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Cyclohexanediones (e.g., sethoxydim) are known to be inhibitors of plastid acetyl-CoA carboxylase (ACCase) of monocotyledonous plants and provoke plant death. When rape leaves were treated with 10−3 M sethoxydim, growth rate, chlorophyll and lipid contents were reduced, but plant resisted to herbicide. [1–14C] Acetate labelling showed that lipid synthesis was affected by sethoxydim, probably through inhibition of chloroplast homomeric ACCase activity, and the fatty acid synthase activity (FAS) was reduced because of malonyl-CoA deficiency. In contrast, sethoxydim treatment provoked an increase in phenylalanine ammonia lyase (PAL) activity with an accumulation of cinnamic acid, naringenin and anthocyanins. The accumulation of anthocyanins seems to reduce the damaging effect of the herbicide stress. Thus, in plant cell, the flux of carbon seems to be oriented towards protective mechanisms, and the two ACCases could have an important role in this orientation. 相似文献
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崔玉东 《中国预防兽医学报》2000,(Z1)
用血清调理的酵母聚糖（ｓｅｒｕｍ－ｏｐｓｏｎｉｚｅｄ ｚｙｍｏｓａｎ ,ｓＯＺ）刺激多性核白细胞（ＰＭＮ）引起的Ｏ２－产生受到ｐ３８ＭＡＰＫ抑制物（ＳＢ２０３５８０）,ＰＩ３－Ｋ抑制物（ｗｏｒｔｍａｎｎｉｎ）和ＰＫＣ抑制物（ＧＦ１０９２０３Ｘ）的明显抑制,这些抑制物也明显引起ｓＯＺ诱导的一种ＮＡＤＰＨ氧化酶的胞浆成分 ｐ４７ｐｈｏｘ的磷酸化。可是流式细胞分析表明,ＳＢ２０３５８０和 ｗｏｒｔｍａｎｎｉｎ使吞噬作用减弱,而 ＧＦＩＯ９２０３Ｘ使吞噬作用增强。这些结果表明,虽然ＰＩ３－Ｋ和ｐ３８ ＭＡＰＫ都参与ＮＡＤＰＨ氧化酶激活和吞噬作用的信号传导,但ＮＡＤＰＨ氧化酶激活的信号传导途径与吞噬作用的信号传导途径不同。 相似文献
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【目的】研究磷脂酰肌醇3-激酶（PI3K）催化产物磷脂酰肌醇3-磷酸（PI3P）对紫外线B（UV-B）诱导保卫细胞中过氧化氢（H2O2）产生和气孔关闭的影响,为进一步阐明植物细胞转导UV-B辐射信号的机制提供依据。【方法】以蚕豆（Vicia faba L.）表皮条为材料,采用PI3K的抑制剂沃曼青霉素（WM）和LY294002（LY）来抑制PI3P的形成,采用二苯基碘（DPI）和水杨基氧肟酸（SHAM）分别抑制H2O2形成的NADPH氧化酶途径和细胞壁过氧化物酶途径,通过气孔开度分析和激光扫描共聚焦显微镜技术,确定PI3P在0.8 W•m-2 UV-B辐射诱导蚕豆保卫细胞H2O2产生和气孔关闭中的作用。【结果】WM和LY能显著抑制UV-B诱导的保卫细胞H2O2产生和气孔关闭;外源H2O2处理能显著逆转WM和LY对UV-B诱导气孔关闭的抑制效应,但WM和LY不能抑制外源H2O2诱导的气孔关闭;UV-B诱导的保卫细胞H2O2产生和气孔关闭能被活性氧清除剂和SHAM显著抑制,但不能被DPI抑制。【结论】PI3P通过诱导蚕豆保卫细胞中产生于过氧化物酶途径的H2O2形成来介导UV-B辐射诱导的气孔关闭。 相似文献
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The interactions of puroindolines with polar lipids were investigated using polarization of fluorescence probes preincorporated into a liposomal bilayer containing PC, PI, PS, MGDG, DGDG, and sulfolipids. The intrinsic fluorescence of Trp residue method was also used. Regardless of the kind of lipid used for liposome preparation, proteins interacted with the liposomes. Conformational changes of the proteins were observed simultaneously with the change in the molecule packing in the lipid bilayer of the liposomes. Puroindoline interactions with the surface of the liposomes have explicit importance for the net charge of this surface. The strong interaction between the proteins and lipids takes place in the presence of a ligand with a negative charge. The obtained results confirm that lipids take part in puroindoline–starch granule surface interactions. 相似文献
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Øyvind J Hansen Velmurugu Puvanendran Jens Petter Jøstensen Christian Ous 《Aquaculture Research》2011,42(7):1026-1033
