PIF4 interacts with ABI4 to serve as a transcriptional activator complex to promote seed dormancy by enhancing ABA biosynthesis and signaling.

Transcriptional regulation plays a key role in the control of seed dormancy, and many transcription factors (TFs) have been documented. However, the mechanisms underlying the interactions between different TFs within a transcriptional complex regulating seed dormancy remain largely unknown. Here, we showed that TF PHYTOCHROME-INTERACTING FACTOR4 (PIF4) physically interacted with the abscisic acid (ABA) signaling responsive TF ABSCISIC ACID INSENSITIVE4 (ABI4) to act as a transcriptional complex to promote ABA biosynthesis and signaling, finally deepening primary seed dormancy. Both pif4 and abi4 single mutants exhibited a decreased primary seed dormancy phenotype, with a synergistic effect in the pif4/abi4 double mutant. PIF4 binds to ABI4 to form a heterodimer, and ABI4 stabilizes PIF4 at the protein level, whereas PIF4 does not affect the protein stabilization of ABI4. Subsequently, both TFs independently and synergistically promoted the expression of ABI4 and NCED6, a key gene for ABA anabolism. The genetic evidence is also consistent with the phenotypic, physiological and biochemical analysis results. Altogether, this study revealed a transcriptional regulatory cascade in which the PIF4-ABI4 transcriptional activator complex synergistically enhanced seed dormancy by facilitating ABA biosynthesis and signaling.

Exploring the causal relationship between inflammatory cytokines and inflammatory arthritis: A Mendelian randomization study.

OBJECTIVES: Previous studies have reported an association between inflammatory cytokines and inflammatory arthritis, including Ankylosing spondylitis (AS), rheumatoid arthritis (RA), and psoriatic arthritis (PsA). This study aims to explore the causal relationship between inflammatory cytokines and AS, RA, and PsA using Mendelian randomization (MR). METHODS: We conducted a bidirectional two-sample MR analysis using genetic summary data from a publicly available genome-wide association study (GWAS) that included 41 genetic variations of inflammatory cytokines, as well as genetic variant data for AS, RA, and PsA from the FinnGen consortium. The main analysis method used was Inverse variance weighted (IVW) to investigate the causal relationship between exposure and outcome. Additionally, other methods such as MR Egger, weighted median (WM), simple mode, and weighted mode were employed to strengthen the final results. Sensitivity analysis was also performed to ensure the reliability of the findings. RESULTS: The results showed that macrophage colony-stimulating factor (MCSF) was associated with an increased risk of AS (OR = 1.163, 95 % CI = 1.016-1.33, p = 0.028). Conversely, high levels of TRAIL and beta nerve growth factor (ß-NGF) were associated with a decreased risk of AS (OR = 0.892, 95 % CI = 0.81-0.982, p = 0.002; OR = 0.829, 95 % CI = 0.696-0.988, p = 0.036). Four inflammatory cytokines were found to be associated with an increased risk of PsA: vascular endothelial growth factor (VEGF) (OR = 1.161, 95 % CI = 1.057-1.275, p = 0.002); Interleukin 12p70 (IL12p70) (OR = 1.189, 95 % CI = 1.049-1.346, p = 0.007); IL10 (OR = 1.216, 95 % CI = 1.024-1.444, p = 0.026); IL13 (OR = 1.159, 95 % CI = 1.05-1.28, p = 0.004). Interleukin 1 receptor antagonist (IL-1rα) was associated with an increased risk of seropositive RA (OR = 1.181, 95 % CI = 1.044-1.336, p = 0.008). Similarly, genetic susceptibility to inflammatory arthritis was found to be causally associated with multiple inflammatory cytokines. Lastly, the sensitivity analysis supported the robustness of these findings. CONCLUSIONS: This study provides additional insights into the relationship between inflammatory cytokines and inflammatory arthritis, and may offer new clues for the etiology, diagnosis, and treatment of inflammatory arthritis.

Development and validation of a machine learning-based nomogram for predicting HLA-B27 expression.

