The OsMYC2-JA feedback loop regulates diurnal flower-opening time via cell wall loosening in rice.

Diurnal flower-opening time (DFOT), the time of spikelet opening during the day, is an important trait for hybrid rice (Oryza sativa L.) seed production. Hybrids between indica and japonica rice varieties have strong heterosis, but the parental lines usually have different, nonoverlapping DFOTs. This reduces the success of hybrid seed production in crosses between indica and japonica subspecies, thus hindering the utilization of indica and japonica inter-subspecies heterosis. However, little is known about the molecular mechanisms regulating DFOT in rice. Here, we obtained japonica rice lines with a DFOT 1.5 h earlier than the wild type by overexpressing OsMYC2, a gene encoding a key transcription factor in the jasmonate (JA) signaling pathway. OsMYC2 is activated by JA signaling and directly regulates the transcription of genes related to JA biosynthesis and cell wall metabolism. Overexpressing OsMYC2 led to significantly increased JA contents and decreased cellulose and hemicellulose contents in lodicule cells, as well as the softening of lodicule cell walls. This may facilitate the swelling of lodicules, resulting in early diurnal flower-opening. These results suggest that the OsMYC2-JA feedback loop regulates DFOT in rice via cell wall remodeling. These findings shed light on the understanding of regulatory mechanism of the DFOT of plants, which should promote the development of indica and japonica varieties suitable for hybrid rice breeding.

Controlling diurnal flower-opening time by manipulating the jasmonate pathway accelerates development of indica-japonica hybrid rice breeding.

Inter-subspecific indica-japonica hybrid rice (Oryza sativa) has the potential for increased yields over traditional indica intra-subspecies hybrid rice, but limited yield of F1 hybrid seed production (FHSP) hinders the development of indica-japonica hybrid rice breeding. Diurnal flower-opening time (DFOT) divergence between indica and japonica rice has been a major contributing factor to this issue, but few DFOT genes have been cloned. Here, we found that manipulating the expression of jasmonate (JA) pathway genes can effectively modulate DFOT to improve the yield of FHSP in rice. Treating japonica cultivar Zhonghua 11 (ZH11) with methyl jasmonate (MeJA) substantially advanced DFOT. Furthermore, overexpressing the JA biosynthesis gene OPDA REDUCTASE 7 (OsOPR7) and knocking out the JA inactivation gene CHILLING TOLERANCE 1 (OsHAN1) in ZH11 advanced DFOT by 1- and 2-h respectively; and knockout of the JA signal suppressor genes JASMONATE ZIM-DOMAIN PROTEIN 7 (OsJAZ7) and OsJAZ9 resulted in 50-min and 1.5-h earlier DFOT respectively. The yields of FHSP using japonica male-sterile lines GAZS with manipulated JA pathway genes were significantly higher than that of GAZS wildtype. Transcriptome analysis, cytological observations, measurements of elastic modulus and determination of cell wall components indicated that the JA pathway could affect the loosening of the lodicule cell walls by regulating their composition through controlling sugar metabolism, which in turn influences DFOT. This research has vital implications for breeding japonica rice cultivars with early DFOT to facilitate indica-japonica hybrid rice breeding.

Discovery of a novel antifungal agent: All-hydrocarbon stapling modification of peptide Aurein1.2.

Aurein1.2 is secreted by the Australian tree frog Litoria aurea and is active against a broad range of infectious microbes including bacteria, fungi, and viruses. Its antifungal potency has garnered considerable interest in developing novel classes of natural antifungal agents to fight pathogenic infection by fungi. However, serious pharmacological hurdles remain, hindering its clinical translation. To alleviate its susceptibility to proteolytic degradation and improve its antifungal activity, six conformationally locked peptides were synthesized through hydrocarbon stapling modification and evaluated for their physicochemical and antifungal parameters. Among them, SAU2-4 exhibited significant improvement in helicity levels, protease resistance, and antifungal activity compared to the template linear peptide Aurein1.2. These results confirmed the prominent role of hydrocarbon stapling modification in the manipulation of peptide pharmacological properties and enhanced the application potential of Aurein1.2 in the field of antifungal agent development.

Related Factors of CRKP Infection in Neurosurgery and Comparison of Therapeutic Effects of Tigecycline Versus Polymyxin B for CRKP Infection.

Objective: This paper aimed to identify the factors related to Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection in neurosurgical patients, and to compare the therapeutic effects of tigecycline versus polymyxin B against CRKP infection, so as to provide a reliable reference for neurosurgery in future prevention and treatment of CRKP infection. Methods: One hundred and fifty cases of KPN treated in the neurosurgery department of our hospital from January 1, 2019 to December 31, 2021 were selected, 50 of which were found to be infected with CRKP and the other 100 were detected with carbapenem-sensitive Klebsiella pneumoniae (CSKP) by culture, analysis of factors associated with infection with CRKP. Subsequently, CRKP-infected patients were randomized into a group treated with Ti (group Ti) and a group treated with PB (group PB). The clinical efficacy, bacterial clearance, adverse reactions, and pre- and post-treatment hepatorenal function were comparatively analyzed. Results: Based on the Logistic regression analysis, tracheal intubation (or mechanical ventilation), combination of multiple underlying diseases, presence of impaired consciousness, and use of carbapenem antibiotics are independent risk factors for CRKP infection (P < .05). Ti and PB groups had no evident differences in clinical efficacy and bacterial clearance (P > .05); however, Ti group presented a worse hepatorenal function and a higher incidence of adverse reactions than PB group (P < .05). Conclusions: Tracheal intubation (or mechanical ventilation), multiple underlying diseases, consciousness disturbance, and use of carbapenem antibiotics are related factors affecting CRKP infection in neurosurgical patients. Both Ti and PB have excellent therapeutic efficacy, but the former has more obvious toxicity and side effects.

