PLANT MOLECULAR BIOLOGY
·
2025
·Vol. 115
·期 2
·1-13
·
IF 3.8
Liu Yitong,Liu Shuangrong,Jing Yanjun,Li Jialong,Lin Rongcheng
Seed dormancy enables plants to delay germination until conditions are favorable for the survival of the next generation. Seed dormancy and germination are controlled by a combination of external and internal signals, in which light and ethylene act as critical regulators. However, how light and ethylene are interlinked to control these two processes remains to be investigated. Here, we show that ethylene and its precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), promote seed germination under light. Light facilitates the conversion of ACC to ethylene, in which phytochrome B (phyB) and FAR-RED ELONGATED HYPOCOTYL3 (FHY3) are functionally required. ACC oxidases (ACOs) catalyze the conversion of ACC to ethylene, among which ACO1 is specifically and predominantly expressed in imbibed seeds. Ethylene induces FHY3 protein accumulation in imbibed seeds, whereby FHY3 directly binds to ACO1 promoter and specifically mediates light-promoted ACO1 expression. Light promotes ACO1 protein accumulation. Overexpression of ACO1 significantly promotes seed germination, and almost completely restores the dormant defect of fhy3 loss-of-function mutants. In summary, this study reveals an ethylene-responsive regulatory cascade of phyB-FHY3-ACO1 that integrates external light input with internal factors to regulate seed dormancy and germination.
研究领域:
植物生物学
·
分子遗传学
·
发育生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Algal Research-Biomass Biofuels and Bioproducts
·
2021
·
IF 4.401
Xuehua Liu,Lijun Wang,Songcui Wu,Lu Zhou,Shan Gao,Xiujun Xie,Lepu Wang,Wenhui Gu,Guangce Wang
The formation of resting cells/spores in marine diatoms helps them to survive in environmental changes, whose sedimentation characteristics also drive enhanced carbon fluxes export to the deep ocean. However, the molecular mechanism underlying the transformation remains unclear. Based on the upregulation of ferritin during dormancy in microorganism and its' crucial role in coping with environmental stress, we constructed the ferritin overexpression and silence strains in model marine diatom, Phaeodactylum tricornutum (FTN-OE and FTN Si, respectively). The morphological transformation from fusiform to ovoid were observed among the FTN-OE strains but not the wide type and FTN-Si strains. These FTN-OE oval cells exhibited typical characteristics of resting cells and benthic adaptation, such as lower growth rates, low-light adaptation, silicified valves, the excretion of exopolymeric substances, upregulation of stress-resistant proteins and increased nitrate reserves. Furthermore, FTN-OE oval cells showed increased abscisic acid synthesis and signaling pathways in the transcriptome and proteome . And the abscisic acid signal was detected in FTN-OE oval cells exclusively (2.96 ng g −1 FW), but absent in the FTN Si, FTN-OE fusiform or WT cells. Overall, our results demonstrate that ferritin overexpression in marine diatom have a close relationship with morphological transformation from fusiform to ovoid morphotype , after which they enter a resting stage, which is accompanied by abscisic acid accumulation. This improves our understanding of the molecular processes in diatom resting cells/spores' formation and suggests that ferritin accumulation might improve the sequestration of photosynthetically fixed atmospheric CO 2 into the deep sea.
研究领域:
海洋生物学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Shuyao Ye,Jincheng Dai,Wei Li,Yao Yang,Zhengliang Huang,Jingdai Wang,Yongrong Yang
The reduction in the entangled state of the nascent ultrahigh-molecular-weight polyethylene (UHMWPE) is of fundamental importance to enhance its processability and mechanical properties. However, it remains a challenge to retard the formation of entanglements during polymerization above 60 °C because the chain propagation rate is notably higher than the chain crystallization rate. Herein, we present a feasible method for synthesizing the weakly entangled polyethylene via nitrogen microbubble-assisted polymerization. The mass transfer of ethylene inside the growing polyethylene particles is found to dominate the chain propagation process, which is influenced by the nitrogen bubble size. The contact/interval time (10–3 s) between the microbubbles and the particles, observed by a high-speed camera, appears several orders less than the chain propagation time. Consequently, such frequent contact/separation instantly blocks/recovers the reactant transfer on the solvent–particle interphase, causing an intermittent “dormancy effect” to retard the chain propagation and facilitate the chain crystallization. Therefore, the less entangled polyethylene is synthesized at a relatively high activity.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2020
·
IF 5.006
Pengjia Yang,Wentao Zhong,Baiyu Jiang,Biao Zhang,Zhisheng Fu,Zhiqiang Fan
Propagation chains with 1,2 and 2,1 last-inserted monomer unit in 1-hexene polymerization with MgCl 2 -supported Ziegler-Natta catalysts were quench-labeled by thiophene-2-carbonyl chloride, and the two kinds of 2-thenoyl-labeled chain ends were determined by 1 H NMR analysis. The number of labeled chains was noticeably smaller than the number of dead chains formed by chain transfer with alkylaluminum cocatalyst, and grew with time more slowly than the latter, showing that side reactions between the quencher and Al-polymeryl moieties are negligible. The active sites with 2,1 last-inserted monomer were halted in dormant state, which lead to their gradual accumulation in the 30 s polymerization process. The catalyst containing phthalate type internal donor has higher percentage of dormant sites as compared with the catalyst containing diol ester. The combination of acyl chloride quench-labeling and 1 H NMR analysis forms a reliable and easily accessible method of tracing and characterizing active sites in transition metal catalyzed olefin polymerization.
