scholarly journals Improvement of the photosynthetic activity of Moldavian dragonhead (Dracocephalum moldavica L.) through foliar application of a nitrophenolate–based biostimulant

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.

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 387 ◽  
Author(s):  
Wanda Wadas ◽  
Tomasz Dziugieł

This paper analyses the effects of foliar application of the seaweed extracts Bio-algeen S90 (Ascophyllum nodosum) and Kelpak SL (Ecklonia maxima), as well as the humic and fulvic acids ini HumiPlant (leonardite extract), on the assimilation area and chlorophyll content of very early potato cultivars (‘Denar’, ‘Lord’, Miłek’). The field experiment was carried out in central-eastern Poland over three growing seasons, using Luvisol. The biostimulants were applied according to the manufacturers’ recommendations. The use of biostimulants resulted in enlargement of the assimilation area, but had no effect on the specific leaf area (SLA) or chlorophyll content (Soil Plant Analysis Development (SPAD) value). The assimilation area was larger, on average, by 0.0505 m2 and leaf area index (LAI) was higher by 0.30 compared with the plants from the control group without a biostimulant. The SLA and SPAD depend on the cultivar and weather conditions, or nitrogen and magnesium content in soil, to a greater extent. The biostimulants enhanced abiotic stress tolerance and increased marketable tuber yield (diameter above 30 mm) 75 days after planting (the end of June), on average by 2.15 t·ha−1. Bio-algeen S90 and Keplak SL produced better results in a warm and very wet growing season, whereas HumiPlant produced better results in a year with lower air temperature and with drought periods during potato growth. No correlations were found between the tuber yield and assimilation area or between the tuber yield and SPAD value, although a significant negative correlation was found between the tuber yield and SLA.


2011 ◽  
Vol 6 (No. 1) ◽  
pp. 21-29 ◽  
Author(s):  
H. Khaled ◽  
H.A. Fawy

In this study, the effects were investigated of salinity, foliar and soil applications of humic substances on the growth and mineral nutrients uptake of Corn (Hagein, Fardy10), and the comparison was carried out of the soil and foliar applications of humic acid treatments at different NaCl levels. Soil organic contents are one of the most important parts that they directly affect the soil fertility and textures with their complex and heterogenous structures although they occupy a minor percentage of the soil weight. Humic acids are an important soil component that can improve nutrient availability and impact on other important chemical, biological, and physical properties of soils. The effects of foliar and soil applications of humic substances on the plant growth and some nutrient elements uptake of Corn (Hagein, Fardy10) grown at various salt concentrations were examined. Sodium chloride was added to the soil to obtain 20 and 60mM saline conditions. Solid humus was applied to the soil one month before planting and liquid humic acids were sprayed on the leaves twice on 20<sup>th</sup> and 40<sup>th</sup> day after seedling emergence. The application doses of solid humus were 0, 2 and 4 g/kg and those of liquid humic acids were 0, 0.1 and 0.2%. Salinity negatively affected the growth of corn; it also decreased the dry weight and the uptake of nutrient elements except for Na and Mn. Soil application of humus increased the N uptake of corn while foliar application of humic acids increased the uptake of P, K, Mg,Na,Cu and Zn. Although the effect of interaction between salt and soil humus application was found statistically significant, the interaction effect between salt and foliar humic acids treatment was not found significant. Under salt stress, the first doses of both soil and foliar application of humic substances increased the uptake of nutrients.


Agronomy ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 31 ◽  
Author(s):  
Mirza Hasanuzzaman ◽  
M. Bhuyan ◽  
Kamrun Nahar ◽  
Md. Hossain ◽  
Jubayer Mahmud ◽  
...  

