsChi and 23 ShChi genes, which were divided into 6 groups, were identified from the wild sugarcane species Saccharum spontaneum and Saccharum hybrid cultivar R570, respectively. Transcriptome analysis and real-time quantitative PCR revealed that SsChi genes responded to smut pathogen stress. The chitinase crude extracted from the leaves of transgenic Nicotiana benthamiana plants overexpressing ScChiVII1 (a homologous gene of SsChi22a) inhibited the hyphal growth of Fusarium solani var. coeruleum and Sporisorium scitamineum. Notably, the chitinase and catalase activities and the jasmonic acid content in the leaves of ScChiVII1 transgenic N. benthamiana increased after inoculation with F solani var. coeruleum, but the salicylic acid, hydrogen peroxide, and malondialdehyde contents decreased. Comprehensive RNA sequencing of leaves before (0day) and after inoculation (2days) revealed that ScChiVII1 transgenic tobacco enhanced plant disease resistance by activating transcription factors and disease resistance-related signaling pathways, and modulating the expression of genes involved in the hypersensitive response and ethylene synthesis pathways. Taken together, this study provides comprehensive information on the chitinase gene family and offers potential genetic resources for disease resistance breeding in sugarcane.

Pathogenesis related proteins: milestones in five decades of research

Pathogenesis related proteins: milestones in five decades of research

The fungal effector AaAlta1 inhibits PATHOGENESIS-RELATED PROTEIN10-2-mediated callose deposition and defense responses in apple.

Apple leaf spot, caused by Alternaria alternata f. sp mali (ALT), poses a substantial threat to the global apple (Malus × domestica Borkh.) industry. Fungal effectors promote pathogen infestation and survival by interfering with plant immune responses. In our study, we investigated the secretion of effector proteins by the virulent ALT7 strain. Using mass spectrometry, we identified the effector AaAlta1, which belongs to the Alt a 1 protein family (AA1s). Further analysis confirmed that ALT7 secretes AaAlta1. AaAlta1 knockdown mutants displayed reduced pathogenicity in apple tissue culture seedlings, while overexpression strains exhibited enhanced pathogenicity compared to the wild-type ALT7 strain. Using immunoprecipitation followed by mass spectrometry, we isolated pathogenesis-related protein 10-2 (PR10-2) as an interaction partner of AaAlta1 in apple. Knockdown mutants of AaAlta1 showed increased PR10-2-mediated callose deposition in apple, a critical plant defense response. The enhanced defense responses in apple substantially reduced their susceptibility to infection by these ALT7 mutants. Our findings delineate an infection strategy whereby ALT7 secretes AaAlta1 to suppress PR10-2, thereby circumventing the apple defense system.

Root-Knot Nematode Early Infection Suppresses Immune Response and Elicits the Antioxidant System in Tomato

The immune response in plants is regulated by several phytohormones and involves the overexpression of defense genes, including the pathogenesis-related (PR-) genes. The data reported in this paper indicate that nematodes can suppress the immune response by inhibiting the expression of defense genes. Transcripts from nine defense genes were detected by qRT-PCR in the roots of tomato plants at three and seven days post-inoculation (dpi) with living juveniles (J2s) of Meloidogyne incognita (root-knot nematodes, RKNs). All the salicylic acid (SA)-responsive genes tested (PR-1, PR-2, PR-4b, PR-5) were down-regulated in response to nematode infection. On the contrary, the expression of jasmonic acid (JA)-responsive genes, including ACO (encoding the enzyme 1-aminocyclopropane-1-carboxylic acid oxidase, which catalyzes the last step of ethylene (ET) biosynthesis) and JERF3 (Jasmonate Ethylene Response Factor 3), was unaffected by the infection. Conversely, the effect of nematode attack on the activities of the defense enzymes endoglucanase and endochitinase, encoded by PR-2 and PR-3, respectively, changed depending on the tested dpi. At 5 dpi, both enzymes were inhibited in inoculated plants compared to healthy controls. The genes encoding glutathione peroxidase (GPX) and catalase (CAT), both part of the antioxidant plant system, were highly overexpressed. Additionally, the activity of the antioxidant enzymes superoxide dismutase (SOD), CAT, and ascorbate peroxidase (APX) was enhanced in infected roots. Isoelectrofocusing of root extracts revealed novel SOD isoforms in samples from inoculated plants. Furthermore, plants were pre-treated with an array of key compounds, including hormone generators, inhibitors of SA or JA-mediated defense pathways, reactive oxygen species (ROS) scavengers and generators, inhibitors of ROS generation, and compounds that interfere with calcium-mediated metabolism. After treatments, plants were inoculated with RKNs, and nematodes were allowed to complete their life cycle. Factors of plant growth and infection level in treated plants were compared with those from untreated inoculated plants. Generally, compounds that decreased SA and/or ROS levels increased infection severity, while those that reduced JA/ET levels did not affect infection rates. ROS generators induced resistance against the pests. Compounds that silence calcium signaling by preventing its intake augmented infection symptoms. The data shown in this paper indicate that SA-mediated plant immune responses are consistently suppressed during the early stages of nematode infection, and this restriction is associated with the activation of the antioxidant ROS-scavenging system.