研究领域:
高分子化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
PeerJ
·
2018
·
IF 2.118
Faheem Afzal Shah,Jun Ni,Jing Chen,Qiaojian Wang,Wenbo Liu,Xue Chen,Caiguo Tang,Songling Fu,Lifang Wu
Sapium sebiferum , an ornamental and bio-energetic plant, is propagated by seed. Its seed coat contains germination inhibitors and takes a long time to stratify for germination. In this study, we discovered that the S. sebiferum seed coat (especially the tegmen) and endospermic cap (ESC) contained high levels of proanthocyanidins (PAs). Seed coat and ESC removal induced seed germination, whereas exogenous application with seed coat extract (SCE) or PAs significantly inhibited this process, suggesting that PAs in the seed coat played a major role in regulating seed germination in S. sebiferum . We further investigated how SCE affected the expression of the seed-germination-related genes. The results showed that treatment with SCE upregulated the transcription level of the dormancy-related gene, gibberellins (GAs) suppressing genes, abscisic acid (ABA) biosynthesis and signalling genes. SCE decreased the transcript levels of ABA catabolic genes, GAs biosynthesis genes, reactive oxygen species genes and nitrates-signalling genes. Exogenous application of nordihydroguaiaretic acid, gibberellic acid, hydrogen peroxide and potassium nitrate recovered seed germination in seed-coat-extract supplemented medium. In this study, we highlighted the role of PAs, and their interactions with the other germination regulators, in the regulation of seed dormancy in S. sebiferum .
研究领域:
植物学
·
植物生理学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
BIOMATERIALS
·
2019
·
IF 10.273
Chen Chen,Weiwei Su,Yanyan Liu,Jiawen Zhang,Changjing Zuo,Zhenwei Yao,Wenbo Bu
Oxygen is known as an irreplaceable gas in the lives of most eukaryotic cells, yet researchers underestimate its importance, as in the case in many studies of tumors. The variable oxygen content of malignant solid tumors increases the difficulty of treatment. Thus, it could be reasonably inferred that the tumor oxygen microenvironment , if efficiently and completely regulated, could bring certain changes to existing therapies. Based on this speculation, an acid-responsive, oxygen-scavenging and anaerobic-sensitizing nanoparticle was designed to regulate the oxygen level of solid tumor by creating an artificial anaerobic environment in our study. The Mg 2 Si core, which acted as a deoxygenating agent, was able to consume tumor oxygen and cause cell dormancy, while the incorporated hydrophobic tirapazamin (TPZ) helped to kill the now-dormant tumor cells. This simple and nontoxic nanoparticle achieved controllable factitious anaerobic circumstance in solid tumor for the first time, displaying the considerable potential and promising application of tumor gaseous microenvironment regulation therapy.
研究领域:
肿瘤学
·
生物医学工程
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Ecology and Evolution
·
2023
·
IF 3
Qin Shanshan,Xia Tian,Li Gongzheng,Gu Lei,Sun Yunfei,Yang Zhou
Herbicide pollution is persistent, which not only has a negative impact on individual organisms, but also may alter population dynamics and stability of interspecific relationships. Cladocerans, an important part of zooplankton, are often simultaneously exposed to environmental pollutants and predation risk in the aquatic environment. To evaluate the combined effects of atrazine and fish predation risk on the population traits of cladocerans, we exposed Daphnia pulex to different concentrations of atrazine (0, 0.05, 0.10, and 1.0 mg L−1) with or without fish (Rhodeus ocellatus) kairomone, recorded the key population traits, and fitted Gaussian model to population dynamics. Results showed that fish kairomone increased the population density at the end of the experiment and resting eggs production, and tended to decrease the total biomass and the average dry weight per individual of D. pulex. Atrazine reduced the total biomass, the average dry weight per individual, and resting eggs production of D. pulex populations. Atrazine also decreased the population density at the end of the experiment of D. pulex in fish kairomone treatment, and attenuated the promoting effect of fish kairomone on resting eggs production and the reduction of the total biomass. The findings highlighted the importance of considering the combined impact of environmental pollutants and predation risks on zooplankton populations.
