摘要：
<jats:title>Abstract</jats:title><jats:sec>
<jats:title>Background</jats:title>
<jats:p>Hydrogen sulfide (H<jats:sub>2</jats:sub>S) is a novel signaling molecule involved in the growth and development of plants and their response to stress. However, the involvement of H<jats:sub>2</jats:sub>S in promoting the growth and development of tobacco plants is still unclear.</jats:p>
</jats:sec><jats:sec>
<jats:title>Results</jats:title>
<jats:p>In this study, we explored the effect of pre-soaking or irrigating the roots of tobacco plants with 0.0, 2.0, 4.0, 6.0, and 8.0mM of sodium hydrosulfide (NaHS) on endogenous H<jats:sub>2</jats:sub>S production, antioxidant enzymatic and cysteine desulfhydrase activities, seed germination, agronomic traits, photosynthetic pigments contents, and root vigor. The results revealed that exogenous NaHS treatment could significantly promote endogenous H<jats:sub>2</jats:sub>S production by inducing gene expression of <jats:italic>D/L-CD</jats:italic> and the activities of D/L-CD enzymes. Additionally, a significant increase in the agronomic traits and the contents of photosynthetic pigments, and no significant difference in carotenoid content among tobacco plants treated with 0.0 to 8.0mM of NaHS was observed. Additionally, a significant increase in the germination speed, dry weight, and vigor of tobacco seeds, whereas no significant effect on the percentage of seed germination was observed on NaHS treatment. Furthermore, NaHS treatment could significantly increase the activity of superoxide dismutase (SOD) and peroxidase (POD) enzymes, which reduces damage due to oxidative stress by maintaining reactive oxygen species homeostasis.</jats:p>
</jats:sec><jats:sec>
<jats:title>Conclusions</jats:title>
<jats:p>These results would aid in enhancing our understanding of the involvement of H<jats:sub>2</jats:sub>S, a novel signaling molecule to promote the growth and development of tobacco plants.</jats:p>
</jats:sec>
作者机构：
[Duan, Linlin; Duan, Haitao; Duan, HT; Jia, Dan; Li, Jian] Wuhan Res Inst Mat Protect, State Key Lab Special Surface Protect Mat & Applic, Wuhan 430030, Peoples R China.;[Duan, Linlin; Duan, Haitao; Duan, HT; Jia, Dan; Li, Jian] Hubei Longzhong Lab, Xiangyang 441000, Peoples R China.;[Liu, Jianfang] Wuhan Polytech Univ, Coll Life Sci & Technol, Wuhan 430030, Peoples R China.
通讯机构：
[Duan, HT ] W;Wuhan Res Inst Mat Protect, State Key Lab Special Surface Protect Mat & Applic, Wuhan 430030, Peoples R China.;Hubei Longzhong Lab, Xiangyang 441000, Peoples R China.
摘要：
<jats:title>Abstract</jats:title><jats:p>In this work, the advantage of Coulomb repulsion in the intermolecular forces experienced by molecules on the solid-liquid nanosized contact interface is taken, and the superior friction-reducing property of Cu<jats:sub>3</jats:sub>(PO<jats:sub>4</jats:sub>)<jats:sub>2</jats:sub>·3H<jats:sub>2</jats:sub>O (CuP) oil-based additives has been confirmed for titanium alloy. Three-dimensional (3D) CuP nanoflowers (CuP-Fs) with a strong capillary absorption effect are prepared to achieve the homogeneous mixing of solid CuP and lubricating oil. Lubrication by CuP-Fs additives for titanium alloy, friction coefficient (COF) can be reduced by 73.68%, and wear rate (WR) reduced by 99.69%. It is demonstrated that the extraordinary friction-reducing property is due to the repulsive solid-liquid interface with low viscous shear force originating from Coulomb repulsion between polar water molecules in CuP and non-polar oil molecules. However, any steric hindrance or connection between this repulsive solid-liquid interface will trigger the adhesion and increase the viscous shear force, for example, dispersant, hydrogen bondings, and shaky adsorbed water molecules. Besides, the lamellar thickness of CuP and the molecular size of lubricant both have a great influence on tribological properties. Here the lubrication mechanism based on interface Coulomb repulsion is proposed that may help broaden the scope of the exploration in low-friction nanomaterial design and new lubricant systems.</jats:p>
作者机构：
[Duan, Linlin; Duan, Haitao; Li, Guozheng; Duan, HT; Jia, Dan] Wuhan Res Inst Mat Protect, State Key Lab Special Surface Protect Mat & Applic, Wuhan 430030, Peoples R China.;[Duan, Linlin; Duan, Haitao; Li, Guozheng; Duan, HT; Jia, Dan] Hubei Longzhong Lab, Xiangyang 441000, Peoples R China.;[Liu, Jianfang] Wuhan Polytech Univ, Coll Life Sci & Technol, Wuhan 430030, Peoples R China.;[Cheng, Bingxue] Tsinghua Univ, State Key Lab Tribol Adv Equipment, Beijing 100084, Peoples R China.