Transcriptome analysis for the identification of spot blotch responsive genes and miRNAs in wheat

Spot blotch caused by Bipolaris sorokiniana is one of the most devastating foliar diseases of wheat particularly in South Asian countries including India, Nepal, Bangladesh etc. In the present study, using whole genome transcriptome sequencing data from two contrasting genotypes for spot blotch disease (one resistant and the other susceptible), at three time points after inoculation, we identified a large number of differentially expressed genes (DEGs) and many microRNAs (miRNAs) with their target genes (in silico). The mean number of reads in six libraries were 39.8 millions with a range of 32.1–44.9 million reads per library. The reads from resistant and susceptible genotypes were aligned. The aligned reads had a mean of 32.4 million with a range of 25.0–37.1 million reads. The raw data were deposited into the National Center for Biotechnology Information (NCBI) database under the SRA accession number PRJNA1182498. The DEGs included 5294 upregulated and 4383 downregulated genes. Functional annotation and enrichment analysis showed that the main pathways enriched for the DEGs included photosynthesis-antenna proteins, MAPK signaling pathways, plant-pathogen interactions, circadian rhythm-plant, etc. These DEGs mainly encoded proteins with leucine rich repeat (LRR) domain, F-box-like domain, non-specific serine/threonine-protein kinases (S/TPK), wall-associated receptor kinases (WAKs), etc. Many DEGs also belonged to the following families of transcription factors (TFs): ERF, NAC, WRKY, GRAS, MYB etc. Few DEGs were also associated with pathogenesis related (PR) proteins including PR 1.1, PR 1.2, PR 1.17 and PR 1.19. The results of the present study may be utilized by plant breeders, geneticists and bioinformatician for further research.

Effect of elevated ammonium on biotic and abiotic stress defense responses and expression of related genes in cucumber (Cucumis sativus L.) plants

Ammonium (NH4+) enhances plant defense mechanisms but can be phytotoxic as the sole nitrogen source. To investigate the impact of a balanced NH4+ and NO3− ratio on plant defense parameters without adverse effects, cucumber plants (Cucumis sativus L.) were grown under control (14 mM NO3− + 2 mM NH4+) and elevated level of NH4+ (eNH4+, 8 mM NO3−+ 8 mM NH4+). Plants subjected to eNH4+ showed significantly increased shoot and root biomass by about 41% and 47%, respectively. Among the antioxidant enzymes studied, ascorbate peroxidase (EC 1.11.1.11) activity was increased up to 3.3 fold in eNH4+ compared with control plants, which was associated with enhanced resistance to paraquat. Upregulation of PATHOGENESIS RELATED PROTEIN 4 (PR4) and LIPOXYGENASE 1 (LOX1), accompanied by increased concentrations of salicylic acid and nitric oxide, conferred more excellent resistance of eNH4+ plants to powdery mildew infection. However, the expression levels of ACC OXIDASE 1 (ACO1) and RESPIRATORY BURST OXIDASE HOMOLOGS B (RBOHB) were lower in eNH4+ plants, which was consistent with decreased NADPH oxidase activity and lower leaf H2O2 levels. The biosynthesis of phenolics was enhanced, whereas the activities of polymerizing enzymes and lignin deposition were reduced by half in eNH4+ plants. Besides, a significant effect on plant biomass under salt or drought stress has not been observed between control and eNH4+ plants. These results showed that different defense pathways are distinctively affected by eNH4+ treatment, and the NH4+ to NO3− ratio may play a role in fine-tuning the plant defense response.