研究领域:
环境科学
·
生态学
·
水生毒理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
·
2017
·Vol. 124
·期 2
·469-479
·
IF 2.099
T. Cheng,X. Xu,W. Zhang,L. Chen,T. Liu
Aims To establish a proper protoplast-preparation route from enriched motile flagellates and nonmotile resting cells of Haematococcus pluvialis . Methods and Results Through cultivations in two mixotrophic media, enriched Haematococcus flagellates and resting cells were respectively produced and applied in enzymatic protoplast preparations. Great differences of enzymatic sensitivity and osmotic-lability were identified between them. Flagellates showed the same osmotic-lability as protoplasts and the extracellular matrix-removing rate was applied for an evaluation of protoplast-releasing. During the treatment of flagellates, an addition of more than 0·2 mmol l −1 Ca 2+ was found to be essential for maintenance of high cellular viability. More than 80% cellular viability and a 90% protoplast-releasing rate were obtained simultaneously after 2–3 h treatment of 0·06% proteinase K in 0·05 mol l −1 Tris-HCl (pH7·8) buffer with 0·2 mmol l −1 CaCl 2 and 0·2 mol l −1 sorbitol/mannitol. For resting cells, a treatment of both 0·12% proteinase K and a combination of 2% cellulase + 1% snailase could function similarly in order to degrade the cellulosic cell wall, while the protoplast yield was limited to about 40%, due to the existence of an undegradable secondary wall in the mature resting cell. Conclusion Proteinase K was efficient for protoplast-releasing from either flagellates or resting cells. Due to the great difference of enzymatic sensitivity and osmotic-lability between flagellates and resting cells, it was necessary to select a different enzymatic treating process based upon the main cell type in the culture. A better protoplast-preparing efficiency was obtained from Haematococcus cells when flagellates were in the majority. Significance and Impact of the Study The protoplast preparation of H. pluvialis was firstly established based on two main cell types of H. pluvialis , motile flagellates and nonmotile resting cells. Increase of flagellate stability and viable protoplast-preparing efficiency through addition of Ca 2+ in enzymatic solution was firstly reported.
研究领域:
微生物学
·
生物技术
·
植物科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Wei Li,Tao Guo,Zaitian He,Jingdai Wang,Yongrong Yang
Investigating the correlation between the active center structure and chain structures of the synthesized polyethylene in Ziegler–Natta catalysts has remained a persistent challenge due to the diversity and complexity of their active sites, limiting the development of advanced catalysts for the synthesis of high-performance polyethylene. Here, we present a strategy for the stepwise removal of active species in classical ZN catalysts. The reaction product formed between disilanolisobutyl polyhedral oligomeric silsesquioxane (2OH-POSS) and TiCl4 is successfully separated from the original catalyst by exploiting the solubility of 2OH-POSS in n-hexane, achieving a significant reduction in titanium content from 10.2 wt % to just 0.77 wt %. Advanced spectroscopic characterizations (e.g., EPR, CO-FTIR, and UV–vis) reveal a synergistic interplay between MgCl2 lattice reorganization and titanium removal during this detitanation process. As detitanation progresses, residual active Ti species on the MgCl2 surfaces facilitate the formation of isolated Ti3+ sites. More significantly, this process dramatically enhances the formation of dormant active species, achieving the maximum content of 24.56 wt %. The catalysts enriched with dormant active species enhance the uniformity of the short-chain branching distribution in synthesized ethylene/1-hexene copolymers. Notably, upon hydrogen introduction during ethylene polymerization, these dormant-species-enriched catalysts simultaneously reduce the polyethylene molecular weight while unexpectedly enhancing the activity by 52.9%, representing the first report of such coupled effects in the ethylene polymerization of Ziegler–Natta catalysts.
