Efficient Translocation Research Articles

Dissecting the pH Sensitivity of Kinesin-Driven Transport.

Kinesin-1 is a crucial motor protein that drives the microtubule-based movement of organelles, vital for cellular function and health. Mostly studied at pH 6.9, it moves at approximately 800 nm/s, covers about 1 μm before detaching, and hydrolyzes one ATP per 8 nm step. Given that cellular pH is dynamic and alterations in pH have significant implications for disease, understanding how kinesin-1 functions across different pH levels is crucial. To explore this, we executed single-molecule motility assays paired with precise optical trapping techniques over a pH range of 5.5-9.8. Our results show a consistent positive relationship between increasing pH and the enhanced detachment (off rate) and speed of kinesin-1. Measurements of the nucleotide-dependent off rate show that kinesin-1 exhibits the highest rate of ATPase activity at alkaline pH, while it demonstrates the optimal number of ATP turnover and cargo translocation efficiency at the acidic pH. Physiological pH of 6.9 optimally balances the biophysical activity of kinesin-1, potentially allowing it to function effectively across a range of pH levels. These insights emphasize the crucial role of pH homeostasis in cellular function, highlighting its importance for the precise regulation of motor proteins and efficient intracellular transport.

The T4bSS of Legionella features a two-step secretion pathway with an inner membrane intermediate for secretion of transmembrane effectors.

To promote intracellular survival and infection, Legionella spp. translocate hundreds of effector proteins into eukaryotic host cells using a type IV b protein secretion system (T4bSS). T4bSS are well known to translocate soluble as well as transmembrane domain-containing effector proteins (TMD-effectors) but the mechanisms of secretion are still poorly understood. Herein we investigated the secretion of hydrophobic TMD-effectors, of which about 80 were previously reported to be encoded by L. pneumophila. A proteomic analysis of fractionated membranes revealed that TMD-effectors are targeted to and inserted into the bacterial inner membranes of L. pneumophila independent of the presence of a functional T4bSS. While the T4bSS chaperones IcmS and IcmW were critical for secretion of all tested TMD-effectors, they did not influence inner membrane targeting of these proteins. As for soluble effector proteins, translocation of all investigated TMD-effectors depended on a C-terminal secretion signal. A deeper analysis of the TMD-effector SidF showed that this signal needed to be presented towards the cytoplasmic side of the inner membrane and that a small periplasmic loop was required for efficient translocation. We propose that strongly hydrophobic TMD-effectors are secreted in a two-step secretion process: Initially, an inner membrane intermediate is formed, that is extracted towards the cytoplasmic side, possibly by the help of the type IV coupling protein complex and subsequently secreted into eukaryotic host cells by the T4bSS core complex. Overall, our study highlights the amazing versatility of T4bSS to secrete soluble and TMD-effectors from different subcellular locations of the bacterial cell.

Study on the enhancement effect of EDTA and oxalic acid on phytoremediation of Cr(VI) from soil using Datura stramonium L.

This study investigated the enhancing effects of soil treatment with ethylene diamine tetraacetic acid (EDTA) and oxalic acid (OA) on the remediation of Cr(VI) contaminated soil by Datura stramonium L. A greenhouse pot experiment was conducted, where Cr(VI) contaminated soil was treated with 100 mg/kg Cr(VI) and varying concentrations of EDTA (5 and 10 mmol/kg) and OA (5 and 10 mmol/kg). The effects of these soil treatments on biomass, chlorophyll content, antioxidant enzyme activities, and Cr(VI) enrichment and translocation efficiency of D. stramonium were evaluated. The results showed that added OA to soil significantly increased the biomass and chlorophyll content of D. stramonium. The addition of 10 mmol/kg of OA to soil increased the plant biomass by 67.16 % and chlorophyll b content by 40.01 %. In addition, OA soil treatment significantly enhanced the activities of superoxide dismutase (SOD) by 6.36 %, peroxidase (POD) by 163.13 %, catalase (CAT) by 36.92 %, and ascorbate peroxidase (APX) by 32.12 %, which effectively alleviated the oxidative stress induced by Cr(VI). In contrast, soil treatment with a high concentration of EDTA (10 mmol/kg) significantly reduced plant biomass and chlorophyll content, although it increased the biological concentration factor (BCF) of the stem and leaf, as well as the translocation factor (TF). In conclusion, appropriate amounts of EDTA and OA added to soil can enhance the phytoremediation efficiency of D. stramonium grown in Cr(VI) contaminated soil, with OA added to soil being more effective than addition of EDTA. This study revealed the potential mechanisms of chelating agents EDTA and OA in enhancing the phytoremediation of Cr(VI) contaminated soil by D. stramonium, providing a scientific basis for further optimization of phytoremediation techniques.

