Engineering the cyanobacterial ATP-driven BCT1 bicarbonate transporter for functional targeting to C3 plant chloroplasts.

The ATP-driven bicarbonate transporter 1 (BCT1), a four-component complex in the cyanobacterial CO2-concentrating mechanism, could enhance photosynthetic CO2 assimilation in plant chloroplasts. However, directing its subunits (CmpA, CmpB, CmpC and CmpD) to three chloroplast sub-compartments is highly complex. Investigating BCT1 integration into Nicotiana benthamiana chloroplasts revealed promising targeting strategies using transit peptides from the intermembrane space protein Tic22 for correct CmpA targeting, while the transit peptide of the chloroplastic ABCD2 transporter effectively targeted CmpB to the inner envelope membrane. CmpC and CmpD were targeted to the stroma by RecA and recruited to the inner envelope membrane by CmpB. Despite successful targeting, expression of this complex in CO2-dependent Escherichia coli failed to demonstrate bicarbonate uptake. We then used rational design and directed evolution to generate new BCT1 forms that were constitutively active. Several mutants were recovered, including a CmpCD fusion. Selected mutants were further characterized and stably expressed in Arabidopsis thaliana, but the transformed plants did not have higher carbon assimilation rates or decreased CO2 compensation points in mature leaves. While further analysis is required, this directed evolution and heterologous testing approach presents potential for iterative modification and assessment of CO2-concentrating mechanism components to improve plant photosynthesis.

Antagonistic effect of Bacillus and Pseudomonas combinations against Fusarium oxysporum and their effect on disease resistance and growth promotion in watermelon.

AIMS: We aimed to develop an effective bacterial combination that can combat Fusarium oxysporum infection in watermelon using in vitro and pot experiments. METHODS AND RESULTS: In total, 53 strains of Bacillus and 4 strains of Pseudomonas were screened. Pseudomonas strains P3 and P4 and Bacillus strains XY-2-3, XY-13, and GJ-1-15 exhibited good antagonistic effects against F. oxysporum. P3 and P4 were identified as Pseudomonas chlororaphis and Pseudomonas fluorescens, respectively. XY-2-3 and GJ-1-15 were identified as B. velezensis, and XY-13 was identified as Bacillus amyloliquefaciens. The three Bacillus strains were antifungal, promoted the growth of watermelon seedlings and had genes to synthesize antagonistic metabolites such as bacilysin, surfactin, yndj, fengycin, iturin, and bacillomycin D. Combinations of Bacillus and Pseudomonas strains, namely, XY-2-3 + P4, GJ-1-15 + P4, XY-13 + P3, and XY-13 + P4, exhibited a good compatibility. These four combinations exhibited antagonistic effects against 11 pathogenic fungi, including various strains of F. oxysporum, Fusarium solani, and Rhizoctonia. Inoculation of these bacterial combinations significantly reduced the incidence of Fusarium wilt in watermelon, promoted plant growth, and improved soil nutrient availability. XY-13 + P4 was the most effective combination against Fusarium wilt in watermelon with the inhibition rate of 78.17%. The number of leaves; aboveground fresh and dry weights; chlorophyll, soil total nitrogen, and soil available phosphorus content increased by 26.8%, 72.12%, 60.47%, 16.97%, 20.16%, and 16.50%, respectively, after XY-13 + P4 inoculation compared with the uninoculated control. Moreover, total root length, root surface area, and root volume of watermelon seedlings were the highest after XY-13 + P3 inoculation, exhibiting increases by 265.83%, 316.79%, and 390.99%, respectively, compared with the uninoculated control. CONCLUSIONS: XY-13 + P4 was the best bacterial combination for controlling Fusarium wilt in watermelon, promoting the growth of watermelon seedlings, and improving soil nutrient availability.

Assembly and Repair of Photosystem II in Chlamydomonas reinhardtii.

