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1.
Plants (Basel) ; 13(3)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38337880

RESUMO

JAZ proteins function as transcriptional regulators that form a jasmonic acid-isoleucine (JA-Ile) receptor complex with coronatine insensitive 1 (COI1) and regulate plant growth and development. These proteins also act as key mediators in signal transduction pathways that activate the defense-related genes. Herein, the role of OsJAZ4 in rice blast resistance, a severe disease, was examined. The mutation of OsJAZ4 revealed its significance in Magnaporthe oryzae (M. oryzae) resistance and the seed setting rate in rice. In addition, weaker M. oryzae-induced ROS production and expression of the defense genes OsO4g10010, OsWRKY45, OsNAC4, and OsPR3 was observed in osjaz4 compared to Nipponbare (NPB); also, the jasmonic acid (JA) and gibberellin4 (GA4) content was significantly lower in osjaz4 than in NPB. Moreover, osjaz4 exhibited a phenotype featuring a reduced seed setting rate. These observations highlight the involvement of OsJAZ4 in the regulation of JA and GA4 content, playing a positive role in regulating the rice blast resistance and seed setting rate.

2.
Phys Chem Chem Phys ; 26(3): 2387-2394, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38168687

RESUMO

Prussian blue framework materials are expected to be the next generation of electrode materials for commercial batteries because their three-dimensional framework structures facilitate the rapid transport and storage of ions and a variety of redox processes. This work compared the calculations of the model before and after the dispersion correction, and the model considering the effect of van der Waals force was more stable. In addition, the distances between H, C and N atoms were within the range of van der Waals force. Thus it was confirmed that NH4+ was adsorbed on the Ax site in the Prussian blue framework material (AxMa[Mb(CN)6]) by van der Waals interaction, and the charge transfer was mainly achieved by the interaction between the H atom in NH4+ and the N atom in the Prussian blue framework. On this basis, the properties of NH4+ batteries were theoretically screened for the Fe-based Prussian blue analogues (PBAs) with different Ma elements (Ma = Co, Cu, Fe, Mg, Mn, Ni, V or Zn). Considering the regulating effect of different metal elements on the electronic structures of PBAs, MgFe and ZnFe PBAs as the electrode materials of NH4+ batteries are expected to show excellent electrochemical energy storage performance in organic electrolytes.

3.
Food Chem X ; 20: 101042, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38144827

RESUMO

The high sensitivity to color browning during room-temperature storage was a significant factor in limiting the development of fresh spinach noodles (FSN). The practice of humidity-controlled heat treatment (HCHT) at varying temperatures, relative humidity, and time was carried out to limit enzyme activity and improve the quality of FSN. Results showed that HCHT could maximize the color preservation of fresh spinach noodle quality while effectively inactivating polyphenol oxidase and the yeasts, and mold count in FSN during storage was almost undetectable after mild conditions (80 °C). The hardness and chewiness of HCHT noodles were significantly increased, but the free sulfhydryl content was reduced. At 80 °C, 90 %, 5 min, protein structural aggregation was found in the microstructure of HCHT fresh spinach noodles. HCHT also caused partial gelatinization, as evidenced by the decrease in starch gelatinization enthalpy from 5.49 to 4.77 J/g, although the gelatinization degree of FSN was comparatively low.