Distinct accumulation patterns, translocation efficiencies, and impacts of nano-fertilizer and nano-pesticide in wheat through foliar versus soil application

The use of nano-chemicals in agriculture has been shown to enhance crop production through soil additions or foliar sprays. However, the accumulation pattern, translocation efficiency, mode of action of nanomaterials (NMs) via different application methods remain unclear. In this study, wheat was treated with CuO-NPs/CeO2-NPs (50 and 100 nm) for 21 days using soil and foliar application separately. Foliar spray resulted in higher accumulation and more efficient translocation of NMs compared to soil addition. Smaller NMs exhibited higher accumulation and transfer capabilities under the same application method. The accumulation of CuO-NPs was approximately 20 times greater than that of CeO2-NPs, particularly under the soil addition treatment. Scanning electron microscopy analysis demonstrated that NMs could directly enter wheat leaves via stomata during foliar application. Wheat growth was inhibited by roughly 15 % following CuO-NPs exposure, whereas no significant effects on growth were observed with CeO2-NPs. By integrating nontargeted metabolomics analysis with targeted physiological characteristics assessments, it was revealed that CuO-NPs mainly disturbed nitrogen metabolism pathways and induced oxidative damage. In contrast, CeO2-NPs enhanced carbohydrates related biological processes such as starch and sucrose metabolism, glycolysis, and TCA cycle, which are crucial for carbon metabolism. These findings suggest that the type of nanomaterial is a crucial factor to consider when evaluating their foliar or soil application in agriculture.

PH-Responsive MOF Nanoparticles Equipped with Hydrophilic "Armor" Assist Fungicides in Controlling Peanut Southern Blight.

The development of novel, safe, and efficient pest and disease control technologies for agricultural crops remains a pivotal area of research. In this study, by combining ZIF-8 and ZIF-90, a water-stable, pH-responsive bilayer MOF nanoparticle (NP) named Z8@Z90 was created, and tebuconazole (TEB) was added to form T@Z8@Z90, used for controlling peanut southern blight. The loading efficiency of TEB within the T@Z8@Z90 reached 26.15%, enabling rapid release in acidic environments triggered by oxalic acid (OA) secreted by Sclerotium rolfsii. In vitro experiments showed that T@Z8@Z90 can regulate the oxalic acid secretion of S. rolfsii and destroy its cell membrane structure. Additional experiments revealed that T@Z8@Z90 reduced sclerotial formation, decreased the total protein content of sclerotia, and influenced their sensitivity to pesticides, thereby mitigating the risk of reinfection by S. rolfsii. Notably, T@Z8@Z90 exhibited efficient translocation within peanut seedlings, being absorbed through the roots and transported to the leaves. At a concentration of 200 mg/L, T@Z8@Z90 exhibited high safety profiles for peanut seedling growth compared to the TEB suspension. Moreover, T@Z8@Z90 is safer for earthworms than TEB SC. Overall, this study offers valuable insights for the management of soil-borne diseases in agriculture and contributes to the advancement of sustainable agricultural practices.

Insights into Translocation of Arginine-Rich Cell-Penetrating Peptides across a Model Membrane.