Oxygenic photosynthetic organisms use Photosystem II (PSII) to oxidize water and reduce plastoquinone. Here, we review the mechanisms by which PSII is assembled and turned over in the model green alga Chlamydomonas reinhardtii. This species has been used to make key discoveries in PSII research due to its metabolic flexibility and amenability to genetic approaches. PSII subunits originate from both nuclear and chloroplastic gene products in Chlamydomonas. Nuclear-encoded PSII subunits are transported into the chloroplast and chloroplast-encoded PSII subunits are translated by a coordinated mechanism. Active PSII dimers are built from discrete reaction center complexes in a process facilitated by assembly factors. The phosphorylation of core subunits affects supercomplex formation and localization within the thylakoid network. Proteolysis primarily targets the D1 subunit, which when replaced, allows PSII to be reactivated and completes a repair cycle. While PSII has been extensively studied using Chlamydomonas as a model species, important questions remain about its assembly and repair which are presented here.

Harnessing ultrasound in photocatalysis: Synthesis and piezo-enhanced effect: A review.

The photocatalytic technique has drawn far-ranging interests in addressing the current issues; however, its property suffers from the limited visible light response and rapid recombination of carriers. To address these issues, two specific approaches have been proposed to enhance the photocatalytic activity: (1) ultrasound-assisted synthesis has been utilized to prepare photocatalysts, resulting in refined grain size, increased specific surface area, and reduced photogenerated carrier recombination; (2) sonophotocatalysis and piezoelectric enhanced photocatalysis have been developed to accelerate the reaction, which utilizes the synergism between ultrasound and light. On one side, sonophotocatalysis generates cavitation bubbles which induce more reactive radicals for redox reactions. On the other side, ultrasound induces deformation of the piezoelectric material structure, which changes the internal piezoelectric potential and improves the photocatalytic performance. Currently, intensive efforts have been devoted to related research and great progress has been reached with applications in pollutant degradation, new energy production, and other fields. This work starts by elucidating the fundamental concept of ultrasound-assisted photocatalyst synthesis and photocatalysis. Then, the synergistic behavior between ultrasonic and light in ultrasonic-assisted photocatalysis has been thoroughly discussed, including pollutant degradation, water splitting, and bacterial sterilization. Finally, the challenge and outlook are investigated and proposed.

Effect of in situ vermicomposting combined with biochar application on soil properties and crop yields in the tomato monoculture system.

Vermicompost and biochar have been widely used to improve soil conditions. However, little information is available regarding the efficiency and effectiveness of in situ vermicomposting with biochar (IVB) in monoculture soils. In this study, we estimated the effects of IVB on soil physiochemical and microbial properties, crop yields, and fruit quality under the tomato monoculture system. The soil treatments considered were (i) untreated monoculture soil (MS, control), (ii) MS plus 1.5 t/ha biochar applied to soil surface (MS+1.5BCS), (iii) MS plus 3 t/ha biochar applied to soil surface (MS+3BCS), (iv) MS mixed with 1.5 t/ha biochar (MS+1.5BCM), (v) MS mixed with 3 t/ha biochar (MS+3BCM), (vi) in situ vermicomposting (VC), (vii) VC plus 1.5 t/ha biochar applied to VC surface (VC+1.5BCS), (viii) VC plus 3 t/ha biochar applied to VC surface (VC+3BCS), (ix) VC mixed with 1.5 t/ha biochar (VC+1.5BCM), and (x) VC mixed with 3 t/ha biochar (VC+3BCM). In general, soil pH varied from 7.68 to 7.96 under VC-related treatments. The microbial diversity was much higher in bacterial communities (OTU: 2284-3194, Shannon index: 8.81-9.91) than in fungal communities (OTU: 392-782, Shannon index: 4.63-5.71) in VC-related treatments. Specifically, Proteobacteria was the dominant bacterial phylum, followed by Bacteroidota, Chloroflexi, Patescibacteria, Acidobacteriota, Firmicutes, and Myxococcota. It is worth noting that IVB-related treatments could increase the relative abundance of Acidobacteria and reduced the relative abundance of Bacteroidetes. In addition, the VC+1.5BCM treatment exhibited the greatest yield (9377.6 kg/667m2) and simultaneously showed higher fruit quality (vitamin C, 28.94 mg/100g; soluble sugar, 20.15%) as compared to other treatments. Our results suggested that in situ vermicomposting with biochar can improve soil properties and enhance both crop yields and fruit quality under the tomato monoculture system.

Identification of key genes in sepsis by WGCNA.

