INFLUENCE OF INORGANIC NITROGENOUS COMPOUNDS ON TOBACCO SEED GERMINATION INDUCED BY GIBBERELLIN A3, KINETIN AND AMMONIUM SALTS OF ORGANIC ACIDS

1. Investigations were made on the influence of inorganic nitrogenouscompounds upon the the germination of tobacco seeds (Nicotianatabacum L. var. virginica (AGDH.) COM. "Bright Yellow") inducedby GA₃, kinetin and ammonium salts of organic acids. Potassiumnitrate, ammonium chloride, ammonium sulfate and ammonium nitrategreatly increase the germination of the seeds induced by theabove reagents, while these inorganic salts, given alone, arealmost ineffective in causing germination.
2. Kinetin was shownto induce germination of tobacco seeds inthe dark. The discrepancywith the results of previous investigationsin this respectwas discussed.
3. It was inferred that nitrogenous metabolismis involved in theprocess of dark-germination of tobacco seedsas induced by theabove-stated stimulating factors and promotedby inorganic nitrogenoussubstances.

(Received July 17, 1961; )     

DYNAMICS OF THREE ORGANIC ACIDS (MALIC,ACETIC AND SUCCINIC ACID) IN SUNFLOWER EXPOSED TO CADMIUM AND LEAD

Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg?L^–1 Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb100 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely.     

THE INFLUENCE OF HYPOCAPNIA UPON INTRACELLULAR pH AND UPON SOME CARBOHYDRATE SUBSTRATES, AMINO ACIDS AND ORGANIC PHOSPHATES IN THE BRAIN

Abstract— In order to evaluate the influence of hypocapnia upon the energy metabolism of the brain, lightly anaesthetized rats were hyperventilated to arterial CO₂ tensions of 26, 15 and 10 mm Hg respectively, with subsequent measurements of intracellular pH and of tissue concentrations of carbohydrate substrates, amino acids and organic phosphates. At P_co1= 26 there was a moderate increase in the intracellular pH but when the P_co2 was reduced further to 10 mm Hg the intracellular pH returned to normal, or slightly subnormal, values. The reduction in P_Co2 was accompanied by increased cerebral cortical concentrations of lactate, pyruvate, citrate, α-ketoglutarate, malate and glutamate and by decreased aspartate concentrations. It is concluded that the accumulation of metabolic acids explains the normal value for intracellular pH at very low CO₂ tensions. Previous results obtained in man indicate that there is an increased anaerobic production of lactic acid in the brain in extreme hypocapnia. At comparable CO₂ tensions the present results showed a small fall in phosphocreatine and a small rise in ADP. However, since the ammonia concentrations were normal or decreased and since there was an increase in citrate, the results give no direct support to the hypothesis of an activation of phosphofructokinase. Since the cerebral venous P_o2 was reduced to 20 mm Hg at an arterial CO₂ tension of 10 mm Hg the accumulation of acids was probably secondary to tissue hypoxia. However, since there was no, or only a very small, increase in the calculated cytoplasmic NADH/NAD⁺ ratio, it appears less likely that acids accumulated due to lack of NAD⁺.     

柠檬酸,葡萄糖和有机质对植物磷素吸收和土壤磷素形态的影响

研究了柠檬酸、葡萄糖和有机质（栎树类凋落物和三叶草茎叶）对几种栽培和野生植物磷素吸收以及高度风化老成土中磷素形态的影响。在未加入无机磷的情况下,连续加入柠檬酸溶液增加了温室盆栽大豆（Ｇｌｙｃｉｎｅｍａｘ（Ｌ．）Ｍｅｒｒ．）和高粱（Ｓｏｒｐｈｕｍｂｉｃｏｌｏｒ）对磷素的吸收。这表明,柠檬酸可以溶解土壤中被铁、铝氧化物固定的磷。当无机磷和柠檬酸溶液同时加入后。由于有机配位体能够阻止土壤对磷素的吸附和固定,植物对磷的吸收总量明显高于仅仅加入无机磷的对照。不论是否加入无机磷,葡萄糖均没有增加植物对磷素的吸收,但却改变了土壤中磷素的形态。该试验的结果还表明,Ｈｅｄｌｄｙ等人提出的土壤磷素分级方法不适于有机质含量很低的酸性土壤。在另一种性质极为相似的酸性土壤中施入粉碎的栎树（Ｑｕｅｒｃｕｓｓｐｐ．）凋落物和三叶草（ＴｒｉｆｏｌｉｕｍＰｒａｔｅｎｓｅ）后,野生商陆（Ｐｈｙｔｏｌａｃｃａａｍｅｒｉｃａｎａ）吸收磷素的能力增强。通过进一步对土壤中的磷素进行化学分级,结果表明,这些有机物质可以改变土壤中磷素存在的形态。本文还就有机质分解过程中的中间产物对土壤磷素有效性的影响机理进行了探讨。     