4.
Medicine (Baltimore) ; 102(34): e34806, 2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37653767

RESUMO

BACKGROUND: Although colonoscopic retroflexion has been proved effective in reducing missed adenomas, there is still a lack of comprehensive and in-depth research focused on the ascending colon. We aimed to conduct a randomized controlled trial and tandem colonoscopy to investigate whether cecal retroflexion observed during colonoscopy can reduce missed adenomas in the ascending colon. METHODS: Men and women required to be between 45 and 80 years of age were screened for enrollment in the trial. Patients were randomly assigned according to a 1:1 ratio to either the trial group or control group. Patients in the trial group underwent 2 forward examination and a cecal retroflexion observed in the ascending colon, while patients in the control group underwent only 2 forward examinations in the ascending colon. The primary outcome was adenoma miss rate. The secondary outcomes contained adenoma detection rate, polyp miss rate, polyp detection rate, insertion time and withdrawal time. Differences between groups in the primary outcome and in the other categorical indicators were tested using chi-squared test and Fisher exact test. For the comparison of continuous outcomes, the Student t test was applied. RESULTS: A total of 60 subjects were eligible for the study between April to June 2020, of which 55 were randomized and eligible for analysis (26 to the control group and 29 to the trial group). The characteristics of patients were no significant differences statistically between the trial group and the control group. Similarly, the characteristics of the colonoscopy procedures included cecal insertion distance, the length of cecum and ascending colon, insertion time, withdrawal time, quality of bowel preparation, numerical rating scale for pain, polyps detected, and adenomas detected, and there were no significant differences statistically between the 2 groups (P = .864, P = .754, P = .700, P = .974, P = .585, P = .835, P = .373, P = .489). The characteristics of the polyps were also no significant differences statistically between the 2 groups. CONCLUSION: This pilot trial failed to show benefit of cecal retroflexion observed on adenoma missing of ascending colon during colonoscopy; however, further conclusions require a prospective study with a higher level of evidence. (NCT03355443).


Assuntos
Adenoma , Colo Ascendente , Masculino , Humanos , Feminino , Estudos Prospectivos , Projetos Piloto , Ceco , Colonoscopia , Adenoma/diagnóstico
5.
aBIOTECH ; 4(2): 108-123, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37581021

RESUMO

Lipid droplets are important storages in fungal conidia and can be used by plant pathogenic fungi for infection. However, the regulatory mechanism of lipid droplets formation and the utilization during fungal development and infection are largely unknown. Here, in Magnaporthe oryzae, we identified a lipid droplet-associated protein Nem1 that played a key role in lipid droplets biogenesis and utilization. Nem1 was highly expressed in conidia, but lowly expressed in appressoria, and its encoded protein was localized to lipid droplets. Deletion of NEM1 resulted in reduced numbers of lipid droplets and decreased content of diacylglycerol (DAG) or triacylglycerol (TAG). NEM1 was required for asexual development especially conidia production. The Δnem1 mutant was nearly loss of virulence to host plants due to defects in appressorial penetration and invasive growth. Remarkably, Nem1 was regulated by the TOR signaling pathway and involved in the autophagy process. The Ser303 residue of Nem1 could be phosphorylated by the cAMP-PKA signaling pathway and was important for biological function of Nem1. Together, our study revealed a regulatory mechanism of lipid biogenesis and metabolism during the conidium and appressorium formation of the rice blast fungus. Supplementary Information: The online version contains supplementary material available at 10.1007/s42994-023-00098-5.

6.
J Fungi (Basel) ; 9(7)2023 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-37504764

RESUMO

Studies on the population structure and variation of Magnaporthe oryzae in fields are of great significance for the control of rice blast disease. In this study, a total of 462 isolates isolated from different areas of Hunan Province in 2016 and 2018 were analyzed for their population structure and variation tendency. The results showed that from 2016 to 2018, the concentration of fungal races of M. oryzae increased and the diversity decreased; furthermore, 218 isolates in 2016 belonged to ZA, ZB, ZC, ZE, ZF and ZG, with a total of 6 groups and 29 races, in which the dominant-population ZB group accounted for 66.2%; meanwhile, in 2018, 244 isolates were classified into 4 groups and 21 races, including ZA, ZB, ZC and ZG, in which the dominant-population ZB group accounted for 72.54%. In 2018, isolates of ZD, ZE and ZF populations were absent, and the number of total races and isolates of the ZA and ZC groups decreased. Fungal pathogenicity was identified, with 24 monogenic lines (MLs) carrying 24 major R genes. The resistance frequency of R genes to fungal isolates in 2018 decreased significantly, in which except Pikm was 64.5%, the other monogenic lines were less than 50%. Rep-PCR analysis for isolates of Guidong in Hunan also showed that fungal diversity decreased gradually. The influence of R genes on fungal variation was analyzed. The pathogenicity of isolates purified from Xiangwanxian 11 planted with monogenic lines was significantly more enhanced than those without monogenic lines. All the results indicated that in recent years, the fungal abundance in Hunan has decreased while fungal pathogenicity has increased significantly. This study will greatly benefit rice-resistance breeding and the control of rice blast disease in Hunan Province.