BACKGROUND: HLA-B27 positivity is normal in patients undergoing rheumatic diseases. The diagnosis of many diseases requires an HLA-B27 examination. METHODS: This study screened totally 1503 patients who underwent HLA-B27 examination, liver/kidney function tests, and complete blood routine examination in First Affiliated Hospital of Guangxi Medical University. The training cohort included 509 cases with HLA-B27 positivity whereas 611 with HLA-B27 negativity. In addition, validation cohort included 147 cases with HLA-B27 positivity whereas 236 with HLA-B27 negativity. In this study, 3 ML approaches, namely, LASSO, support vector machine (SVM) recursive feature elimination and random forest, were adopted for screening feature variables. Subsequently, to acquire the prediction model, the intersection was selected. Finally, differences among 148 cases with HLA-B27 positivity and negativity suffering from ankylosing spondylitis (AS) were investigated. RESULTS: Six factors, namely red blood cell count, human major compatibility complex, mean platelet volume, albumin/globulin ratio (ALB/GLB), prealbumin, and bicarbonate radical, were chosen with the aim of constructing the diagnostic nomogram using ML methods. For training queue, nomogram curve exhibited the value of area under the curve (AUC) of 0.8254496, and C-value of the model was 0.825. Moreover, nomogram C-value of the validation queue was 0.853, and the AUC value was 0.852675. Furthermore, a significant decrease in the ALB/GLB was noted among cases with HLA-B27 positivity and AS cases. CONCLUSION: To conclude, the proposed ML model can effectively predict HLA-B27 and help doctors in the diagnosis of various immune diseases.

Abscisic acid inhibits primary root growth by impairing ABI4-mediated cell cycle and auxin biosynthesis.

Cell cycle progression and the phytohormones auxin and abscisic acid (ABA) play key roles in primary root growth, but how ABA mediates the transcription of cell cycle-related genes and the mechanism of crosstalk between ABA and auxin requires further research. Here, we report that ABA inhibits primary root growth by regulating the ABA INSENSITIVE4 (ABI4)-CYCLIN-DEPENDENT KINASE B2;2 (CDKB2;2)/CYCLIN B1;1 (CYCB1;1) module-mediated cell cycle as well as auxin biosynthesis in Arabidopsis (Arabidopsis thaliana). ABA induced ABI4 transcription in the primary root tip, and the abi4 mutant showed an ABA-insensitive phenotype in primary root growth. Compared with the wild type (WT), the meristem size and cell number of the primary root in abi4 increased in response to ABA. Further, the transcription levels of several cell-cycle positive regulator genes, including CDKB2;2 and CYCB1;1, were upregulated in abi4 primary root tips. Subsequent chromatin immunoprecipitation (ChIP)-seq, ChIP-qPCR, and biochemical analysis revealed that ABI4 repressed the expression of CDKB2;2 and CYCB1;1 by physically interacting with their promoters. Genetic analysis demonstrated that overexpression of CDKB2;2 or CYCB1;1 fully rescued the shorter primary root phenotype of ABI4-overexpression lines, and consistently, abi4/cdkb2;2-cr or abi4/cycb1;1-cr double mutations largely rescued the ABA-insensitive phenotype of abi4 with regard to primary root growth. The expression levels of DR5promoter-GFP and PIN1promoter::PIN1-GFP in abi4 primary root tips were significantly higher than those in WT after ABA treatment, with these changes being consistent with changes in auxin concentration and expression patterns of auxin biosynthesis genes. Taken together, these findings indicated that ABA inhibits primary root growth through ABI4-mediated cell cycle and auxin-related regulatory pathways.

B2, an abscisic acid mimic, improves salinity tolerance in winter wheat seedlings via improving activity of antioxidant enzymes.

Salinity severely inhibits growth and reduces yield of salt-sensitive plants like wheat, and this effect can be alleviated by plant growth regulators and phytohormones, among which abscisic acid (ABA) plays a central role in response to various stressful environments. ABA is highly photosensitive to light disruption, which this limits its application. Here, based on pyrabactin (a synthetic ABA agonist), we designed and synthesized a functional analog of ABA and named B2, then evaluated its role in salt resistance using winter wheat seedlings. The phenotypes showed that B2 significantly improved the salt tolerance of winter wheat seedlings by elevating the biomass. The physiological analysis found that B2 treatment reduced the generation rate of O2 -, electrolyte leakage, the content of proline, and the accumulation of malonaldehyde (MDA) and H2O2 and also significantly increased the contents of endogenous hormones zeatin riboside (ZA) and gibberellic acid (GA). Further biochemical analysis revealed that the activities of various antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX), were enhanced by B2, and the activities of antioxidase isozymes SOD3, POD1/2, and APX1/2 were particularly increased, largely resembling ABA treatment. The abiotic stress response-related gene TaSOS1 was significantly upregulated by B2, while the TaTIP2;2 gene was suppressed. In conclusion, an ABA analog B2 was capable to enhance salt stress tolerance in winter wheat seedlings by stimulating the antioxidant system, providing a novel regulator for better survival of crops in saline soils and improving crop yield.

