Profiling of Phakopsora pachyrhizi transcriptome revealed co-expressed virulence effectors as prospective RNA interference targets for soybean rust management.

Soybean rust (SBR), caused by an obligate biotrophic pathogen Phakopsora pachyrhizi, is a devastating disease of soybean worldwide. However, the mechanisms underlying plant invasion by P. pachyrhizi are poorly understood, which hinders the development of effective control strategies for SBR. Here we performed detailed histological characterization on the infection cycle of P. pachyrhizi in soybean and conducted a high-resolution transcriptional dissection of P. pachyrhizi during infection. This revealed P. pachyrhizi infection leads to significant changes in gene expression with 10 co-expressed gene modules, representing dramatic transcriptional shifts in metabolism and signal transduction during different stages throughout the infection cycle. Numerous genes encoding secreted protein are biphasic expressed, and are capable of inhibiting programmed cell death triggered by microbial effectors. Notably, three co-expressed P. pachyrhizi apoplastic effectors (PpAE1, PpAE2, and PpAE3) were found to suppress plant immune responses and were essential for P. pachyrhizi infection. Double-stranded RNA coupled with nanomaterials significantly inhibited SBR infection by targeting PpAE1, PpAE2, and PpAE3, and provided long-lasting protection to soybean against P. pachyrhizi. Together, this study revealed prominent changes in gene expression associated with SBR and identified P. pachyrhizi virulence effectors as promising targets of RNA interference-based soybean protection strategy against SBR.

SIAH1 Promotes the Pyroptosis of Cardiomyocytes in Diabetic Cardiomyopathy via Regulating IκB-α/NF-κВ Signaling.

Inflammation-mediated dysfunction of cardiomyocytes is the main cause of diabetic cardiomyopathy (DCM). The present study aimed to investigate the roles of siah E3 ubiquitin protein ligase 1 (SIAH1) in DCM. The online dataset GSE4172 was used to analyze the differentially expressed genes in myocardial inflammation of DCM patients. RT-qPCR was conducted to detect mRNA levels. Enzyme-Linked Immunosorbent Assay (ELISA) was performed to detect cytokine release. Western blot was used to detect protein expression. Lactate dehydrogenase (LDH) assay was used to determine cytotoxicity. In vitro ubiquitination assay was applied to determine the ubiquitination of nuclear factor kappa B inhibitor alpha (1κВ-α). Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was used to detect the death of cardiomyocytes. Flow cytometry was applied for determining cardiomyocyte pyroptosis. The results showed that SIAH1 was overexpressed in human inflammatory cardiomyopathy. High expression of SIAH1 was associated with inflammatory response. SIAH1 was also overexpressed lipopolysaccharide (LPS)-induced inflammatory cardiomyopathy model in vitro. However, SIAH1 knockdown suppressed the inflammatory-related pyroptosis of cardiomyocytes. SIAH1 promoted the ubiquitination of 1κВ-α and activated nuclear factor kappa В (NF-κВ) signaling, which promoted the pyroptosis of cardiomyocytes. In conclusion, SIAH1 exacerbated the progression of human inflammatory cardiomyopathy via inducing the ubiquitination of 1κВ-α and activation of NF-κВ signaling. Therefore, SIAHI/IκB-α/NF-κB signaling may be a potential target for human inflammatory cardiomyopathy.

Receptor-like cytoplasmic kinases of different subfamilies differentially regulate SOBIR1/BAK1-mediated immune responses in Nicotiana benthamiana.

Cell-surface receptors form the front line of plant immunity. The leucine-rich repeat (LRR)-receptor-like kinases SOBIR1 and BAK1 are required for the functionality of the tomato LRR-receptor-like protein Cf-4, which detects the secreted effector Avr4 of the pathogenic fungus Fulvia fulva. Here, we show that the kinase domains of SOBIR1 and BAK1 directly phosphorylate each other and that residues Thr522 and Tyr469 of the kinase domain of Nicotiana benthamiana SOBIR1 are required for its kinase activity and for interacting with signalling partners, respectively. By knocking out multiple genes belonging to different receptor-like cytoplasmic kinase (RLCK)-VII subfamilies in N. benthamiana:Cf-4, we show that members of RLCK-VII-6, -7, and -8 differentially regulate the Avr4/Cf-4-triggered biphasic burst of reactive oxygen species. In addition, members of RLCK-VII-7 play an essential role in resistance against the oomycete pathogen Phytophthora palmivora. Our study provides molecular evidence for the specific roles of RLCKs downstream of SOBIR1/BAK1-containing immune complexes.