Genome-Wide Identification and Stress Responses of Cowpea Thaumatin-like Proteins: A Comprehensive Analysis.

Cowpea (Vigna unguiculata (L.) Walp.) is an important legume cultivated mainly in regions with limited water availability across the African and American continents. Its productivity is significantly affected by environmental stresses. Thaumatin-like proteins (TLPs), which belong to the PR-5 (pathogenesis-related 5) protein family, are known to be responsive to both biotic and abiotic stresses. However, their role remains controversial, with some TLPs associated with plant defense (particularly against fungal infections) and others associated with abiotic stresses response. In this study, we evaluated the structural diversity and gene expression of TLPs in cowpea (VuTLPs) under different stress conditions, including biotic [mechanical injury followed by inoculation with Cowpea Aphid-borne Mosaic Virus (CABMV) or Cowpea Severe Mosaic Virus (CPSMV)] and abiotic (root dehydration). Genomic anchoring of VuTLPs revealed 34 loci encoding these proteins. Neighbor- joining analysis clustered the VuTLPs into three distinct groups. We identified 15 segmental duplication and 6 tandem duplication gene pairs, with the majority of VuTLP genes found to be under purifying selection. Promoter analysis associated VuTLPs with bHLH, Dof-type, and MYB- related transcription factors, supporting their diverse roles. Diversity in VuTLP function was also observed in their expression profiles under the studied stress conditions. Gene expression data showed that most VuTLPs are recruited within the first minutes after biotic stress imposition. For the root dehydration assay, the most transcripts were up-regulated 150 min post-stress. Moreover, the gene expression data suggested that VuTLPs exhibit functional specialization depending on the stress condition, highlighting their diverse roles and biotechnological potential.

Turnip mosaic virus selectively subverts a PR-5 thaumatin-like, plasmodesmal protein to promote viral infection.

Pathogenesis-related (PR) proteins are induced by abiotic and biotic stresses and generally considered as part of the plant defense mechanism. However, it remains yet largely unclear if and how they are involved in virus infection. Our recent quantitative, comparative proteomic study identified three PR-5 family proteins that are significantly differentially accumulated in the plasmodesmata (PD)-enriched fraction isolated from Nicotiana benthamiana leaves infected by turnip mosaic virus (TuMV). In this study, we employed the TuMV-Arabidopsis pathosystem to characterize the involvement of two Arabidopsis orthologs, AtOSM34 and AtOLP of the three N. benthamiana PR-5-like proteins. We show that AtOSM34 and AtOLP are PD-localized proteins and their expression is up- and downregulated in response to TuMV infection, respectively. Deficiency or overexpression of AtOLP does not affect viral RNA accumulation. Knockdown of AtOSM34 inhibits TuMV infection, whereas its overexpression promotes viral infection. We further demonstrate that AtOSM34 functions as a proviral factor through diminishing PD callose deposition to promote viral intercellular movement, targeting the viral replication complex to enhance viral replication, and suppressing the ROS-mediated antiviral response. Taken together, these data suggest that TuMV has evolved the ability to selectively upregulate and subvert AtOSM34, a PR-5 family protein to assist its infection.