Design, Synthesis, and Action Mechanism of 1,3-Benzodioxole Derivatives as Potent Auxin Receptor Agonists and Root Growth Promoters.

Deeper and longer roots allow crops to survive and flourish, but our understanding of the plant growth regulators promoting root system establishment is limited. Here, we report that, a novel auxin receptor agonist, named K-10, had a remarkable promotive effect on root growth in both Arabidopsis thaliana and Oryza sativa through the enhancement of root-related signaling responses. Using computer-aided drug discovery approaches, we developed potent lead compound by screening artificial chemicals on the basis of the auxin receptor TIR1 (Transport Inhibitor Response 1), and a series of N-(benzo[d] [1,3] dioxol-5-yl)-2-(one-benzylthio) acetamides, K-1 to K-22, were designed and synthesized. The results of bioassay showed that K-10 exhibited an excellent root growth-promoting activity far exceeding that of NAA (1-naphthylacetic acid). A further morphological investigation of the auxin related mutants (yucQ, tir1) revealed that K-10 had auxin-like physiological functions and was recognized by TIR1, and K-10 significantly enhanced auxin response reporter's (DR5:GUS) transcriptional activity. Consistently, transcriptome analysis showed that K-10 induced a common transcriptional response with auxin and down-regulated the expression of root growth-inhibiting genes. Further molecular docking analysis revealed that K-10 had a stronger binding ability with TIR1 than NAA. These results indicated that this class of derivatives could be a promising scaffold for the discovery and development of novel auxin receptor agonists, and the employment of K-10 may be effective for enhancing root growth and crop production.

A natural single-nucleotide polymorphism variant in sulfite reductase influences sulfur assimilation in maize.

Plants absorb sulfur from the environment and assimilate it into suitable forms for the biosynthesis of a broad range of molecules. Although the biochemical pathway of sulfur assimilation is known, how genetic differences contribute to natural variation in sulfur assimilation remains poorly understood. Here, using a genome-wide association study, we uncovered a single-nucleotide polymorphism (SNP) variant in the sulfite reductase (SiR) gene that was significantly associated with SiR protein abundance in a maize natural association population. We also demonstrated that the synonymous C to G base change at SNP69 may repress translational activity by altering messenger RNA secondary structure, which leads to reduction in ZmSiR protein abundance and sulfur assimilation activity. Population genetic analyses showed that the SNP69C allele was likely a variant occurring after the initial maize domestication and accumulated with the spread of maize cultivation from tropical to temperate regions. This study provides the first evidence that genetic polymorphisms in the exon of ZmSiR could influence the protein abundance through a posttranscriptional mechanism and in part contribute to natural variation in sulfur assimilation. These findings provide a prospective target to improve maize varieties with proper sulfur nutrient levels assisted by molecular breeding and engineering.

Design, synthesis and mode of action of novel 3-chloro-6-pyrazolyl picolinate derivatives as herbicide candidates.

BACKGROUND: Picolinate/picolinic acid compounds are an important class of synthetic auxin herbicides. To explore the herbicidal activity of 6-pyrazolyl picolinate compounds, a series of 3-chloro-6-pyrazolyl-picolinate derivatives was designed and synthesized. RESULTS: Twenty-five 3-chloro-6-pyrazolyl-picolinate derivatives synthesized were tested for herbicidal activity and the IC50 value of compound c5 to the growth of Arabidopsis thaliana root was 27 times lower than that of the commercial herbicide clopyralid. Compound c5 displayed better post-emergence herbicidal activity and broader (Picloram, Clopyralid, Aminopyralid) herbicidal spectrum at a dosage of 400 g ha-1 in comparison with clopyralid; it also was safe to wheat and maize at this dosage. Arabidopsis thaliana phenotypes and expression of auxin-response genes demonstrated that compound c5 might be a novel auxin-type herbicide. Molecular docking analyses revealed that compound c5 had stronger binding ability to receptor AFB5 (auxin signaling F-box protein 5) than clopyralid. CONCLUSION: These 6-pyrazolyl picolinate compounds could be used as potential lead structures for the discovery of a novel synthetic auxin herbicide. © 2021 Society of Chemical Industry.

