Studies on effects of certain quinones: III. Photosynthetic 14CO2 incorporation by Rhodospirillum rubrum

Substituted naphthoquinones, 2,3,-dichloro-1,4-naphthoquinone, and 2-methyl-1,4-naphthoquinone produced marked changes in the pattern of ¹⁴C-distribution during ¹⁴CO₂-fixation by photosynthetic bacterium Rhodospirillum rubrum. The most obvious change in the labeling pattern during photoautotrophic ¹⁴CO₂-fixation was a several-fold increase in 3-phosphoglyceric acid accompanied with a decrease in the amount of glutamate. In photoheterotrophic cells, quinones caused an appreciable increase in ¹⁴C-glycolic acid and concomitant decrease, although not proportional, in the amount of ¹⁴C-sugar phosphate. The level of ¹⁴C-incorporated in poly-β-hydroxybutyrate and ether-extractable lipids was considerably decreased in photoautotrophic and photoheterotrophic cells treated with quinones. The ability of quinones to interfere with the synthesis of NADH and ATP, and their ability to interact with sulfhydryl enzymes and coenzymes appears to be responsible for the changes observed.     

Inhibitory effects of pesticides on growth and respiration of cultured cells

Effects of various drugs including pesticides on the growth and respiration of cultured cells were evaluated comparatively using cell lines derived from mosquito ovary and subcutaneous mouse tissues. The concentration producing 50% inhibition of cell growth, I₅₀ (M), was determined for each of 42 drugs. Inhibitors of respiration and nucleic acid and protein biosyntheses such as rotenone, piericidin A₁, actinomycin D, and puromycin had very high pI₅₀ values of approximately 8. Except for the compounds known to be uncouplers of oxidative phosphorylation, the drugs suppressed the respiration rate of the cultured cells to various degrees. The pI₅₀ value (and the pEC₁₅₀, 150% enhancement of the control, value for uncouplers) was determined for each compound. By examining the relation of pI₅₀ (and pEC₁₅₀) values between cell growth and respiration, the compounds could be classified into two groups according to their modes of inhibitory action against the cultured cells. One mode relates to the inhibition of energy synthesis and the other, perhaps, to interference with the biosynthesis of biomacromolecules.     

施肥对西红柿土壤微生物和土壤呼吸的影响

以不施肥为对照,研究了化肥、有机肥、沼肥对西红柿土壤微生物数量和土壤呼吸的影响.结果表明:施用化肥土壤的细菌数量比对照减少0.6％～57.2％,真菌数量呈现先增加后减少的趋势,放线菌数量比对照增加7.4％ ～65.0％;化肥用量减少一半,土壤的真菌数量增加,放线菌数量减少.施用有机肥土壤的细菌、真菌、放线菌数量比对照分...     

Effect of substituted pyrazoles and related compounds on geotropism in cress seedlings

The effects on root geotropism of three series of compounds related to 2-phenyl-8H-pyrazolo[5,1-a]isoindol-8-one (IV), its 3,3a-dihydro derivative (V) and 5-(2-carboxyphenyl)-3-phenylpyrazole (VI) have been assessed using cress seedlings. Compounds (IV) and (VI), and their derivatives, are highly active, destroying geotropism at concentrations of 10^?7-10^?9M. Substitution with various functional groups and increased molecular size resulted in only minor variation in the level of activity.     

The effect of substituted urea herbicides on the growth of excised tomato roots

The action of 23 herbictdal substituted ureas on the growth of excised tomato roots was studied in order to détérmine whether there is a link between the effects of these herbicides on oxidative phosphorylation and on the growth of non-photosynthetic tissues. Fourteen of these herbicides were inhibitory; chlortoluron and TBU were stimulatory but only in the light. Substituted ureas known to affect plant mitochondria inhibited root growth but to a lesser extent than some which had no action on mitochondria. No clear relationship was found between actions on mitochondria and on root growth. It is suggested that targets other than photosynthesis and oxidative phosphorylation exist for some substituted ureas.     

Effect of propiconazole on substrate amended soil respiration following laboratory and field application

The effect of the fungicide propiconazole (‘Tilt’^TM 250 EC) on substrate-amended soil respiration has been studied in dose-response experiments, following application of the compound in the field and in the laboratory. The field study was supplemented with spray-deposition measurements showing a throughfall at the soil surface of 15-45%, depending on the time of fungicide application. When propiconazole was amended to the soil in low dosages in laboratory conditions, the soil respiration was stimulated. Even at the very high and agriculturally unrealistic dosages in the laboratory experiment, the mean, daily soil respiration almost recovered within the incubation period of 30 days. Given the present conditions, the results did, however, also show that side-effects of the application of the fungicide were provoked at lower dosages in the field, and that they lasted for a considerably longer time than in the laboratory, indicating the importance of indirect effects of fungicide application in field conditions. Possible reasons for the dose-response relationship in the field being different from the one found in the laboratory are discussed.     