7.
Life Sci Alliance ; 6(7)2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37188478

RESUMO

Colorectal cancer (CRC) is one of the most commonly diagnosed malignant tumors of the digestive tract. H2-calponin (CNN2), an actin cytoskeleton-binding protein, is an isoform of the calponin protein family whose role in CRC is still unknown. Research based on clinical samples showed the up-regulation of CNN2 in CRC and its association with tumor development, metastasis, and poor prognosis of patients. Both in vitro loss-of-function and gain-of-function experiments showed that CNN2 participates in CRC development through influencing malignant cell phenotypes. In vivo, xenografts formed by CNN2 knockdown cells also showed a slower growth rate and smaller final tumors. Furthermore, EGR1 was identified as a downstream of CNN2, forming a complex with CNN2 and YAP1 and playing an essential role in the CNN2-induced regulation of CRC development. Mechanistically, CNN2 knockdown down-regulated EGR1 expression through enhancing its ubiquitination, thus decreasing its protein stability in a YAP1-dependent manner. In summary, CNN2 plays an EGR1-dependent promotion role in the development and progression of CRC, which may be a promising therapeutic target for CRC treatment.


Assuntos
Neoplasias Colorretais , Proteínas dos Microfilamentos , Humanos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Neoplasias Colorretais/metabolismo , Ubiquitinação , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Calponinas
8.
Mol Plant Pathol ; 24(4): 374-390, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36775579

RESUMO

Cell wall polysaccharides play key roles in fungal development, virulence, and resistance to the plant immune system, and are synthesized from many nucleotide sugars in the endoplasmic reticulum (ER)-Golgi secretory system. Nucleotide sugar transporters (NSTs) are responsible for transporting cytosolic-derived nucleotide sugars to the ER lumen for processing, but their roles in plant-pathogenic fungi remain to be revealed. Here, we identified two important NSTs, NST1 and NST2, in the rice blast fungus Magnaporthe oryzae. Both NSTs were localized in the ER, which was consistent with a function in transporting nucleotide sugar for processing in the ER. Sugar transport property analysis suggested that NST1 is involved in transportation of mannose and glucose, while NST2 is only responsible for mannose transportation. Accordingly, deletion of NSTs resulted in a significant decrease in corresponding soluble saccharides abundance and defect in sugar utilization. Moreover, both NSTs played important roles in cell wall integrity, were involved in asexual development, and were required for full virulence. The NST mutants exhibited decreasing external glycoproteins and exposure of inner chitin, which resulted in activation of the host defence response. Altogether, our results revealed that two sugar transporters are required for fungal cell wall polysaccharides accumulation and full virulence of M. oryzae.


Assuntos
Magnaporthe , Oryza , Virulência , Nucleotídeos , Manose , Polissacarídeos , Parede Celular , Oryza/microbiologia , Proteínas Fúngicas/genética , Doenças das Plantas/microbiologia
9.
Foods ; 12(4)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36832812

RESUMO

In this study, the rheological behavior of maize kernel was systematically investigated using a dynamic mechanical analyzer. The loss in toughness caused by drying resulted in a downward shift in the relaxation curve and an upward shift in the creep curve. The long relaxation behavior became obvious when the temperature was above 45 °C, resulting from the weakening of hydrogen bonds with temperature. The maize kernel relaxed more rapidly at high temperatures, caused by a reduction in the cell wall viscosity and polysaccharide tangles. The Deborah numbers were all much smaller than one, suggesting that the Maxwell elements showed viscous behavior. Maize kernel, as a viscoelastic material, showed a dominant viscous property at high temperatures. The decline in ß with increasing drying temperature indicated an increase in the width of the relaxation spectrum. A Hookean spring elastic portion made up the majority of the maize kernel creep strain. The order-disorder transformation zone of maize kernel was about 50-60 °C. Due to the complexity of maize kernel, the William-Landel-Ferry constants differed from the universal values; these constants should be ascertained through experiments. Time-temperature superposition was successfully used to describe the rheological behavior. The results show that maize kernel is a thermorheologically simple material. The data acquired in this study can be used for maize processing and storage.