The ETI-dependent receptor-like kinase 1 positively regulates effector-triggered immunity by stabilizing NLR-required for cell death 4 in Nicotiana benthamiana.

Leucine-rich repeat receptor-like kinases (LRR-RLKs) comprise the largest class of membrane-localized receptor-like kinases in plants. Leucine-rich repeat receptor-like kinases are key immune sectors contributing to pattern-triggered immunity (PTI), but whether LRR-RLK mediates effector-triggered immunity (ETI) in plants remains unclear. In this study, we evaluated the function of LRR-RLKs in regulating ETI by using a virus-induced gene silencing (VIGS)-based reverse genetic screening assay, and identified a LRR-RLK named ETI-dependent receptor-like kinase 1 (EDK1) required for ETI triggered by the avirulence effector AVRblb2 secreted by Phytophthora infestans and its cognate receptor Rpi-blb2. Silencing or knockout of EDK1 compromised immunity mediated by Rpi-blb2 and the cell death triggered by recognition of AVRblb2. NLR-required for cell death 4 (NRC4), a signaling component acts downstream of Rpi-blb2, was identified that interacts with EDK1 using the LC-MS analysis and the interaction was further evaluated by co-immunoprecipitation. EDK1 promotes protein accumulation of NRC4 in a kinase-dependent manner and positively regulates resistance to P. infestans in Nicotiana benthamiana. Our study revealed that EDK1 positively regulates plant ETI through modulating accumulation of the NLR signaling component NRC4, representing a new regulatory role of the membrane-localized LRR-RLKs in plant immunity.

The CAP superfamily protein PsCAP1 secreted by Phytophthora triggers immune responses in Nicotiana benthamiana through a leucine-rich repeat receptor-like protein.

The role of cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 (CAP) superfamily proteins in the innate immune responses of mammals is well characterized. However, the biological function of CAP superfamily proteins in plant-microbe interactions is poorly understood. We used proteomics and transcriptome analyses to dissect the apoplastic effectors secreted by the oomycete Phytophthora sojae during early infection of soybean leaves. By transiently expressing these effectors in Nicotiana benthamiana, we identified PsCAP1, a novel type of secreted CAP protein that triggers immune responses in multiple solanaceous plants including N. benthamiana. This secreted CAP protein is conserved among oomycetes, and multiple PsCAP1 homologs can be recognized by N. benthamiana. PsCAP1-triggered immune responses depend on the N-terminal immunogenic fragment (aa 27-151). Pretreatment of N. benthamiana with PsCAP1 or the immunogenic fragment increases plant resistance against Phytophthora. The recognition of PsCAP1 and different homologs requires the leucine-rich repeat receptor-like protein RCAP1, which associates with two central receptor-like kinases BRI1-associated receptor kinase 1 (BAK1) and suppressor of BIR1-1 (SOBIR1) in planta. These findings suggest that the CAP-type apoplastic effectors act as an important player in plant-microbe interactions that can be perceived by plant membrane-localized receptor to activate plant resistance.

The Phytophthora effector Avh94 manipulates host jasmonic acid signaling to promote infection.

The oomycete pathogen Phytophthora sojae is a causal agent of soybean root rot. Upon colonization of soybeans, P. sojae secretes various RXLR effectors to suppress host immune responses, supporting successful infection. Previous research has demonstrated that the RXLR effector Avh94 functions as a virulence effector, but the molecular mechanism underlying its role in virulence remains unknown. Here, we demonstrate that Avh94 overexpression in plants and pathogens promotes Phytophthora infection. Avh94 interacts with soybean JAZ1/2, which is a repressor of jasmonic acid (JA) signaling. Avh94 stabilizes JAZ1/2 to inhibit JA signaling and silencing of JAZ1/2 enhances soybean resistance against P. sojae. Moreover, P. sojae lines overexpressing Avh94 inhibit JA signaling. Furthermore, exogenous application of methyl jasmonate improves plant resistance to Phytophthora. Taken together, these findings suggest that P. sojae employs an RXLR effector to hijack JA signaling and thereby promote infection.