Data-Independent Acquisition Proteomics Unravels the Effects of Iron Ions on Coronatine Synthesis in Pseudomonas syringae pv. tomato DC3000.

Coronatine (COR) is a new type of plant growth regulator that is produced by Pseudomonas syringae pathovars and plays an important role in modulating plant growth, development, and tolerance to multiple stresses. However, the factors affecting COR production are not very clear. In this study, the effects of FeCl3 on COR production were researched. The data-independent acquisition (DIA) approach, which is a proteomic quantitative analysis method, was applied to quantitatively trace COR production and proteomic changes in P. syringae pv. tomato DC3000 under different FeCl3 culture conditions. The results showed that COR production increased with the addition of FeCl3 and that there was significant upregulation in the expression of proteins related to COR synthesis and regulation. In addition, FeCl3 also affected the expression of related proteins involved in various metabolic pathways such as glycolysis and the tricarboxylic acid cycle. Moreover, various precursors such as isoleucine and succinate semialdehyde, as well as other related proteins involved in the COR synthesis pathway, were significantly differentially expressed. Our findings revealed the dynamic regulation of COR production in response to FeCl3 at the protein level and showed the potential of using the DIA method to track the dynamic changes of the P. syringae pv. tomato DC3000 proteome during COR production, providing an important reference for future research on the regulatory mechanism of COR biosynthesis and theoretical support for COR fermentation production.

Engineering Lignin Nanomicroparticles for the Antiphotolysis and Controlled Release of the Plant Growth Regulator Abscisic Acid.

Lignin is the most abundant aromatic biopolymer in nature and is a major byproduct from the paper industry. The unlocking of lignin's potential for high-value applications has gained increasing attention in recent years. In this study, alkali lignin (AL), with a rigid conjugated structure and amphiphilic property, was used as a sustainable and eco-friendly encapsulation material for the protection and controlled release of photosensitive abscisic acid (ABA), an important and widely used plant growth regulator. Cetyltrimethylammonium bromide (CTAB) was used to induce the formation of AL-CTAB nanomicroparticles by self-assembly. The size and morphology of AL-CTAB particles were modified by changing the AL concentration and the dispersion agent. AL (0.3 M) dissolved in tetrahydrofuran could form a uniform size (300 nm) of particles with a regular spherical structure. Subsequently, ABA was loaded on the prepared nanomicroparticles to synthesize the capsule formulation of ABA@AL-CTAB. The controlled-release behavior and the antiphotolysis performance as well as the thermal stability of ABA@AL-CTAB were proved to be superior. Lasting inhibition of Arabidopsis and rice seed germination by ABA@AL-CTAB under light irradiations implied protection of ABA from photolysis. In addition, ABA@AL-CTAB could effectively regulate plant stomata, thereby increasing plant drought resistance. Overall, lignin is suitable for the preparation of agrochemical formulations with excellent controlled release and antiphotolysis performances.

Improved synthetic route of exo-16,17-dihydro-gibberellin A5-13-acetate and the bioactivity of its derivatives towards Arabidopsis thaliana.

BACKGROUND: The use of exo-16,17-dihydro-gibberellin A5-13-acetate (DHGA5 ) in agriculture has been limited by its low synthetic yield. This study was aimed at optimizing the synthetic route of DHGA5 , designing and synthesizing new derivatives with strong plant growth inhibitory activities. RESULTS: Previous synthetic methods were replaced with a shorter, milder and faster reaction route with higher yield (76.3%) of DHGA5 . Based on this novel route, a series of new derivatives were designed and synthesized using DHGA5 as a lead compound and characterized and evaluated for biological activities in Arabidopsis thaliana. Among the 15 tested derivatives, compound 14j showed a lower medium inhibition concentration (IC50 , 73 µm) in Arabidopsis than that of DHGA5 (91 µm). Gibberellin deficient mutant assay further revealed that 14j had very different activities compared to DHGA5 as it specifically inhibits gibberellin biosynthetic pathways. In addition, 14j does not influence the interaction between gibberellin receptors (GID1) and the master growth repressor (RGA) based on yeast two-hybrid assay. CONCLUSION: The optimized synthetic route provides a promising method for large-scale preparation of DHGA5 . Our biological assays indicate that 14j likely acts on gibberellin signaling elements other than GID1. These results indicate that novel plant growth regulators can be developed. © 2019 Society of Chemical Industry.