研究领域:
高分子化学
·
催化化学
·
材料科学
·
聚合物合成
·
配位聚合
·
表面化学
·
多相催化
✓ 已验证
产品关联
DOI
高影响因子
Innovative Food Science & Emerging Technologies
·
2023
·
IF 6.6
Chao Ma,Xiaoqian Zhang,Kaiqiang Wang,Jingya Jiang,Jianhua Zeng,Lanwei Zhang,Pimin Gong
Employing 0.64 mg/mL of rifampin (RFP) for dormancy induction of Lactobacillus bulgaricus sp 1.1, a 2.5-fold survival rate was achieved after spray drying, while the dried bacteria displayed delayed acidifications . Under the same condition for dormancy treatment, division analysis indicated that high proportions of cells would enter into a dormant state with around 90% of non-proliferating bacteria in the original population. Cells shrank with median diameters decreasing from 3.23 to 2.98 μm. The Raman spectrum revealed a lower ATP level, varied protein expression profiles and conformations and saccharides accumulation in bacteria. Protein aggregates formed in dormancy-induced cells may contribute to increased heat resistance which showed a 2 °C rise in the denaturing temperature in the 0.64 mg/mL group. Therefore, dormancy treatments may be developed as a protective strategy for spray-dried L . bulgaricus . Industrial relevance Enhancing the drying tolerance of bacteria is one of the crucial strategies to adapt the industrial production of spray-dried LAB . Our study proved that the non-sporeforming dormancy pre-treatment can promote the spray-dried viability of L . bulgaricus by triggering suppressed metabolism activity and protein aggregation. The non-sporeforming dormant state has potential to be exploited in industrial production of spray-dried LAB with a high viable cell density to reduce the cost of probiotics and related products.
研究领域:
微生物学
·
食品科学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
BIOMATERIALS
·
2023
·
IF 14
Wei Jiang,Zuoxiu Tie,Chi Yu,Yu Chen,Dan Liu,Bin Li
Although inhibiting the energy metabolism of tumor cells has become an effective measure to enhance chemotherapy, tumor cells can still escape the lethal effect of chemotherapy by entering a dormancy state with low-energy expenditure. Herein, the glutathione (GSH)-responsive nanoplatform (C-A-D NPs) were constructed to inhibit energy metabolism and lysosomal activity of tumor cells, thereby forcing tumor cells to remain vulnerable to cisplatin . In this system, cisplatin prodrug was reduced to cisplatin by GSH, and D-peptide and apoptozole (Az) were released to inhibit the energy metabolism and autophagy-lysosome pathway of tumor cells. The suppressed autophagy-lysosome pathway prevents tumor cells from entering a low-energy dormancy state, resulting in the loss of resistance to the lethal effect of cisplatin with high-energy expenditure and insufficient energy supply. Such engineered nanoplatform effectively enhances the chemotherapeutic effect of cisplatin by inhibiting intracellular energy metabolism and lysosomal activity, showing great clinical prospects.
研究领域:
肿瘤学
·
药学
·
纳米技术
·
化疗
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Xiaodi Yang,Xiyu Tang,Sisi Yi,Tao Guo,Yue Liao,Yan Wang,Xiangjun Zhang
Intracellular bacteria are recognized as a crucial factor in the persistence and recurrence of infections. The efficacy of current antibiotic treatments faces substantial challenges due to the dormant state formation of intracellular bacteria. In this study, we devised a strategy aimed at reverting intracellular dormant bacteria to a metabolically active state, thereby increasing their vulnerability to antibiotics. We found that oligosaccharides, especially maltodextrin (MD), can be absorbed by dormant S. aureus , leading to their revival and restoration of sensitivity to rifampicin (Rif). We then synthesized a reactive oxygen species (ROS)-responsive MD-prodrug by covalently binding MD with 4-(hydroxymethyl) phenylboronic acid pinacol ester (MD-PBAP) and prepared a ROS-responsive nanoparticles (MDNP) using a nanoprecipitation and self-assembly method. Once internalized by host cells, MDNP was degraded to MD, reactivating dormant S. aureus , and enhancing their susceptibility to Rif. More importantly, MDNP treatment restored the sensitivity of intracellular persistent S. aureus to Rif in both a reservoir transfer model and whole-body infection model. Additionally, MDNP have demonstrated excellent biocompatibility in both in vitro and in vivo settings. These results offer a promising therapeutic avenue for managing persistent intracellular bacterial infections by reviving and resensitizing intracellular dormant bacteria to conventional antibiotics.
研究领域:
药理学
·
微生物学
·
纳米技术
·
传染病学
✓ 已验证
DOI
PubMed
高影响因子
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