An investigation of photosynthetic sucrose production in bean leaves

1977 ◽  
Vol 55 (11) ◽  
pp. 1457-1464 ◽  
Author(s):  
S. C. Fry ◽  
R. G. S. Bidwell
Keyword(s):  
Phaseolus Vulgaris ◽  
The Other ◽  
Glyceric Acid ◽  
Cytoplasmic Fraction ◽  
Other Hand ◽  
Phosphoglyceric Acid ◽  
Detached Leaves ◽  
Chloroplast Fraction ◽  
Bean Leaves

First trifoliate leaves of wax beans. Phaseolus vulgaris, were exposed to 14CO2 in light for periods of 15 to 75 s. Leaves were frozen in liquid N2 and a chloroplast fraction was isolated nonaqueously. The chloroplast fraction contained a small amount of contaminating cytoplasm that could not be removed. Labelled photosynthetic compounds were separated from the whole leaves and from the corresponding chloroplast fractions and their radioactivity was measured.The compounds fell into two groups in their behaviour. Glyceric acid and ribulose, derived from photosynthetic 3-phosphoglyceric acid and ribulose diphosphate respectively, remained largely or exclusively in the chloroplast fraction. Labelled sucrose and serine and glycine, on the other hand, were located in the chloroplast fraction only during the first 15–30 s of 14CO2 supply, and appeared in the cytoplasmic fraction in increasing amounts thereafter. The results suggest that serine and glycine are produced in organelles in the layer of cytoplasm that closely surrounds the chloroplasts and is isolated with them in the non aqueous technique. Sucrose may also be synthesized from photosynthetic intermediates in this layer of cytoplasm. Sucrose was not formed from intermediates of the glycolate pathway in detached leaves.

scholarly journals Incidence of base rot and wilt, sanitary severity and influence about seed pathology by cultivars of common bean (Phaseolus vulgaris)

2019 ◽  
Vol 86 ◽  
Author(s):  
Mateus Paulino Braga ◽  
Luana Machado Rezende ◽  
Lucinete Martins Barbosa Estrela ◽  
Natanael Marcos Lemes ◽  
Anderson Rodrigues Rietjens ◽  
...  
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Test Method ◽  
The Other ◽  
Other Hand ◽  
Seed Pathology ◽  
Random Samples ◽  
Physiological Quality ◽  
The Impact ◽  
The City

ABSTRACT: The objective of this work was to conduct a temporal evaluation of incidence of rot base and sanitary severity, and to relate the impact on the seed pathology of common bean cultivars. In the 2015-2016 harvest, in the city of Ipameri, Goiás, ten cultivars of common bean were evaluated (BRS Estilo©, BRS Pérola©, IPR Tangará©, IPR Tuiuiú©, IPR Uirapuru©, IAC Milênio©, Imperador©, IAC F3 R2©, IAC OTG© and IPR Campos Gerais©) and distributed into five blocks, totaling 40 experimental units. The incidence of wilt and base rot and sanitary severity were analyzed by taking ten random samples per block at 21, 28, 56, 63 and 69 days after planting. At the end of 120 days, a total of 20 plants were harvested per cultivar, and 250 seeds were harvested for application of the Blotter Test method. From 21 to 69 days after planting, the cultivars BRS Pérola© and IPR Campos Gerais© deserve to be highlighted for presenting the lowest incidence of wilt in the reproductive and vegetative cycles. The cultivar BRS Pérola© showed the lowest incidence of wilt and sanitary severity. In the analysis of harvested seeds, the cultivar BRS Pérola© presented high physiological quality for all evaluated parameters. On the other hand, Cramberry (OTG)© showed low physiological potential in germination and vigor tests.

Regenerative studies on the detached leaves of Echeveria elegans. Regeneration and growth in leaves

1973 ◽  
Vol 51 (2) ◽  
pp. 451-456 ◽  
Author(s):  
M. V. S. Raju ◽  
James E. Hines
Keyword(s):  
Metabolic Activity ◽  
Dry Weight ◽  
The Other ◽  
Inhibitory Influence ◽  
Other Hand ◽  
Detached Leaves

Detached leaves of Echeveria elegans Bgr. produce both roots and shoots. However, when their bases are severed, they tend to produce only roots. It was observed that roots had to be present on detached leaves, bases removed or not, in order to have an increase in size and also in dry weight. The growth in size was found to be due mainly to enlargement of cells, and the increase in dry weight was presumably due to maintenance of normal metabolic activity in the detached leaves. Thus detached leaves of E. elegans have a greater potential for growth than is normally realized by the leaves that are mature and still attached to the parent axis. The vigorously growing shoots seem to have an inhibitory influence on growth in the detached leaves. Roots on detached leaves, on the other hand, seem to play an important role not only in the delaying of senescence but also in reducing the inhibitory influence of shoots. Roots alone appeared to bring about "uncontrolled" enlargement of cells and consequently lesions were formed on the leaves, which finally died off. Thus growth, regeneration, and senescence in the detached leaves appear to be correlative phenomena.

