scholarly journals Preliminary investigation on the interaction between some physiological processes in donors and acceptors of assimilates

2015 ◽  
Vol 42 (1) ◽  
pp. 143-162 ◽  
Author(s):  
Z. Starck

The interaction between physiological processes in donors and acceptors of <sup>14</sup>C-assimilates was studied in sunflower and bean plants with temporarily limited supply of assimilates (shading a few days and then replacing in natural light conditions (NL)). An extended period of shading (4-7 days) affected growth of plants and reduced photosynthetic activity, especially in sunflower. The proportion of <sup>14</sup>C-transported to roots decreased and that to the stern increased as an effect of preshading and did not significantly change in plants replaced in natural light conditions a few days before <sup>14</sup>CO<sub>2</sub>-exposure. In preshaded blades and roots the rate of dark respiration decreased, but soon improved after a few days of NL conditions following the shading period. Absorption of <sup>32</sup>P coincided with root respiration and sugar content in bean plant, in contrast to sunflower where <sup>32</sup>P-absorption, calculated per l g of root dry matter in preshaded plants exceeded that in control ones.

1970 ◽  
Vol 48 (5) ◽  
pp. 861-866 ◽  
Author(s):  
Q. A. Fattah ◽  
D. J. Wort

A 0.5% aqueous spray of potassium naphthenates was applied to the foliage of 14-day-old plants of bush bean, Phaseolus vulgaris L. cultivar Top Crop, and the plants were then grown under light intensities of 16.1, 10.76, and 5.38 klx at 26 °C for 7, 14, and 21 days. Photosynthesis, dark respiration, and phosphorylase activity were significantly greater (0.05 level) in treated plants at the end of all three growth periods under all light conditions. Significant stimulation of phosphoglycerate kinase developed more slowly under the lower light intensities. The stimulation of nitrate reductase and glutamic–pyruvic transaminase in treated plants reached a significant level between 7 and 14 days after treatment, and subsequently increased. The percentage increases of all the processes, over corresponding values in control plants, were greatest in plants grown at the highest light intensity.


2018 ◽  
Vol 10 ◽  
pp. 01009
Author(s):  
Sławomir Kocira ◽  
Agnieszka Sujak ◽  
Tomasz Oniszczuk ◽  
Agnieszka Szparaga ◽  
Mariusz Szymanek ◽  
...  

Application of biostimulants instigates many physiological processes that enhance nutrition efficiency, abiotic stress tolerance, and quality traits of crops, regardless of their nutrient content. One of such preparations is Atonik which contains nitrophenol compounds naturally occurring in plant cells. Several studies have confirmed its beneficial effect on the growth, development, and improved metabolic activity of plants. Therefore, it seems advisable to investigate the effect of Atonik preparation on the photosynthetic activity of Moldavian dragonhead (Dracocephalum moldavica L.). The reported study was carried out in 2014 in Perespa, Poland. Over the growing season, Atonik was foliar-applied at a dose of 0.3 L/ha (0.1%) and 0.6 L/ha (0.2%) by single and double spraying of plants. Chlorophyll content and nitrogen status (N) were estimated by a Chlorophyll Meter SPAD-502 Plus. The foliar application of Atonik was found to improve the efficiency of the photosynthetic apparatus and chlorophyll content in the leaves of Dracocephalum moldavica plants, but the results were dependent on biostimulant concentration and number of its applications, and on the date of measurement. To conclude, Atonik is an environmental-friendly preparation which has a positive impact on the metabolic processes of plants.


2014 ◽  
Vol 55 (4) ◽  
pp. 577-588
Author(s):  
Jadwiga Stopińska

Leaf growth and chlorophyll level in GA<sub>3</sub>-treated bean, and leaf growth and transpiration intensity in ABA-treated bean plants were studied at two potassium concentrations in the medium (1 and 3 mM KNO<sub>3</sub>). The plants were grown on Hoagland's solution and growth regulators were applied to the shoot growth apexes. Both GA<sub>3</sub> and K<sup>+</sup> ions were found to stimulate growth of primary leaves and increase their potassium amount. GA<sub>3</sub> contrary to K<sup>+</sup> slightly decreased the potassium content in leaves Both factors reduced the chlorophyll content but did not affect the total chlorophyll amount in these organs Interaction between GA<sub>3</sub> and K<sup>+</sup> ions was of additive nature. The effect of ABA and K<sup>+</sup> ions on growth of both kinds of leaves and on the amount and content of potassium in them were antagonistic. The inhibitory effect of the hormone was stronger at higher potassium concentration in the medium. Either factor reduced transpiration intensity in leaves, however, the inhibitory effect of the growth regulator was stronger at lower potassium concentration. The potassium level modified both the physiological effect of the regulators and the sensitivity of bean particularly to ABA.


