Showing papers by "Institut national de la recherche agronomique published in 1980"

Agropine in “null-type” crown gall tumors: Evidence for generality of the opine concept

Abstract: Agrobacterium Ti (tumor-inducing) plasmids, the causative agents of crown gall disease, fall into four genetic groups based on the patterns of octopine and nopaline synthesis (by crown gall tumors) and catabolism (by Agrobacterium tumefaciens) for which they are responsible. Two classes of Ti plasmids induce tumors that synthesize neither octopine nor nopaline. The existence of these Ti plasmids challenged the view that opines such as octopine and nopaline play a central role in crown gall biology. We now report the occurrence of an opine in tumors induced by one of these classes of Ti plasmids, the “null-type” plasmids typified by pTi Bo542. The opine was purified by biological enrichment based on its utilization by bacteria containing pTi Bo542 but not by bacteria lacking a Ti plasmid. The mass spectrum and biological properties of this opine are identical to those of agropine, an opine recently discovered in octopine-type tumors. We propose that null-type Ti plasmids now be named for their signal opine, agropine-type Ti plasmids.

Selecting broilers for low or high abdominal fat: initial observations.

Abstract: 1. Two lines of broiler breeders were selected for three generations using a high (fatty line) or a low (lean line) ratio of abdominal fat to live weight as criterion in males at 9 weeks of age. 2. The heritability of this character remained high in both lines. 3. By the third generation, the progress achieved was much more marked in males than in females. The difference between the females of both lines was nevertheless significant. 4. The differences between the two lines were already discernible at 4 weeks of age. 5. Selecting for low or high abdominal fat content was accompanied by a better food conversion ratio in males of the lean line. 6. Selecting for the amount of abdominal fat produced similar effects on the other fatty deposits.

Soluble Sugars, Respiration, and Energy Charge during Aging of Excised Maize Root Tips.

Abstract: Oxygen uptake and energy charge were monitored during aging of excised maize root tips and related to the soluble sugar content and exogenous sugar supply. Oxygen uptake declined immediately after excision to 50 to 30% of its initial value after 8 and 24 hours of aging at 25 C. There was also a sharp decline of the total sugar content (glucose, fructose, and sucrose). Starch content was very low at the time of excision and almost negligible 5 hours later. During the same period, the respiratory quotient declined from 1 to 0.75 and then remained stable. The addition of exogenous sugars induced a rapid rise of the respiratory rate which stabilized at a level correlated to the external sugar concentration. Addition of 0.2 molar glucose was necessary to restore the respiratory rate to the initial, also the maximum, level. These results indicate that metabolic activity of root tips is highly reliant on sugar import and carbohydrate reserves at the time of excision cannot compensate for the cessation of import. The control of respiration by substrate supply is in good agreement with the failure for dinitrophenol to stimulate oxygen uptake in aged sugar-depleted root tips. The energy charge remained constant at about 0.9, irrespective of the presence or absence of glucose and in spite of a large decline of respiratory activity in aged, sugar-depleted tissues.

Nutritional requirements of protoplast-derived, haploid tobacco cells grown at low cell densities in liquid medium.

Abstract: Preliminary attempts to define a completely synthetic medium able to support divisions of haploid tobacco mesophyll protoplasts at low initial densities have failed. High protoplast concentrations together with large amounts of naphtaleneacetic acid in the medium (3 mg l-1 NAA) were required for maximal induction of protoplast division. However, cell suspensions derived from haploid protoplasts after four days of preculture at high initial cell densities could be diluted to densities as low as 1–4 cells ml-1, provided the concentration of NAA in the medium was lowered to below 0.3 mg l-1. The optimal NAA supply for low cell density growth was affected by the nature of the nitrogen source. A simple minimal medium which supports the growth of these haploid cells with a plating efficiency of 30–40%, independent of the cell density in the range of 1–4 to 3·104 cells ml-1, has been established. In this medium inositol was the only vitamin stringently required for growth. Growth of cells at low densities was also possible in a medium initially containing 3 mg l-1 NAA, provided it was conditioned by the growth of protoplasts at high densities. Preliminary experiments with [14C]NAA showed that the amount of free NAA remaining in the medium after preincubation at high densities was drastically reduced. Simultaneously, NAA conjugates accumulated in the medium. The implications of these results are discussed.

