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1.
The effect of ten amino acids as the sole nitrogen source for the growth of Cladosporium herbarum (Link.) Fr. and Trichothecium roseum (Bull.) Link. was studied in order to clarify the fungus-host plant relationship. Special attention was paid to some rare non-protein amino acids of legumes. The best nitrogen sources for both fungi were γ-aminobutyric acid, arginine, serine and proline. Cladosporium could use homoarginine and canavanine, but these two amino acids were not used by Trichothecium when each was given as the only nitrogen source. Both fungi utilized ornithine, homoserine and a,γ-diaminobutyric acid to a limited extent. Pipecolic acid was not growth promoting. The growth-retarding effects of rare non-protein amino acids (homoarginine, canavanine, a,γ-diaminobutyric acid and pipecolic acid) were usually reversed by higher concentrations of their normal analogues. It is possible that rare non-protein amino acids may slightly protect the host plant against fungal infections, but there are clear differences between fungi in their reaction to non-protein amino acids.  相似文献   

2.
Sphagnum nemoreum Scop. thalli were grown under sterile conditions in order to study their ability to use certain carbohydrates for their growth, with special reference to the sugars occurring free in Sphagnum peat. It was found that Sphagnum nemoreum thallus could not grow at ail in vitro unless some organic carbon source war present. Growth was dependent on both the quality and the quantity of the sugar. Sucrose (1 per cent) proved to be the best carbon source and light intensity did not have any marked influence on growth under these conditions. Glucose and fructose were also growth promoting. Glucose is the main free sugar in the peat. Mannose (0.25 per cent) was almost as good a carbon source as sucrose in the same concentration. It is known that mannose accumulates in the Sphagnum peat during humification. and so does rhanmose, which was utilized to some extent. These two sugars are inhibitory to many mono–and dicotyledons. Ribose, galactose. arabinose and xylose were found to be toxic to Sphagnum.  相似文献   

3.
SYNOPSIS. Euglena gracilis (bacillaris variety, strain SM-L1, streptomycin-bleached) used the following amino adds (10−3 M) as sole nitrogen source for growth on a defined medium: glycine, alanine, valine, leucine, isoleucine, serine, threonine, and glutamic acid. Aspartic acid was used at 10−2 M. Glutamine and asparagine were used at 10−3 M and were better N sources than their parent dicarboxylic amino acids. Not used as sole N source for growth were phenylalanine, tyrosine, tryptophan, cysteine, cystine, methionine, proline, hydroxyproline, histidine, arginine, lysine, and taurine. Astasia longa (Jahn strain) was more restricted than Euglena and used only asparagine and glutamine as N sources for growth.  相似文献   

4.
5.
Morphactin ester applied as a bark band to stems of Monterey pine seedlings (Pinus radiata D. Don) at first stimulated and then inhibited the rate of stem elongation over a 20-day period. The inhibition was caused by a direct action of morphactin on the shoot rather than by indirect action on the root system. 14C labelled morphactin applied to the bark accumulated in the shoot apices and the amount accumulated could be related to the inhibition of growth. More than 70% of labelled material isolated from roots and shoot apices was in the form of a metabolite similar to the carboxylic acid derivative of the morphactin ester. A preparation of 14C labelled acid derivative applied to the bark was translocated to the shoot apex and to the roots and inhibited stem elongation.  相似文献   

6.
庆大霉素是氨基糖苷类广谱抗生素,其不仅用于临床治病,而且广泛应用于畜牧业。由于其发酵周期长,产素率低,生产成本高,因此改进生产方法势在必行。本文报道了在绛红色小单孢菌产生庆大霉素的培养过程中,添加一定量的甘氨酸、蛋氨酸、赖氨酸、酪氨酸能够有效地提高微生物细胞的代谢能力,缩短发酵培养周期,提高产素率。本方法是在小试(摇瓶)成功基础上,用5L玻璃发酵罐运转一个多月,取一个月的平均罐批数据表明:新方法较原工艺发酵周期缩短30% ~45%,罐批产量增加14% 左右,产素率提高30 % ~95%(因菌种生产能力不同而异),产品质量符合中国药典2000版(CP2000)、英国药典2000版(BP2000)、美国药典26版(USP26),生产成本大幅度降低,具有很强的市场竞争力。  相似文献   