10.
Gastroenterol Rep (Oxf) ; 11: goac082, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36632626

RESUMO

Background: Bone morphogenetic protein receptor type 1A (BMPR1A) is responsible for two individual Mendelian diseases: juvenile polyposis syndrome and hereditary mixed polyposis syndrome 2, which have overlapping phenotypes. This study aimed to elucidate whether these two syndromes are just two subtypes of a single syndrome rather than two isolated syndromes. Methods: We sequenced the BMPR1A gene in 186 patients with polyposis and colorectal cancer, and evaluated the clinicopathological features and phenotypes of the probands and their available relatives with BMPR1A mutations. Results: BMPR1A germline mutations were found in six probands and their three available relatives. The numbers of frameshift, nonsense, splice-site, and missense mutations were one, one, two, and two, respectively; two of the six mutations were novel. Typical juvenile polyps were found in only three patients. Two patients had colorectal cancer rather than any polyps. Conclusions: Diseases in BMPR1A germline mutation carriers vary from mixed polyposis to sole colorectal cancer, and typical juvenile polyps do not always occur in these carriers. The variety of phenotypes reflected the features of BMPR1A-mutation carriers, which should be recognized as a spectrum of one syndrome. Genetic testing may be a good approach to identifying BMPR1A-related syndromes.

11.
Phys Chem Chem Phys ; 25(6): 4724-4731, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36661895

RESUMO

In the present work, we evaluated the hydrogen evolution reaction (HER) performance of transition metal (Co, Fe, Ni, Mn, and Mo) doped vanadium carbides (VC). In addition, the doping atoms were screened separately on the (100), (110) and (111) crystal planes to analyze the differences in HER activities. Among all the calculated models, Mn-VC(100) exhibited the best catalytic hydrogen evolution performance with a Gibbs free energy for hydrogen adsorption (ΔGH*) of 0.0012 eV. Doping Mn greatly improved the HER performance of VC(100) by enhancing the adsorption of hydrogen on the catalyst surface. The analysis of the electronic density of states and charge transfer confirmed that doping transition metal atoms into the surfaces of the VC model successfully optimized the electronic structure and promoted catalytic reaction kinetics. Besides, the relationship between the catalytic activity and pH value of different models was considered, and doping Co atoms on the (100) crystal plane could effectively modify the pH value range applicable for the efficient HER. Interestingly, even if the same metal atoms were doped, various active sites of VC models exhibited different catalytic performances due to disparate exposed crystal planes and pH values. This indicates that the main exposed crystal surfaces and the pH range of application need to be considered when selecting the appropriate doping element for the catalyst.

12.
Int J Biol Macromol ; 222(Pt B): 2868-2877, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36228816

RESUMO

Acid hydrolysis is a crucial method for modifying granular starch, but it is often conducted at low temperatures (below 55 °C) for an extended period of time to prevent crystallinity loss. The high-temperature acid hydrolysis (HTAH) behavior of heat-moisture treated (HMT) starch at 69 °C was investigated for the first time. The crystalline structure of starch was enhanced by HMT, confirmed by its rheological, thermal, and infrared Fourier transform spectroscopy results. The amorphous structure of HMT starch was preferentially hydrolyzed with high reactivity, related to a fast hydrolysis stage (4.17 × 10-2 min-1). And the crystalline flakes were separated from starch granules, accompanied by strengthened molecular interactions. HMT starch was transformed from 16.98 µm granules to 158 nm thick and 2.57 µm broad flakes with a 6.40 % increase in crystallinity after 40 min of hydrolysis. For native starch, the HTAH destroyed the crystalline structure due to gelatinization, resulting mainly gelatinous aggregates. These evidenced that the hydrolysis of granular starch was successfully performed at a relatively high temperature by introducing heat-moisture pre-treatment. This study could provide a novel perspective on the combination of increasing temperature and pre-treatment for granular starch hydrolysis intensification design, as well as a strategy for efficiently preparing small-sized crystalline starch, which has promising applications in Pickering emulsion and material filler.