Cell suspension culture extract of Eriobotrya japonica attenuates growth and induces apoptosis in prostate cancer cells via targeting SREBP-1/FASN-driven metabolism and AR.

BACKGROUND: Castration-resistant prostate cancer (CRPC) is one of the main causes of male cancer mortality. There is currently no effective treatment to cure this deadly prostate cancer (PCa) progression. However, recent research showed that activation of lipogenesis leads to CRPC progression. It provides a rationale to target the highly lipogenic activity as a novel and promising therapy against lethal CRPC. PURPOSES: The present study aims to evaluate the anticancer efficacy and the molecular mechanism of cell suspension culture extract from Eriobotrya japonica (EJCE) in PCa, including CRPC. METHODS: Cell growth, migration and invasion analyses were performed by MTT method, a wound healing assay and the transwell method, respectively. Apoptosis was assessed by a flow cytometry-based Annexin V-FITC/PI assay, caspase enzymatic activity and Western blot analyses. Lipogenesis was determined by a Fatty Acid Quantification Kit and an Oil Red O staining. The in vivo experiment was conducted by a xenograft mouse model. RESULTS: PCa cell growth, migration and invasion were significantly affected by EJCE. EJCE decreased expression of sterol regulatory element-binding protein-1 (SREBP-1) and fatty acid synthase (FASN) in PCa cells, two main factors for lipogenesis. By inhibiting SREBP-1/FASN, EJCE reduced the intracellular fatty acid levels and lipid droplet accumulation in PCa. Moreover, EJCE down-regulated the androgen receptor (AR) and prostate-specific antigen (PSA) in PCa cells. Significantly, EJCE exhibited the potential anticancer activity by suppressing the growth and leading to apoptosis of CRPC tumors in a xenograft mouse model. CONCLUSION: These results reveal a novel therapeutic molecular mechanism of EJCE in PCa. Blockade of SREBP-1/FASN-driven metabolism and AR by EJCE could be employed as a potent opportunity to cure malignant PCa.

Emerging Therapeutic Activity of Davallia formosana on Prostate Cancer Cells through Coordinated Blockade of Lipogenesis and Androgen Receptor Expression.

BACKGROUND: Prostate cancer (PCa) is the most prevalent malignancy diagnosed in men in Western countries. There is currently no effective therapy for advanced PCa aggressiveness, including castration-resistant progression. The aim of this study is to evaluate the potential efficacy and determine the molecular basis of Davallia formosana (DF) in PCa. Methods: LNCaP (androgen-sensitive) and C4-2 (androgen-insensitive/castration-resistant) PCa cells were utilized in this study. An MTT-based method, a wound healing assay, and the transwell method were performed to evaluate cell proliferation, migration, and invasion. Intracellular fatty acid levels and lipid droplet accumulation were analyzed to determine lipogenesis. Moreover, apoptotic assays and in vivo experiments were conducted. RESULTS: DF ethanol extract (DFE) suppressed proliferation, migration, and invasion in PCa cells. DFE attenuated lipogenesis through inhibition of the expression of sterol regulatory element-binding protein-1 (SREBP-1) and fatty acid synthase (FASN). Moreover, DFE decreased androgen receptor (AR) and prostate-specific antigen (PSA) expression in PCa cells. We further showed the potent therapeutic activity of DFE by repressing the growth and leading to apoptosis of subcutaneous C4-2 tumors in a xenograft mouse model. CONCLUSIONS: These data provide a new molecular basis of DFE in PCa cells, and co-targeting SREBP-1/FASN/lipogenesis and the AR axis by DFE could be employed as a novel and promising strategy for the treatment of PCa.

Risk assessment of the total testing process based on quality indicators with the Sigma metrics.