7.
8.
Entodinium longinucleatum grown in vitro in the presence of bacteria engulfed a wide range of bacterial species at rates of 130–3400 bacteria/h/protozoon (from suspensions of 10 bacteria/ml), but showed a preference for Klebsiella aerogenes and Proteus mirabilis which occurred in the growth medium. Some of the bacteria were digested with release of soluble material into the medium. Free amino acids were incorporated by the protozoa in the presence of chloramphenicol at rates of 5·4–15·1 nmol/h/106 protozoa and approximately 40% of the amino acid-carbon was incorporated into protein. There was no appreciable synthesis of protozoal protein from carbohydrate. Evidence was obtained that the protozoa obtained the amino acids required for growth largely from engulfed bacteria.  相似文献   

9.
K. W. Joy 《Plant physiology》1969,44(6):845-848
Lemna minor grown in sterile culture on a minerals-sucrose medium can utilize as nitrogen source, in order of increasing growth rate: ammonia, nitrate, a mixture of glutamic and aspartic acids plus arginine, or a balanced mixture of amino acids (hydrolyzed casein). Maximum growth is found with nitrate plus hydrolyzed casein.Many synthetic mixtures of amino acids are unable to support growth. Many single amino acids are inhibitory, and when added (at 2 mm or less) to cultures, growing in the presence of nitrate, cause a decrease in growth rate or even death of the plants (e.g. with alanine, valine, methionine or leucine). Some of these inhibitory effects are also found when the amino acid is added to cultures growing on ammonia or hydrolyzed casein. Arginine was the only amino acid of those tested which gave a marked stimulation of growth when added to cultures growing with inorganic nitrogen.The rapid rate of growth, sterile nature of tissue, decreased biological variation of samples containing many plants and ability to utilize different culture media make this an attractive organism for studies on higher plant metabolism.  相似文献   

10.
Protein synthesis in very young leaves utilizes carbon fromphotosynthesis and from translocated sucrose, and nitrogen translocatedin both xylem and phloem. The carbon of young leaf protein isderived mainly from assimilated CO2, while translocated sucrosecontributes proportionately more of its carbon to insolublecarbohydrate. Most protein amino-acids become labelled from14CO2, glutamate being the notable exception. Glutamine or glutamateis synthesized from sucrose in roots, and is translocated toyoung leaves. It is suggested that a small but significant proportionof the nitrogen requirement of the young leaf is translocatedfrom roots as glutamine, in the phloem. Inorganic nitrogen istranslocated in xylem.  相似文献   

11.
12.
The levels of free amino acids in suspension cultures of Catharanthusroseus were monitored for 96 h after stationary-phase cellswere transferred to fresh complete (‘+Pi’)  相似文献   

13.
条件必需氨基酸对放射损伤大鼠血浆蛋白的影响   总被引:1,自引:1,他引:0  
观察条件必需氨基酸对放射损伤大鼠血浆蛋白的影响。以雄性Wistar大鼠 6 9只 ,普通饲料喂养 6天 ,随机分成A、B、C、D四组 ,A、B、C组各 2 0只、D组 9只。A、B、C三组动物均接受 6 .5Gy的γ线全身照射 ,D组动物不照射。照射后在A组饲料中添加 3%精氨酸 +5 %牛磺酸 +1%谷氨酰胺 ;B组饲料中添加与A组等氮量的甘氨酸 (10 .91% ) ;C组及D组仍喂普通饲料。照射后 7及 14天测血浆总蛋白、白蛋白、前白蛋白、纤维结合蛋白。结果显示A组在饲料摄入量、体重及血浆总蛋白、白蛋白、前白蛋白、纤维结合蛋白水平等方面均优于B组及C组。提示饲料中增加条件必需氨基酸含量可以改善进食 ,促进体重恢复及蛋白质合成 ,进而提高受照大鼠应激能力  相似文献   

14.
氨基酸对蛇足石杉叶状体增殖及石杉碱甲积累的影响   总被引:1,自引:0,他引:1  
陈曼  涂艺声 《植物学报》2017,52(2):218-224
通过在培养基中添加不同浓度的天冬氨酸、赖氨酸和色氨酸, 探究其对蛇足石杉(Huperzia serrata)叶状体生长、石杉碱甲积累及SOD酶活性的影响。结果表明: 添加天冬氨酸后, 叶状体干重生物量比对照提高18.50%-25.75%, 石杉碱甲含量亦明显高于对照, 其最适天冬氨酸浓度为0.5 mmol·L-1; 添加1 mmol·L-1色氨酸后, 叶状体相对增殖率显著高于对照, 但其石杉碱甲积累量略低于对照; 添加赖氨酸后, 叶状体相对增殖量、干重生物量及石杉碱甲含量均低于对照。添加一定浓度的天冬氨酸使SOD酶活性适当提高, 同时叶状体石杉碱甲积累量增加, 而长期保持高水平的SOD酶活性对叶状体积累石杉碱甲不利。  相似文献   