It is well-known that membrane deformation and water pores contribute to the spontaneous translocation of arginine-rich cell-penetrating peptides (CPPs). We confirm this through the observation of the spontaneous translocation of single R9 (nona-arginine) and Tat (48-60) peptides across a model membrane using the weighted ensemble (WE) method within all-atom molecular dynamics (MD) simulations. Furthermore, we demonstrate that membrane deformation and the presence of a water pore reduce the effective charge of the CPP and the bending rigidity of the model membrane during translocation. We find that R9 disturbs the model membrane more than Tat (48-60), leading to more efficient translocation of R9 across the model membrane.

Cytosolic delivery of monobodies using the bacterial type III secretion system inhibits oncogenic BCR: ABL1 signaling

BackgroundThe inability of biologics to pass the plasma membrane prevents their development as therapeutics for intracellular targets. To address the lack of methods for cytosolic protein delivery, we used the type III secretion system (T3SS) of Y. enterocolitica, which naturally injects bacterial proteins into eukaryotic host cells, to deliver monobody proteins into cancer cells. Monobodies are small synthetic binding proteins that can inhibit oncogene signaling in cancer cells with high selectivity upon intracellular expression. Here, we engineered monobodies targeting the BCR::ABL1 tyrosine kinase for efficient delivery by the T3SS, quantified cytosolic delivery and target engagement in cancer cells and monitored inhibition of BCR::ABL1 signaling.MethodsIn vitro assays were performed to characterize destabilized monobodies (thermal shift assay and isothermal titration calorimetry) and to assess their secretion by the T3SS. Immunoblot assays were used to study the translocation of monobodies into different cell lines and to determine the intracellular concentration after translocation. Split-Nanoluc assays were performed to understand translocation and degradation kinetics and to evaluate target engagement after translocation. Phospho flow cytometry and apoptosis assays were performed to assess the functional effects of monobody translocation into BCR:ABL1-expressing leukemia cells.ResultsTo enable efficient translocation of the stable monobody proteins by the T3SS, we engineered destabilized mutant monobodies that retained high affinity target binding and were efficiently injected into different cell lines. After injection, the cytosolic monobody concentrations reached mid-micromolar concentrations considerably exceeding their binding affinity. We found that injected monobodies targeting the BCR::ABL1 tyrosine kinase selectively engaged their target in the cytosol. The translocation resulted in inhibition of oncogenic signaling and specifically induced apoptosis in BCR::ABL1-dependent cells, consistent with the phenotype when the same monobody was intracellularly expressed.ConclusionHence, we establish the T3SS of Y. enterocolitica as a highly efficient protein translocation method for monobody delivery, enabling the selective targeting of different oncogenic signaling pathways and providing a foundation for future therapeutic application against intracellular targets.

Enhancing phytoremediation of bauxite mine subsoil by Jatropha curcas L. using sewage sludge and poultry sludge

Phytoremediation is a sustainable technology for cleaning up heavy metal contamination at mining sites. However, degraded soils at these sites create a harsh environment for plants to survive and properly yield biomass. In this study, sewage sludge and poultry sludge were applied as soil amendments in bauxite mine subsoil to determine their impact on the growth and heavy metal uptake of Jatropha curcas L. Both sewage sludge and poultry sludge were applied at 25% and 50%. J. curcas was grown in the amended soils for 120 days under greenhouse conditions. Changes in soil physico-chemical properties, plant growth and heavy metal uptake of J. curcas were determined after that. An increase in EC, CEC, total C, total N, total available P and total extractable K was detected in the amended soils. These improvements enhanced the growth of J. curcas, particularly in the development of above-ground plant biomass. Increased plant biomass subsequently led to higher bioaccumulation and translocation efficiency of Al, Fe, Pb and Zn. As a result, higher heavy metal removal of up to 98.03% was detected in the amended treatments. The findings indicated that the application of sewage sludge and poultry sludge improves soil conditions for plant development.