Highly efficient synthesis of benzodioxins with a 2-site quaternary carbon structure by secondary amine-catalyzed dual Michael cascade reactions.

Salicylic acids and substituted ynones were employed as substrates to afford a class of valuable 4H-benzo[d][1,3]dioxin-4-ones with a 2-site quaternary carbon structure in up to 92% yield by secondary amine-catalyzed dual Michael cascade reactions under mild reaction conditions. The α,ß-unsaturated ketone as the key intermediate in the cascade process was successfully separated and characterized. As a result, a new reaction route for ynone species is demonstrated, which is totally different from the existing allenamine activation model.

Synthesis of Pelorol and Its Analogs and Their Inhibitory Effects on Phosphatidylinositol 3-Kinase.

There are numerous biologically active substances with novel structures and unique physiological functions in marine organisms. These substances are important sources of new lead compounds. Pelorol is a natural product isolated from marine organisms that possesses a novel structure with high bioactivity. In this paper, the synthesis of pelorol has been completed, and the synthesis of some intermediates has been optimized and scaled up. Five pelorol analogs have also been prepared. Preliminary biological activity testing demonstrated that compounds 5 and 6 might be potential lead compounds for cancer therapy.

An Improved and Efficient Process for the Preparation of (+)-cloprostenol.

An improved and efficient synthesis of (+)-cloprostenol has been accomplished in nine steps and 26% overall yield from commercially available (-)-Corey lactone 4-phenylbenzoate alcohol . The present route avoids tedious purifications and requires only one column chromatography operation, which reduces the generation of waste and is suitable for large-scale preparation.

Mesoporous CdO/CdGa2O4 microsphere for rapidly detecting triethylamine at ppb level.

Developing fast, accurate and sensitive triethylamine gas sensors with low detection limits is paramount to ensure the safety of workers and the public. However, sensors based on single metal oxide materials still suffer from drawbacks such as low response sensitivity and long response and recovery times. To address these challenges, in this work, a series of mesoporous CdO/CdGa2O4 microspheres were synthesized. We optimized the sensor's sensing performance to triethylamine by fine-tuning the ratio of CdO to CdGa2O4. Among them, CdO:3CdGa2O4-based sensor demonstrates a rapid response time of 2 s to detect 100 ppm of triethylamine, with a high response value of 211 and exceptional selectivity. Furthermore, it exhibits a low detection limit of 20 ppb for triethylamine, making it suitable for practically testing fish freshness. Crucially, electron transfer between the heterojunctions increases the chemically adsorbed oxygen on the materials' surface, thereby enhancing the sensor's response sensitivity to triethylamine. This discovery provides new insights and methodologies for the design of highly efficient triethylamine gas sensors.

Transcriptome analysis expands underlying mechanisms of quorum sensing mediating heterotrophic nitrification-aerobic denitrification process at low temperature.

Quorum sensing (QS) could regulate the behavior of microbial communities and help them resist adverse low-temperature environments. A newly isolated heterotrophic nitrification-aerobic denitrification (HN-AD) bacterium, strain YB1107, exhibited strong tolerance to harsh cold environments, removing 93.5 % of ammonia within 36 h and achieving a maximum specific growth rate of 0.28 h-1 at 10 °C. Strain YB1107 secreted large amounts of N-butanoyl-L-homoserine or N-octanoyl-L-homoserine lactones in response to cold stimuli. The add-back experiments indicated that these two signaling molecules jointly manipulated microbial physiological behavior by improving ammonia oxidation and biofilm formation, while inhibiting aerobic denitrification. The transcriptome analysis revealed that QS systems enhanced the cold resistance of HN-AD bacteria by promoting nitrogen assimilation and reducing dissimilation through regulating related genes. This study provided new molecular insights into how QS mediated HN-AD at low temperatures and laid the foundation for the potential applications of psychrophilic HN-AD bacteria in wastewater treatment.

Synthesis of six-membered spirooxindoles via a chiral Brønsted acid-catalyzed asymmetric intramolecular Friedel-Crafts reaction.

By means of the direct condensation of N-aminoethylpyrroles and isatins, followed by a chiral phosphoric acid-catalyzed asymmetric intramolecular Friedel-Crafts reaction, a new class of valuable chiral 3',4'-dihydro-2'H-spiro[indoline-3,1'-pyrrolo[1,2-a]pyrazin]-2-ones bearing a quaternary carbon stereocenter were successfully synthesized in good to excellent yields and with moderate to good enantioselectivities under mild reaction conditions.

Design, Synthesis, and Biological Evaluation of Substituted Pyrimidines as Potential Phosphatidylinositol 3-Kinase (PI3K) Inhibitors.

Three series of substituted pyrimidines were designed and synthesized. All target compounds were screened for kinase inhibitory activities against PI3Kα, and most IC50 values were found within the nanomolar range. Compounds 5d and 5p displayed comparable activities relative to the positive control 5a. 5p also showed a significant isozyme selectivity (PI3Kß/α). Furthermore, the cytotoxicities of these pyrimidines against human cancer cell lines were evaluated and the in vivo anticancer effect of 5d was also tested.

Palladium-catalyzed Suzuki cross-coupling of N'-tosyl arylhydrazines.

The first palladium-catalyzed Suzuki cross-coupling of N'-tosyl arylhydrazines with various organoboron reagents has been developed for the preparation of biaryl compounds in high yields. N'-Tosyl arylhydrazine as a readily available and stable electrophile also demonstrated its generality in a number of coupling reactions.