Background Evidence-based evaluation of laboratory performances including pre-analytical, analytical and post-analytical stages of the total testing process (TTP) is crucial to ensure patients receiving safe, efficient and effective care. To conduct risk assessment, quality management tools such as Failure Mode and Effect Analysis (FMEA) and the Failure Reporting and Corrective Action System (FRACAS) were constantly used for proactive or reactive analysis, respectively. However, FMEA and FRACAS faced big challenges in determining the scoring scales and failure prioritization in the assessment of real-world cases. Here, we developed a novel strategy, by incorporating Sigma metrics into risk assessment based on quality indicators (QIs) data, to provide a more objective assessment of risks in TTP. Methods QI data was collected for 1 year and FRACAS was applied to produce the risk rating based on three variables: (1) Sigma metrics for the frequency of defects; (2) possible consequence; (3) detection method. The risk priority number (RPN) of each QI was calculated by a 5-point scale score, where a value of RPN > 50 was rated as high-risk. Results The RPNs of two QIs in post-analytical phase (TAT of Stat biochemistry analyte and Timely critical values notification) were above 50 which required rigorous monitoring and corrective actions to eliminate the high risks. Nine QIs (RPNs between 25 and 50) required further investigation and monitoring. After 3 months of corrective action the two identified high-risk processes were successfully reduced. Conclusions The strategy can be implemented to reduce identified risk and assuring patient safety.

An EFR-Cf-9 chimera confers enhanced resistance to bacterial pathogens by SOBIR1- and BAK1-dependent recognition of elf18.

The transfer of well-studied native and chimeric pattern recognition receptors (PRRs) to susceptible plants is a proven strategy to improve host resistance. In most cases, the ectodomain determines PRR recognition specificity, while the endodomain determines the intensity of the immune response. Here we report the generation and characterization of the chimeric receptor EFR-Cf-9, which carries the ectodomain of the Arabidopsis thaliana EF-Tu receptor (EFR) and the endodomain of the tomato Cf-9 resistance protein. Both transient and stable expression of EFR-Cf-9 triggered a robust hypersensitive response (HR) upon elf18 treatment in tobacco. Co-immunoprecipitation and virus-induced gene silencing studies showed that EFR-Cf-9 constitutively interacts with SUPPRESSOR OF BIR1-1 (SOBIR1) co-receptor, and requires both SOBIR1 and kinase-active BRI1-ASSOCIATED KINASE1 (BAK1) for its function. Transgenic plants expressing EFR-Cf-9 were more resistant to the (hemi)biotrophic bacterial pathogens Pseudomonas amygdali pv. tabaci (Pta) 11528 and Pseudomonas syringae pv. tomato DC3000, and mounted an HR in response to high doses of Pta 11528 and P. carotovorum. Taken together, these data indicate that the EFR-Cf-9 chimera is a valuable tool for both investigating the molecular mechanisms responsible for the activation of defence responses by PRRs, and for potential biotechnological use to improve crop disease resistance.

Anti-arthritic and anti-inflammatory effects of (-)-Epicatechin-3-O-ß-d-allopyranoside, a constituent of Davallia formosana.

BACKGROUND: (-)-Epicatechin-3-O-ß-d-allopyranoside (ECAP) is isolated from the popular Chinese herbal medicine Davallia formosana, which has been used to treat bone diseases including bone fracture, arthritis, and osteoporosis. PURPOSE: To investigate the antiarthritic and the anti-inflammatory effect of ECAP on a mouse model of collagen-induced arthritis (CIA) and in vitro. METHODS: Male DBA/1 J mice were immunized by administering an intradermal injection of 100 µg of type II collagen in Freund's complete adjuvant. The control groups (vehicle) and ECAP were administered orally at doses of 1 ml/kg (H2O), 50 and 100 mg/ml/kg once a day from Day 22 to Day 42 after primary immunization. Paw swelling, arthritis severity score, and histological changes were examined. Enzyme-linked immunosorbent assay was used to measure the levels of cytokines, including tumor necrosis factor alpha (TNF-α), interleukin (IL)-10, IL-17, IL-4, and interferon-γ (IFN-γ), in splenocytes. Furthermore, the anti-inflammatory activities of ECAP were investigated in vitro by measuring nitric oxide (NO) levels in lipopolysaccharide (LPS)-activated RAW264.7 macrophages. RESULTS: In the CIA model, the oral administration of ECAP ameliorated paw edema and reduced the arthritis severity score and disease incidence. Histopathological examination demonstrated that ECAP treatment effectively protected the bone and cartilage of knee joints from erosion, lesion formation, and deformation compared with the vehicle treatment. ECAP also reduced IL-1ß and MMP-9 expression in inflamed joints. Compared with the vehicle-treated mice with CIA, the reduced severity of the disease in ECAP-treated mice was associated with decreased levels of TNF-α and IL-17 and increased levels of IL-10 and IL-4 in the supernatants of splenocyte cultures. Flow cytometry analysis demonstrated that ECAP increased the population of CD4+CD25+ regulatory T cells, thereby inhibiting the B cell population. Anticollagen IgG1 and IgG2a levels decreased in the serum of ECAP-treated mice. ECAP suppressed LPS-induced NO production in RAW264.7 macrophages. CONCLUSION: The administration of ECAP effectively suppressed inflammation and inflammatory pain and adjuvant-induced arthritis, indicating its therapeutic potential in the treatment of rheumatoid arthritis.