Metabolic Activity and Energy Charge of Excised Maize Root Tips under Anoxia: CONTROL BY SOLUBLE SUGARS

Abstract: Energy charge and fermentative metabolism under anoxia were monitored in excised maize root tips after various times of aging in air and were related to their soluble sugar content. The energy charge value, which was 0.9 in air irrespective of the time of aging, dropped to a lower value within minutes of transfer to a nitrogen atmosphere. This value was dependent upon sugar content of the tissues which was itself a function of aging. The energy charge value after transfer to nitrogen was 0.6 in freshly excised tissue but only 0.2 in tissue aged for 4 hours. When aged tissues supplied with 0.2 molar glucose were transferred to nitrogen, the energy charge was 0.6, irrespective of the time of aging. When 0.2 molar glucose was added under nitrogen, energy charge rose to 0.6. This rise was faster in root tips aged for 8 hours than those aged for 24 hours.The rate of ethanol plus lactate production (representing 60 and 10%, respectively, of the total sugar consumption in anoxia) was closely correlated to the level of energy charge. It is concluded that, in anoxia, there is a quantitative relationship between the energy charge value and the level of metabolic activity via fermentative pathways.

N-terminal amino acid sequence homology of storage protein components from barley and a diploid wheat

Abstract: Wild barley (Hordeum spontaneum) and the wild diploid wheat Triticum boeoticum were possibly the first plants cultivated by early man1, giving rise to the domesticated forms Hordeum vulgare L. and Triticum monococcum L. In addition, T. boeoticum may have contributed the A genome to polyploid wheats, including common bread wheat (Triticum aestivum)2 which is a hexaploid with genome composition ABD. Hordeum seems to be the older genus, having diverged from some common ancestor before the divergence of Triticum and other genera of the subtribe Triticinae3. Prolamins constitute the major storage protein fraction of both barley and wheat; they are located in the endosperm of the caryopsis and are soluble in alcohol–water solutions4. Barley and wheat prolamins (hordeins and gliadins, respectively) contain large amounts of glutamine and proline, which together make up 50–75 mol per cent of total amino acids4,5. The hordeins and gliadins are complex mixtures of components6–8 that seem to be encoded by clusters of duplicated genes that have diverged to produce many distinguishable protein components. Despite the complexity of the gliadin mixture, the components retain considerable homology in their N-terminal region9,10 and this has been reported for zeins, the prolamins of maize (Zea mays)11, as well. Here, we report that a purified C-hordein component from barley is homologous in amino acid sequence with a purified ω-gliadin component from T. monococcum at 23 of 27 residues at the N-terminus. This result is in accord with the close relationship between the two species and indicates that, despite the propensity of prolamin genes to tolerate mutations, a significant portion of their sequences can be conserved over a period of time, which, although not accurately known, probably amounts to millions of years.

Relationship Between the Sterol Content of Yeast Cells and Their Fermentation Activity in Grape Must

Abstract: In grape must of high sugar concentration, yeast growth, the viability rate of "resting" yeast cells, and fermentation activity were stimulated under certain conditions of aeration and temperature. This stimulation might be interpreted as being a result of the yeast cell sterol content. The addition of certain sterols to the fermenting medium was able to increase this sterol content. According to aeration conditions of the medium, which determined the sterol content of yeasts, the sterols added in the medium acted as (i) growth factors, (ii) fermentation inhibitors, and (iii) survival factors for the yeast.

Pisum sativum AND Vicia faba CARBOHYDRATES: STUDIES OF FRACTIONS OBTAINED AFTER DRY AND WET PROTEIN EXTRACTION PROCESSES

Abstract: The distribution and the composition of the oligosaccharides, starch, and cell-wall polysaccharides were determined on the lower protein air-classified flours of broadbeans, smooth peas, and wrinkled peas and the starchy by-products obtained after the wet process. α-Galactosides are still present in the air-classified fractions whereas they are almost extracted by wet process. In contrast, the fiber content was high in the starchy by-product and in both cases, the sugar constituents of hemicelluloses material indicate that the fraction still present is not representative of the initial hemicelluloses. Starches were isolated in a high yield (60%) from air-classified flours whereas the isolation was not possible from the starchy by-product, probably due to the high hemicelluloses content preventing their extraction. The laboratory scale purification has led to refined starches with no effect of the process on the granules as viewed by light and electron microscopies.