Among the plant nutrients, potassium (K) is one of the vital elements required for plant growth and physiology. Potassium is not only a constituent of the plant structure but it also has a regulatory function in several biochemical processes related to protein synthesis, carbohydrate metabolism, and enzyme activation. Several physiological processes depend on K, such as stomatal regulation and photosynthesis. In recent decades, K was found to provide abiotic stress tolerance. Under salt stress, K helps to maintain ion homeostasis and to regulate the osmotic balance. Under drought stress conditions, K regulates stomatal opening and helps plants adapt to water deficits. Many reports support the notion that K enhances antioxidant defense in plants and therefore protects them from oxidative stress under various environmental adversities. In addition, this element provides some cellular signaling alone or in association with other signaling molecules and phytohormones. Although considerable progress has been made in understanding K-induced abiotic stress tolerance in plants, the exact molecular mechanisms of these protections are still under investigation. In this review, we summarized the recent literature on the biological functions of K, its uptake, its translocation, and its role in plant abiotic stress tolerance.


2021 ◽  
Vol 118 (45) ◽  
pp. e2108458118
Author(s):  
Wariya Sanrattana ◽  
Thibaud Sefiane ◽  
Simone Smits ◽  
Nadine D. van Kleef ◽  
Marcel H. Fens ◽  
...  

Serine proteases are essential for many physiological processes and require tight regulation by serine protease inhibitors (SERPINs). A disturbed SERPIN–protease balance may result in disease. The reactive center loop (RCL) contains an enzymatic cleavage site between the P1 through P1’ residues that controls SERPIN specificity. This RCL can be modified to improve SERPIN function; however, a lack of insight into sequence–function relationships limits SERPIN development. This is complicated by more than 25 billion mutants needed to screen the entire P4 to P4’ region. Here, we developed a platform to predict the effects of RCL mutagenesis by using α1-antitrypsin as a model SERPIN. We generated variants for each of the residues in P4 to P4’ region, mutating them into each of the 20 naturally occurring amino acids. Subsequently, we profiled the reactivity of the resulting 160 variants against seven proteases involved in coagulation. These profiles formed the basis of an in silico prediction platform for SERPIN inhibitory behavior with combined P4 to P4’ RCL mutations, which were validated experimentally. This prediction platform accurately predicted SERPIN behavior against five out of the seven screened proteases, one of which was activated protein C (APC). Using these findings, a next-generation APC-inhibiting α1-antitrypsin variant was designed (KMPR/RIRA; / indicates the cleavage site). This variant attenuates blood loss in an in vivo hemophilia A model at a lower dosage than the previously developed variant AIKR/KIPP because of improved potency and specificity. We propose that this SERPIN-based RCL mutagenesis approach improves our understanding of SERPIN behavior and will facilitate the design of therapeutic SERPINs.


2021 ◽  
Vol 13 (10) ◽  
pp. 31
Author(s):  
Walquíria F. Teixeira ◽  
Evandro B. Fagan ◽  
Antônio P. M. Machado ◽  
Daniel Fortune ◽  
Fernando R. Moreira

Soybean is one of the world&rsquo;s most economically important crops and several factors can affect the productivity of this culture. Among these factors is the supply of needed nitrogen, especially in the reproductive stage, as it acts in photosynthetic activity and in grain filling. In view of this, the objective of our work was to evaluate the effect of foliar application of nitrogen in different reproductive stages in soybean culture. Two sources of nitrogen were used: conventional urea and urea-formaldehyde/triazone, both applied in reproductive stages R2, R3, R4, or R5, as well as a control treatment without foliar application of nitrogen. Plants submitted to foliar application of urea-formaldehyde/triazone showed an increase in nitrogen metabolism (percentage of nitrogen derived from the atmosphere [Ndfa] and nitrate reductase activity [NR]), an increase in peroxidase (POD), and the consequent reduction in hydrogen peroxide (H2O2) in all stages of application of this treatment. When urea-formaldehyde/triazone was applied in R4, it resulted in a 7% increase in yield. The application of conventional urea in reproductive stages R4 and R5 increased nitrogen metabolism and resulted in an increase in yield by 4%. However, conventional urea reduced yield when applied in stages R2 and R3. The use of low doses of foliar nitrogen in stages R4 and R5, increased nitrogen metabolism in soybean plants. The timing of the application has a direct impact on the results with the slow-release nitrogen (urea formaldehyde /triazone) showing better results when applied in stage R4 and better results for conventional urea in R5.