Involvement of plasma membrane H+-ATPase in the nitrate-nutrition uptake and utilization in indica rice

Utilization of nitrogen by crops is essential for sustainable agriculture. The transport of nitrate (NO3−) across the plasma membrane is a critical gateway for N uptake and subsequent utilization. This process requires proton (H+) coupled cotransport, which is driven by proton motive force, provided by plasma membrane (PM) H+-ATPase. In this report, two indica rice varieties [Meixiangzhan 2 (MXZ) and Jifengyou 1002 (JFY)] in South China were selected and cultivated in hydroponic solution with 0.5 mM or 2.0 mM NO3− as the N source. The JFY exhibited stronger growth with higher biomass than MXZ under both 0.5 mM and 2.0 mM NO3−. PM H+-ATPase activity of JFY roots was significantly higher than that of MXZ. The higher PM H+-ATPase activity in JFY was consistent with a higher abundance of PM H+-ATPase protein and higher transcription levels of OSAs, such as OSA2, OSA7 and OSA8 in roots, OSA3, OSA7 and OSA8 in leaves. The expression of nitrate transporters (OsNRT1;1b, OsNRT2.1, OsNRT2.2, and OsNAR2.1) were also higher in roots or shoots of JFY than those in MXZ. Under 0.5 mM and 2.0 mM NO3−, the NO3− absorption and translocation rate, nitrate content, as well as nitrate reductase (NR) activity were all significantly higher in JFY, as compared to those in MXZ. Taken together, in JFY and MXZ, a higher level of PM H+-ATPase protein and higher activity coupled with greater efficiency in nitrate uptake, translocation and assimilation, suggesting the existence of a close correlation between PM H+-ATPase and nitrate utilization in indica rice. PM H+-ATPase may one of the elite genes that can contribute to nitrate use efficiency in rice.

Investigating the impacts of different degrees of deficit irrigation and nitrogen interactions on assimilate translocation, yield, and resource use efficiencies in winter wheat

Water and nitrogen (N) are recognized as the primary determinants influencing the development and output of winter wheat. They affect the growth of winter wheat not only through their own changes, but also through their interaction. The translocation and accumulation of pre- and post-anthesis assimilates (including dry matter and N) are important physiological processes in winter wheat, which are closely related to the resource use efficiency and yield. However, a dearth of research exists that examines the complex interplay between varying water levels, especially severe water deficit, and N deficiency levels on the growth dynamics of winter wheat. The purpose of this study was to quantify and compare the effects of different degrees of water deficit and N interaction on assimilate translocation, water and N use efficiency and yield of winter wheat. A four-year long-term field experiment conducted under the rain-out shelter including four irrigation and two N levels was launched during 2019–2023. This method avoided the impact of precipitation on water treatment and helped to achieve serious water deficit treatment. The findings indicated that the higher N application improved the wheat's ability by 49.6 % - 362.3 % to utilize the available soil water. The pre- and post-anthesis translocation and accumulation of assimilates (including dry matter and N) in winter wheat increase alongside elevated levels of water and N application, except under severe water deficit treatment. Plants under mild to moderate water deficit were better able to translocate the pre-anthesis assimilates. However, the severe water deficit hindered the re-translocation of assimilates before anthesis. Providing additional N during periods of severe water scarcity leads to a 13.4 % - 44.7 % reduction in water use efficiency (WUE). Furthermore, both the irrigation water use efficiency and WUE diminished by 10.3 % - 60.5 % and 4.5 % - 41.4 % with higher levels of irrigation, while improved by 24.4 % - 48.2 % and 12.6 % - 39.4 % with higher N application rates. Conversely, N partial factor productivity and N use efficiency followed the opposite trend. Similar to WUE, increasing N application under severe water deficit would result in a yield reduction of 38.7 %. The reduction in crop yield resulting from severe water stress was primarily ascribed to the decline in the kernels number per spike (up to 74.9 %), with the reduction in spike number per unit area following closely behind (up to 29.1 %). This integrated approach, combining resource use efficiency with a detailed assessment of assimilate dynamics, provides a holistic view of how water and N management strategies impact winter wheat performance. The findings will offer precise insights for developing targeted irrigation and N scheduling strategies for sustaining both winter wheat production and environmental sustainability.