Bioassay-guided purification of sesquiterpenoids from the fruiting bodies of Fomitopsis pinicola and their anti-inflammatory activity.

Twelve undescribed sesquiterpenoids, fomitopins A-L (1-12), were isolated via bioassay-guided purification from the bracket fungus Fomitopsis pinicola (Sw.) P. Karst, and this fungus have been reported to exhibit anti-microbial and anti-inflammatory activities. The structures of 1-12 were elucidated by spectroscopic and spectrometric analyses and their absolute configurations were further confirmed by ECD simulations. Ten isolated compounds were evaluated for their anti-inflammatory potential and compound 11 exhibited the most significant inhibition of superoxide anion generation and elastase release with IC50 values of 0.81 ± 0.15 and 0.74 ± 0.12 µM. These newly purified sesquiterpenoids could be potential candidates for further anti-inflammatory studies.

CLE9 peptide-induced stomatal closure is mediated by abscisic acid, hydrogen peroxide, and nitric oxide in Arabidopsis thaliana.

CLE peptides have been implicated in various developmental processes of plants and mediate their responses to environmental stimuli. However, the biological relevance of most CLE genes remains to be functionally characterized. Here, we report that CLE9, which is expressed in stomata, acts as an essential regulator in the induction of stomatal closure. Exogenous application of CLE9 peptides or overexpression of CLE9 effectively led to stomatal closure and enhanced drought tolerance, whereas CLE9 loss-of-function mutants were sensitivity to drought stress. CLE9-induced stomatal closure was impaired in abscisic acid (ABA)-deficient mutants, indicating that ABA is required for CLE9-medaited guard cell signalling. We further deciphered that two guard cell ABA-signalling components, OST1 and SLAC1, were responsible for CLE9-induced stomatal closure. MPK3 and MPK6 were activated by the CLE9 peptide, and CLE9 peptides failed to close stomata in mpk3 and mpk6 mutants. In addition, CLE9 peptides stimulated the induction of hydrogen peroxide (H2 O2 ) and nitric oxide (NO) synthesis associated with stomatal closure, which was abolished in the NADPH oxidase-deficient mutants or nitric reductase mutants, respectively. Collectively, our results reveal a novel ABA-dependent function of CLE9 in the regulation of stomatal apertures, thereby suggesting a potential role of CLE9 in the stress acclimatization of plants.

Baicalin, Baicalein, and Lactobacillus Rhamnosus JB3 Alleviated Helicobacter pylori Infections in Vitro and in Vivo.

