Transcriptome analysis of differentially expressed genes in rice seedling leaves under different nitrate treatments on resistance to bacterial leaf blight.

Nitrogen (N), as one of the most abundant mineral elements in rice, not only is the primary limiting factor for rice yield, but also impacts plant disease resistance by modulating plant morphology, regulating biochemical characteristics, as well as enhancing metabolic processes. Bacterial blight, a severe bacterial disease caused by Xanthomonas oryzae pv. oryzae (Xoo), significantly impairing rice yield and quality. Previous studies have shown that moderate application of nitrate nitrogen can improve plant disease resistance. However, further exploration is urgently required to investigate the involvement of the nitrate nitrogen signaling pathway in conferring resistance against bacterial leaf blight. In this study, we employed transcriptome sequencing to analyze the differentially expressed genes under various concentrations of nitrate supply duringrice bacterial blight infection. Our research reveals that nitrate nitrogen supply influences rice resistance to bacterial leaf blight. Through transcriptomic profiling of rice leaves inoculated under different nitrate nitrogen concentrations, we identified 4815 differentially expressed genes (DEGs) among four comparison groups, with notable differences in DEG enrichment between low and high nitrate nitrogen conditions, with some members of the NPF family implicated and we preliminarily elucidated the molecular regulatory network in which nitrate nitrogen participates in bacterial leaf blight resistance. Our findings provide a novel insight into a mechanism involving the nitrate nitrogen drive wider defense in rice.

A positive feedback regulation of SnRK1 signaling by autophagy in plants.

SnRK1, an evolutionarily conserved heterotrimeric kinase complex that acts as a key metabolic sensor in maintaining energy homeostasis in plants, is an important upstream activator of autophagy that serves as a cellular degradation mechanism for the healthy growth of plants. However, whether and how the autophagy pathway is involved in regulating SnRK1 activity remains unknown. In this study, we identified a clade of plant-specific and mitochondria-localized FCS-like zinc finger (FLZ) proteins as currently unknown ATG8-interacting partners that actively inhibit SnRK1 signaling by repressing the T-loop phosphorylation of the catalytic α subunits of SnRK1, thereby negatively modulating autophagy and plant tolerance to energy deprivation caused by long-term carbon starvation. Interestingly, these AtFLZs are transcriptionally repressed by low-energy stress, and AtFLZ proteins undergo a selective autophagy-dependent pathway to be delivered to the vacuole for degradation, thereby constituting a positive feedback regulation to relieve their repression of SnRK1 signaling. Bioinformatic analyses show that the ATG8-FLZ-SnRK1 regulatory axis first appears in gymnosperms and seems to be highly conserved during the evolution of seed plants. Consistent with this, depletion of ATG8-interacting ZmFLZ14 confers enhanced tolerance, whereas overexpression of ZmFLZ14 leads to reduced tolerance to energy deprivation in maize. Collectively, our study reveals a previously unknown mechanism by which autophagy contributes to the positive feedback regulation of SnRK1 signaling, thereby enabling plants to better adapt to stressful environments.

ABI5-FLZ13 module transcriptionally represses growth-related genes to delay seed germination in response to ABA.

The bZIP transcription factor ABSCISIC ACID INSENSITIVE5 (ABI5) is a master regulator of seed germination and post-germinative growth in response to abscisic acid (ABA), but the detailed molecular mechanism by which it represses plant growth remains unclear. In this study, we used proximity labeling to map the neighboring proteome of ABI5 and identified FCS-LIKE ZINC FINGER PROTEIN 13 (FLZ13) as a novel ABI5 interaction partner. Phenotypic analysis of flz13 mutants and FLZ13-overexpressing lines demonstrated that FLZ13 acts as a positive regulator of ABA signaling. Transcriptomic analysis revealed that both FLZ13 and ABI5 downregulate the expression of ABA-repressed and growth-related genes involved in chlorophyll biosynthesis, photosynthesis, and cell wall organization, thereby repressing seed germination and seedling establishment in response to ABA. Further genetic analysis showed that FLZ13 and ABI5 function together to regulate seed germination. Collectively, our findings reveal a previously uncharacterized transcriptional regulatory mechanism by which ABA mediates inhibition of seed germination and seedling establishment.

Genome-wide Identification and Characterization of FCS-Like Zinc Finger (FLZ) Family Genes in Maize (Zea mays) and Functional Analysis of ZmFLZ25 in Plant Abscisic Acid Response.