2019 ◽  
Vol 13 (2) ◽  
pp. 151-160
Author(s):  
Diana Mateus-Cagua ◽  
Gustavo Rodríguez-Yzquierdo

Biostimulants can potentially improve plant growth and development, modifying physiological processes. This study evaluated the effect of four biostimulants on the growth of ‘Hartón’ plantain plants and the leaf gas exchange during the vegetative phase. This experiment was developed on a plantain farm’s nursery in Fuente de Oro (Colombia) with a randomized complete block design with four replicates. The treatments were the biostimulants: Bactox WP®: Bacillus subtilis (Bs); Baliente®: Bacillus amyloliquefaciens (Ba); Tierra Diatomeas®: silicon dioxide (Si); Re-Leaf®: salicylic acid (SA) and the control (water). All products had a positive effect on the accumulation of total dry matter (DM) (between 58.4 and 21.9%) and on the photosynthetic activity (a maximum of 110 and 24.3% in first and second evaluation), as compared to the control, while no differences were found (P>0.05) for the foliar emission rate and chlorophyll content between the treatments. The plants treated with Bs had the greatest DM accumulation at the end of the study and a constant, high photosynthetic activity. All the while Bs, Ba and Si managed to stimulate greater early photosynthetic activity. According to the results, the use of these biostimulants during the vegetative phase had an effect on the physiological processes that enhance DM accumulation in plantain plants, which could be potentially useful for the transplanting stage and increase the reserves used during their establishment and development in the field.


2006 ◽  
Vol 1 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Khadijeh Bavi . ◽  
Bahman Kholdebarin . ◽  
Ali Moradshahi .

1977 ◽  
Vol 55 (12) ◽  
pp. 1650-1659 ◽  
Author(s):  
D. Chevallier ◽  
R. Douce ◽  
F. Nurit

The effect of DBMIB, antimycine A, and FCCP on respiration and photosynthesis of intact chlorophyllic moss (Funaria hygrometrica) spore was investigated.Antimycine A (1 μM) strongly inhibited dark respiration, was without effect on photosynthesis at high light intensities (above the saturation plateau values), and stimulated photosynthesis at low light intensities (below the saturation plateau values).DBMIB (3 μM) inhibited photosynthesis and was without effect, even under light conditions, on the dark respiration. Low amount of FCCP (3 μM) partially inhibited oxygen production at high light intensities. In this case, the inhibition observed was partially relieved by 1 μM antimycine A or 30 μM of KCN; higher concentration of FCCP totally inhibited the oxygen production.It seems likely, therefore, that in the chlorophyllic moss spore the cytochrome oxidase pathway is not functioning under high light intensities and that this inhibition of respiration is attributable to the low cytoplasmic ADP:ATP ratio.


2007 ◽  
Vol 37 (9) ◽  
pp. 1714-1722 ◽  
Author(s):  
Heather M. Joesting ◽  
Brian C. McCarthy ◽  
Kim J. Brown

Restoration attempts to reintroduce American chestnut trees to the eastern deciduous forest by means of a disease-resistant Chinese–American hybrid seed are in progress. Knowing the light conditions required for optimum seedling performance is necessary to maximize the success of reintroduction. American chestnut ( Castanea dentata (Marsh.) Borkh.) seedlings were planted in two replicate forests in Vinton County, Ohio, in areas that had been thinned (more available light) and in control areas (intact canopy, less available light). The photosynthetic capacity of 12 seedlings per treatment was assessed using an infrared gas-exchange analyzer. Seedlings in the thinned treatment reached light-saturating rates of photosynthesis at an irradiance level approximately 33% higher than did the seedlings in the control treatment. Seedlings grown in the thinned treatment had a significantly greater maximum rate of photosynthesis (Amax), dark respiration rate (Rd), and daily carbon gain per seedling than seedlings grown in the control treatment. The light compensation point (LCP), quantum efficiency (ϕ), leaf mass per area (LMA), and leaf nitrogen concentration per unit leaf area (Narea) were not significantly different between treatments. American chestnut seedlings in the thinned treatment clearly maximize leaf-level photosynthetic capacity. These results will aid land managers in planning reintroduction trials by providing information on the light conditions required for maximum seedling success.


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