Foliar iodine application: a strategy for tomato biofortification and yield optimization

Iodine (I) is a beneficial micronutrient for crop plants and essential for human health, yet approximately two billion people worldwide suffer from I deficiency, resulting in significant health issues. Agricultural soils often lack sufficient I, resulting in crops with low I content. However, tomatoes have shown potential to accumulate I when supplemented externally, making them an ideal candidate for I biofortification, particularly as an alternative to iodized salt for individuals on low-sodium diets. This two-year greenhouse pot experiment evaluated the effectiveness of foliar application of potassium iodide (KI) in biofortifying two commercial tomato hybrids. Different concentrations of I (0, 1, 3, 6, and 9 mM/plant) were applied as foliar treatments to assess their effects on physiological parameters, yield attributes, and quality traits, especially I enrichment in tomato fruit. The results demonstrated that foliar application of KI significantly increased fruit I contents at concentrations that also promoted overall plant growth and development. These findings underscored the efficient translocation of I through the phloem in tomatoes. I enrichment in tomato fruits ranged up to 5.27 mg/kg, exceeding the recommended daily allowance (RDA) of 150 μg/day. Even lower doses of 1–3 mM KI were effective in achieving significant I enrichment suitable for biofortification programs. In conclusion, tomato emerged as an excellent candidate for agronomic biofortification with I due to the practicality, and affordability of foliar application. The study highlights the potential of foliar I application as a feasible strategy for addressing global I deficiency, emphasizing its suitability for widespread adoption by farmers.

Insights into Transient Dimerisation of Carnitine/Acylcarnitine Carrier (SLC25A20) from Sarkosyl/PAGE, Cross-Linking Reagents, and Comparative Modelling Analysis.

The carnitine/acylcarnitine carrier (CAC) is a crucial protein for cellular energy metabolism, facilitating the exchange of acylcarnitines and free carnitine across the mitochondrial membrane, thereby enabling fatty acid β-oxidation and oxidative phosphorylation (OXPHOS). Although CAC has not been crystallised, structural insights are derived from the mitochondrial ADP/ATP carrier (AAC) structures in both cytosolic and matrix conformations. These structures underpin a single binding centre-gated pore mechanism, a common feature among mitochondrial carrier (MC) family members. The functional implications of this mechanism are well-supported, yet the structural organization of the CAC, particularly the formation of dimeric or oligomeric assemblies, remains contentious. Recent investigations employing biochemical techniques on purified and reconstituted CAC, alongside molecular modelling based on crystallographic AAC dimeric structures, suggest that CAC can indeed form dimers. Importantly, this dimerization does not alter the transport mechanism, a phenomenon observed in various other membrane transporters across different protein families. This observation aligns with the ping-pong kinetic model, where the dimeric form potentially facilitates efficient substrate translocation without necessitating mechanistic alterations. The presented findings thus contribute to a deeper understanding of CAC's functional dynamics and its structural parallels with other MC family members.

Does Nitrogen Fertilization Improve Nitrogen-Use Efficiency in Spring Wheat?