Effects of environmental temperature on heat production, energy retention, protein and fat gain in early weaned piglets

Abstract: 1. Six experiments, each involving two groups of six piglets, were designed to study the influence of environmental temperature on heat production, energy retention and protein and fat gain in early weaned piglets. Immediately after weaning, at a mean age of 25 d, the animals were raised in two open circuit respiratory chambers. Each chamber was equipped with a totally wired cage. The piglets were paired-fed and maintained at environmental temperatures of 20, 24 or 28 degrees. Four replicates were used for each temperature. Metabolizable energy, heat production and nitrogen balance were measured during two consecutive periods (A and B), each of 6 d duration. 2. Heat production was higher at 20 degrees than at 24 and 28 degrees during periods A and B. Energy retention was negative during period A, it was positive during period B and increased with temperature. 3. Protein deposition was always positive and independent of environmental temperature. The net efficiency of protein utilization was 0.77. 4. Body fat was mobilized during period A at a higher rate at 20 degrees than 28 degrees. During period B, fat gain increased with increase in temperature. 5. The calculated ME requirement for maintenance amounted to 411 kJ/kg body-weight 0.75 per d at 28 degrees. 6. The critical temperature of early weaned piglets raised in intensive modern housing and fed at about 90% of the ad lib, intake is close to 28 degrees during the first 12 d after weaning.

First report of host b-protein appearance in response to a fungal infection in tobacco

Abstract: Infection of leaves of N. tabacum cv. Burley 49, cv. Judy's Pride Burley and the reciprocal hybrids with Thielaviopsis basicola induced necrotic local lesions and host specific b-proteins, whose number varied with the cultivar of tobacco studied. TMV infection induced the same b-proteins, together with necroses, in cv. Burley 49 and the hybrids but none in the susceptible cultivar Judy's Pride Burley. A new b-protein (b1′) of mol. wt similar to b1, b2 and b3 (15 500) was detected in the hybrids after fungal and virus infection. Evidence is presented that the information coding for this protein must have come from the cultivar Judy's Pride Burley. The link between b-protein synthesis and resistance to parasites in tobacco is underlined.

Resistance of 17 mesophilic lactic Streptococcus bacteriophages to pasteurization and spray-drying.

Abstract: For 17 phages active against Streptococcus cremoris, Str. lactis and Str. lactis subsp. diacetylactis, the killing efficiency of pasteurization (log No/N) at 72 degrees C for 15 s in skim-milk showed large variations from greater than 6 to 0; the efficienty of killing during spray-drying ranged from 3.7 to 0.2 and phages survived well storage of milk powder at room temperature. Destruction in a heat exchanger was found to be greater than that calculated from biphasic curves obtained by heating phages in sealed ampoules. No relationship was established between lytic classification of phages and their heat resistance.

Ultrafiltration of whey

Abstract: Utilization of ultrafiltration for the treatment of whey is increasing in the world dairy industry, due to the progress made in membrane technology itself and a better knowledge of the behaviour of whey components. Pretreatment of whey either by heating accompanied or not with pH adjustment or by ionic strength regulation or by prefiltration has the greatest effect on permeation rate. Preconcentration of whey also improves performances of ultrafiltration equipment. Two new potentialities for whey proteins, made possible by properties of new membranes are also presented.

Etude de la dynamique d'une communaute adventice: I — Evolution de la flore adventice au cours du cycle vegetatif d'une culture

