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991.
992.
Shi Kai Fan Jia Yuan Ye Lin Lin Zhang Hong Shan Chen Hai Hua Zhang Ya Xin Zhu Xing Xing Liu Chong Wei Jin 《Plant, cell & environment》2020,43(1):275-291
Although the alteration of DNA methylation due to abiotic stresses, such as exposure to the toxic metal cadmium (Cd), has been often observed in plants, little is known about whether such epigenetic changes are linked to the ability of plants to adapt to stress. Herein, we report a close linkage between DNA methylation and the adaptational responses in Arabidopsis plants under Cd stress. Exposure to Cd significantly inhibited the expression of three DNA demethylase genes ROS1/DML2/DML3 (RDD) and elevated DNA methylation at the genome-wide level in Col-0 roots. Furthermore, the profile of DNA methylation in Cd-exposed Col-0 roots was similar to that in the roots of rdd triple mutants, which lack RDD, indicating that Cd-induced DNA methylation is associated with the inhibition of RDD. Interestingly, the elevation in DNA methylation in rdd conferred a higher tolerance against Cd stress and improved cellular Fe nutrition in the root tissues. In addition, lowering the Fe supply abolished improved Cd tolerance due to the lack of RDD in rdd. Together, these data suggest that the inhibition of RDD-mediated DNA demethylation in the roots by Cd would in turn enhance plant tolerance to Cd stress by improving Fe nutrition through a feedback mechanism. 相似文献
993.
一株源自渤海海域高温酸败油井采出水的硫酸盐还原菌筛选与活性抑制 总被引:3,自引:1,他引:2
【背景】海域油藏环境中硫酸盐还原菌(sulfate-reducing prokaryotes,SRP)的生长和代谢能够产生大量H_2S,引发酸败(souring)及微生物腐蚀等多方面的问题。但有关油藏生境中SRP的微生物多样性与生理活性及其危害控制的认识仍十分有限。【目的】深入了解我国渤海海域某高温酸败油藏中SRP的生理特点,探究SRP危害的控制策略。【方法】采用Hungate厌氧纯培养技术从渤海海域某高温酸败油井采出水中分离筛选SRP,并考察优势菌株的生理特点,综合16S rRNA基因序列比对分析菌株系统发育地位,着重评价不同杀菌剂及使用剂量对优势菌株产H_2S活性的抑制效力。【结果】酸败采出井的采出水中优势SRP菌株WJ_1的细胞呈长杆状,菌体长度为2.0-5.5μm,有运动性。WJ_1与解糖泽恩根氏菌(Soehngenia saccharolytica)模式菌株BOR-Y~T的16S rRNA基因序列一致性达99%。WJ_1最适生长温度约为37°C,能够耐受60°C高温;最适pH值约为8.0 (范围5.0-10.0),最适盐度约为0%-3%,盐度高于5%不能生长。WJ_1可利用丙酸钠、乳酸钠、乙酸盐等多种碳源,能以硫酸盐、亚硫酸盐、硫代硫酸盐为唯一电子受体产生H2S,不能利用单质硫。次氯酸钠(600 mg/L)、苄基三甲基氯化铵(600 mg/L)对WJ_1产H_2S活性无明显抑制效果。戊二醛(30 mg/L)、溴硝醇(10 mg/L)或四羟甲基硫酸磷(120 mg/L)可抑制WJ_1产H_2S活性达30 d以上。【结论】渤海海域某高温酸败油井采出水中优势SRP菌株WJ_1与S. saccharolytica BOR-Y~T的16S rRNA基因序列一致性最高,但两者生理特性差异明显;溴硝醇、戊二醛、四羟甲基硫酸磷是控制该酸败油井的潜在有效杀菌剂。 相似文献
994.
Jin Xiao-Ye Shen Chun-Mei Chen Chong Guo Yu-Xin Cui Wei Wang Yi-Jie Zhang Wen-Qing Kong Ting-Ting Zhu Bo-Feng 《Molecular biology reports》2020,47(2):1079-1087
Molecular Biology Reports - Tibetans living in the Qing-Tibet plateau show unique genetic features since they are exposed to the high altitude environment. Accordingly, it is necessary for us to... 相似文献
995.
Kuan‐Hung Lin Syue‐Yi Lyu Hsien‐Wei Yeh Yi‐Shan Li Ning‐Shian Hsu Chun‐Man Huang Yung‐Lin Wang Hao‐Wei Shih Zhe‐Chong Wang Chang‐Jer Wu Tsung‐Lin Li 《Protein science : a publication of the Protein Society》2020,29(7):1655-1666
Though reactive flavin‐N5/C4α‐oxide intermediates can be spectroscopically profiled for some flavin‐assisted enzymatic reactions, their exact chemical configurations are hardly visualized. Structural systems biology and stable isotopic labelling techniques were exploited to correct this stereotypical view. Three transition‐like complexes, the α‐ketoacid…N5‐FMNox complex ( I ), the FMNox‐N5‐aloxyl‐C′α?‐C4α+ zwitterion ( II ), and the FMN‐N5‐ethenol‐N5‐C4α‐epoxide ( III ), were determined from mandelate oxidase (Hmo) or its mutant Y128F (monooxygenase) crystals soaked with monofluoropyruvate (a product mimic), establishing that N5 of FMNox an alternative reaction center can polarize to an ylide‐like mesomer in the active site. In contrast, four distinct flavin‐C4α‐oxide adducts ( IV – VII ) from Y128F crystals soaked with selected substrates materialize C4α of FMN an intrinsic reaction center, witnessing oxidation, Baeyer–Villiger/peroxide‐assisted decarboxylation, and epoxidation reactions. In conjunction with stopped‐flow kinetics, the multifaceted flavin‐dependent reaction continuum is physically dissected at molecular level for the first time. 相似文献
996.