Effects of spraying nano-materials on the absorption of metal(loid)s in cucumber.

This report investigates the spraying of nano-silica and fullerene on cucumber leaves to expose their ability to reduce the toxicity and uptake of metal(loid)s. Cucumber seedlings were randomly divided into six treatment groups: 10 mg/L nano-SiO2, 20 mg/L nano-SiO2, 10 mg/L Fullerene, 20 mg/L Fullerene, 5 mg/L Fullerene + 5 mg/L nano-SiO2, and 10 mg/L Fullerene + 10 mg/L nano-SiO2. Nano-silica-treated plants exhibited evidence of the potential mitigation of metal(loid)s poisoning. Specifically, results showed that 20 mg/L of nano-silica promoted Cd uptake by plants; comparatively, 10 mg/L of nano-silica did not significantly increase the silicon content in plants. Both low-concentration combined treatment and low-concentration fullerene groups inhibited metal(loid)s uptake by plants. Scanning electron microscopy (SEM) was then used to observe the surface morphology of cucumber leaves. Significant differences were observed on disease resistance in plants across the different nano-material conditions. Collectively, these findings suggest that both nano-silica materials and fullerene have the potential to control metal(loid)s toxicity in plants.

Design, synthesis, biological activities, and dynamic simulation study of novel thiourea derivatives with gibberellin activity towards Arabidopsis thaliana.

Computer-aided drug design has advanced by leaps and bounds, and has been widely used in various fields, and especially in the field of drug discovery. Although the crystal structure of the gibberellin (GA) receptor GID1A had been reported in previous studies, there is still a lack of designs of gibberellin functional analogue based GID1A. In the present study, a series of 30 thiourea derivatives were designed, synthesized and biologically assayed. The results suggested that the synthetic compounds had good GA-like activities. Furthermore, the structure-activity relationship of the synthetic compounds was discussed, and the dynamic simulation and docking study revealed the binding properties of the GID1A receptor and compounds Y1, Y11, and Y21.

Highly active nanobiocatalysis in deep eutectic solvents via metal-driven enzyme-surfactant nanocomposite.

Metal-driven papain-surfactant nanocomposite (PA@MSNC), a novel soft nanobiocatalyst, was successfully prepared via one-pot self-assembly technique in aqueous solution for the biosynthesis of N-(benzyloxycarbonyl)-L-alanyl-L-glutamine (Z-Ala-Gln) dipeptide in deep eutectic solvents (DESs). The metal-driven self-assembly process generated PA@MSNC as nanospheres of ˜130 nm in diameter, with high protein loading and relative enzyme activity of 420 mg/g and 80% (4270 U/g protein), respectively. PA@MSNC showed high apparent substrate affinity and catalytic efficiency. The stability of PA@MSNC at high temperature and extreme pH was significantly higher than that of free PA. Catalysis efficiency for the biosynthesis of Z-Ala-Gln by PA@MSNC in choline chloride: glycerol reaction medium was 1.69-fold higher than that of free PA, achieving a high product yield of 75.7% within 4 h. PA@MSNC also showed better techno-economic performance. We propose that enzyme-surfactant nanocomposite via metal-driven dynamically reversible coordination interactions contribute simultaneously promotes catalytic flexibility and configurational stability. The generated PA@MSNC has potential practical implications for green synthesis of dipeptide in DESs.

Phospholipase D encapsulated into metal-surfactant nanocapsules for enhancing biocatalysis in a two-phase system.