Assuntos
Temperatura Alta , Zea mays , Hidrólise , Temperatura , Amido/química , Ácidos
13.
Front Plant Sci ; 13: 934195, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36212313

RESUMO

Calcium (Ca2+) is the most abundant divalent cation in plants, and cellular levels of Ca2+, which functions as a nutrient and secondary messenger, play a critical role in plant immunity. In the present study, we found that FERONIA-like receptor 1 (FLR1) positively regulates Magnaporthe oryzae resistance and that expression of FLR1 is strongly induced in response to Ca2+ deficiency. In addition, the Ca content in the shoots of flr1 was lower than that in wild-type, and the M. oryzae-sensitive phenotype of the flr1 mutant was not rescued by exogenous application of Ca2+. Moreover, RNA sequencing revealed 2,697 differentially expressed genes (DEGs) in the flr1 mutant compared with wild-type, and some of these DEGs are involved in cellular metal ion homeostasis and transition metal ion homeostasis. Changes in expression of overlapping genes between the flr1 mutant and in plants under low-Ca2+ treatment were consistent in terms of direction, indicating that FLR1 is involved in Ca2+ homeostasis. In summary, we detected FLR1-mediated resistance to M. oryzae, a phenomenon associated with Ca2+ homeostasis.

14.
Am J Cancer Res ; 12(8): 3745-3759, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36119845

RESUMO

This study aimed to explore the biological function and the molecular mechanism of the action of zinc-finger protein 516 (ZNF516) in suppressing stem cell-like characteristics and tumor progression in colorectal cancer (CRC). The expression profiles of ZNF516 in clinical samples and from The Cancer Genome Atlas (TCGA) CRC database were analyzed. Cell transfection was used to overexpress and knockdown ZNF516 in CRC cells. Cell counting kit-8 (CCK8) assays, transwell assays and flow cytometry were used to study cell proliferation, invasion and stem cell-like characteristics, respectively. Cycloheximide (CHX) was used to examine the effect of ZNF516 expression on Sox2 degradation. Finally, the effects of ZNF516 on tumor growth and metastasis were tested on xenograft tumor models and lung metastasis models in immunocompromised mice. We found that the expression level of ZNF516 was lower in TCGA CRC tissue and clinical CRC samples compared with that in normal colorectal mucosal cells. Overexpression of ZNF516 in CRC cells inhibited cell proliferation, colony formation, migration and invasion, whereas ZNF516 knockdown showed the opposite effects. In addition, ZNF516 overexpression inhibited the sphere-forming ability of CRC cells and suppressed the expression of CD133, CD44 and Oct4 in CRC cells. ZNF516 decreased the stability of Sox2 through a mechanism mediated by EGFR. By in vivo experiments using mouse tumor models, we further confirmed that ZNF516 attenuated tumor growth and alleviated lung metastasis in mice. In conclusion, ZNF516 functions as a tumor suppressor by regulating the transcription of Sox2 to inhibit cell proliferation, invasion, and the development of stem cell-like characteristics in CRC cells.