METABOLISM OF GLUTAMIC ACID AND RELATED AMINO ACIDS IN THE BRAIN STUDIED WITH 14C-LABELLED GLUCOSE, BUTYRIC ACID AND GLUTAMIC ACID IN HYPERCAPNIC RATS

Abstract— The influence of hypercapnia on the metabolism of glutamic acid, aspartic acid, glutamine and GABA in rat brain was studied using three different precursors. Acute hypercapnia induced a fall in the concentration of glutamic and aspartic acid, and a rise in the concentration of glutamine and GABA. Acute hypercapnia had a profound effect on the relative specific radioactivity of glutamine indicating that the excess glutamine, present in the brain in hypercapnia, was synthetized from glutamic acid in the compartment where it could become quickly labelled from butyric and glutamic acid, but not from glucose. This effect was maintained in chronic hypercapnia.     

EFFECT OF HYPOTHERMIA UPON ORGANIC PHOSPHATES, GLYCOLYTIC METABOLITES, CITRIC ACID CYCLE INTERMEDIATES AND ASSOCIATED AMINO ACIDS IN RAT CEREBRAL CORTEX

—The influence of hypothermia upon the metabolism of the brain was studied by reducing body temperature in N₂O-anaesthetized rats to 32, 27 or 22°C, with subsequent measurements of organic phosphates, glycolytic metabolites, citric acid cycle intermediates and associated amino acids. Hypothermia was maintained for either 1 or 2 h and the effect of anaesthesia was evaluated by maintaining unanaesthetized animals at 22°C. Hypothermia had no influence on the cerebral cortical concentrations of ATP, ADP or AMP and there was only a small increase in phosphocreatine. Since the tissue concentrations of glucose and glycogen were reduced, it is concluded that the well known resistance of the hypothermie brain to ischaemia is unrelated to increased energy stores. Hypothermia was accompanied by decreases in the tissue concentrations of fructose-1,6-diphosphate, dihydroxyacetone phosphate, 3-phosphoglycerate, pyruvate, lactate, α-ketoglutarate, succinate and malate, but not of glucose-6-phosphate or citrate. These results indicate that metabolic flux is retarded mainly at the phosphofructokinase and isocitrate dehydrogenase steps. The largest relative reduction was seen in α-ketoglutarate, which was possibly secondary to accumulation of ammonia. There was no change in GABA, but a decrease in glutamate and increases in aspartate and alanine. These, changes are compatible with shifts in the aspartate and alanine aminotransferase reactions, possibly induced by the fall in α-ketoglutarate.     

THE EFFECT OF HYPERTHERMIA UPON OXYGEN CONSUMPTION AND UPON ORGANIC PHOSPHATES, GLYCOLYTIC METABOLITES, CITRIC ACID CYCLE INTERMEDIATES AND ASSOCIATED AMINO ACIDS IN RAT CEREBRAL CORTEX

The influence of hyperthermia on cerebral blood flow, cerebral metabolic rate for oxygen and cerebral metabolite levels was studied by increasing body temperature from 37° to 40°C and 42°C in rats under nitrous oxide anaesthesia maintained at constant arterial CO₂ tension. The metabolic rate for oxygen increased by 5-6% per degree centigrade. At 42°C the increase in cerebral blood Row was comparable to that in the metabolic rate. The increased temperatures were not accompanied by changes in organic phosphates (phosphocreatine, ATP, ADP or AMP) or in lactate/pyruvate ratio. There was an increase in the tissue to blood glucose concentration ratio. At steady state, there was an increase in glucose-6-phosphate but no other changes in glycolytic metabolites or citric acid cycle intermediates, and the only change in amino acids studied (glutamate, glutamine, aspartate, alanine and GABA) was an increase in glutamate concentration.     

茉莉酸甲酯、水杨酸和一氧化氮诱导怀槐悬浮细胞合成异黄酮及细胞结构变化

本文对比研究了茉莉酸甲酯(MeJA)、水杨酸(SA)和一氧化氮(NO)三种激发子对怀槐悬浮培养物异黄酮合成及细胞结构变化的影响。结果表明,在三种激发子的作用下怀槐细胞异黄酮合成量显著提高:200μmol/L MeJA、100μmol/L SA及50μmol／L SNP处理培养细胞9d后,异黄酮含量分别为同期对照的417．18％、185．45％和222．45％。同时细胞内发现染色很深的电子致密小体(EDB),其数量随着异黄酮含量的升高而增加,亦在第九天达到最多,与异黄酮积累呈现正相关性。推测激发子可能诱导植物细胞结构变化来响应次生代谢产物的合成。     