旁路氧化作用对嘧菌酯抑制辣椒炭疽菌孢子萌发和菌丝生长的影响

 研究表明,旁路氧化作用能够降低辣椒炭疽菌对嘧菌酯的敏感性。离体培养条件下,旁路氧化在辣椒炭疽菌野生菌株的孢子萌发中提供大于95倍生理功能的补偿作用;在菌丝生长中提供20~35倍的补偿作用。但在接种前用嘧菌酯处理辣椒,旁路氧化作用并不明显,嘧菌酯对辣椒炭疽病有良好的保护、治疗、铲除和抗产孢作用。用嘧菌酯处理过的病斑产生的分生孢子萌发活力和致病力下降。炭疽菌离体下的菌丝耗氧率测定表明,10μg/mL嘧菌酯处理1 h对菌丝呼吸耗氧有良好的抑制作用,其抑制效果随药剂浓度提高而略有增加。随处理时间延长,药剂对菌丝耗氧的抑制作用下降,但仍然抑制菌丝生长。研究证明:延长处理时间,呼吸作用对药剂的敏感性下降的机理不是因为旁路氧化途径增强,也不是因为基质中药剂效力的下降,而是存在其它机制。     

植物生长调节剂对烟草生长发育及钾素吸收与分配影响研究

通过盆栽试验,采用不同钾素水平,在烟草植株打顶后夹吸不同的植物生长调节剂对烟草生长发育进行研究。研究表明,不同钾水平对烟草植株的株高、最大叶面积、根体积、倒二叶叶面积均没有显著的促进作用,但是能够显著增加根鲜重,而烟株打顶后夹吸生长调节剂能显著地促进烟草植株的株高、最大叶面积、根体积、根鲜重、倒二叶叶面积的增长。同时,植物生长调节剂能明显提高不同部位烟叶中的钾含量和各部位钾素的积累量,促进钾素从根、茎部向叶部的转移,显著提高烟草的品质,其中表油菜素内酯(BR)与赤霉素(GA3)处理效果最为明显。     

条锈病侵染对小麦抗氰呼吸和活性氧代谢的影响

 以不同抗病性的小麦为材料,观察了条锈病菌侵染小麦幼苗叶片时活性氧代谢和抗氰呼吸发生、运行的变化。讨论了二者在长期病程下的平衡关系。实验显示:接种8d后,感病小麦中H₂O₂含量开始高于抗病小麦,O₂^-·含量变化差异不明显。SOD、CAT和POD活性整体上表现为接种后的前4d有所上升,接种4d之后呈下降的趋势;感病小麦中3种抗氧化酶的活性均高于抗病小麦。条锈菌侵染下小麦幼苗抗氰呼吸容量和运行活性的变化在两类小麦中与H₂O₂的变化一致,在侵染初期上升缓慢,以后迅速上升;aoxl的mRNA水平仅在侵染后4d的幼苗叶片中略有上升,在以后的侵染过程中没有发生显著的变化。我们推测,活性氧可以在多种水平上参与条锈病菌侵染下抗氰呼吸的诱导,而抗氰呼吸也在某种程度上参与小麦在条锈病菌侵染下活性氧的清除与机体的生理保护机制。     

邻烯丙基苯酚对番茄灰霉病菌全细胞呼吸的影响

 利用Oxygraphy液相氧电极研究了植物源杀菌剂邻烯丙基苯酚对番茄灰霉病菌(Botrytis cinerea)全细胞呼吸的影响。结果显示,邻烯丙基苯酚处理浓度为5、10 mg/L,菌丝细胞的呼吸速率较对照分别增加了19.58%和24.56%;处理浓度为150 mg/L,可显著抑制菌丝细胞的呼吸,抑制率达到77.49%,表明邻烯丙基苯酚具有低浓度刺激而高浓度抑制灰霉病菌细胞呼吸的双重影响。用药剂处理萌芽期、非萌芽期的分生孢子,测定呼吸的结果表明,药剂对孢子的呼吸作用效果与对菌丝的相似,但以萌芽期分生孢子最为敏感。以0.01 mol/L琥珀酸钠作为病菌细胞呼吸底物时,10 mg/L邻烯丙基苯酚对病菌细胞的呼吸速率具有抑制作用,而添加0.1 mol/L葡萄糖和0.01 mol/L丙酮酸钠两种底物时却表现出刺激病菌细胞呼吸的作用,表明邻烯丙基苯酚对细胞呼吸的影响和氧化底物密切相关。反应液中单独添加呼吸电子传递链特异性位点抑制剂鱼藤酮20μmol/L、嘧菌酯10 mg/L和叠氮化钠0.01 mol/L后,病菌菌丝细胞呼吸均受到显著抑制,抑制率分别为48.94%、33.08%和39.18%。随后再添加10 mg/L邻烯丙基苯酚,不改变这种抑制效果。单独添加旁路氧化酶抑制剂水杨肟酸2 mM不影响病菌菌丝的呼吸,随后再添加10 mg/L邻烯丙基苯酚后,两者协同作用则可显著抑制菌丝的呼吸。     