FCS-like zinc finger family proteins (FLZs), a class of plant-specific scaffold of SnRK1 complex, are involved in the regulation of various aspects of plant growth and stress responses. Most information of FLZ family genes was obtained from the studies in Arabidopsis thaliana, whereas little is known about the potential functions of FLZs in crop plants. In this study, 37 maize FLZ (ZmFLZ) genes were identified to be asymmetrically distributed on 10 chromosomes and can be divided into three subfamilies. Protein interaction and subcellular localization assays demonstrated that eight typical ZmFLZs interacted and partially co-localized with ZmKIN10, the catalytic α-subunit of the SnRK1 complex in maize leaf mesophyll cells. Expression profile analysis revealed that several ZmFLZs were differentially expressed across various tissues and actively responded to diverse abiotic stresses. In addition, ectopic overexpression of ZmFLZ25 in Arabidopsis conferred hypersensitivity to exogenous abscisic acid (ABA) and triggered higher expression of ABA-induced genes, pointing to the positive regulatory role of ZmFLZ25 in plant ABA signaling, a scenario further evidenced by the interactions between ZmFLZ25 and ABA receptors. In summary, these data provide the most comprehensive information on FLZ family genes in maize, and shed light on the biological function of ZmFLZ25 in plant ABA signaling.

Study on the Preparation of Cellulose Acetate Separation Membrane and New Adjusting Method of Pore Size.

As a kind of eco-friendly (biodegradable) material and with a natural anti-fouling ability, cellulose acetate (CA) is more suitable for single-use membrane (especially in bioprocess). In this study, the method for preparing CA membrane by Vapor-assisted Nonsolvent Induced Phase Separation (VNIPS) was studied. The influences of ratio compositions (solid content, acetone/N,N-Dimethylacetamide ratio, glycerol/CA ratio) and membrane preparation conditions (evaporation time, evaporation temperature and humidity) on the microstructure and other properties were systematically evaluated. Results indicated that acetone/N,N-Dimethylacetamide ratio and glycerol/CA ratio had great influence on the cross-section structure of membranes. Additionally, the membrane with homogeneous sponge-like porous structure could be prepared stably within certain limits of ratios. Under the premise of keeping the content of other components fixed, the separation membrane with a full sponge pore structure can be obtained when the ratio of glycerol/CA is ≥2.5 or the acetone/solvent ratio is between 0.25 and 0.5. Evaporation time and temperature, humidity and other membrane preparation conditions mainly affected the surface morphology and the pore size. This kind of high-performance membrane with homogeneous sponge-like pore and controllable surface morphology could be potentially used for bioseparation processes.

Improving the anti-fouling property and permeate flux of hollow fiber composite nanofiltration membrane using ß-cyclodextrin.

Hollow fiber composite NF membranes with improved anti-fouling property and water flux were prepared via interfacial polymerizationand layer-by-layer method using polyethylenimine (PEI), isophthaloyl dichloride (IPC), and ß-cyclodextrin (ß-CD). The chemical structures and the morphologies of the resultant NF membranes were characterized by attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM). The effects of ß-CD concentration on membrane morphologies, nanofiltration performances, surface hydrophilicities and anti-fouling properties were investigated. It was found that the permeate flux increased with increasing the ß-CD concentration, and no decline of rejection was observed. The results showed that the introduction of ß-CD improved surface hydrophilicities and anti-fouling performances of composite hollow fiber NF membranes. The water contact angles decreased from 61.3° to 23° within creasing the concentration of ß-CD from 0 to 2.0 wt.%. The resultant hollow fiber composite NF membrane showed an excellent anti-fouling property with the flux recovery ratio of 97.6%, which was much better than that of the original polyamide (PA) NF membranes.

A novel positively charged composite nanofiltration membrane based on polyethyleneimine with a tunable active layer structure developed via interfacial polymerization.

A novel positively charged composite nanofiltration (NF) membrane with tunable active layer structure was successfully developed via interfacial polymerization on a polysulfone (PSF) ultrafiltration (UF) membrane surface, using polyethyleneimine (PEI) as the monomer of the aqueous phase, and a mixture of isophthaloyl dichloride (IPC) and tri-mesoyl chloride (TMC) as the monomer of the organic phase. Interestingly, a synergetic effect of the mass ratio of IPC and TMC was observed on the pore size and the structure of the active layer of the resultant polyamide (PA)/polysulfone (PSF) composite NF membrane. The rejection (R) to the inorganic electrolytes increased with the mass ratio of IPC to TMC, while the permeate flux (F) escalated up to a 1 : 1 mixing ratio of IPC to TMC and dropped at higher mixing ratios. The rejection to different inorganic electrolytes decreased in the order of ZnCl2, MgCl2, CaCl2, CuCl2, MgSO4, NaCl, and Na2SO4. At ambient temperature and 0.4 MPa, the optimized membrane demonstrated R and F to 1 g L-1 MgCl2 aqueous solution as 98.1% and 27.6 L m-2 h-1, respectively. Its rejection to various dyes reduced significantly in the order of cationic red X-GTL (100%), rhodamine B (94.2%), cationic gold yellow X-GL (93.5%), and brilliant blue KN-R (43.9%), in agreement with the decrease in the molecular weight (M w) and the overall charges of the dye.