To investigate the effects and mechanism of prolonged inorganic nitrogen (N) fertilization on the N-use efficiency of spring wheat (Triticum aestivum L.), a long-term study initiated in 2003 was conducted. The study analyzed how N fertilization affects dry matter translocation, N translocation, soil NO3-N, and N-use efficiency. Five different N-fertilizer rate treatments were tested: N0, N52.5, N105, N157.5, and N210, corresponding to annual N fertilizer doses of 0, 52.5, 105.0, 157.5, and 210.0 kg N ha−1, respectively. Results showed that increasing N-fertilizer rates significantly enhanced the two-year average dry matter accumulation amount (DMA) at maturity by 22.97–56.25% and pre-flowering crop growth rate (CGR) by 17.11–92.85%, with no significant increase beyond 105 kg N ha−1. However, no significant correlation was observed between the dry matter translocation efficiency (DTE) and wheat grain yield. Both insufficient and excessive N applications resulted in an imbalanced N distribution favoring vegetative growth over reproductive growth, thus negatively impacting N-use efficiency. At maturity, the N-fertilized treatments significantly increased the two-year average N accumulation amount (NAA) by 52.04–129.98%, with no further increase beyond 105 kg N ha−1. N fertilization also improved the two-year average N translocation efficiency (NTE) by 56.89–63.80% and the N contribution proportion (NCP) of wheat vegetative organs by 27.79–57.83%, peaking in the lower-N treatment (N52.5). However, high-N treatment (N210) led to an increase in NO3-N accumulation in the 0–100 cm soil layer, with an increase of 26.27% in 2018 and 122.44% in 2019. This higher soil NO3-N accumulation in the 0–100 cm layer decreased NHI, NUE, NAE, NPFP, and NMB. Additionally, N fertilization significantly reduced the two-year average N harvest index (NHI) by 9.89–12.85% and N utilization efficiency (NUE) by 11.14–20.79%, both decreasing with higher N application rates. The NAA followed the trend of anthesis > maturity > jointing. At the 105 kg N ha−1 rate, the highest N agronomic efficiency (NAE) (9.31 kg kg−1), N recovery efficiency (NRE) (38.32%), and N marginal benefit (NMB) (10.67 kg kg−1) were observed. Higher dry matter translocation amount (DTA) and N translocation amount (NTA) reduced NHI and NUE, whereas higher NTE improved NHI, NUE, and N partial factor productivity (NPFP). Overall, N fertilization enhanced N-use efficiency in spring wheat by improving N translocation rather than dry matter translocation.

Rapid Vacuolar Sorting of the Borate Transporter BOR1 Requires the Adaptor Protein Complex AP-4 in Arabidopsis.

Plants maintain nutrient homeostasis by controlling the activities and abundance of nutrient transporters. In Arabidopsis thaliana, the borate (B) transporter BOR1 plays a role in the efficient translocation of B under low-B conditions. BOR1 undergoes polyubiquitination in the presence of sufficient B and is then transported to the vacuole via multivesicular bodies (MVBs) to prevent B accumulation in tissues at a toxic level. A previous study indicated that BOR1 physically interacts with µ subunits of adaptor protein complexes AP-3 and AP-4, both involved in vacuolar sorting pathways. In this study, we investigated the roles of AP-3 and AP-4 subunits in BOR1 trafficking in Arabidopsis. The lack of AP-3 subunits did not affect either vacuolar sorting or polar localization of BOR1-GFP, whereas the absence of AP-4 subunits resulted in a delay in high-B-induced vacuolar sorting without affecting polar localization. Super-resolution microscopy revealed a rapid sorting of BOR1-GFP into AP-4-positive spots in the trans-Golgi network (TGN) upon high-B supply. These results indicate that AP-4 is involved in sequestration of ubiquitinated BOR1 into a TGN-specific subdomain "vacuolar-trafficking zone," and is required for efficient sorting to MVB and vacuole. Our findings elucidate the rapid vacuolar sorting process facilitated by AP-4 in plant nutrient transporters.

Structural insights into the chloroplast protein import in land plants

Chloroplast proteins are imported via the translocon at the outer chloroplast membrane (TOC)-translocon at the inner chloroplast membrane (TIC) supercomplex, driven by an ATPase motor. The Ycf2-FtsHi complex has been identified as the chloroplast import motor. However, its assembly and cooperation with the TIC complex during preprotein translocation remain unclear. Here, we present the structures of the Ycf2-FtsHi and TIC complexes from Arabidopsis and an ultracomplex formed between them from Pisum. The Ycf2-FtsHi structure reveals a heterohexameric AAA+ ATPase motor module with characteristic features. Four previously uncharacterized components of Ycf2-FtsHi were identified, which aid in complex assembly and anchoring of the motor module at a tilted angle relative to the membrane. When considering the structures of the TIC complex and the TIC-Ycf2-FtsHi ultracomplex together, it becomes evident that the tilted motor module of Ycf2-FtsHi enables its close contact with the TIC complex, thereby facilitating efficient preprotein translocation. Our study provides valuable structural insights into the chloroplast protein import process in land plants.