Effect of some substituted benzonitriles on photosynthetic activity of spinach and wheat in vivo and in vitro

The inhibitory effects of nine nitro and/or bromo-substituted benzonitrile compounds on the photosynthetic electron flow in isolated chloroplasts and on the in vivo CO₂ fixation of spinach (Spinacia oteracea L.) and wheat (Triticum aesticum L. cv. Bezoslaya) were investigated. Bromoxynil and 3-nitro-5-hromo-4-hydroxy-bcnzonitrile were the strongest and equally effective inhibitors of Ihe in vivo CO₂ fixation of spinach, hut in wheat the nitro-bromo-compound is ineffective and 3-nitro-benzonitrile is even more inhibitory than bromoxynil. None of the substances affected DCPIPH → methylviologen reduction. In the inhibition of the DCPIP reduction only the 3,5-disuhstituted 4-hydroxy-derivatives were effective. The fact that these compounds affect only the PS II reaction with both H₂O and DPC as electron donors suggests a site of inhibition on the reducing side of PS II, between Ihe PS II reaction centre and ihe DCPIP Site. It is suggested that in the inhibition of the DCPIP reduction only steric factors are important and the different electron configuration of the sterieally similar molecules may be involved only in the absorption and translocation processes of the compounds.     

Effects of temperature, light and certain growth regulating substances on sprouting, rooting and growth of single-node rhizome and shoot segments of Paspalum distichum L.

The rate of sprouting, rooting and early growth of both single-node stem and rhizome segments of Paspalum distichum L. increased as incubation temperatures increase to about 30°C and then declined at 40°C. There was little growth at 10°C. Single-node shoots remained viable at cooler temperatures after 1 days’incubation at 45°C, and 35% remained viable after 2 days’incubation at 45°C. Both shoot and rhizome segments sprouted and rooted at alternating temperatures of 45°C/28°C and 45°C/22°C. Generally sprouting and rooting of shoot segments were faster than in rhizome segments, but the response to temperature was similar for both sprouting and rooting of single-node shoot and rhizome segments. Single-node shoot segments sprouted faster in 16-h day lengths than in the dark. Rooting was better in the dark at 10°C, unaffected by light at 22 and 28°C, and faster in the light at 35 and 40°C. Sprouting, rooting and early growth were enhanced by gibberellin A₃, kinetin and indole-3-acetic acid. Shoots collected at different seasons differed in their sprouting and rooting responses at various incubation temperatures. These patterns varying in response to seasonal temperature fluctuations may provide a survival mechanism for P. distichum.     

水位对巴音布鲁克天鹅湖高寒湿地土壤呼吸的影响

以新疆维吾尔自治区天山中部巴音布鲁克天鹅湖高寒湿地为研究区域,结合室内水位控制试验,初探土壤水位对土壤呼吸的影响,结果表明:1)土壤呼吸与土壤水位呈现显著的负相关性(r=-0.997;p=0.003),5cm、0cm、-10cm、-20cm水位梯度下土壤呼吸速率平均值分别为1.27、2.49、4.60、6.21μmol·m~(-2)·s~(-1)。2)不同水位处理下土壤碳排放量差异性达到极显著水平(p<0.01),5cm、0cm、-10cm、-20cm水位条件下土壤碳排放量分别为0.11、0.22、0.40、0.54mol·m~(-2)·d~(-1)。3)不同水位条件下土壤呼吸速率与5cm土壤温度均表现为显著正相关关系,淹水条件下水温与土壤呼吸速率表现为显著正相关性,且随着土壤水位的下降水温与土壤呼吸的相关性系数减弱。各水位梯度土壤呼吸速率与5cm土壤温度均呈显著的指数函数关系,水位降低显著提高了土壤呼吸温度敏感性系数(Q10)(p<0.05)。     

根控肥（CULTAN）对小麦生长发育及品质的影响

根据德国波恩大学Sommer教授提出的CULTAN的原理与山西临汾研究了根控肥和传统施肥处理对小麦生长发育及品质的影响,结果表明:根控肥处理比传统施肥处理不论从小麦的生长发育,还是品质方面都表现出较好的优势,尤其是硫铵、尿素和DCD添加剂混合物的根控肥处理其面团的吸水率、稳定时间和评价值明显提高.同时根控肥处理土壤剖面中碱解氮的含量显著高于传统施肥处理.因此在生产优质强筋小麦的地区,应推广施用根控肥,达到优质小麦产量与品质的协调统一.     