When the body damages its own tissues in response to an infection, sepsis develops. Medical treatments are limited. It's important to understand the molecular mechanism behind sepsis pathogenesis and identify potential molecular treatment targets. We made two modules based on how genes work together by using WGCNA analysis. The light-green GSE131761 module and the blue GSE137342 module had the strongest links to sepsis. A gene ontology (GO) analysis showed that most of the genes in the lightgreen module were involved in the inflammatory response, specific granule, and immune receptor activity. Most of the genes in the blue module were significantly more likely to have the GO terms proteasomal protein catabolic process, ubiquitin ligase complex, and ubiquitin-like protein transferase activity. The KEGG analysis showed that the genes in module lightgreen were mostly involved in the TNF signaling pathway, while the genes in module blue were mostly involved in the Prion disease pathway. There were two hub genes that were found. In the end, ANKRD22 and VNN1 were singled out as crucial genes. This study used WGCNA to investigate sepsis-associated susceptibility modules and genes. Our study identified two modules and two key genes as essential components in sepsis etiology, which may improve our understanding of its molecular mechanisms.

Biodegradable Films Prepared from Pulp Lignocellulose Adhesives of Urea Formaldehyde Resin Modified by Biosulfonate.

Traditional low-density polyethylene (LDPE) film causes environmental pollution; there is a pressing need to make new bio-based polymers for alternative products, to meet agricultural production needs and for sustainable ecological development. In this study, urea-formaldehyde resin (UF) was modified with polyvinyl alcohol (PVA) and 1-2.5% bio-based sulfonate (BBS). The influence of BBS inducing on the functional groups, microstructure, and thermal behavior was evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). A biodegradable film was prepared with modified UF resin as adhesive and pulp lignocellulose as raw material. The biodegradable mulch film samples were tested for biodegradability, water retention, and cooling soil temperature characters using LDPE and no mulching (NM) as a control. The results showed that with the increase of BBS content, the viscosity and reactivity of modified PUF resin increased, and the free formaldehyde content decreased. A 2%BBS modified PUF resin (2.0BBS/PUF) accelerated the curing process of the PUF resin, formed a flexible macromolecular network structure, and enhanced the toughness of the resin. The biodegradable mulch prepared with PUF, BBS, and 2.0BBS/PUF as adhesives had good water retention. BBS modification increased the degradation rate of mulch by 17.53% compared to the PUF. Three biodegradable films compared with LDPE and NM significantly reduced the soil temperature under summer cucumber cultivation, and the 2.0BBS/PUF coating had the lowest diurnal temperature difference, which provided a suitable soil environment for crop growth.

Simultaneously Enhanced Thermal Conductivity and Dielectric Breakdown Strength in Sandwich AlN/Epoxy Composites.

Polymer-based composites with high thermal conductivity and dielectric breakdown strength have gained increasing attention due to their significant application potential in both power electronic devices and power equipment. In this study, we successfully prepared novel sandwich AlN/epoxy composites with various layer thicknesses, showing simultaneously and remarkably enhanced dielectric breakdown strength and thermal conductivity. The most optimized sandwich composite, with an outer layer thickness of 120 µm and an inner layer thickness of 60 µm (abbreviated as 120-60) exhibits a high through-plane thermal conductivity of 0.754 W/(m·K) (4.1 times of epoxy) and has a dielectric breakdown strength of 69.7 kV/mm, 8.1% higher compared to that of epoxy. The sandwich composites also have higher in-plane thermal conductivity (1.88 W/(m·K) for 120-60) based on the novel parallel models. The sandwich composites with desirable thermal and electrical properties are very promising for application in power electronic devices and power equipment.

Selective and sensitive detection of chronic myeloid leukemia using fluorogenic DNAzyme probes.

One of the major challenges facing the early diagnosis of chronic myelogenous leukemia (CML) patients today is enhancing the simplicity, rapidness, sensitivity and specificity of detection assay for easy clinical implementation. RNA-cleaving fluorogenic DNAzymes (RFDs) are single-stranded DNA molecules with catalytic activity and can produce fluorescent signals when combined with specific targets. As K562 cells were the first established human immortalized myelogenous leukemia line, we try to screen several RFDs using the crude extracellular mixture of K562 cells through the SELEX process. We obtained an RFD probe A1-3 that is able to distinguish K562 cells from other tumor cell lines. 10 nM of A1-3 can induce an increase of detectable fluorescence signal. Moreover, the RFD assay system can work well for target detection in complex serum matrix. The optimized RFD assay system with low cost also has a desirable ability to exactly distinguish K562 cells after truncation of 20 bases in the 5'end of A1-3. This study is the first report to investigate the RFD system for detection of K562 cells using cell culture supernatants as the complex target. This RFD assay system could potentially be applied for the diagnosis of CML.