16.
Plant Dis ; 2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35815958

RESUMO

Palm grass (Setaria palmifolia) has been used as an ornamental plant and vegetable crop (Wu, 2009; Plarre, 1995). In June 2019, 2-10 mm severe leaf lesions with gray centers and brown-yellow edges were observed on the leaves of palm grass in Liuyang city (28°43'N, 114°12'E), Hunan province, China (Fig. 1A). Disease incidence on leaves was 20 - 40%. The infected leaves were collected and disinfected with 75% alcohol for 30 sec and 1% sodium hypochlorite for 1 min, followed by three rinses in sterilized ddH2O, dried on sterilized filter paper, and incubated on water agar for 48 h under continuous fluorescent light at 26℃. Then, typical pyriform and 2-septate conidia (23.97 - 30.37 × 7.42 - 9.98 µm, N = 30) appeared at the lesions (Fig. 1B). Four single-spore were captured, and then grew on oatmeal tomato agar for seven days under continuous fluorescent light at 26℃ to obtain four isolates (LY-ZY-7a, -7b, -9b and -9c) and produce conidia for inoculation tests. The colony morphology of LY-ZY-7b on OTA was gray and floccose, and the growth rate was 6.15 - 6.31 mm/d at 26 °C (Fig. 1C). Spores of LY-ZY-7b were washed off with sterilized ddH2O plus 0.025% Tween-20 to make spore suspensions. For scratch inoculation, 10 µL spore suspension (1 × 105 spores/mL) was inoculated on the wound scratched with a sterilized pin along the vein (3 mm × 3 mm) on palm grass middle leaf of 4-week-old seedlings. The inoculated leaves were sealed in a 15-cm Petri dish. For spray inoculation, 20 mL spore suspension (5 × 104 spores/mL) was made and sprayed on ten healthy palm grasses of 4-week-old seedlings. Plants used as negative controls were sprayed with sterilized ddH2O plus 0.025% Tween-20 (Liu et al. 2022; Zhang et al. 2014). After inoculation, all plants were put into transparent boxes to maintain > 95% humidity and covered with black plastic bags for one day. Then, the boxes containing the plants were placed in a growth chamber at 26°C (12 h light / 12 h darkness photoperiod). After six days, typical blast-type lesions with brown-yellow edges were visible on the leaves. Control plants did not show symptoms (Fig. 1D, 1E). Microscopical examination showed that the conidia and conidiophore recovered from the lesion of the inoculated plants have the same morphology as those recovered from natural infected tissues (Fig. 1F, 1G). The colony morphology of the pathogen isolated from the artificially inoculated tissue was consistent with that of isolate LY-ZY-7b (Fig. 1C). The spore suspension (5 × 104 spores/mL) of isolate LY-ZY-7b and one rice-infecting strain P131 (Yang et al., 2010) was made and sprayed onto 4-week-old seedlings of three rice cultivars. But unfortunately, isolate LY-ZY-7b could not cause any disease lesions on the tested rice cultivars, whereas strain P131 produced many typical blast lesions on rice leaves (Fig. 1H). Then, the fungal genetic identity of four isolates (LY-ZY-7a, -7b, -9b, and -9c) was confirmed by comparison of the sequence obtained from partial DNA of Actin (ACT), ITS, and RPB1 loci from our isolates and those previously published by Klaubauf et al. 2014. The nucleotide sequences of ACT, ITS, and RPB1 were submitted to GenBank ON228695-ON228697 (ACT), ON210978-ON210980 (ITS), ON228698-ON228701 (RPB1). A phylogenetic tree deduced from a maximum likelihood analysis based on combined ACT-ITS-RPB1 sequence data of Pyricularia showed that these four isolates (LY-ZY-7a, -7b, -9b, and -9c) clustered together on Pyricularia oryzae, with a high bootstrap support value (Fig. 2). Based on morphological characteristics and molecular phylogeny, these four isolates were identified as P. oryzae (Klaubauf et al. 2014; Qi et al. 2019). To our knowledge, this is the first report of blast disease on palm grass caused by P. oryzae in China, which will help develop disease management strategies against palm grass blast. Moreover, as a host of P. oryzae, palm grass might contribute as an inoculum source for blast diseases on cereal crops (such as rice, wheat, and barley) caused by P. oryzae in the field.

17.
J Agric Food Chem ; 70(23): 6993-7003, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35667655

RESUMO

Endophytes can benefit the growth and stress resistance of host plants by secreting bioactive components. Thiamine is an essential vitamin involved in many metabolic pathways and can only be synthesized by microbes and plants. In this study, we found that thiamine could inhibit the development of the phytopathogen Magnaporthe oryzae and decrease the rice blast index under field conditions. In the thiamine biosynthesis pathway, the key enzyme ShTHIC of an endophyte Streptomyces hygroscopicus OsiSh-2 and OsTHIC of rice (Oryza sativa) were highly homologous. Gene overexpression or knockout approaches revealed that both THIC contributed to thiamine synthesis and resistance to M. oryzae. Furthermore, S. hygroscopicus OsiSh-2 colonization led to a decrease in the thiamine synthesis level of rice but still maintained thiamine homeostasis in rice. However, inoculation with the ShTHIC knockout strain ΔTHIC reduced the thiamine content in rice, although the thiamine synthesis level of rice was increased. After infection with M. oryzae, blast resistance was dramatically improved in OsiSh-2-inoculated rice but decreased in ΔTHIC-inoculated rice compared with non-inoculated rice. This result demonstrated that ShTHIC could regulate thiamine biosynthesis and consequently assist blast resistance in the OsiSh-2-rice symbiont. Our results revealed a novel blast-resistance mechanism mediated by a key thiamine biosynthetic enzyme from an endophyte OsiSh-2.