通讯机构：
[Duan, HT ] W;Wuhan Res Inst Mat Protect, State Key Lab Special Surface Protect Mat & Applic, Wuhan 430030, Peoples R China.;Hubei Longzhong Lab, Xiangyang 441000, Peoples R China.
摘要：
In this work, a self-assembled hybrid phosphate nanoflower (HPN) containing Ba3(PO4)2 and NaBaPO4 was synthesized via BaCO3 primary crystals inducement. A ball-on-disc reciprocating tribometer was used to explore the tribological behavior of HPN as an additive for polyalphaolefin 8 (PAO8) on titanium alloy. Compared with the neat PAO8, after being lubricated with PAO8 containing HPN, the friction coefficient and wear rate decreased by 74.98% and 99.89%, respectively. The tribofilm at the friction interface was characterized and conformed by SEM, EDS, XPS, and cross-sectional TEM. As an additive to PAO8, HPN can participate in the formation of tribofilm and exhibit superior friction-reducing and anti-wear properties for titanium alloy. It was demonstrated that due to the P-O-Ti bonds, HPN can easily adsorb and deposit at the friction interface to form a tribofilm against wear. Besides, the simulation experiments showed that the repulsive force at the solid-liquid interface between HPN and oil molecules is the key to friction reduction and lubrication, and the comparative tribological experiments of different types of base oils were performed to verify the results of molecular dynamics.
摘要：
The mitogen-activated protein kinase (MAPK) signaling cascade is a unique and relatively conserved signaling pathway in eukaryotes, transmitting extracellular signals into cells through successive phosphorylation and eliciting appropriate responses from the organism. While its mechanism in plant immune response has been partially elucidated in Arabidopsis, it has been rarely examined in Tartary buckwheat (Fagopyrum tataricum). Based on the conserved MAPK domain, we identified 16 MAPK family genes in Tartary buckwheat. The FtMAPKs have similar structures and motif compositions, indicating that this gene family is conserved yet functionally diverse. Using quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis, we observed significant expression variation in 15 genes across different organs, except for FtMAPK12. FtMAPK9 showed specific expression in vegetative organs, FtMAPK4 in reproductive organs, and FtMAPK1 and FtMAPK10 in leaves and flowers, respectively, indicating their regulatory roles in Tartary buckwheat development. Following drought and salt stress treatments, 12 and 14 FtMAPKs, respectively, showed significantly altered expression in leaves exhibiting notable biological oxidation. Among these, FtMAPK3, FtMAPK4, and FtMAPK8 demonstrated highly significant changes across both treatments. Transcriptome analysis confirmed these findings, suggesting that these three genes play pivotal roles in Tartary buckwheat's response to abiotic stress and hold potential for molecular breeding improvements.
摘要：
Although cytochrome P450 enzymes are the most versatile biocatalysts in nature, there is insufficient comprehension of the molecular mechanism underlying their functional innovation process. Here, by combining ancestral sequence reconstruction, reverse mutation assay, and progressive forward accumulation, we identified 5 founder residues in the catalytic pocket of flavone 6-hydroxylase (F6H) and proposed a "3-point fixation" model to elucidate the functional innovation mechanisms of P450s in nature. According to this design principle of catalytic pocket, we further developed a de novo diffusion model (P450Diffusion) to generate artificial P450s. Ultimately, among the 17 non-natural P450s we generated, 10 designs exhibited significant F6H activity and 6 exhibited a 1.3- to 3.5-fold increase in catalytic capacity compared to the natural CYP706X1. This work not only explores the design principle of catalytic pockets of P450s, but also provides an insight into the artificial design of P450 enzymes with desired functions.