Ya Qi Cheng Shou Bi Wang Jia Hui Liu Lin Jin Ying Liu Chao Yang Li Ya Ru Su Yu Run Liu Xuan Sang Qi Wan Chang Liu Liu Yang Zhi Chong Wang 《Cell proliferation》2020,53(8)
The tumour microenvironment (TME) plays a pivotal role in tumour fate determination. The TME acts together with the genetic material of tumour cells to determine their initiation, metastasis and drug resistance. Stromal cells in the TME promote the growth and metastasis of tumour cells by secreting soluble molecules or exosomes. The abnormal microenvironment reduces immune surveillance and tumour killing. The TME causes low anti‐tumour drug penetration and reactivity and high drug resistance. Tumour angiogenesis and microenvironmental hypoxia limit the drug concentration within the TME and enhance the stemness of tumour cells. Therefore, modifying the TME to effectively attack tumour cells could represent a comprehensive and effective anti‐tumour strategy. Normal cells, such as stem cells and immune cells, can penetrate and disrupt the abnormal TME. Reconstruction of the TME with healthy cells is an exciting new direction for tumour treatment. We will elaborate on the mechanism of the TME to support tumours and the current cell therapies for targeting tumours and the TME—such as immune cell therapies, haematopoietic stem cell (HSC) transplantation therapies, mesenchymal stem cell (MSC) transfer and embryonic stem cell‐based microenvironment therapies—to provide novel ideas for producing breakthroughs in tumour therapy strategies. 相似文献
997.
目的:探讨沙丁胺醇、布地奈德不同雾化吸入联合头孢哌酮钠舒巴坦钠对慢性阻塞性肺疾病急性加重期(AECOPD)患者血气指标和肺功能的影响。方法:选取本院2015年1月至2018年10月期间收治的210例AECOPD住院患者作为研究对象,随机分为对照组(头孢哌酮钠舒巴坦钠治疗)、持续雾化组(沙丁胺醇、布地奈德持续雾化治疗+头孢哌酮钠舒巴坦钠)、先后雾化组(先给予沙丁胺醇雾化、后给予布地奈德雾化治疗+头孢哌酮钠舒巴坦钠),每组各70例,对比三组的临床疗效、血气指标、肺功能及不良反应。结果:先后雾化组总有效率为91.43%,高于持续雾化组的78.57%及对照组的67.14%(P0.05)。先后雾化组患者治疗5天后氧分压(PaO_2)、氧饱和度(SaO_2)高于持续雾化组及对照组,且持续雾化组高于对照组(P0.05);先后雾化组患者治疗5天后二氧化碳分压(PaCO_2)低于持续雾化组及对照组,且持续雾化组低于对照组(P0.05)。先后雾化组患者第一秒用力呼气容积(FEV_1)、用力肺活量(FVC)、第一秒用力呼吸容积占用力肺活量的百分比(FEV_1/FVC%)、第一秒用力呼气容积占预计值百分比(FEV_1%)高于持续雾化组及对照组,且持续雾化组高于对照组(P0.05)。三组不良反应总发生率比较无统计学差异(P0.05)。结论:沙丁胺醇、布地奈德先后雾化吸入联合头孢哌酮钠舒巴坦钠治疗AECOPD患者疗效确切,可提高患者肺功能,改善血气相关指标。 相似文献
998.
2019年中国植物科学家在国际综合性学术期刊及植物科学主流期刊发表的论文数量大幅增加, 在光生物学、植物抗逆和分子进化等若干领域取得了重要成果。其中, 硅藻光合膜蛋白超分子结构和功能研究入选2019年度中国科学十大进展和中国生命科学十大进展; 植物抗病小体的结构与功能研究入选2019年度中国生命科学十大进展。该文评述了2019年中国科学家在植物科学若干领域取得的重要研究进展, 以期追踪和报道当前中国植物科学领域发展的前沿和热点及展示中国科学家所取得的辉煌成果。 相似文献
999.
Ching‐Long Yeh Chong‐Sheng Leou Tian‐Chuan Hsu Chuan‐Rong Yeh 《Nordic Journal of Botany》2011,29(4):417-419
A new orchid species, Gastrodia sui C. S. Leou, T. C. Hsu & C. L. Yeh is described and illustrated from Taiwan. The new species is closely related to G. callosa J. J. Sm. but distinguishable by the number and position of calli inside the perianth tube, the fused ratio of perianth lobes, and the structure of the lip and column. It is so far only found in the area of Mt Lilung in southern Taiwan. 相似文献
1000.