RESTITUTION OF CEREBRAL ENERGY STATE, AS WELL AS OF GLYCOLYTIC METABOLITES, CITRIC ACID CYCLE INTERMEDIATES AND ASSOCIATED AMINO ACIDS AFTER 30 MINUTES OF COMPLETE ISCHEMIA IN RATS ANAESTHETIZED WITH NITROUS OXIDE OR PHENOBARBITAL

Restitution of cerebral cortex concentrations of organic phosphates, glycolytic metabolites, citric acid cycle intermediates, associated amino acids, and ammonia, following a 30 min period of complete ischemia, was studied in rats anaesthetized with either 70% N₂O or 150 mg·kg^-1 of phenobar-bital. Following a 90 min period of recirculation the pattern of restitution was similar in the two groups. Thus, all animals showed recovery of phosphocreatine concentrations, restitution of the adenylate energy charge to about 99% of control, and disappearance of lactate accumulated during the ischemia. Analyses of glycolytic metabolites indicated inhibition of glycolysis at the phosphofructokinase step, possibly caused by accumulation of citrate. Measured citric acid cycle intermediates indicated extensive normalization of mitochondrial metabolism. Changes in amino acid concentrations consisted of a fall in glutamate concentration, a rise in aspartate/glutamate ratio, a fall in GABA concentration, and a rise in alanine concentration. However, ammonia concentration was close to normal, and the size of the amino acid pool did not change. It is concluded that although the results do not exclude damage to a small part of the neuronal population, they demonstrate that, irrespective of the type of anaesthesia used, the majority of brain cells must have survived 30 min of complete ischemia without signs of irreversible metabolic damage.     

潮间带耐铅菌与铅等重金属有机质关系初析

胶州湾潮间带有较多铅、铜、镉、锌及有机碳、氢、氮等污染物,因而也有较多耐铅菌(Lead-Tolerant Bacteria缩写作LTB,下同)等相应的微生物。LTB等微生物参与这些污染物的价态,类型变化和迁移活动。潮间带LTB量的时空变化曾有过报道,但对LTB与环境因子间的关系未探讨过,而LTB的利用则有赖于环境因子,因此探索LTB与铅等重金属、有机质的关系,对阐明污染物归宿,生态变化和污染治理     

不同链长脂肪酸对斑马鱼的性腺脂肪酸组成、繁殖力与仔鱼成活率的影响

将体质健壮的4月龄斑马鱼(Danio rerio)亲鱼[雄鱼(0.36±0.05) g/尾, 雌鱼(0.59±0.06) g/尾]雌雄各180尾, 随机平均分配在室内斑马鱼循环系统的18个养殖缸中。在斑马鱼基础饲料(对照组)中分别添加7 g/kg n-3HUFA (高不饱和脂肪酸, Highly unsaturated fatty acid)(HUFA组)及10 g/kg MCFA (中链脂肪酸, Medium chain fatty acid)(MCFA组), 制成3组等氮等脂饲料, 饲养90d后, 探究不同链长脂肪酸对斑马鱼的性腺脂肪酸组成、繁殖力和仔鱼成活率的影响。结果表明: (1)3组雌鱼性腺的脂肪酸组成均受到所饲喂饲料脂肪酸组成的影响, 其相关系数均在0.8以上。HUFA组雌鱼性腺中EPA和DHA的相对含量显著高于MCFA组及对照组(P<0.05), 而MCFA组与对照组之间无显著差异; HUFA组油酸的相对含量显著低于MCFA组及对照组(P<0.05), 而MCFA组与对照组之间无显著差异; HUFA组及MCFA组亚麻酸的相对含量与对照组之间均无显著差异, 但MCFA组显著高于HUFA组(P<0.05)。(2)HUFA组及MCFA组雌鱼的成熟系数、绝对繁殖力、体重与体长的相对繁殖力均显著高于对照组(P<0.05), 同时在雌鱼绝对繁殖力、相对繁殖力上, HUFA组显著高于MCFA组(P<0.05)。(3)将对照组雄鱼与各组雌鱼配对繁殖的结果显示, 分别与HUFA组及MCFA组雌鱼配对繁殖后的雌鱼的绝对产卵量、相对产卵量和仔鱼成活率均显著高于与对照组雌鱼的配对, 同时以上指标HUFA组雌鱼均显著高于MCFA组雌鱼(P<0.05)。将对照组雌鱼与各组雄鱼配对繁殖的结果表明, 与HUFA组雄鱼配对后其受精率均显著高于与MCFA组及对照组雄鱼的配对(P<0.05)。综上所述, 试验饲料显著影响斑马鱼雌鱼性腺的脂肪酸组成, HUFA及MCFA均可以促进斑马鱼雌鱼的繁殖性能和仔鱼成活率的提高, 在试验条件下, HUFA的效果更好。