2019 ◽  
Vol 6 (02) ◽  
pp. 81-88
Author(s):  
Gerson Hans Maure ◽  
Muhammad Achmad Chozin ◽  
Edi Santosa

Winged bean (Fabaceae) is a tropical crop that has high nutrient content, and almost all parts of the plant are edible. The research aimed to evaluate the growth and production of winged bean in an intercropping system with tomato. The study was conducted at the Cikabayan Experimental Field of Bogor Agricultural University, Bogor, Indonesia, in a randomized block design with three replications during the rainy season of December 2017 to June 2018. Winged beans were planted in high and low population densities and intercropped with three tomato genotypes, “Tora”, F70030081-12-16-3 and “Apel Belgia”. Monoculture winged bean was assigned as control. Tomatoes were planted between the rows of the winged beans in the intercropping treatment. The results showed that the growth of winged bean in monoculture and intercropping systems was not significantly different. The photosynthetic activity of winged bean at three to five weeks after planting remained high, indicating that the vegetative growth was optimal in both systems. Intercropping increased the winged bean number of pods per plant by 12.66-19.52% compared to monoculture, irrespective of population density. Therefore, winged bean could be considered as suitable to grow in intercropping systems.


2019 ◽  
Vol 52 (1) ◽  
pp. 74-78
Author(s):  
S. Buhăianu ◽  
Doina Carmen Jităreanu

Abstract Chlorophylls from plants are photosynthetic pigments. Their quantity offers valuable informations about photosynthetic activity, growing and developing of plants. Photosynthetic pigments decrease quantitatively during senescence process or in stress conditions. The present study has been realized in laboratory conditions with material harvested from spontaneous flora. The purpose of this research was the investigation of variations of chlorophyll content from samples of biological material collected from Nepeta pannonica L. and Abies alba Mill. plants, from Câmpulung Moldovenesc and Cacica areas, Suceava county, Romania. The targeted phenophases were growth and flowering. There were realized acetonic extracts from samples for spectrophotometric determinations. Obtained data were processed to estabilish chlorophyll a and b content. There were observed that at Abies alba species, from both locations, the chlorophyll a content grew during flowering phenophase, while the chlorophyll b content had little variations. At Nepeta pannonica species, the chlorophyll a and b content decreased visibly during the flowering, due to stress. Leaves of plants from this species presented a intense green color in the growing phenophase, while during flowering phenophase they had a purple or yellow coloration. Obtained results revealed a different dynamics of chlorophyll content at studied species.


2021 ◽  
Vol 35 (2) ◽  
Author(s):  
Amine Khoulati ◽  
E. Saalaoui

An experiment was carried out in a greenhouse to study the effect of aqueous extracts of Crocus sativus L. by-products on tomato plants. Three concentrations of tepals and corms were used by fertigation: 1 g/L, 2 g/L, and 3 g/L. The aqueous extract of the stigmas was used as a foliar application at 0.6 g/L. The experiment was carried out in a completely randomized block with three repetitions for each concentration. The concentration of tepal extract at 3 g/L significantly (p≤0.05) increased the plants' height, the chlorophyll a, b content. The same results were observed for the foliar treatment with stigmas; however, there was no effect of tepal extract on the carotenoid content. On the other hand, the concentration 2 g/L of the corms extract had a positive impact (p≤0.05) in the chlorophyll b content while the concentration of 3 g/L increased the plant's height, the chlorophyll a (p≤0.05). Current results indicate that Crocus sativus by-products could improve certain physiological aspects of the recipient plants and new and natural biostimulants.