Helicobacter pylori infection is associated with chronic gastritis, peptic ulcers, and gastric cancer. The flavonoid compounds baicalin and baicalein found in many medicinal plants exhibit an anti-inflammatory effect. The administration of Lactobacillus strains reducing the risk of H. pylori infection is well accepted. In this study, the therapeutic effects against H. pylori infection of baicalin, baicalein, and L. rhamnosus JB3 (LR-JB3), isolated from a dairy product, were investigated. Compared to baicalin, baicalein exhibited stronger anti-H. pylori activity and cytotoxicity on human gastric cancer epithelial AGS cells. Baicalin and baicalein both suppressed the vacA gene expression of H. pylori and interfered with the adhesion and invasion ability of H. pylori to AGS cells, as well as decreased H. pylori-induced interleukin (IL)-8 expression. In the mice infection model, high dosages of baicalin and baicalein inhibited H. pylori growth in the mice stomachs. Serum IL-1ß levels and H. pylori-specific serum IgM and IgA levels in mice treated with baicalin and baicalein were decreased. Moreover, a synergistic therapeutic effect of baicalein and LR-JB3 on eradicating H. pylori infections was observed. Thus, administrating baicalin, baicalein, or LR-JB3 for an H. pylori infection could offer similar therapeutic effects to administering antibiotics while not disturbing the balance of gut microbiota. This study revealed the effects of baicalin, baicalein, and LR-JB3 on attenuating the virulence of H. pylori. The synergistic effect with baicalein and LR-JB3 provides the experimental rationale for testing the reliability, safety, and efficacy of this approach in higher animals and perhaps ultimately in humans to eradicate H. pylori infections. PRACTICAL APPLICATION: Baicalin and baicalein exert health promotion and avoidance of H. pylori infections by interfering with H. pylori growth and virulence. Lactobacillus rhamnosus JB3 was used to reduce the gastric inflammation caused by H. pylori infection.

Feedback Control-Based Navigation of a Flying Insect-Machine Hybrid Robot.

This study reports the first ever demonstration of the aero navigation of a free-flying insect based on feedback control. Instead of imitating the complicated kinetics and mechanisms of insect locomotion, a live insect can be directly transformed into a soft robot by embedding it with artificial devices. Since many insects can perform acrobatics aerially, thereby exhibiting far greater flexibility than current man-made flyers, correctly commanding the internal structures of an insect to perform based on the instructions would be a breakthrough. Herein, beetles (Mecynorrhina torquata) were chosen as the flying platform, and an inertial measurement unit-implemented electronic backpack was designed and manufactured to remotely command the beetles. To achieve horizontal flight control, multiple flight muscles of the beetles, that is, the basalar and third axillary muscles were stimulated to control the flight directions. However, the beetles were found to gradually adapt to the electrical stimulation, and the flight corrections were elicited by generating compensatory flight forces during a long-lasting stimulation (>300 ms), which were revealed by the decrease in induced lateral force. Based on this finding, a proportional derivative feedback controller was designed to navigate the flying beetles based on the predetermined path using frequency-dependent electrical pulses. To avoid a continuous stimulation, we proposed a stimulation protocol which separated two stimulations with a 50-ms rest. Compared to long stimulations (>300 ms), a 150-ms stimulation with 200-ms update interval was more efficient in correcting the flight direction of the beetles.

Identification of Lycopodium Alkaloids Produced by an Ultraviolet-Irradiated Strain of Paraboeremia, an Endophytic Fungus from Lycopodium serratum var. longipetiolatum.

12- epi-Lycopodine (1), a Lycopodium alkaloid, along with lycopodine (2) and huperzine A (3), were discovered in the mycelium of Paraboeremia sp. Lsl3KI076, a UV-irradiated strain of Paraboeremia sp. Lsl3, an endophytic fungus from Lycopodium serratum Thunb. var. longipetiolatum Spring. Additionally, a trace of 1 was isolated from Phlegmariurus nummulariifolius (Blume) Ching, and the structure was elucidated on the basis of spectroscopic data. This is the first report proving that a new naturally occurring Lycopodium alkaloid can be obtained from an endophytic fungus.

Strigolactone-triggered stomatal closure requires hydrogen peroxide synthesis and nitric oxide production in an abscisic acid-independent manner.

Accumulating data indicate that strigolactones (SLs) are implicated in the response to environmental stress, implying a potential effect of SLs on stomatal response and thus stress acclimatization. In this study, we investigated the molecular mechanism underlying the effect of SLs on stomatal response and their interrelation with abscisic acid (ABA) signaling. The impact of SLs on the stomatal response was investigated by conducting SL-feeding experiments and by analyzing SL-related mutants. The involvement of endogenous ABA and ABA-signaling components in SL-mediated stomatal closure was physiologically evaluated using genetic mutants. Pharmacological and genetic approaches were employed to examine hydrogen peroxide (H2 O2 ) and nitric oxide (NO) production. SL-related mutants exhibited larger stomatal apertures, while exogenous SLs were able to induce stomatal closure and rescue the more widely opening stomata of SL-deficient mutants. The SL-biosynthetic genes were induced by abiotic stress in shoot tissues. Disruption of ABA-biosynthetic genes, as well as genes that function in guard cell ABA signaling, resulted in no impairment in SL-mediated stomatal response. However, disruption of MORE AXILLARY GROWTH2 (MAX2), DWARF14 (D14), and the anion channel gene SLOW ANION CHANNEL-ASSOCIATED 1 (SLAC1) impaired SL-triggered stomatal closure. SLs stimulated a marked increase in H2 O2 and NO contents, which is required for stomatal closure. Our results suggest that SLs play a prominent role, together with H2 O2 /NO production and SLAC1 activation, in inducing stomatal closure in an ABA-independent mechanism.