Transcriptomic responses of Solanum tuberosum cv. Pirol to arbuscular mycorrhiza and potato virus Y (PVY) infection

Arbuscular mycorrhizal fungi (AMF) serve as both plant symbionts and allies in resisting pathogens and environmental stresses. Mycorrhizal colonization of plant roots can influence the outcomes of plant-pathogen interactions by enhancing specific host defense mechanisms. The transcriptional responses induced by AMF in virus-infected plants remain largely unexplored. In the presented study, we employed a comprehensive transcriptomic approach and qPCR to investigate the molecular determinants underlying the interaction between AMF and potato virus Y (PVY) in Solanum tuberosum L. Our primary goal was to identify the symbiosis- and defense-related determinants activated in mycorrhizal potatoes facing PVY. Through a comparative analysis of mRNA transcriptomes in experimental treatments comprising healthy and PVY-infected potatoes colonized by two AMF species, Rhizophagus regularis or Funneliformis mosseae, we unveiled the overexpression of genes associated with mycorrhiza, including nutrient exchange, lipid transfer, and cell wall remodeling. Furthermore, we identified several differentially expressed genes upregulated in all mycorrhizal treatments that encoded pathogenesis-related proteins involved in plant immune responses, thus verifying the bioprotective role of AMF. We investigated the relationship between mycorrhiza levels and PVY levels in potato leaves and roots. We found accumulation of the virus in the leaves of mycorrhizal plants, but our studies additionally showed a reduced PVY content in potato roots colonized by AMF, which has not been previously demonstrated. Furthermore, we observed that a virus-dependent reduction in nutrient exchange could occur in mycorrhizal roots in the presence of PVY. These findings provide an insights into the interplay between virus and AMF.

CAP superfamily proteins (VdPRYs) manipulate plant immunity and contribute to the virulence of Verticillium dahliae

ABSTRACT CAP (cysteine-rich secretory proteins, antigen5, pathogenesis-related proteins) superfamily proteins are widely distributed, can be subdivided into 11 subfamilies, and form a unique branch in fungi, named PRY proteins. Verticillium dahliae is a soil-borne fungal pathogen of vascular plants that causes plant Verticillium wilt. However, the roles of CAP superfamily proteins in this fungus is unclear. Here, four CAP superfamily members with a conserved domain were identified in V. dahliae: VdPRY1, VdPRY2, VdPRY3, and VdPRY4. VdPRY1 and VdPRY3 were found to be key in suppressing plant immune responses. Moreover, these four members are highly expressed during early infection of cotton by V. dahliae. Deleting VdPRY1, VdPRY2, or VdPRY3 reduced the fungus’s ability to cause disease, but VdPRY4 deletion did not affect virulence. Deletion of any of four members did not impact fungal growth or carbon source use. Yeast two-hybrid experiments suggest that these proteins may function through interactions with each other. This investigation has, for the initial time, elucidated the pivotal roles of V. dahliae CAP superfamily proteins in inhibiting plant immunity and exerting virulence during interaction with the host plant.

The SA-WRKY70-PR-Callose Axis Mediates Plant Defense Against Whitefly Eggs.

The molecular mechanisms of plant responses to phytophagous insect eggs are poorly understood, despite their importance in insect-plant interactions. This study investigates the plant defense mechanisms triggered by the eggs of whitefly Bemisia tabaci, a globally significant agricultural pest. A transcriptome comparison of tobacco plants with and without eggs revealed that whitefly eggs may activate the response of defense-related genes, including those involved in the salicylic acid (SA) signaling pathway. SA levels are induced by eggs, resulting in a reduction in egg hatching, which suggests that SA plays a key role in plant resistance to whitefly eggs. Employing Agrobacterium-mediated transient expression, virus-induced gene silencing assays, DNA-protein interaction studies, and bioassays, we elucidate the regulatory mechanisms involved. Pathogenesis-related proteins NtPR1-L1 and NtPR5-L2, downstream of the SA pathway, also affect whitefly egg hatching. The SA-regulated transcription factor NtWRKY70a directly binds to the NtPR1-L1 promoter, enhancing its expression. Moreover, NtPR1-L1 promotes callose deposition, which may impede the eggs' access to water and nutrients. This study establishes the SA-WRKY70-PR-callose axis as a key mechanism linking plant responses and defenses against whitefly eggs, providing new insights into the molecular interactions between plants and insect eggs.