Methods for enhancing enzyme activities in two-phase systems are getting more attention. Phospholipase D (PLD) was successfully encapsulated into metal-surfactant nanocapsules (MSNCs) using a one-pot self-assembly technique in an aqueous solution. The highest yield for the production of high-value phosphatidylserine (PS) from low-value phosphatidylcholine (PC) in the two-phase system was achieved by encapsulating PLD into MSNCs formed from Ca2+ which gave an enzyme activity that was 133.6% of that of free PLD. The PLD@MSNC transformed the two-phase system into an emulsion phase system and improved the organic solvent tolerance, pH and thermal stabilities as well as the storage stability and reusability of the enzyme. Under optimal conditions, PLD@MSNC generated 91.9% PS over 8 h in the two-phase system, while free PLD generated only 77.5%.

Lignosulfonate Improves Photostability and Bioactivity of Abscisic Acid under Ultraviolet Radiation.

Abscisic acid (ABA), as a commonly used plant growth regulator, is easy to be degraded and lose its bioactivity under sunshine. To select an eco-friendly and efficient photoprotectant for the improvement of photostability and bioactivity of ABA when exposed to ultraviolet (UV) light, we tested the effects of three biodegradable natural-derived high polymers, sodium lignosulfonates 3A [molecular weight (MW) > 50000, with degree of sulfonation (DS) of 0.48] and NA (20000 < MW < 50000, with DS of 0.7) and calcium lignosulfonate CASA (MW < 20000, with DS of 0.7), on the photodegradation of ABA. Lignosulfonates 3A, NA, and CASA showed significant photostabilizing capability on ABA. Lignosulfonate 3A showed preferable photostabilizing effects on ABA compared to CASA, while NA showed an intermediate effect. That indicated that lignosulfonate with a high MW and low DS had a stronger UV absorption and the hollow aggregate micelles formatted by lignosulfonate protect ABA from UV damage. Approximately 50% more ABA was kept when 280 mg/L ABA aqueous solution was irradiated by UV light for 2 h in the presence of 2000 mg/L lignosulfonate 3A. The bioactivity on wheat (JIMAI 22) seed germination was greatly kept by 3A in comparison to that of ABA alone. The 300 times diluent of 280 mg/L ABA plus 2000 mg/L 3A after 2 h of irradiation showed 20.8, 19.3, and 9.3% more inhibition on shoot growth, root growth, and root numbers of wheat seed, separately, in comparison to ABA diluent alone. We conclude that lignosulfonate 3A was an eco-friendly and efficient agent to keep ABA activity under UV radiation. This research could be used in UV-sensitive and water-soluble agrichemicals and to optimize the application times and dosages of ABA products.

Characterization of glutathione S-transferases in the detoxification of metolachlor in two maize cultivars of differing herbicide tolerance.

Glutathione S-transferases (GSTs) have been widely studied in relation to their role in herbicide tolerance and detoxification. However, a detailed characterization of GSTs from herbicide tolerant and sensitive maize cultivars is still lacking. In this study, we determined the mechanism of differential tolerance between two maize cultivars which had 4-fold difference tolerance to metolachlor. The metabolism rate of metolachlor was more rapid in the tolerant cultivar (Zea mays L. cv Nongda86) than the susceptible one (Zea mays L. cv Zhengda958). Addition of the GST inhibitor ethacrynic acid reduced the metabolism of metolachlor indicating the involvement of GSTs in the differential detoxification of metolachlor. The expression profiles of 32 GST isozymes were measured using quantitative RT-PCR. The results showed the expression of GST genes were slightly up-regulated in Nongda86, but severely inhibited in Zhengdan958 24h after metolachlor treatment. The genes GSTI, GSTIII, GSTIV, GST5, GST6 and GST7, which can detoxify chloroacetanilide herbicides, were all expressed higher in Nongda86 compared to Zhendgan958. The result of GST activity was consistent with the gene expression profiles. Collectively, higher-level expression of GST genes, leading to higher GST activity and faster herbicide detoxification, appears to be responsible for the difference in tolerance to metolachlor in two maize cultivars.

Synthesis of Gibberellic Acid Derivatives and Their Effects on Plant Growth.

A series of novel C-3-OH substituted gibberellin derivatives bearing an amide group were designed and synthesized from the natural product gibberellic acid (GA3). Their activities on the plant growth regulation of rice and Arabidopsis were evaluated in vivo. Among these compounds, 10d and 10f exhibited appreciable inhibitory activities on rice (48.6% at 100 µmol/L) and Arabidopsis (41.4% at 100 µmol/L), respectively. These results provide new insights into the design and synthesis of potential plant growth regulators.