Abstract: Resume: Un dispositif experimental a ete mis en place pour comparer les effets du travail du sol et du desherbage chimique sur la dynamique d'une communaute adventice (agrophytocenose). Les auteurs decrivent la methodologie detude et presentent la flore adventice du ce dispositif. Au cours du cycle cultural, la densite des mauvaises herbes passe par un maximum qui se situe en avril dans l'orge d'hiver et en mai dans l'orge de printemps. Le stock en semences viables du sol s'eleve a environ 7000 individus par m2 sur 30 cm de profondeur et les levees de mauvaises herbes du semis a la recolte de l'orge n'ont represente que 6.6% de ce stock. La densite des semences dans le sol est plus elevee entre 0–10 cm et 10–20 cm qu'entre 20–30 cm; leur viabilite est superieure a 80% pour la majorite des especes et elle est independante de la profondeur d'enfouissement. Summary: Study of the dynamics of a weed community. I: Evolution of the weed flora during the growth cycle of a crop An experiment was laid out to compare the effects of soil working and chemical weed control on the dynamics of a weed community (agrophytocenosis). The authors describe the methodology of study and present the weed flora of this experiment. During the crop cycle, weed density reached a peak, which occurred in April in winter barley and in May in spring barley. The stock of viable seeds in the soil amounted to about 7000 seeds/m2 over a depth of 30 cm and weed emergence from sowing to harvesting the barley was higher between 0 and 10 cm and 10 and 20 cm than between 20 and 30cm; for most species viability was more than 80% and was independent of the depth of burial. Zusammenfassung Studie zur Dynmaik einer Unkrautgesellschaf t: I. Entwicklung der Unkrautflora wahrend der Vegetationsperiode einer Kultur Es wurden Feldversuche durchgefuhrt, um die Wirkungen von Bodenbearbeitung und chemischer Unkrautbekampfung aufdie Dynamik einer Unkrautgesellschaft (Agrophytozonose) zu vergleichen. Die Autoren beschreiben ihr methodisches Vorgehen und stellen die Unkraflora des Versuchs vor. Wahrend der Vegetationsperiode erreicht die Dichte der Unkrauter ein Maximum, das bei Wintergerste im April und bei Sommergerste im Mai liegt. Der Vorrat lebensfahiger Samen im Boden belauft sich auf etwa 7000 Individuen je m2 und 30 cm Tiefe, von denen zwischen Saat und Ernte der Gerste jedoch nur 6.6% auflaufen. Die Samendichte im Boden ist zwischen 0 und 10 cm und zwischen 10 und 20 cm hoher als zwischen 20–30 cm. Die Lebensfahigkeit der Samen liegt bei den meisten Arten uber 80% und ist von der Tiefe unabhangig.

Multicomponent sex pheromone in Agrotis segetum: preliminary analysis and field evaluation.

Abstract: Abdominal rinses of calling females of the turnip moth, Agrotis segetum, were analyzed by capillary gas chromatography combined with flame ionization detection, electroantennographic detection and mass spectrometry. Traces of a compound showing the retention time and high elec- trophysiological activity of (Z)-5-decenyl acetate could be detected only by electroantennography. In addition, (Z)-7-dodecenyl acetate, (Z)-9-dodecenyl acetate, dodecyl acetate and a compound resembling (E)-5-dodecenyl acetate were found. A mixture of these 5 compounds was as attractive in the field as were virgin females, while (Z)-8-dodecenyl acetate, which was also found in the female, was a strong inhibitor. Wind tunnel and field experiments indicate that (Z)-5-decenyl acetate, (Z)-7-dodecenyl acetate and probably (Z)-9-dodecenyl acetate are essential for attraction.

Immunocytochemical demonstration of met-enkephalin in the central nervous system of the domestic fowl.

Abstract: In the central nervous system of the male domestic fowl, met-enkephalin (ENK) immunoreactive perikarya and fiber tracts as well as extensive but sharply delimited fiber networks were visualized by means of the PAP technique. The most striking results were: (1) The demonstration of an association of ENK-containing structures with branchial nerves; (2) the spatial relationship of ENK-containing perikarya and fibers to somatostatin (SOM) and arginine-vasotocin (AVT)-immunoreactive systems; (3) the presence of dense and extensive ENK fiber networks within (a) the caudo-basal wall of the third ventricle and (b) the septal-preoptic area; in both regions mainly ENK fibers, but also SOM and AVT fibers, may cross to the contralateral side.

Prolactin, testicular growth and LH receptors in the ram following light and 2-Br-alpha-ergocryptine (CB-154) treatments.

Abstract: The influence of prolactin (PRL) on testicular growth and luteinizing hormone receptors (LH-R) in the ram has been investigated. Unoccupied LH-R were estimated in the 5000 X g testicularmembrane fraction.The specificactivityof the (‘25Il-oLH (enzymatically radioiodinated) was 20-40 �iCi4tgand maximum binding activityreached 15-25%. Kinetic curves indicated that incubation for 20 h at 20#{176}C was the optimum condition to obtain the maximum specific binding activity. Enzymatic treatmenthas demonstrated the lipoprotein structure of the LH-R. The specificityof the assay was confined to LH or human chorionic gonadotropin molecules. The equilibrium associationconstant (Ka) of the LH/receptor interactionwas 10i0 M -i and the number of LH-R determined using Scatchard analysis was “vS fmoles/mg membrane protein.The precision of the assay was 18%. Plasma prolactin levelsdecreased by CB-154 treatment or increasedby photostimulation did not change either the LH-R number or the equilibrium association constant. However, in the two experiments, a delay in the beginning of testiculargrowth was observed in rams treatedwith CB154. In contrast to what has been found in rodents,these resultssuggest that,in the case of seasonal variations,high plasma prolactin levelsinfluencechanges in testicularactivity without any involvement of the speculated regulationby prolactinof the LH-R number.