15.
支链氨基酸对运动大鼠氨基酸代谢和运动能力的影响   总被引:3,自引:1,他引:3  
观察了支链氨基酸(BCAA)对大鼠运动能力和血清游离氨基酸代谢的影响。实验用21只雄性wistar大鼠,随机分为3组:正常组、游泳对照组和游泳补充BCAA组。2个运动组每天游泳训练1h,10天后游泳6h,观察补充BCAA对大鼠游泳运动能力和血清游离氨基酸水平的影响。实验结果表明,补充BCAA可明显提高大鼠游泳存活率,抑制血清中必需氨基酸、非必需氨基酸和总氨基酸水平升高,游泳运动后大鼠的血清中乳酸和LDH的升高幅度有所降低,抑制骨骼肌LDH活力的下降。说明补充BCAA可明显提高大鼠的运动能力,减少运动造成的蛋白质分解  相似文献   

16.
The effects of several growth regulators and amino acids onin vitro organogenesis of Torenia fournieri Lind. were determinedusing internodal segments. Treatment with 2,4-D1 resulted innodular callus formation, while NAA and IAA induced roots constantlybut much less frequently shoot buds. Individually BA, zeatin,and 4-PU induced bud formation, but these shoot buds did notdevelop further. Formation of buds by cytokinin was influencedby a simultaneous application of NAA or 2,4-D, but not of IAA,its degree being reduced when BA was simultaneously appliedwith NAA or 2,4-D. When zeatin or kinetin was added with NAA,numerous roots were induced. The effects of various L-amino acids on in vitro organogenesiswere also investigated using the defined medium in which KNO3was a principal source of nitrogen. The formation of buds wasconsiderably stimulated by alanine and asparagine, and slightlyby glutamic acid in the medium containing both NAA and BA, inwhich bud formation was easily induced. On the other hand, allamino acids except for glutamic acid and aspartic acid inhibitedroom formation in this medium. Root formation was greatly stimulated by proline, alanine, glutamine,glutamic acid, and aspartic acid, and slightly by arginine andtryptophan in the medium containing NAA but no BA. Glutamicacid and aspartic acid also enhanced bud formation in this medium.  相似文献   

17.
18.
光质对水稻幼苗蛋白质、氨基酸含量的影响   总被引:10,自引:0,他引:10  
蓝光对水稻幼苗可溶性蛋白积累的促进效应,在幼苗生长的初期比较明显;第5天,幼苗的可溶性蛋白质、蛋白氮、非蛋白氮以及Asp、Asn、Glu、Gln等游离氨基酸含量都远远高于白光或红光的处理。随着苗龄的增加,蓝光的促进作用减弱,到第17天,各项指标都低于白光处理的幼苗。红光处理的幼苗可溶性蛋白始终低于白光或蓝光的处理,其Asn、Gln两种酰胺含量在第10天以后明显高于同期的白光或蓝光的处理。  相似文献   

19.
Growth and nitrate reductase activity (NRA) of Atropa belladonnacells were studied in medium supplemented with NaNO3, NH4NO3,and amino acid precursors to tropane alkaloids. Growth and NRAwere stimulated by NH4+ and by proline, by proline plus ornithine,but not by glutamate, in NO3-containing medium. Testedamino acids inhibited neither utilization of inorganic nitrogennor growth. (Received September 30, 1988; Accepted August 28, 1989)  相似文献   

20.
光质对水稻幼苗蛋白质、氨基酸含量的影响   总被引:1,自引:0,他引:1  
蓝光对水稻幼苗可溶性蛋白积累的促进效应,在幼苗生长的初期比较明显;第5天,幼苗的可溶性蛋白质、蛋白氮、非蛋白氮以及Asp、Asn、Glu、Gln等游离氨基酸含量都远远高于白光或红光的处理。随着苗龄的增加,蓝光的促进作用减弱,到第17天,各项指标都低于白光处理的幼苗。红光处理的幼苗可溶性蛋白始终低于白光或蓝光的处理,其 Asn、Gln 两种酰胺含量在第10天以后明显高于同期的白光或蓝光的处理。  相似文献   

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