Self-Assembled Hydrazide-Based Nanochannels: Efficient Water Translocation and Salt Rejection.

Nature has ingeniously developed specialized water transporters that effectively reject ions, including protons, while transporting water across membranes. These natural water channels, known as aquaporins (AQPs), have inspired the creation of Artificial Water Channels (AWCs). However, replicating superfast water transport with synthetic molecular structures that exclude salts and protons is a challenging task. This endeavor demands the coexistence of a suitable water-binding site and a selective filter for precise water transportation. Here, we present small-molecule hydrazides 1b-1d that self-assemble into a rosette-type nanochannel assembly through intermolecular hydrogen bonding and π-π stacking interactions, and selectively transport water molecules across lipid bilayer membranes. The experimental analysis demonstrates notable permeability rates for the 1c derivative, enabling approximately 3.18 × 108 water molecules to traverse the channel per second. This permeability rate is about one order of magnitude lower than that of AQPs. Of particular significance, the 1c ensures exclusive passage of water molecules while effectively blocking salts and protons. MD simulation studies confirmed the stability and water transport properties of the water channel assembly inside the bilayer membranes at ambient conditions.

Negatively Charged Carbon Dots Employed Symplastic and Apoplastic Pathways to Enable Better Plant Delivery than Positively Charged Carbon Dots.

Efficient delivery of nanoparticles (NPs) to plants is important for agricultural application. However, to date, we still lack knowledge about how NPs' charge matters for its translocation pathway, i.e., symplastic and apoplastic pathways, in plants. In this study, we synthesized and used negatively charged citrate sourced carbon dots (C-CDs, -37.97 ± 1.89 mV), Cy5 coated C-CDs (Cy5-C-CDs, -41.90 ± 2.55 mV), positively charged PEI coated carbon dots (P-CDs, +43.03 ± 1.71 mV), and Cy5 coated P-CDs (Cy5-P-CDs, +48.80 ± 1.21 mV) to investigate the role of surface charges and coatings on the employed translocation pathways (symplastic and apoplastic pathways) of charged NPs in plants. Our results showed that, different from the higher fluorescence intensity of P-CDs and Cy5-P-CDs in extracellular than intracellular space, the fluorescence intensity of C-CDs and Cy5-C-CDs was similar between intracellular and extracellular space in cucumber and cotton roots. It suggests that the negatively charged CDs were translocated via both symplastic and apoplastic pathways, but the positively charged CDs were mainly translocated via the apoplastic pathway. Furthermore, our results showed that root applied negatively charged C-CDs demonstrated higher leaf fluorescence than did positively charged P-CDs in both cucumber (8.09 ± 0.99 vs 3.75 ± 0.23) and cotton (7.27 ± 1.06 vs 3.23 ± 0.22), indicating that negatively charged CDs have a higher translocation efficiency from root to leaf than do positively charged CDs. It should be noted that CDs do not affect root cell activities, ROS level, and photosynthetic performance in cucumber and cotton, showing its good biocompatibility. Overall, this study not only figured out that root applied negatively charged CDs employed both symplastic and apoplastic pathways to do the transportation in roots compared with mainly the employment of apoplastic pathway for positively charge CDs, but also found that negatively charge CDs could be more efficiently translocated from root to leaf than positively charged CDs, indicating that imparting negative charge to NPs, at least CDs, matters for its efficient delivery in crops.

Enhancing Photosynthesis and Plant Productivity through Genetic Modification.