通讯机构：
[Min, T ] W;Wuhan Polytech Univ, Coll Food Sci & Engn, Wuhan 430023, Peoples R China.
关键词：
Cinnamaldehyde;Fresh -cut Chinese water chestnuts;Reactive oxygen species (ROS);AsA-GSH cycle
摘要：
The quality of fresh -cut Chinese water chestnuts (CWCs) rapidly deteriorates with prolonged storage time, thus affecting its commercial value. This study aimed to investigate the effect of cinnamaldehyde (CA) treatment on the quality of fresh -cut CWCs and its mechanism of action. CA treatment maintained good appearance and higher total soluble solids content (TSS) of fresh -cut CWCs and also significantly inhibited microbial proliferation, respiration, phenylalanine ammonia-lyase activity (PAL) and enzymatic browning substance content. Moreover, CA treatment increased the antioxidant capacity and defense function -related enzyme activities (PPO and POD) of fresh -cut CWCs, and suppressed center dot OH production rate and MDA content. Meanwhile, CA treatment significantly increased the content of antioxidant compounds and enzyme activities of the AsA-GSH cycle system. In conclusion, CA can inhibit surface discoloration of fresh -cut CWCs and extend their shelf life, thus increasing their commercial value.
摘要：
The myofibrillar protein (MP) of duck meat is prone to excessive oxidation during thermal processing, resulting in a decline in its overall quality. In this paper, the effect of shikimic acid on the oxidative structure of duck muscle fibrin was studied. The findings showed that, at a mass ratio of 1:50,000 (g/g) between shikimic acid and MP, the carbonyl content of MP was reduced by 74.20%, while the sulfhydryl content was increased by 73.56%. MP demonstrated the highest denaturation temperature, whereas its thermal absorption was the lowest. The percentage of α-helixes and β-sheets increased by 16.72% and 24.74%, respectively, while the percentage of irregular structures decreased by 56.23%. In addition, the surface hydrophobicity index of MP exhibited a significant decrease (p < 0.05), while there was a significant increase in its free radical-scavenging ability (p < 0.05). Molecular fluorescence spectrum analysis showed that shikimic acid could bind to MP, altering the internal environment of MP and enhancing its thermal stability. FTIR analysis showed that shikimic acid could enhance the distribution of protein particle sizes by reducing irregular structures, the proportion of β-rotation, and the degree of protein aggregation. It is hoped that this research can offer scientific support for improving meat processing technology.
作者机构：
[Jiang, Jiang; Liao, Rongfeng] Anhui Med Univ, Dept Urol, Affiliated Hosp 1, Hefei, Anhui, Peoples R China.;[Jiang, Jiang] Anhui Med Univ, Dept Ophthalmol, Affiliated Hosp 3, Hefei, Anhui, Peoples R China.;[Wang, Shu] Anhui Med Univ, Dept Geriatr, Affiliated Hosp 3, Hefei, Anhui, Peoples R China.;[Li, Yun] Wuhan Polytech Univ, Sch Biol & Pharmaceut Engn, Wuhan, Peoples R China.;[Li, Yun] Kindstar Global Precis Med Inst, Wuhan, Peoples R China.
通讯机构：
[Liao, RF ] A;Anhui Med Univ, Dept Urol, Affiliated Hosp 1, Hefei, Anhui, Peoples R China.