Vaccine Potential and Diversity of the Putative Cell Binding Factor (CBF, NMB0345/NEIS1825) Protein of Neisseria meningitidis.

The cbf gene from Neisseria meningitidis strain MC58 encoding the putative Cell Binding Factor (CBF, NMB0345/NEIS1825) protein was cloned into the pRSETA system and a ~36-kDa recombinant (r)CBF protein expressed in Escherichia coli and purified by metal affinity chromatography. High titres of rCBF antibodies were induced in mice following immunization with rCBF-saline, rCBF-Al(OH)3, rCBF-Liposomes or rCBF-Zwittergent (Zw) 3-14 micelles, both with and without incorporated monophosphoryl lipid A (MPLA) adjuvant. Anti-rCBF sera reacted in western blots of meningococcal lysates with a single protein band of molecular mass ~29.5 kDa, indicative of mature CBF protein, but did not react with a lysate of a Δnmb0345 mutant (CBF-), demonstrating specificity of the murine immune responses. CBF protein was produced by all strains of meningococci studied thus far and the protein was present on the surface of MC58 (CBF+) bacteria, but absent on Δnmb0345 mutant (CBF-) bacteria, as judged by FACS reactivity of anti-rCBF sera. Analysis of the NEIS1825 amino acid sequences from 6644 N. meningitidis isolates with defined Alleles in the pubmlst.org/Neisseria database showed that there were 141 ST types represented and there were 136 different allelic loci encoding 49 non-redundant protein sequences. Only 6/6644 (<0.1%) of N. meningitidis isolates lacked the nmb0345 gene. Amongst serogroup B isolates worldwide, ~68% and ~20% expressed CBF encoded by Allele 1 and 18 respectively, with the proteins sharing >99% amino acid identity. Murine antisera to rCBF in Zw 3-14 micelles + MPLA induced significant serum bactericidal activity (SBA) against homologous Allele 1 and heterologous Allele 18 strains, using both baby rabbit serum complement and human serum complement (h)SBA assays, but did not kill strains expressing heterologous protein encoded by Alelle 2 or 3. Furthermore, variable bactericidal activity was induced by murine antisera against different meningococcal strains in the hSBA assay, which may correlate with variable surface exposure of CBF. Regardless, the attributes of amino acid sequence conservation and protein expression amongst different strains and the ability to induce cross-strain bactericidal antibodies indicates that rCBF could be a potential meningococcal vaccine antigen and merits further testing.

Photoprotectant improves photostability and bioactivity of abscisic acid under UV radiation.

Photosensitivity causes serious drawback for abscisic acid (ABA) application, but preferable methods to stabilize the compound were not found yet. To select an efficient photoprotectant for the improvement of photostability and bioactivity of ABA when exposed to UV light, we tested the effects of a photostabilizer bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (HS-770) and two UV absorbers 2-hydroxy-4-n-octoxy-benzophenone (UV-531) and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (BP-4) with or without HS-770 on the photodegradation of ABA. Water soluble UV absorber BP-4 and oil soluble UV absorber UV-531 showed significant photo-stabilizing capability on ABA, possibly due to competitive energy absorption of UVB by the UV absorbers. The two absorbers showed no significant difference. Photostabilizer HS-770 accelerated the photodegradation of ABA and did not improve the photo-stabilizing capability of BP-4, likely due to no absorption in UVB region and salt formation with ABA and BP-4. Approximately 26% more ABA was kept when 280mg/l ABA aqueous solution was irradiated by UV light for 2h in the presence of 200mg/l BP-4. What's more, its left bioactivity on wheat seed (JIMAI 22) germination was greatly kept by BP-4, comparing to that of ABA alone. The 300 times diluent of 280mg/l ABA plus 200mg/l BP-4 after 2h irradiation showed more than 13% inhibition on shoot and root growth of wheat seed than that of ABA diluent alone. We concluded that water soluble UV absorber BP-4 was an efficient agent to keep ABA activity under UV radiation. The results could be used to produce photostable products of ABA compound or other water soluble agrichemicals which are sensitive to UV radiation. The frequencies and amounts of the agrichemicals application could be thereafter reduced.