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101.
长期施用稀土对小麦植株中稀土元素含量及分布的影响 总被引:6,自引:0,他引:6
在我国施用稀土时间最长的黑龙江花园农场,研究了连续12a叶面喷施稀土对小麦植株及土壤中稀土元素总含量和分布模式的影响。结果表明:连续12a叶施稀土没有造成土壤中元素含量及分布模式的变化;对小麦拔节始期(喷施稀土7d)后叶部的影响较大,La,Ce最明显增高,叶部稀土元素分布模式与“常乐”稀土中的相一致,与土壤中稀土元素分布模式不同,而在小麦拔节始期的根部、小麦成熟期的根、茎、叶、壳等部位稀土元素分布 相似文献
102.
ChunMei Yin JunJiao Li Dan Wang DanDan Zhang Jian Song ZhiQiang Kong BaoLi Wang XiaoPing Hu Steven J. Klosterman Krishna V. Subbarao JieYin Chen XiaoFeng Dai 《Molecular Plant Pathology》2022,23(8):1122
The arms race between fungal pathogens and plant hosts involves recognition of fungal effectors to induce host immunity. Although various fungal effectors have been identified, the effector functions of ribonucleases are largely unknown. Herein, we identified a ribonuclease secreted by Verticillium dahliae (VdRTX1) that translocates into the plant nucleus to modulate immunity. The activity of VdRTX1 causes hypersensitive response (HR)‐related cell death in Nicotiana benthamiana and cotton. VdRTX1 possesses a signal peptide but is unlikely to be an apoplastic effector because its nuclear localization in the plant is necessary for cell death induction. Knockout of VdRTX1 significantly enhanced V. dahliae virulence on tobacco while V. dahliae employs the known suppressor VdCBM1 to escape the immunity induced by VdRTX1. VdRTX1 homologs are widely distributed in fungi but transient expression of 24 homologs from other fungi did not yield cell death induction, suggesting that this function is specific to the VdRTX1 in V. dahliae. Expression of site‐directed mutants of VdRTX1 in N. benthamiana leaves revealed conserved ligand‐binding sites that are important for VdRTX1 function in inducing cell death. Thus, VdRTX1 functions as a unique HR‐inducing effector in V. dahliae that contributes to the activation of plant immunity. 相似文献
103.
104.
Zheng Xiang Xinwen Chen Lijun Yang Yongshu He Runsheng Jiang Benjamin M. Rosenthal Pengtao Luan S.W. Attwood Yangxian Zuo Ya-ping Zhang Zhaoqing Yang 《Parasitology international》2009,58(3):293-296
Because the excreted sporocysts and/or oocysts of various species of Sarcocystis may not be discriminated morphologically, we sought to validate a diagnostic technique based on variation in the 18S rDNA sequence. Oocysts and/or sporocysts from three taxa of Sarcocystis were collected from human, feline, and canine definitive hosts that had fed upon meats infected with the muscle cysts of Sarcocystis hominis, Sarcocystis fusiformis and a species of Sarcocystis from water buffalo that could not be distinguished from Sarcocystis cruzi. Using a new collection method employing filter paper, these excreted oocysts and sporocysts were subjected to DNA extraction, as were the corresponding muscle cysts. Methods employing PCR–RFLP and DNA sequencing of a partial 18S rDNA gene (ssrRNA) sequence were then used to successfully distinguish among the three taxa. The same, unique restriction digestion pattern characterizes the tissue cysts and oocysts and/or sporocysts of each parasite taxon. The technique makes possible amplification and identification of species specific gene sequences based on DNA extracted from as few as 7 excreted sporocysts (the equivalent of 3 and 1/2 oocysts) from freshly prepared material, or as few as 50 sporocysts from feces samples that had been stored in potassium dichromate (K2Cr2O7) for as long as 6 years. This represents the first report using molecular diagnostic procedures to diagnose oocysts of Sarcocystis in faecal samples, describing a valuable new tool for studying the epidemiology of various Sarcocystis species. 相似文献
105.