摘要：
More and more evidence shows that abnormal lipid metabolism leads to immune system dysfunction in AMD and promotes the occurrence of AMD by changing the homeostasis of ocular inflammation. However, the molecular mechanism underlying the effect of lipid metabolism on the phenotype and function of macrophages is still unclear, and the mechanism of association between AMD and cancer and COVID-19 has not been reported. The purpose of this study is to explore the interaction between lipid metabolism related genes, ferroptosis related genes and immunity in AMD, find out the key genes that affect the ferroptosis of AMD through lipid metabolism pathway and the molecular mechanism that mediates the action of macrophages, and find out the possible mechanism of lipid metabolism and potential co-therapeutic targets between AMD and cancer and COVID-19, so as to improve treatment decision-making and clinical results. For the first time, we have comprehensively analyzed the fatty acid molecule related genes, ferroptosis related genes and immune microenvironment of AMD patients, and determined that mast cells and M1 macrophages are the main causes of AMD inflammation, and found that SCD is the core gene in AMD that inhibits ferroptosis through lipid metabolism pathway, and verified the difference in the expression of SCD in AMD in a separate external data set. Based on the analysis of the mechanism of action of the SCD gene, we found for the first time that Has-miR-199a-3p/RELA/SCD is the core axis of action of lipid metabolism pathway to inhibit the ferroptosis of AMD. By inhibiting the immune checkpoint, we can enhance the immune cell activity of AMD and lead to the transformation of macrophages from M2 to M1, thereby promoting the inflammation and pathological angiogenesis of AMD. At the same time, we found that ACOX2 and PECR, as genes for fatty acid metabolism, may regulate the expression of SCD during the occurrence and development of COVID-19, thus affecting the occurrence and development of AMD. We found that FASD1 may be a key gene for the joint action of AMD and COVID-19, and SCD regulates the immune infiltration of macrophages in glioma and germ line tumors. In conclusion, our results can provide theoretical basis for the pathogenesis of AMD, help guide the treatment of AMD patients and their potentially related diseases and help to design effective drug targets.
摘要：
Identifying functional enzymes for the catalysis of specific biochemical reactions is a major bottleneck in the de novo design of biosynthesis and biodegradation pathways. Conventional methods based on microbial screening and functional metagenomics require long verification periods and incur high experimental costs; recent data-driven methods apply only to a few common substrates. To enable rapid and high-throughput identification of enzymes for complex and less-studied substrates, we propose a robust enzyme's substrate promiscuity prediction model based on positive unlabeled learning. Using this model, we identified 15 new degrading enzymes specific for the mycotoxins ochratoxin A and zearalenone, of which six could degrade >90% mycotoxin content within 3 h. We anticipate that this model will serve as a useful tool for identifying new functional enzymes and understanding the nature of biocatalysis, thereby advancing the fields of synthetic biology, metabolic engineering, and pollutant biodegradation.
通讯机构：
[Peng, WF ] H;Hubei Univ, Environm Microbial Technol Ctr Hubei Prov, Sch Life Sci, State Key Lab Biocatalysis & Enzyme Engn,Hubei Eng, Wuhan 430062, Peoples R China.
摘要：
Being generally regarded as safe, Kluyveromyces lactis has been widely taken for food, feed, and pharmaceutical applications, owing to its ability to achieve high levels of protein secretion and hence being suitable for industrial production of heterologous proteins. Production platform strains can be created through genetic engineering; while prototrophic cells without chromosomally accumulated antibiotics resistance genes have been generally preferred, arising the need for dominant counterselection. We report here the establishment of a convenient counterselection system based on a Frs2 variant, Frs2v, which is a mutant of the alpha-subunit of phenylalanyl-tRNA synthase capable of preferentially incorporating a toxic analog of phenylalanine, r-chloro-phenylalanine (4-CP), into proteins to bring about cell growth inhibition. We demonstrated that expression of Frs2v from an episomal plasmid in K. lactis could make the host cells sensitive to 2 mM 4-CP, and a Frs2v-expressing plasmid could be efficiently removed from the cells immediately after a single round of cell culturing in a 4-CP-contianing YPD medium. This Frs2v-based counterselection helped us attain scarless gene replacement in K. lactis without any prior engineering of the host cells. More importantly, counterselection with this system was proven to be functionally efficient also in Saccharomyces cerevisiae and Komagataella phaffii, suggestive of a broader application scope of the system in various yeast hosts. Collectively, this work has developed a strategy to enable rapid, convenient, and high-efficiency construction of prototrophic strains of K. lactis and possibly many other yeast species, and provided an important reference for establishing similar methods in other industrially important eukaryotic microbes.