The Bacterial Effector AvrPto Targets the Regulatory Coreceptor SOBIR1 and Suppresses Defense Signaling Mediated by the Receptor-Like Protein Cf-4.

Receptor-like proteins (RLPs) and receptor-like kinases (RLKs) are cell-surface receptors that are essential for detecting invading pathogens and subsequent activation of plant defense responses. RLPs lack a cytoplasmic kinase domain to trigger downstream signaling leading to host resistance. The RLK SOBIR1 constitutively interacts with the tomato RLP Cf-4, thereby providing Cf-4 with a kinase domain. SOBIR1 is required for Cf-4-mediated resistance to strains of the fungal tomato pathogen Cladosporium fulvum that secrete the effector Avr4. Upon perception of this effector by the Cf-4/SOBIR1 complex, the central regulatory RLK SOMATIC EMBRYOGENESIS RECEPTOR KINASE 3a (SERK3a) is recruited to the complex and defense signaling is triggered. SOBIR1 is also required for RLP-mediated resistance to bacterial, fungal ,and oomycete pathogens, and we hypothesized that SOBIR1 is targeted by effectors of such pathogens to suppress host defense responses. In this study, we show that Pseudomonas syringae pv. tomato DC3000 effector AvrPto interacts with Arabidopsis SOBIR1 and its orthologs of tomato and Nicotiana benthamiana, independent of SOBIR1 kinase activity. Interestingly, AvrPto suppresses Arabidopsis SOBIR1-induced cell death in N. benthamiana. Furthermore, AvrPto compromises Avr4-triggered cell death in Cf-4-transgenic N. benthamiana, without affecting Cf-4/SOBIR1/SERK3a complex formation. Our study shows that the RLP coreceptor SOBIR1 is targeted by a bacterial effector, which results in compromised defense responses.

The Suppressive Effects of Geniposide and Genipin on Helicobacter pylori Infections In Vitro and In Vivo.

Geniposide and genipin have been found in Gardenia jasminoides Ellis, a traditional Chinese medicine that exhibits multiple biological functions. However, no report showing the effects of geniposide and genipin on gastric protection in Helicobacter pylori infections in vitro and in vivo has been done. In this study, we clarified how geniposide and genipin suppress H. pylori-mediated inflammation in gastric AGS cells and C57BL/6 mice. Our results demonstrated that genipin shows a strong ability to inhibit H. pylori growth and is able to reduce vacA and cagA gene expression of H. pylori in infected AGS cells. Genipin also attenuates the abilities of adhesion and invasion of H. pylori to AGS cells. An attenuation of interleukin (IL)-8 and IFN-γ production caused by genipin was observed to inhibit cell inflammatory responses. In the in vivo experiments, geniposide and genipin both showed suppressive effects on the vacA gene expression in mice after H. pylori infection. The serum levels of IFN-γ, IL-1ß, immunoglobulin A, and Immunoglobulin M were decreased by geniposide and genipin in infected mice. The inflammatory maker COX2 was downregulated in H. pylori-infected mice after exposure to geniposide and genipin. Together, geniposide and genipin effectively exert a healthy promotion to reduce H. pylori infections in vivo by interfering with the growth and virulence of H. pylori as well as attenuating the gastric inflammation caused by an H. pylori infection. PRACTICAL APPLICATION: Geniposide and genipin have a healthy promotion to eradicate H. pylori infections by interfering with the growth and virulence of H. pylori and to attenuate the gastric inflammation caused by an H. pylori infection.