Genome-Wide Identification of PR10 Family Members in Durum Wheat: Expression Profile and In Vitro Analyses of TdPR10.1 in Response to Various Stress Conditions.

The functional characterization of PR10 proteins has been extensively studied in many plant species. However, little is known about the role of TdPR10 in the response of durum wheat (Triticum durum Desf.) to stress. In this study, we identified members of the T. durum PR10 family, which are divided into three major subfamilies based on phylogenetic analyses. The analysis revealed that tandem duplication was the primary driver of the expansion of the T. durum PR10 gene family. Additionally, gene structure and motif analyses showed that PR10 family genes were relatively conserved during evolution. We also identified several cis-regulatory elements in the TdPR10 promoter regions related not only to abiotic and biotic stress but also to phytohormonal responses. In response to abiotic stresses and phytohormones, several TdPR10 genes were highly expressed in the leaves and roots of durum wheat. Moreover, TdPR10.1 family members improve RNase activity, increase LDH protective activity under abiotic stress conditions, and ensure resistance to fungi in vitro. Collectively, these findings provide a basis for further functional studies of TdPR10 genes, which could be leveraged to enhance stress tolerance in durum wheat.

Transcription-Aided Selection (TAS) for Crop Disease Resistance: Strategy and Evidence.

A transcription-aided selection (TAS) strategy is proposed in this paper, which utilizes the positive regulatory roles of genes involved in the plant immunity pathways to screen crops with high disease resistance. Increased evidence has demonstrated that upon pathogen attack, the expression of diverse genes involved in salicylic acid (SA)-mediated SAR are differentially expressed and transcriptionally regulated. The paper discusses the molecular mechanisms of the SA signaling pathway, which plays a central role in plant immunity, and identifies differentially expressed genes (DEGs) that could be targeted for transcriptional detection. We have conducted a series of experiments to test the TAS strategy and found that the level of GmSAGT1 expression is highly correlated with soybean downy mildew (SDM) resistance with a correlation coefficient R2 = 0.7981. Using RT-PCR, we screened 2501 soybean germplasms and selected 26 collections with higher levels of both GmSAGT1 and GmPR1 (Pathogenesis-related proteins1) gene expression. Twenty-three out of the twenty-six lines were inoculated with Peronospora manshurica (Pm) in a greenhouse. Eight showed HR (highly resistant), four were R (resistant), five were MR (moderately resistant), three were S (susceptible), and three were HS (highly susceptible). The correlation coefficient R2 between the TAS result and Pm inoculation results was 0.7035, indicating a satisfactory consistency. The authors anticipate that TAS provides an effective strategy for screening crops with broad-spectrum and long-lasting resistance.

Pathogenesis-related protein, thaumatin-like protein 1b is a transdermal sensitizing allergen of mango fruits in mouse models

ABSTRACT Food allergens can enter the skin and increase the susceptibility to food allergies by producing immunoglobulin (Ig) E. Mango is a popular fruit worldwide and known to be allergenic. Dermal sensitization may occur around the oral cavity during ingestion of mangoes. However, to date, no allergenic proteins in mangoes have been shown to cause dermal sensitization in humans or animal models. Therefore, we aimed to identify mango proteins that sensitize mice percutaneously. The occiput of BALB/c mice was shaved, and a crude mango extract containing sodium dodecyl sulfate was applied to the skin. Mango protein-specific IgE and IgG1 were produced in response to this treatment. Proteins in mangoes that bind to mouse IgG1 and IgE were purified and identified as thaumatin-like protein 1b (TLP1b). This is the first study to identify TLP1b, a pan-allergen belonging to a family of pathogenesis-related proteins, as a mango allergen causing transdermal sensitization in mice.

CAP superfamily proteins in human: a new target for cancer therapy.