Kyoung Ah Kang Rui Zhang Mei Jing Piao Min Jeong Park Ae Ran Kwon Bum Joon Kim Ho Jin You Myung Hee Chung Jin Won Hyun 《Biotechnology and Bioprocess Engineering》2007,12(2):114-120
8-Hydroxydeoxyguanosine (oh8dG) treatment induced senescence-like changes in KG-1 cells, a human acute myelocytic leukemia cell line. The oh8dG-treated cells stained positive for senescence associated β-galactosidase (SA-β-galactosidase) and had enlarged cell shape,
both of which are senescence indexes. The oh8dG-treated cells were also cell growth inhibited and arrested at G1 in the cell cycle. The accumulation of cdk (cyclin dependent kinase) inhibitors, such as p16, p21, and p27, also implies
that cellular senescence was induced in oh8dG-treated cells. However, these changes were not accompanied by cell differentiation or telomerase activity. Taken together,
we conclude that oh8dG treatment of KG-1 cells induces cellular senescence. 相似文献
106.
Munoz Frances M. Patel Priya A. Gao Xinghua Mei Yixiao Xia Jingsheng Gilels Sofia Hu Huijuan 《Purinergic signalling》2020,16(1):97-107
Purinergic Signalling - Astrocytes mediate a remarkable variety of cellular functions, including gliotransmitter release. Under pathological conditions, high concentrations of the purinergic... 相似文献
107.
从海栖热袍菌扩增出编码乳酸脱氢酶的基因并将其插入热激载体pHsh构建表达质粒,在大肠杆菌Escherichia coli中进行表达产生极耐热性乳酸脱氢酶Tm-LDH。基因表达产物通过热处理,可以一步获得接近电泳纯的重组酶。酶学性质研究表明,Tm-LDH的最适反应温度为95℃,最适pH 7.0;纯酶在90℃的半衰期为2 h,在pH 5.5–8.0之间最稳定;SDS-PAGE结果显示分子量为33 kDa,与理论推算值相吻合。以丙酮酸和NADH为底物时,相对于丙酮酸的Km值1.7 mmol/L,Vmax为3.8×104 U/mg;相对于NADH的Km值7.2 mmol/L,Vmax值为1.1×105 U/mg。Tm-LDH基因在T7载体中未能实现高效表达,但是在热激载体pHsh中得到了可溶性超量表达,表达水平达到340 mg/L。该酶在65℃反应条件下,活性达到最高活性的50%,并能保持活性不变,这使该酶能够与常温酶匹配,在辅酶NAD再生体系的建立中具有广泛的用途。 相似文献
108.
濒危植物明党参与非濒危种峨参种子休眠和萌发比较 总被引:11,自引:1,他引:11
研究了濒危植物明党参(Changium smyrnioides)与非濒危种峨参(Anthriscus sylvestris)种子贮存,打破休眠和萌发对水分和温度条件的要求。结果表明,在自然条件下,明党参种子有5个月的休眠期,人工低温(10℃左右)处理40天即可打破休眠;两种植物种子自然温度干燥处理不能打破休眠;两种植物的种子在自然温度变湿层积处理后萌发率最高,萌发持续时间也最长,其中明党参的萌发率地峨参,持续时间短于峨参;自然温度淹水处理大大降低了两种植物种子的萌发率,但明党参仍有7%的萌发率。明党参种子质量和发芽率不应是明党参濒危的直接原因,但因其具有种子产量低,幼苗数量少,存活率高的K-对策,当受到强烈干扰时,种群难以在短期内恢复,容易濒危。 相似文献
109.
简要介绍微生物产多不饱和脂肪酸的生化研究现状,着重从高产菌株的筛选、工程菌株的构建、发酵条件及产业化现状等方面论述微生物发酵生产多不饱和脂肪酸的主要研究进展;概述多不饱和脂肪酸的提取制备技术,并对发酵法生产多不饱和脂肪酸研究目标和发展前景提出了建议. 相似文献
110.