Role of prolactin in the transcription of beta -casein and 28-S ribosomal genes in the rabbit mammary gland.

Abstract: Isolated mammary nuclei were incubated in the presence of HgCTP and the neosynthesized RNA was isolated with a SH-Sepharose column. The concentration of β-casein mRNA and 28-S ribosomal RNA in the neosynthesized RNA fractions was evaluated using [3H]DNA probes complementary to β-casein mRNA and 28-S rRNA respectively. In the unstimulated pseudopregant rabbit, the transcription of both genes was easily detectable. Injections of prolactin progressively enhanced the transcription rate of both genes and preferentially the β-casein gene. A comparison between the transcription rates and the accumulation of the corresponding gene products in the cell revealed that there is a good correlation between these two parameters for the 28-S rRNA gene. By contrast, the acceleration of β-casein gene transcription by prolactin is unable to account for the simultaneous accumulation of β-casein mRNA, indicating that prolactin is a potent stabilizer of casein mRNA. Injections of CB154 into lactating rabbits (a drug which suppresses the secretion of prolactin by hypophysis), induced a rapid drop of β-casein mRNA concentration and a slow decline of β-casein gene transcription. Simultaneously the drug was responsible for a marked and rapid decrease of 28-S rRNA gene transcription, while the concentration of the rRNA remained elevated. During weaning the transcription of the β-casein gene and, to a lower degree, the transcription of the 28-S rRNA gene proceeded more slowly and this phenomenon was accompanied by a progressive decline of the RNA concentrations.

Occurrence of viral haemorrhagic septicaemia in rainbow trout Salmo gairdneri Richardson reared in sea-water

Abstract: Viral haemorrhagic septicaemia (VHS) is reported for the first time in sea-water cultured rainbow trout. Heavy mortalities with typical signs and lesions occurred about 1 month after the trout were transferred from fresh to sea-water. A VHS virus (serotype 1) was isolated from the diseased fish. The mortalities were caused only by the VHS virus and 80 days post transfer of trout to sea-water the mortalities reached 85% of the initial population. The disease was experimentally transmitted to rainhow trout, both in sea-water and freshwater, either by immersing the fish in contaminated water containing S-IO* pfu/ml of virus or by intramuscular injection of various doses of VHSi (710', 710" or 7106 pfu pej. ggh). Death occurred in all infected groups and started earlier in sea-water. Typical signs of VHS were observed in moribund fish. Viral multi-

Effect of Lactose Supplement on Digestion of Lucerne Hay By Sheep. II. Absorption of Magnesium and Calcium in the Stomach

Abstract: Lactose (400 g/day) was added to a diet of lucerne hay (700 g/day chopped). The two diets (hay and hay plus lactose) were fed to four adult sheep fitted with rumen cannulas and simple cannulas at the proximal and distal end of the small intestine. The addition of lactose significantly increased apparent absorption of Mg, Ca and P and decreased slightly the apparent absorption of K. With lactose, absorption of Mg before the duodenum was significantly increased (41 vs 19%), and the increased Mg absorption from the stomach was associated with a net secretion of Mg into the small intestine. When hay was fed with lactose, more Ca was absorbed before the duodenum (30%) than when hay was fed alone (2%) and secretion of Ca into the small intestine was increased. Fermentation of lactose in the rumen induced decreases in pH and ammonia, a high lactate concentration and changes in molar proportions of volatile fatty acids. This work shows that readily fermentable carbohydrate increases stomach absorption of Ca and Mg and suggests that this effect is related to changes in fermentation patterns.

Influence of milk protein concentration on the gelling activity of chymosin and bovine pepsin.

Abstract: Two stages of gelling by the milk-clotting enzymes chymosin and pepsin were studied at different milk protein concentrations, using milk retentates. In each case, enzymic velocity versus protein concentration described a standard hyperbola. According to the experimental conditions such as pH and type of enzyme, which changed the enzyme concentration used, either the quasi-linear part of the hyperbola was observed, or the velocity hardly increased and tended to a limiting value. Gelling occurred with a lower degree of proteolysis of κ-casein when the protein concentration increased but a minimum proteolysis (1% of total nitrogenous matter content) was required for aggregation to take place. Gelling time varied with the protein concentration, the pH and the enzyme concentration. The final degree of proteolysis of κ-casein was the same whatever the substrate concentration used.