Assuntos
Magnaporthe , Oryza , Resistência à Doença/genética , Endófitos/genética , Oryza/genética , Oryza/metabolismo , Doenças das Plantas/genética , Tiamina/metabolismo
18.
Food Chem ; 393: 133458, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35751209

RESUMO

In the present work, the Pickering emulsions with enhanced oxidation stability were fabricated using gliadin (G)/arabinoxylan nanoparticles (GANPs). The influence of different G/AX ratios on the properties of GANPs and corresponding physicochemical characteristics of Pickering emulsions were investigated. Results indicated that the droplet size and ζ-potential of Pickering emulsions declined with the decrease of G/AX ratios. Pickering emulsion with the smallest G/AX ratio (1:4) exhibited excellent oxidative and coalescence stability due to the formation of viscoelastic gel network, which was supported by confocal laser scanning microscopy (CLSM) images. Furthermore, the increase of salt ions in a lower concentration (0-0.2 M) was conducive to the flocculation of the droplets, while further increasing the NaCl concentration impaired the emulsion stability. Such elements revealed that G/AX complex is a promising stabilizer of Pickering emulsions with prominent antioxidant activity, which have favorable potential applications in protecting the functional properties of polyunsaturated fatty acids (PUFAs).


Assuntos
Gliadina , Nanopartículas , Emulsões/química , Gliadina/química , Nanopartículas/química , Tamanho da Partícula , Água/química , Xilanos
19.
Food Chem ; 386: 132854, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-35366630

RESUMO

The impact of freeze-thaw cycles on the physicochemical properties and frying performance of frozen Youtiao dough with chemical leavening agent was investigated. The specific volume of Youtiao made from frozen dough decreased by 66% after 4 freeze-thaw cycles. Meanwhile, the hardness and puncture force showed increasing trends, and the fibrous structure became unclear. The extensibility, storage modulus (G') and loss modulus (G'') of frozen Youtiao dough decreased during freeze-thaw cycles, while the creep compliance increased. Changes in rheological properties demonstrated that frozen Youtiao dough was more deformable and its strength was weakened. Moreover, the sodium dodecyl sulfate (SDS) extractable protein and free sulfhydryl content increased, revealing that protein was depolymerized. The loose structure with large pores and fractured protein network were observed by micromorphology. Freeze-thaw cycles had a detrimental effect on the Youtiao quality, which was related to the deterioration of rheological properties and protein structure of frozen Youtiao dough.


Assuntos
Glutens , Congelamento , Glutens/química , Dureza , Reologia , Dodecilsulfato de Sódio/química
20.
New Phytol ; 235(1): 247-262, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35338654

RESUMO

In eukaryotes, N6 -methyladenosine (m6 A) is abundant on mRNA, and plays key roles in the regulation of RNA function. However, the roles and regulatory mechanisms of m6 A in phytopathogenic fungi are still largely unknown. Combined with biochemical analysis, MeRIP-seq and RNA-seq methods, as well as biological analysis, we showed that Magnaporthe oryzae MTA1 gene is an orthologue of human METTL4, which is involved in m6 A modification and plays a critical role in autophagy for fungal infection. The Δmta1 mutant showed reduced virulence due to blockage of appressorial penetration and invasive growth. Moreover, the autophagy process was severely disordered in the mutant. MeRIP-seq identified 659 hypomethylated m6 A peaks covering 595 mRNAs in Δmta1 appressoria, 114 m6 A peaks was negatively related to mRNA abundance, including several ATG gene transcripts. Typically, the mRNA abundance of MoATG8 was also increased in the single m6 A site mutant ∆atg8/MoATG8A982C , leading to an autophagy disorder. Our findings reveal the functional importance of the m6 A methylation in infection of M. oryzae and provide novel insight into the regulatory mechanisms of plant pathogenic fungi.


Assuntos
Magnaporthe , Oryza , Ascomicetos , Autofagia/genética , Proteínas Fúngicas/genética , Oryza/genética , Oryza/microbiologia , Doenças das Plantas/microbiologia , RNA , RNA Mensageiro/genética
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