Preparation and characterization of a novel positively charged composite hollow fiber nanofiltration membrane based on chitosan lactate.

A positively charged composite hollow fiber nanofiltration (NF) membrane was prepared via interfacial polymerization (IP) between chitosan lactate (CL) and trimesoyl chloride (TMC) on a polyether sulfone (PES) hollow fiber ultrafiltration (UF) membrane. The chemical structure and the morphologies of the resultant NF membranes were characterized with attenuated total reflectance-infrared spectroscopy (ATR-IR) and scanning electron microscopy (SEM). The rejection of NF membrane for different inorganic salt aqueous solutions followed the order: MgCl2 > ZnCl2 > MgSO4 > NaCl > Na2SO4. It suggested that this novel kind of composite hollow fiber NF membrane is positively charged. The molecular weight cut-off (MWCO) was obtained through the rejection of polyethylene glycol (PEG) solutions with different molecular weights (M w). The effect of monomer concentrations, the interfacial polymerization time, and the curing temperature, were investigated, respectively. The rejection and the permeate flux of the resultant composite hollow fiber CL membrane fabricated under the optimal conditions towards a MgCl2 solution of 1000 ppm were 95.1% and 10.3 L m-2 h-1, respectively, at 0.4 MPa and 25 °C. Moreover, the effects of operation conditions on the rejection performance of the composite hollow fiber NF membrane were investigated. It suggested that this novel kind of hollow fiber composite nanofiltration membrane based on CL have excellent stability in rejection performances to salt solutions.

A pH-stable positively charged composite nanofiltration membrane with excellent rejection performance.

A novel kind of pH-stable positively charged composite nanofiltration (NF) membrane with excellent rejection performance was developed via interfacial polymerization on the surface of a polysulfone (PSF) ultrafiltration (UF) membrane, using a mixture of polyethyleneimine (PEI) and piperazine (PIP) as the monomers of the aqueous phase, and cyanuric chloride (CC) as the monomer of the organic phase. The strong electron withdrawing and steric hindrance effects of the chloride group in the molecules of CC could protect the amido bond from the attack of hydrogen ions (H+) or hydroxyl ions (OH-) under acidic or alkaline conditions, thus the resultant polyamide composite membranes could be stable in acidic or alkali aqueous solution. A more compact PA active layer could be developed via mixing PIP into the PEI aqueous solution, where the PIP molecules could fill the pores of the polymer networks. There was no obvious change in the surface morphologies, the chemical structures, and the rejection performances after immersing the resultant polyamine composite NF membranes in the strong acidic solution (pH 1) and the strong alkaline solution (pH 13) for 30 days, respectively. The rejection performances of this kind of polyamine composite NF membranes could be adjusted through adjusting the mass ratio of PEI to PIP in the aqueous phase.

A novel composite of CdS nanorods growing on a polyaniline-Cd2+ particles surface with excellent formaldehyde gas sensing properties at low temperature.

A novel composite, CdS nanorods growing on a polyaniline-Cd2+ particles surface (CdS/PANI) with a hexagonal wurtzite structure phase, was prepared using a hydrothermal synthesis method. Methods of XRD, SEM, and FTIR were used to analyze the structure and morphology of the compounds. SEM shows that CdS/PANI consists of sea urchin-like nanorods of about 200-500 nm in length and about 50 nm in diameter. Furthermore, the FTIR spectra show that some characteristic peaks of CdS/PANI are much weaker than those of PANI and the corresponding peaks shift to a higher wavenumber. In addition, the IR stretching frequency of the Cd-S bond for CdS/PANI moved from 630 cm-1 to 674 cm-1. In the gas sensing experiments, the CdS/PANI-based sensor showed an excellent response to low concentration formaldehyde gas in a wide temperature range of 80-140 °C. The highest response of CdS/PANI could reach about 4.8 to 5 ppm formaldehyde gas at 120 °C. The response and recovery times of the sensor based on CdS/PANI were about 25 s and 30 s to 10 ppm formaldehyde gas, respectively.