2020 ◽  
Vol 8 (Spl-2-AABAS) ◽  
pp. S298-S302
Author(s):  
Vladimir Nikolaevich Vorob’ev ◽  
◽  
Sergei Fedorovich Kotov ◽  
Vera Vladimirovna Nikolenko ◽  
Denis Vladimirovich Tishin ◽  
...  

The current study was carried out to study the influence of light and heavy lanthanides on the physiological process of Crimean-Sagyz/ Krim-saghyz (dandelion - Taraxacum hybernum). Lanthanide belongs to the group of light or heavy; infiltration of dandelion (Crimean saghyz) seeds with light and heavy lanthanides solutions increased the germination energy by 26%. The differences in the influence of light (cerium) and heavy (lutetium) were manifested in the quantum efficiency change of the photosystem 2 (PS II). Treatment of leaves with high concentrations (100 µM) led to a decrease of Y (II), moreover, under the influence of light lanthanide, the decrease was greater by 21%. It is assumed that the effect of the used lanthanides on the dandelion photosynthetic apparatus is multidirectional. Cerium influenced the PS II antenna complex, and lutetium influenced the reaction centers. A 10-fold decrease in the concentration did not change the nature of cerium action, except that Y (II) was restored already on the second day after treatment. The effect of lutetium became noticeable only by the 8th day after treatment when Y (II) became higher than that of untreated plants. Thus, the results of the study suggested that in dandelion leaves, lanthanides with a concentration of 10 µM increased the quantum efficiency of PS II in contrast to cerium.


2021 ◽  
Vol 12 (3) ◽  
pp. 7-16
Author(s):  
Z. Bilousova ◽  
◽  
V. Keneva ◽  
Y. Klipakova ◽  
◽  
...  

To obtain the maximum yield of winter wheat, it is necessary to further optimize the existing cultivation technologies in the direction of their adaptation to changing environmental conditions. One of the areas of adaptation of plants to adverse abiotic factors is the active functioning of the photosynthetic apparatus, which depends on the amount of nutrients introduced. The influence of fertilizer application on the condition of the pigment complex of winter wheat plants in the conditions of the Southern Steppe of Ukraine has been studied. Two varieties of winter wheat were selected for the study: Shestopalivka and Mason. The experiment scheme involved the application of fertilizers at sowing (K0; K12) and foliar treatment with various tank mixtures (urea; urea + magnesium sulfate; urea + magnesium sulfate + potassium monophosphate). The pigment content has been determined by grinding fresh leaves of winter wheat, followed by the addition of a solvent in the form of acetone. Measurements of pigments were performed using a spectrophotometer. According to the research results, it was established that before the foliar treatment the a-chlorophyll content and carotenoids was higher in the plant leaves of the Shestopalivka variety. At the same time, the b-chlorophyll content on the contrary was higher for plants of the Mason variety by 17%, which may be due to the adaptation of plants of this variety to lack of light. On the 3rd day after foliar treatment, a decrease in the pigment content in the plant leaves of all experimental variants has been observed, which was due to the active growth of the photosynthetic surface and a decrease in the total dry matter mass. There was no significant difference between the varieties of the content of photosynthetic pigments in this period. On the 10th day after foliar treatment, an increase in a- and b-chlorophyll content has been observed for both studied varieties, which may be the result of adaptation of the photosynthetic apparatus of winter wheat plants to lighting conditions. Foliar treatment of winter wheat plants with a tank mixture of urea with magnesium sulfate and potassium monophosphate contributed to a further increase in the content of a-chlorophyll by 12-23%, and b-chlorophyll by 5-37% depending on the variety compared to the control. The results of the research testify to the high efficiency of complex application of nitrogen-phosphorus-potassium fertilizers for foliar treatment of winter wheat plants in the BBCH 31 stage, both against the background of pre-sowing application of potassium fertilizers and without it.


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