Enhancing crop photosynthesis through genetic engineering technologies offers numerous opportunities to increase plant productivity. Key approaches include optimizing light utilization, increasing cytochrome b6f complex levels, and improving carbon fixation. Modifications to Rubisco and the photosynthetic electron transport chain are central to these strategies. Introducing alternative photorespiratory pathways and enhancing carbonic anhydrase activity can further increase the internal CO2 concentration, thereby improving photosynthetic efficiency. The efficient translocation of photosynthetically produced sugars, which are managed by sucrose transporters, is also critical for plant growth. Additionally, incorporating genes from C4 plants, such as phosphoenolpyruvate carboxylase and NADP-malic enzymes, enhances the CO2 concentration around Rubisco, reducing photorespiration. Targeting microRNAs and transcription factors is vital for increasing photosynthesis and plant productivity, especially under stress conditions. This review highlights potential biological targets, the genetic modifications of which are aimed at improving photosynthesis and increasing plant productivity, thereby determining key areas for future research and development.

Gene Electrotransfer via Conductivity-Clamped Electric Field Focusing Pivots Sensori-Motor DNA Therapeutics: "A Spoonful of Sugar Helps the Medicine Go Down".

Viral vectors and lipofection-based gene therapies have dispersion-dependent transduction/transfection profiles that thwart precise targeting. The study describes the development of focused close-field gene electrotransfer (GET) technology, refining spatial control of gene expression. Integration of fluidics for precise delivery of "naked" plasmid deoxyribonucleic acid (DNA)in sucrose carrier within the focused electric field enables negative biasing of near-field conductivity ("conductivity-clamping"-CC), increasing the efficiency of plasma membrane molecular translocation. This enables titratable gene delivery with unprecedently low charge transfer. The clinic-ready bionics-derived CC-GET device achieved neurotrophin-encoding miniplasmid DNA delivery to the cochlea to promote auditory nerve regeneration; validated in deafened guinea pig and cat models, leading to improved central auditory tuning with bionics-based hearing. The performance of CC-GET is evaluated in the brain, an organ problematic for pulsed electric field-based plasmid DNA delivery, due to high required currents causing Joule-heating and damaging electroporation. Here CC-GET enables safe precision targeting of gene expression. In the guinea pig, reporter expression is enabled in physiologically critical brainstem regions, and in the striatum (globus pallidus region) delivery of a red-shifted channelrhodopsin and a genetically-encoded Ca2+sensor, achieved photoactivated neuromodulation relevant to the treatment of Parkinson's Disease and other focal brain disorders.

Rice Response to Spermine Foliar Application and Its Association with Aerial Imagery Monitoring Under Water Stress Conditions

Rice is the most consumed food in the world, mainly in Asia and Africa. Malaysia is the second-largest rice importer in Southeast Asia after Indonesia. However, rice yield is limited by water stress. One alternative for a quicker strategy to mitigate water stress is through a combination of foliar spermine application and efficient rice management practices via image monitoring techniques using drone technology. The present study was aimed at evaluating the effects of spermine on rice physiological response and its association with aerial imagery and yield under reproductive during reproductive stage under water stress. The experiment was carried out under greenhouse conditions using a two-factorial randomized complete block design (RCBD), with foliar spermine treatment as the first factor and water stress as the second factor. Physiological parameters showed significantly higher tiller number per pot and photosynthesis rate by 29% and 31%, respectively. Correspondingly, the Normalised Difference Vegetation Index (NDVI) using aerial imagery monitoring showed an increased value in spermine treatments by 2% compared to control. Furthermore, NDVI readings and photosynthetic rate were positively correlated linearly with R2= 0.51. Interestingly, spermine treatments alleviated water stress effects by 40%, 17% and 12% in grain weight per pot, grain number per panicle and percentage filled grain. Biomass partitioning in roots improved by 44% in spermine treatments, even under water stress, due to an efficient translocation of assimilates. In conclusion, spermine foliar application significantly improved growth, grain filling and rice yield production, which was also supported by NDVI values using aerial imagery monitoring.