The CAP (Cysteine-rich secretory protein, Antigen 5, and Pathogenesis-related protein 1) superfamily proteins (CAP proteins) are found in all kingdoms of life. The cysteine-rich secreted proteins are prevalent in human organs and tissues and serve as critical signaling molecules within cells, regulating a wide range of biochemical processes in the human body. Due to their involvement in numerous biological processes, CAP proteins have recently attracted significant attention, particularly in the context of tumorigenesis and cancer therapy. This review summarizes the expression patterns and roles of CAP proteins in various cancers. Additionally, it analyzes the mechanisms by which CAP proteins affect cancer cell proliferation and survival, regulate epithelial-mesenchymal transition, influence drug resistance, and regulate epigenetics. The review reveals that CAP proteins play distinct roles in various signaling pathways, such as the MAPK, PI3K-Akt, and p53 pathways, which are crucial for tumor progression. Furthermore, this review summarizes the tumor-inhibiting function of CAP proteins and their potential as cancer biomarkers. These findings suggest that CAP proteins represent a promising new target for innovative cancer diagnosis and treatment.

Immunity priming and biostimulation by airborne nonanal increase yield of field-grown common bean plants.

Stress-induced volatile organic compounds (VOCs) that induce plant immunity bear potential for biocontrol. Here, we explore the potential of nonanal to enhance the seed yield of common bean (Phaseolus vulgaris) under open field conditions that are realistic for smallholder farmers. Using plastic cups with a nonanal-containing lanolin paste as low-cost dispensers, we observed that exposure of Flor de Junio Marcela (FJM) plants over 48h to airborne nonanal was followed by a 3-fold higher expression of pathogenesis-related (PR) genes PR1 and PR4. Both genes further increased their expression in response to subsequent challenge with the fungal pathogen Colletotrichum lindemuthianum. Therefore, we conclude that nonanal causes resistance gene priming. This effect was associated with ca. 2.5-fold lower infection rates and a 2-fold higher seed yield. Offspring of nonanal-exposed FJM plants exhibited a 10% higher emergence rate and a priming of PR1- and PR4-expression, which was associated with decreased infection by C. lindemuthianum and, ultimately, a ca. 3-fold increase in seed yield by anthracnose-infected offspring of nonanal-exposed plants. Seeds of nonanal-exposed and of challenged plants contained significantly more phenolic compounds (increase by ca 40%) and increased antioxidant and radical scavenging activity. Comparative studies including five widely used bean cultivars revealed 2-fold to 3-fold higher seed yield for nonanal-exposed plants. Finally, a cost-benefit analysis indicated a potential economic net profit of nonanal exposure for some, but not all cultivars. We consider nonanal as a promising candidate for an affordable tool that allows low-income smallholder farmers to increase the yield of an important staple-crop without using pesticides.

Antagonistic manipulation of ER-protein quality control between biotrophic pathogenic fungi and host induced defense

The interaction of plants with pathogens during infection is a multifaceted process involving various molecules deriving from both partners. A current goal in combating pathogen virulence is to induce plant resistance using environmentally friendly compounds. Here, we show that chitosan-based nanoparticles loaded with the defense hormone salicylic acid, can efficiently activate defense responses and reactive oxygen species (ROS) production and PATHOGENESIS RELATED-1 (PR1) expression in Arabidopsis thaliana leaves, and reduce conidial germination of the biotrophic pathogenic fungus Podosphaera xanthii. Transcriptomic and proteomic analyses identified immune response-related upregulated transcripts and proteins after nanoparticle application, highlighting the Leucine Rich Repeat (LRR)-, Systemic Acquired Resistance (SAR)-, and glutathione-related protein groups. Examination of P. xanthii during infection at control conditions, identified ribosomal, hydrolase-related, putative secreted and effector proteins, while nanoparticle application significantly downregulated their expression. An in-depth investigation of the highly expressed proteins in P. xanthii and Arabidopsis revealed the involvement of components of endoplasmic reticulum protein quality control (ERQC) in the pathogen-host interaction. The RPS27A effector protein was identified in fungal virulence, while endoplasmic reticulum (ER) protein processing- and glycosyltransferase-related proteins were implicated in plant's induced defense response following nanoparticle application. Overall, these findings demonstrate that the ERQC is dynamically manipulated by both the pathogen for efficient virulence and by elicitors for plant induced defense.