Effects of two weaning diets that differed in phospholipid (PL) classes on growth, survival and deformities of cod larvae and early juveniles were evaluated. Cod larvae were fed rotifers until 21 days post hatch (dph) and then weaning onto dry diet started. One group of larvae were fed a control diet with low levels of phosphatidylcholine (PC), PE and phosphatidylinositol (PI) and the other group of larvae were fed with an experimental diet containing higher levels of PC, PE and PI. Larvae fed with the control diet were significantly smaller than larvae fed with the experimental diet at the end of the experiment. Swim bladder abnormalities were significantly higher in larvae fed with control diet at 35 dph than the larvae fed with experimental diet; however, no significant difference was evident at 42 dph. Vertebral deformities were significantly higher in larvae fed with control diet and scoliosis was significantly different between the treatments. Survival was also significantly higher in the experimental group. Our results indicate that dietary levels of PL, PC and PI may affect the cod larval growth, survival and deformities. More detail studies are needed to find out the optimal levels of these important PL classes in larval cod diets. 相似文献
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重组人磷脂酰肌醇3-激酶p110β催化亚基的原核表达 总被引：2，自引：2，他引：2
目的：表达人磷脂酰肌醇3－激酶p110β催化亚基。方法：将构建有人磷脂酰肌醇3－激酶（phosphatidylinositol 3-kinase,PI3-K)p110β催化亚基cDNA的重组质粒，转化大肠杆菌BL21（DE3），用IPTG进行诱导表达。用磷脂酰肌醇－4、5－二磷酸、[γ-^32P]ATP与重组PI 3－K p110β催化亚基一起保温的方法测定PI 3－K的活性；^32P标记的磷脂用氯仿和甲醇抽提、板薄层层析和放射自显影来分析。结果：SDS－PAGE显示表达出－110kD的新蛋白质分子，重组蛋白占菌体总蛋白的比例为15％，大多数重组蛋白以可溶性形成存在。wortmannin是PI3－K特异的抑制剂，wortmannin对重组PI 3－K p110β亚基有抑制作用，这种抑制作用呈剂量依赖关系（2.5-20nmol/L)。结论：重组蛋白是有活性的人PI3－Kp110β催化亚基。 相似文献
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Camilla Røsjø Trond Berg Ketil Manum Tor Gjøen Sigurdur Magnusson Magny S. Thomassen 《Fish physiology and biochemistry》1994,13(2):119-132
Effects of different incubation temperatures (2, 8, 14 and 20°C) and hepatocyte membrane fatty acid composition on the rate
of internalization and lysosomal degradation of the ligand, mannosylated albumin, that is taken up by receptor-mediated endocytosis,
were investigated in rainbow trout (Oncorhynchus mykiss, Walbaum). The fish were kept at a water temperature ranging from 9 to 14°C and fed pelleted diets coated with either capelin
oil (control), EPA/DHA-concentrate (rich in n-3 polyunsaturated fatty acids) or soybean oil (rich in n-6 unsaturated fatty
acids) for at least 3 months prior to sampling. The endocytic uptake mediated by the mannose receptor was very efficient at
all temperatures studied. Lysosomal degradation, on the other hand, came to a halt below 8°C. The activation energies for
uptake and degradation were 54.6 and 164.2 kJ/mol respectively. No negative effects of increased amounts of either n-3 or
n-6 fatty acids were observed on the endocytic parameters studied. On the contrary, multivariate analysis indicated a positive
relationship between high levels of n-6 fatty acids and low unsaturation index in the phosphatidylcholine (PC) fraction of
the hepatocytes and the internalization rate of 2°C, meaning that the rate of receptor-mediated endocytosis may be affected
by membrane fatty acid composition. 相似文献
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甘蔗磷脂酰肌醇转运蛋白基因ScSEC14响应干旱和盐胁迫 总被引：1，自引：0，他引：1
Sec14-like磷脂酰肌醇转运蛋白(Sec14-like phosphatidylinositol transfer proteins, PITPs), 广泛存在于真核生物细胞中, 参与肌醇磷酸代谢、膜运输、极性生长、信号转导、逆境胁迫等多种重要的生命过程。甘蔗中响应干旱和盐胁迫的Sec14-like基因尚未见报道。本研究从甘蔗受黑穗病胁迫的转录组数据库中获得一条SEC14基因序列, 并利用RT-PCR技术克隆得到甘蔗SEC14基因cDNA全长序列, 命名为ScSEC14 (GenBank登录号为MG571103)。生物信息学分析显示, ScSEC14基因全长1617 bp, 包含一个1008 bp的完整开放阅读框, 编码335个氨基酸; ScSEC14为不稳定的亲水性蛋白, 不存在信号肽; 蛋白二级结构元件多为α-螺旋, 具有典型的SEC14结构域和CRAL_TRIO_N结构域。此外, 系统进化树分析揭示, 该蛋白属于Sec14-like蛋白家族的SSH (soybean Sec14 homolog group)亚家族。亚细胞定位结果表明, ScSEC14蛋白主要定位于细胞膜。实时荧光定量PCR分析发现, ScSEC14基因在甘蔗中组成型表达, 在蔗皮中的表达量最低, 蔗叶中的表达量最高, 约为蔗皮的4.9倍; 该基因在PEG、NaCl、CaCl2和水杨酸(SA)胁迫下的表达量均上调。因此, 甘蔗ScSEC14基因可能参与Ca 2+和SA介导的抗逆信号通路, 积极响应逆境胁迫, 尤其调节了干旱和高盐环境下的抗逆性。 相似文献