Apple Glycosyltransferase MdUGT73AR4 Glycosylates ABA to Regulate Stomatal Movement Involved in Drought Stress.

Abscisic acid (ABA) is a drought-stress-responsive hormone that plays an important role in the stomatal activity of plant leaves. Currently, ABA glycosides have been identified in apples, but their glycosyltransferases for glycosylation modification of ABA are still unidentified. In this study, the mRNA expression of glycosyltransferase gene MdUGT73AR4 was significantly up-regulated in mature apple leaves which were treated in drought stress by Real-Time PCR. It was hypothesised that MdUGT73AR4 might play an important role in drought stress. In order to further characterise the glycosylation modification substrate of glycosyltransferase MdUGT73AR4, we demonstrated through in vitro and in vivo functional validation that MdUGT73AR4 can glycosylate ABA. Moreover, the overexpression lines of MdUGT73AR4 significantly enhance its drought stress resistance function. We also found that the adversity stress transcription factor AREB1B might be an upstream transcription factor of MdUGT73AR4 by bioinformatics, EMSA, and ChIP experiments. In conclusion, this study found that the adversity stress transcription factor AREB1B was significantly up-regulated at the onset of drought stress, which in turn positively regulated the downstream glycosyltransferase MdUGT73AR4, causing it to modify ABA by mass glycosylation and promoting the ABA synthesis pathway, resulting in the accumulation of ABA content, and displaying a stress-resistant phenotype.

Development of lignin hydrogel reinforced polypyrrole rich electrode material for supercapacitor and sensing applications.

The preparation of natural polymer-based highly conductive hydrogels with reliable durability for applications in supercapacitors (SCs) is still challenging. Herein, a facile method to prepare alkaline lignin (AL)-based polypyrrole (PPy)-rich, high-conductive PPy@AL/PEGDGE gel was reported, where AL was used as a dopant, polyethylene glycol diglycidyl ether (PEGDGE) as a cross-linking agent, and PPy as a conducting polymer. The PPy@AL/PEGDGE gel electrode materials with hollow structures were prepared by electrochemical deposition and chemical etching method and then assembled into sandwich-shaped SCs. Cyclic voltammetry (CV), galvanotactic charge discharge (GCD), electrochemical impedance spectroscopy (EIS) and cycling stability tests of the PPy@AL/PEGDGE SCs were performed. The results demonstrated that the SCs can achieve a conductivity of 25.9 S·m-1 and a specific capacitance of 175 F·g-1, which was 127.4 % higher compared to pure PPy (77 F·g-1) electrode. The highest energy density and power density for the SCs were obtained at 23.06 Wh·kg-1 and 5376 W·kg-1, respectively. In addition, the cycling performance was also higher than that of pure PPy assembled SCs (50 %), and the capacitance retention rate can reach 72.3 % after 1000 cycles. The electrode materials are expected to be used as sensor and SCs devices.

Synthesis, Herbicidal Activity, and Molecular Mode of Action Evaluation of Novel Aryloxyphenoxypropionate/Amide Derivatives Containing a Quinazolinone Moiety.

To develop aryloxyphenoxypropionate herbicides with a novel structure and improved activity, a total of 39 aryloxyphenoxypropionate/amide derivatives containing quinazolinone moiety were synthesized and further bioevaluated. The bioassay results in the greenhouse showed that most of the target compounds had good herbicidal activity under postemergence conditions, of which, QPP-I-6 displayed excellent herbicidal activity against Echinochloa crusgalli, Digitaria sanguinalis, Spartina alterniflora, Eleusine indica, and Pennisetum alopecuroides with inhibition rates >90% at a dosage of 187.5 g ha-1. More importantly, QPP-I-6 displayed higher crop safety to Gossypium hirsutum, Glycine max, and Arachis hypogaea than the commercial herbicide quizalofop-p-ethyl. Studying the molecular mode of action by phenotypic observation, membrane permeability evaluation, transcriptomic analysis, and in vivo ACCase activity evaluation reveals that QPP-I-6 is a novel ACCase inhibitor. The present work demonstrates that QPP-I-6 can serve as a lead compound for further developing novel ACCase-inhibiting herbicides.

Di-aldehyde tunicate cellulose nanocrystal (D-tCNC) aerogels for drug delivery: Effect of D-tCNC composition on aerogel structure and release properties.

Aerogels as drug carriers have the characteristics of a large specific surface area, high porosity and an elastic skeleton structure. Compared with traditional drug carriers, the use of aerogels as drug carriers can avoid the complexity of drug delivery and improve the efficiency of drug loading. In this work, the oxidation of tunicate cellulose nanocrystals (tCNCs) with NaIO4 was used to prepare di-aldehyde tunicate cellulose nanocrystals (D-tCNCs). Tetracycline (TC) was used as a drug model and pH-responsive drug-loaded aerogels were prepared by the Schiff base reaction between TC and the aldehyde group on D-tCNCs. The chemical structure, crystallinity, morphology, compression properties, porosity, swelling rate and drug loading properties were investigated by FT-IR, XRD, SEM and universal testing machines. The results showed that the porosity and equilibrium swelling ratio of the D-tCNC-TC aerogels were 95.87 % and 17.52 g/g, respectively. The stress of the D-tCNC-TC aerogel at 15 % compression was 0.07 MPa. Moreover, the analysis of drug-loaded aerogels indicated that the drug loading and encapsulation rates of D-tCNC-TC aerogels were 16.86 % and 78.75 %, respectively. In in vitro release experiments, the cumulative release rate of drug-loaded aerogel at pH = 1.2 and pH = 7.4 was 87.5 % and 79.3 %, respectively. These results indicated that D-tCNC-TC aerogels have good drug loading capacity and are pH-responsive in the pH range of 1.2 to 7.4. The prepared D-tCNC-TC aerogels are expected to be applied in drug delivery systems.

Preparation and characterization of highly conductive lignin aerogel based on tunicate nanocellulose framework.

The highly conductive and elastic three-dimensional mesh porous material is an ideal platform for the fabrication of high electrical conductivity conductive aerogels. Herein, a multifunctional aerogel that is lightweight, highly conductive and stable sensing properties is reported. Tunicate nanocellulose (TCNCs) with a high aspect ratio, high Young's modulus, high crystallinity, good biocompatibility and biodegradability was used as the basic skeleton to prepare aerogel by freeze-drying technique. Alkali lignin (AL) was used as the raw material, polyethylene glycol diglycidyl ether (PEGDGE) was used as the cross-linking agent, and polyaniline (PANI) was used as the conductive polymer. Preparation of aerogels by freeze-drying technique, in situ synthesis of PANI, and construction of highly conductive aerogel from lignin/TCNCs. The structure, morphology and crystallinity of the aerogel were characterized by FT-IR, SEM, and XRD. The results show that the aerogel has good conductivity (as high as 5.41 S/m) and excellent sensing performance. When the aerogel was assembled as a supercapacitor, the maximum specific capacitance can reach 772 mF/cm2 at 1 mA/cm2 current density, and maximum power and energy density can reach 59.4 µWh/cm2 and 3600 µW/cm2, respectively. It is expected the aerogel can be applied in the field of wearable devices and electronic skin.