Nicotinamide adenine dinucleotide metabolism in plants. II. Responses of nicotinamide nucleotides to chemical regulators in bean leaves

1974 ◽  
Vol 52 (4) ◽  
pp. 707-713 ◽  
Author(s):  
S. C. Chen ◽  
H. R. Godavari ◽  
E. R. Waygood
Keyword(s):  
Phaseolus Vulgaris ◽  
Nicotinic Acid ◽  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine ◽  
Phaseolus Vulgaris L ◽  
Cyclic Pattern ◽  
Nad Metabolism ◽  
Detached Leaves ◽  
Time Periods ◽  
Bean Leaves

Incorporation of nicotinic acid-7-14C into nicotinamide adenine dinucleotide by the trifoliate leaves of the bean plant (Phaseolus vulgaris L. var. Brittle Wax) was studied for varying time periods from 5 min to 48 h. Nine radioactive compounds were isolated and identified as all the possible intermediates of NAD metabolism operating in a cyclic pattern. All the intermediates were labelled rapidly and N-methyl nicotinic acid (trigonelline) was detected within 5 min. About 80% of the nicotinic acid fed was accumulated in trigonelline. Senescence induced by floating detached leaves on water enhanced incorporation of the label into nucleotides, NAD > NADP. Treatment with growth regulators altered the NAD/NADP ratios. Benzimidazole and kinetin enhanced NADP synthesis while benzyladenine and ethionine reduced NADP synthesis. The regulator-mediated NADP synthesis is enhanced by light and appears to be inversely related to the synthesis of trigonelline.

Sodium Exchange in the Cytoplasm and Nucleus of Amphibian Oocytes

1974 ◽  
Vol 16 (2) ◽  
pp. 465-471
Author(s):  
T. J. CENTURY ◽  
S. B. HOROWITZ
Keyword(s):  
Low Temperature ◽  
Cell Surface ◽  
Rate Constant ◽  
Rana Pipiens ◽  
The Other ◽  
Cytoplasmic Fraction ◽  
Single Fraction ◽  
Ringer’S Solution ◽  
Other Hand ◽  
Sodium Exchange

Oocytes of Rana pipiens were incubated in 22Na-Ringer's solution and 22Na-23Na exchange in the nucleus and cytoplasm followed by low-temperature microdissection. Cytoplasmic sodium consists of 2 kinetic fractions: the larger (88%) slowly exchanging (t½ ∼ 2 days), and the smaller (12%) rapidly exchanging (t½ ∼ 53 min). Nuclear sodium consists of a single fraction whose concentration is similar and whose rate constant is identical with that of the rapidly exchanging cytoplasmic fraction. Our findings are consistent with a model of compartmentalization in which rapidly exchanging sodium is nearly uniformly distributed in the water of the nucleus and cytoplasm and its exchange limited by movement through the cell surface. On the other hand, slowly exchanging sodium is restricted to the cytoplasm, sorbed to or sequestered in some as yet unidentified cytoplasmic constituent.

Translocation of Herbicides in Detached Bean Leaves

Weed Science ◽  
1968 ◽  
Vol 16 (3) ◽  
pp. 352-356 ◽  
Author(s):  
O. A. Leonard ◽  
R. K. Glenn
Keyword(s):  
Phaseolus Vulgaris ◽  
Phosphoric Acid ◽  
Dicarboxylic Acid ◽  
Prior Treatment ◽  
Dichlorophenoxyacetic Acid ◽  
Transport Studies ◽  
Detached Leaves ◽  
Upward Transport ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Bean Leaves

Labeled 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2, 4, 5-T), 2-methoxy-3,6-dichlorobenzoic acid (dicamba), 4-amino-3, 5, 6-trichloropicolinic acid (picloram), 1,2-dihydropyridazine-3,6-dione (MH), assimilates, and phosphoric acid were absorbed and transported basipetally from the lamina into the petioles of detached bean leaves (Phaseolus vulgaris L.). Upward transport in the lamina was slight, except when the petioles were in water. In contrast, labeled 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) was not transported basipetally, but some acropetal transport did occur. Vein-loading and transport of labeled assimilates, 2,4-D, dicamba, MH, and phosphate were greatly reduced by a prior treatment with 7-oxabicyclo(2.2.1)heptane-2,3-dicarboxylic acid (endothall). Detached leaves hold promise for use in absorption and transport studies.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Life Beyond 1MeV

1980 ◽  
Vol 38 ◽  
pp. 30-33
Author(s):  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
Past Experience ◽  
The Other ◽  
Good Case ◽  
Other Hand ◽  
The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

Can the Academic Self-Concept be Positive and Realistic?

2005 ◽  
Vol 19 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Reimer Kornmann
Keyword(s):  
Academic Performance ◽  
Opposite Effect ◽  
Self Esteem ◽  
Point Of View ◽  
The Other ◽  
Self Concept ◽  
High Ability ◽  
Self Image ◽  
Other Hand

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

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