培肥模式对旱作全膜双垄沟播玉米生长及土壤呼吸的影响

针对旱作全膜双垄沟播玉米培肥模式单一及碳排放理论薄弱的问题,依托大田试验研究了不施氮肥对照(CK)和等氮(纯N 200 kg·hm^-2)条件下3个不同氮源(单施化肥,N;商品有机肥配施化肥, NM;单施有机肥, M)对玉米生长、产量、土壤呼吸速率及碳排放量的影响。结果表明:土壤呼吸速率随玉米生育时期的推进呈先增大后减小的趋势,开花期是土壤呼吸的峰值期,土壤呼吸速率达5.38μmol·m^-2·s^-1;土壤碳排放总量与玉米干物质积累、生长速率、叶面积指数及净同化率均呈极显著正相关关系;玉米产量、碳排放量和碳排放效率在商品有机肥配施化肥和单施化肥处理间无显著差异,分别较对照增加了121.2%、41.9%、54.5%和151.4%、31.9%、92.9%。说明商品有机肥配施化肥在增加了碳排量的同时增加了玉米的产量,进而提高了碳排放效率。     

播期对玉米生长发育和产量的影响

基于2012—2014年在辽宁省庄河市和锦州市进行的玉米分期播种试验资料,对辽宁地区玉米生长及产能受温度影响情况进行分析。试验分为5个播期,播期间隔10~15 d不等,种植密度约为4.2株·m~(-2),每个播期分为4个重复小区,分别观测玉米生长指标。结果表明:在日照和水分条件适宜的情况下,玉米在各生长发育期所持续的时间与相应期间的温度存在着负相关关系。播种~出苗阶段持续时间在日最低气温15℃以下随着温度升高而逐渐缩短,15℃以上则逐渐增加。吐丝~成熟阶段持续时间则随着播期的延后而延长。玉米在出苗~吐丝阶段,各播期温度条件相当,差别并不显著。吐丝~成熟期≥10℃的活动积温和气温日较差分别在1 500℃·d左右和8℃~8.5℃的范围内对产量的形成更加有利。     

β-Oxidation of certain growth regulators by plant tissues

The growth-regulating activity and metabolism, in pea and wheat tissues, of y-(chloro-phenoxy)-, y-(2,4-dichlorophenoxy)- and y-(N, N-diniethylthiocarbamoylthio)-substituted butyric, β-hydroxy-butyric, crotonic and vinylacetic acids have been investigated. With the exception of y-(2,4-dichlorophenoxy) vinylacetic acid in pea tissue, members of the two phenoxy series were degraded to the corresponding phenoxyacetic acid. Although members of the 2,4-dichlorophenoxy series were less easily metabolised, both series exhibited similar activity. Other than with the y-phenoxyvinylacetic acids, there were no appreciable differences in metabolism or growth-regulating activity between members within a series. No evidence for the metabolism of y-(2,4-dichlorophenoxy)vinylacetic acid in pea tissue was found and this acid was also less active in the pea tests. Members of the N, N-dimethyl-thiocarbamoylthio series of acids, however, were less regular in their metabolic and growth-regulating patterns. The substituted crotonic acid was inactive and unstable whilst pea tissue was found to metabolise the substituted acetic acid to inactive N-methylcarbamoylthioacetic acid. The results with all active acids fit the accepted theory of metabolism by β-oxidation.     

Effect of diflubenzuron on growth and carbohydrate hydrolases ofTribolium castaneum

The potency of diflubenzuron is much greater in inhibiting growth and development of 1st instar larvae ofTribolium castaneum than of 4th instar larvae, as expressed by death at the apolytic stage and retardation of larval development. A dose-dependent decrease in the activity of trehalase, invertase and amylase was obtainedin vivo with the increase in diflubenzuron concentration. At 5 ppm dietary concentration, a reduction of 37 and 27% in invertase and trehalase activity, respectively, was obtained in 4th instar larvae fed for 3 days on treated diet. The amylase activity was affected to a lesser extent. The observed disturbances of trehalase activity might hamper the supply of glucose needed for chitin build-up and those of invertase and amylase activity might affect feeding. Diflubenzuron does not inhibit these enzymesin vitro; hence, thein vivo effect seems to result from general disturbances in carbohydrate metabolism.     

有机酸和维生素对玉米幼苗生长的影响

采用溶液培养和土培试验研究了维生素,有机酸浸种及灌根对玉米幼苗生长的影响。溶液培养试验表明,２０μｇ／ｇ的有机酸和乌囊素单独处理和混合处理,可抑制种子根生长,减少植株对磷的吸收,降低生物学产量;