[A developmental research on wild Dipsacus asper in Chongqing Wulong district].

In order to study the distribution and dynamics growth of wild Dipsacus asper resources in the Wulong district of Chongqing, 9 sample plots were selected for 12 consecutive months in the natural distribution area of the D. asper in Wulong district by using the sample line + plot survey method to conduct a field survey. The results showed that D.asper was distributed in forest edge wasteland or shrub-grassland, and growbetter with loose yellow-brownsoil or red soil, and poor with lithologic soil or impounded surface water.The growth curve of the plant height from June to July and the ground fresh weight from July to August showed a turning point, it might consume large amounts of nutrients during its flowering period, resulting in the restriction of vegetative growth.The highest temperature in the distribution area of D.asperoides in Wulong district is less than 30 °C, the minimum temperature is about 0 °C, and the rainfall is 1 241-1 392 mm. Its growth environment is no severecold in winter, no heat in summer, and abundant rainfall.The main growth stage of D.asper is from July to October, and the range of root dry rate was 0.162 5-0.239 7 in Xiangkou, 0.154 9-0.223 6 in Baima Mountain, and 0.143 7-0.203 3 Xiannv Mountain. The vegetative growth and dry matter accumulation synchronized in the main growth stage, and the accumulation rate of dry matter was faster than that of vegetative growth. The correlation analysis between indicators and root fresh weight showed that the fresh weight of the aerial part and root fresh weight had the best correlation.

Biosimilars: Key regulatory considerations and similarity assessment tools.

A biosimilar drug is defined in the US Food and Drug Administration (FDA) guidance document as a biopharmaceutical that is highly similar to an already licensed biologic product (referred to as the reference product) notwithstanding minor differences in clinically inactive components and for which there are no clinically meaningful differences in purity, potency, and safety between the two products. The development of biosimilars is a challenging, multistep process. Typically, the assessment of similarity involves comprehensive structural and functional characterization throughout the development of the biosimilar in an iterative manner and, if required by the local regulatory authority, an in vivo nonclinical evaluation, all conducted with direct comparison to the reference product. In addition, comparative clinical pharmacology studies are conducted with the reference product. The approval of biosimilars is highly regulated although varied across the globe in terms of nomenclature and the precise criteria for demonstrating similarity. Despite varied regulatory requirements, differences between the proposed biosimilar and the reference product must be supported by strong scientific evidence that these differences are not clinically meaningful. This review discusses the challenges faced by pharmaceutical companies in the development of biosimilars.

Root-Zone Warming Differently Benefits Mature and Newly Unfolded Leaves of Cucumis sativus L. Seedlings under Sub-Optimal Temperature Stress.

Sub-optimal temperature extensively suppresses crop growth during cool-season greenhouse production. Root-zone (RZ) warming is considered an economical option to alleviate crop growth reduction. In this study we cultivated cucumber seedlings in nutrient solution under different air-RZ temperature treatments to investigate the effects of RZ warming on seedling growth- and photosynthesis-related parameters in leaves. The air-RZ temperature treatments included sub-optimal RZ temperature 13°C and sub-optimal air temperature 20/12°C (day/night) (S13), RZ warming at 19°C and sub-optimal air temperature (S19), and RZ warming at 19°C and optimal air temperature 26/18°C (day/night) (O19). In addition, for each air-RZ temperature treatment, half of the seedlings were also treated with 2% (m/m) polyethylene glycol (PEG) dissolved in nutrient solution to distinguish the effect of root-sourced water supply from RZ temperature. At the whole-plant level, S19 significantly increased the relative growth rate (RGR) by approximately 18% compared with S13, although the increase was less than in O19 (50%) due to delayed leaf emergence. S19 alleviated both diffusive and metabolic limitation of photosynthesis in mature leaves compared with S13, resulting in a photosynthetic rate similar to that in O19 leaves. In newly unfolded leaves, S19 significantly promoted leaf area expansion and alleviated stomatal limitation of photosynthesis compared with S13. PEG addition had a limited influence on RGR and leaf photosynthesis, but significantly suppressed new leaf expansion. Thus, our results indicate that under sub-optimal temperature conditions, RZ warming promotes cucumber seedling growth by differently benefiting mature and newly unfolded leaves. In addition, RZ warming enhanced root-sourced water supply, mainly promoting new leaf expansion, rather than photosynthesis.

A Cytoplasmic Protein Ssl3829 Is Important for NDH-1 Hydrophilic Arm Assembly in Synechocystis sp. Strain PCC 6803.

Despite significant progress in clarifying the subunit compositions and functions of the multiple NDH-1 complexes in cyanobacteria, the assembly factors and their roles in assembling these NDH-1 complexes remain elusive. Two mutants sensitive to high light for growth and impaired in NDH-1-dependent cyclic electron transport around photosystem I were isolated from Synechocystis sp. strain PCC 6803 transformed with a transposon-tagged library. Both mutants were tagged in the ssl3829 gene encoding an unknown protein, which shares significant similarity with Arabidopsis (Arabidopsis thaliana) CHLORORESPIRATORY REDUCTION7. The ssl3829 product was localized in the cytoplasm and associates with an NDH-1 hydrophilic arm assembly intermediate (NAI) of about 300 kD (NAI300) and an NdhI maturation factor, Slr1097. Upon deletion of Ssl3829, the NAI300 complex was no longer visible on gels, thereby impeding the assembly of the NDH-1 hydrophilic arm. The deletion also abolished Slr1097 and consequently reduced the amount of mature NdhI in the cytoplasm, which repressed the dynamic assembly process of the NDH-1 hydrophilic arm because mature NdhI was essential to stabilize all functional NAIs. Therefore, Ssl3829 plays an important role in the assembly of the NDH-1 hydrophilic arm by accumulating the NAI300 complex and Slr1097 protein in the cytoplasm.

NdhV Is a Subunit of NADPH Dehydrogenase Essential for Cyclic Electron Transport in Synechocystis sp. Strain PCC 6803.

Two mutants sensitive to heat stress for growth and impaired in NADPH dehydrogenase (NDH-1)-dependent cyclic electron transport around photosystem I (NDH-CET) were isolated from the cyanobacterium Synechocystis sp. strain PCC 6803 transformed with a transposon-bearing library. Both mutants had a tag in the same sll0272 gene, encoding a protein highly homologous to NdhV identified in Arabidopsis (Arabidopsis thaliana). Deletion of the sll0272 gene (ndhV) did not influence the assembly of NDH-1 complexes and the activities of CO2 uptake and respiration but reduced the activity of NDH-CET. NdhV interacted with NdhS, a ferredoxin-binding subunit of cyanobacterial NDH-1 complex. Deletion of NdhS completely abolished NdhV, but deletion of NdhV had no effect on the amount of NdhS. Reduction of NDH-CET activity was more significant in ΔndhS than in ΔndhV. We therefore propose that NdhV cooperates with NdhS to accept electrons from reduced ferredoxin.

A three-component dicamba O-demethylase from Pseudomonas maltophilia, strain DI-6: purification and characterization.

Dicamba O-demethylase is a multicomponent enzyme that catalyzes the conversion of the herbicide 2-methoxy-3,6-dichlorobenzoic acid (dicamba) to 3,6-dichlorosalicylic acid (DCSA). The three components of the enzyme were purified and characterized. Oxygenase(DIC) is a homotrimer (alpha)3 with a subunit molecular mass of approximately 40 kDa. FerredoxinDIC and reductaseDIC are monomers with molecular weights of approximately 14 and 45 kDa, respectively. EPR spectroscopic analysis suggested the presence of a single [2Fe-2S](2+/1+) cluster in ferredoxinDIC and a single Rieske [2Fe-2S](2+; 1+) cluster within oxygenaseDIC. Consistent with the presence of a Rieske iron-sulfur cluster, oxygenaseDIC displayed a high reduction potential of E(m,7.0) = -21 mV whereas ferredoxinDIC exhibited a reduction potential of approximately E(m,7.0) = -171 mV. Optimal oxygenaseDIC activity in vitro depended on the addition of Fe2+. The identification of formaldehyde and DCSA as reaction products demonstrated that dicamba O-demethylase acts as a monooxygenase. Taken together, these data suggest that oxygenaseDIC is an important new member of the Rieske non-heme iron family of oxygenases.